Adding upstream version 1.3+ds.upstream/1.3+dsupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

123 files changed, 24875 insertions, 0 deletions

diff --git a/src/display/CMakeLists.txt b/src/display/CMakeLists.txt
new file mode 100644
index 0000000..70214bb
--- /dev/null
+++ b/src/display/CMakeLists.txt
@@ -0,0 +1,134 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+set(display_SRC
+    cairo-utils.cpp
+    curve.cpp
+    drawing-context.cpp
+    drawing-group.cpp
+    drawing-image.cpp
+    drawing-item.cpp
+    drawing-paintserver.cpp
+    drawing-pattern.cpp
+    drawing-shape.cpp
+    drawing-surface.cpp
+    drawing-text.cpp
+    drawing.cpp
+    nr-3dutils.cpp
+    nr-filter-blend.cpp
+    nr-filter-colormatrix.cpp
+    nr-filter-component-transfer.cpp
+    nr-filter-composite.cpp
+    nr-filter-convolve-matrix.cpp
+    nr-filter-diffuselighting.cpp
+    nr-filter-displacement-map.cpp
+    nr-filter-flood.cpp
+    nr-filter-gaussian.cpp
+    nr-filter-image.cpp
+    nr-filter-merge.cpp
+    nr-filter-morphology.cpp
+    nr-filter-offset.cpp
+    nr-filter-primitive.cpp
+    # nr-filter-skeleton.cpp
+    nr-filter-slot.cpp
+    nr-filter-specularlighting.cpp
+    nr-filter-tile.cpp
+    nr-filter-turbulence.cpp
+    nr-filter-units.cpp
+    nr-filter.cpp
+    nr-light.cpp
+    nr-style.cpp
+    nr-svgfonts.cpp
+
+    control/canvas-temporary-item-list.cpp
+    control/canvas-temporary-item.cpp
+    control/snap-indicator.cpp
+
+    control/canvas-item.cpp
+    control/canvas-item-bpath.cpp
+    control/canvas-item-catchall.cpp
+    control/canvas-item-context.cpp
+    control/canvas-item-ctrl.cpp
+    control/canvas-item-curve.cpp
+    control/canvas-item-drawing.cpp
+    control/canvas-item-grid.cpp
+    control/canvas-item-group.cpp
+    control/canvas-item-guideline.cpp
+    control/canvas-item-quad.cpp
+    control/canvas-item-rect.cpp
+    control/canvas-item-text.cpp
+    control/canvas-page.cpp
+
+    # -------
+    # Headers
+    cairo-templates.h
+    cairo-utils.h
+    curve.h
+    dither-lock.h
+    drawing-context.h
+    drawing-group.h
+    drawing-image.h
+    drawing-item.h
+    drawing-item-ptr.h
+    drawing-paintserver.h
+    drawing-pattern.h
+    drawing-shape.h
+    drawing-surface.h
+    drawing-text.h
+    drawing.h
+    initlock.h
+    nr-3dutils.h
+    nr-filter-blend.h
+    nr-filter-colormatrix.h
+    nr-filter-component-transfer.h
+    nr-filter-composite.h
+    nr-filter-convolve-matrix.h
+    nr-filter-diffuselighting.h
+    nr-filter-displacement-map.h
+    nr-filter-flood.h
+    nr-filter-gaussian.h
+    nr-filter-image.h
+    nr-filter-merge.h
+    nr-filter-morphology.h
+    nr-filter-offset.h
+    nr-filter-primitive.h
+    nr-filter-skeleton.h
+    nr-filter-slot.h
+    nr-filter-specularlighting.h
+    nr-filter-tile.h
+    nr-filter-turbulence.h
+    nr-filter-types.h
+    nr-filter-units.h
+    nr-filter-utils.h
+    nr-filter.h
+    nr-light-types.h
+    nr-light.h
+    nr-style.h
+    nr-svgfonts.h
+    rendermode.h
+    tags.h
+
+    control/canvas-temporary-item-list.h
+    control/canvas-temporary-item.h
+    control/snap-indicator.h
+
+    control/canvas-item.h
+    control/canvas-item-bpath.h
+    control/canvas-item-buffer.h
+    control/canvas-item-catchall.h
+    control/canvas-item-context.h
+    control/canvas-item-ctrl.h
+    control/canvas-item-curve.h
+    control/canvas-item-drawing.h
+    control/canvas-item-enums.h
+    control/canvas-item-grid.h
+    control/canvas-item-group.h
+    control/canvas-item-guideline.h
+    control/canvas-item-ptr.h
+    control/canvas-item-quad.h
+    control/canvas-item-rect.h
+    control/canvas-item-text.h
+    control/canvas-page.h
+)
+
+# add_inkscape_lib(display_LIB "${display_SRC}")
+add_inkscape_source("${display_SRC}")
diff --git a/src/display/README b/src/display/README
new file mode 100644
index 0000000..0482a4e
--- /dev/null
+++ b/src/display/README
@@ -0,0 +1,26 @@
+
+
+This directory contains code for: rendering graphics on the canvas,
+"picking" objects on the canvas based on closeness to cursor, directing
+events (mouse button, key press, etc.) to the correct object.
+
+The code can be divided into two types: handling SVG elements
+(DrawingItem and derived classes) and handling controlled items
+(SPCanvasItem and derived structures/classes).
+
+Currently we rely on the "Cairo" graphics library for rendering.
+
+DrawingItem:
+
+  Item belonging to the drawing. These are rendered via the
+  CanvasArena canvas item.
+
+CanvasItem:
+
+  See README in control sub-directory.
+
+To do:
+
+* Split into three directories: drawing, control, common (partially done).
+* Rename control directory to canvas directory.
+* Remove SPCurve.
diff --git a/src/display/cairo-templates.h b/src/display/cairo-templates.h
new file mode 100644
index 0000000..d23343e
--- /dev/null
+++ b/src/display/cairo-templates.h
@@ -0,0 +1,658 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Cairo software blending templates.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2010 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef SEEN_INKSCAPE_DISPLAY_CAIRO_TEMPLATES_H
+#define SEEN_INKSCAPE_DISPLAY_CAIRO_TEMPLATES_H
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"  // only include where actually required!
+#endif
+
+#include <glib.h>
+
+#ifdef HAVE_OPENMP
+#include <omp.h>
+// single-threaded operation if the number of pixels is below this threshold
+static const int OPENMP_THRESHOLD = 2048;
+#endif
+
+#include <cmath>
+#include <algorithm>
+#include <cairo.h>
+#include "display/nr-3dutils.h"
+#include "display/cairo-utils.h"
+
+/**
+ * Blend two surfaces using the supplied functor.
+ * This template blends two Cairo image surfaces using a blending functor that takes
+ * two 32-bit ARGB pixel values and returns a modified 32-bit pixel value.
+ * Differences in input surface formats are handled transparently. In future, this template
+ * will also handle software fallback for GL surfaces.
+ */
+template <typename Blend>
+void ink_cairo_surface_blend(cairo_surface_t *in1, cairo_surface_t *in2, cairo_surface_t *out, Blend blend)
+{
+    cairo_surface_flush(in1);
+    cairo_surface_flush(in2);
+
+    // ASSUMPTIONS
+    // 1. Cairo ARGB32 surface strides are always divisible by 4
+    // 2. We can only receive CAIRO_FORMAT_ARGB32 or CAIRO_FORMAT_A8 surfaces
+    // 3. Both surfaces are of the same size
+    // 4. Output surface is ARGB32 if at least one input is ARGB32
+
+    int w = cairo_image_surface_get_width(in2);
+    int h = cairo_image_surface_get_height(in2);
+    int stride1   = cairo_image_surface_get_stride(in1);
+    int stride2   = cairo_image_surface_get_stride(in2);
+    int strideout = cairo_image_surface_get_stride(out);
+    int bpp1   = cairo_image_surface_get_format(in1) == CAIRO_FORMAT_A8 ? 1 : 4;
+    int bpp2   = cairo_image_surface_get_format(in2) == CAIRO_FORMAT_A8 ? 1 : 4;
+    int bppout = std::max(bpp1, bpp2);
+
+    // Check whether we can loop over pixels without taking stride into account.
+    bool fast_path = true;
+    fast_path &= (stride1 == w * bpp1);
+    fast_path &= (stride2 == w * bpp2);
+    fast_path &= (strideout == w * bppout);
+
+    int limit = w * h;
+
+    guint32 *const in1_data = reinterpret_cast<guint32*>(cairo_image_surface_get_data(in1));
+    guint32 *const in2_data = reinterpret_cast<guint32*>(cairo_image_surface_get_data(in2));
+    guint32 *const out_data = reinterpret_cast<guint32*>(cairo_image_surface_get_data(out));
+
+    // NOTE
+    // OpenMP probably doesn't help much here.
+    // It would be better to render more than 1 tile at a time.
+    #if HAVE_OPENMP
+    int numOfThreads = get_num_filter_threads();
+    #endif
+
+    // The number of code paths here is evil.
+    if (bpp1 == 4) {
+        if (bpp2 == 4) {
+            if (fast_path) {
+                #if HAVE_OPENMP
+                #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+                #endif
+                for (int i = 0; i < limit; ++i) {
+                    *(out_data + i) = blend(*(in1_data + i), *(in2_data + i));
+                }
+            } else {
+                #if HAVE_OPENMP
+                #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+                #endif
+                for (int i = 0; i < h; ++i) {
+                    guint32 *in1_p = in1_data + i * stride1/4;
+                    guint32 *in2_p = in2_data + i * stride2/4;
+                    guint32 *out_p = out_data + i * strideout/4;
+                    for (int j = 0; j < w; ++j) {
+                        *out_p = blend(*in1_p, *in2_p);
+                        ++in1_p; ++in2_p; ++out_p;
+                    }
+                }
+            }
+        } else {
+            // bpp2 == 1
+            #if HAVE_OPENMP
+            #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+            #endif
+            for (int i = 0; i < h; ++i) {
+                guint32 *in1_p = in1_data + i * stride1/4;
+                guint8  *in2_p = reinterpret_cast<guint8*>(in2_data) + i * stride2;
+                guint32 *out_p = out_data + i * strideout/4;
+                for (int j = 0; j < w; ++j) {
+                    guint32 in2_px = *in2_p;
+                    in2_px <<= 24;
+                    *out_p = blend(*in1_p, in2_px);
+                    ++in1_p; ++in2_p; ++out_p;
+                }
+            }
+        }
+    } else {
+        if (bpp2 == 4) {
+            // bpp1 == 1
+            #if HAVE_OPENMP
+            #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+            #endif
+            for (int i = 0; i < h; ++i) {
+                guint8  *in1_p = reinterpret_cast<guint8*>(in1_data) + i * stride1;
+                guint32 *in2_p = in2_data + i * stride2/4;
+                guint32 *out_p = out_data + i * strideout/4;
+                for (int j = 0; j < w; ++j) {
+                    guint32 in1_px = *in1_p;
+                    in1_px <<= 24;
+                    *out_p = blend(in1_px, *in2_p);
+                    ++in1_p; ++in2_p; ++out_p;
+                }
+            }
+        } else {
+            // bpp1 == 1 && bpp2 == 1
+            if (fast_path) {
+                #if HAVE_OPENMP
+                #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+                #endif
+                for (int i = 0; i < limit; ++i) {
+                    guint8 *in1_p = reinterpret_cast<guint8*>(in1_data) + i;
+                    guint8 *in2_p = reinterpret_cast<guint8*>(in2_data) + i;
+                    guint8 *out_p = reinterpret_cast<guint8*>(out_data) + i;
+                    guint32 in1_px = *in1_p; in1_px <<= 24;
+                    guint32 in2_px = *in2_p; in2_px <<= 24;
+                    guint32 out_px = blend(in1_px, in2_px);
+                    *out_p = out_px >> 24;
+                }
+            } else {
+                #if HAVE_OPENMP
+                #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+                #endif
+                for (int i = 0; i < h; ++i) {
+                    guint8 *in1_p = reinterpret_cast<guint8*>(in1_data) + i * stride1;
+                    guint8 *in2_p = reinterpret_cast<guint8*>(in2_data) + i * stride2;
+                    guint8 *out_p = reinterpret_cast<guint8*>(out_data) + i * strideout;
+                    for (int j = 0; j < w; ++j) {
+                        guint32 in1_px = *in1_p; in1_px <<= 24;
+                        guint32 in2_px = *in2_p; in2_px <<= 24;
+                        guint32 out_px = blend(in1_px, in2_px);
+                        *out_p = out_px >> 24;
+                        ++in1_p; ++in2_p; ++out_p;
+                    }
+                }
+            }
+        }
+    }
+
+    cairo_surface_mark_dirty(out);
+}
+
+template <typename Filter>
+void ink_cairo_surface_filter(cairo_surface_t *in, cairo_surface_t *out, Filter filter)
+{
+    cairo_surface_flush(in);
+
+    // ASSUMPTIONS
+    // 1. Cairo ARGB32 surface strides are always divisible by 4
+    // 2. We can only receive CAIRO_FORMAT_ARGB32 or CAIRO_FORMAT_A8 surfaces
+    // 3. Surfaces have the same dimensions
+
+    int w = cairo_image_surface_get_width(in);
+    int h = cairo_image_surface_get_height(in);
+    int stridein   = cairo_image_surface_get_stride(in);
+    int strideout = cairo_image_surface_get_stride(out);
+    int bppin = cairo_image_surface_get_format(in) == CAIRO_FORMAT_A8 ? 1 : 4;
+    int bppout = cairo_image_surface_get_format(out) == CAIRO_FORMAT_A8 ? 1 : 4;
+    int limit = w * h;
+
+    // Check whether we can loop over pixels without taking stride into account.
+    bool fast_path = true;
+    fast_path &= (stridein == w * bppin);
+    fast_path &= (strideout == w * bppout);
+
+    guint32 *const in_data  = reinterpret_cast<guint32*>(cairo_image_surface_get_data(in));
+    guint32 *const out_data = reinterpret_cast<guint32*>(cairo_image_surface_get_data(out));
+
+    #if HAVE_OPENMP
+    int numOfThreads = get_num_filter_threads();
+    #endif
+
+    // this is provided just in case, to avoid problems with strict aliasing rules
+    if (in == out) {
+        if (bppin == 4) {
+            #if HAVE_OPENMP
+            #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+            #endif
+            for (int i = 0; i < limit; ++i) {
+                *(in_data + i) = filter(*(in_data + i));
+            }
+        } else {
+            #if HAVE_OPENMP
+            #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+            #endif
+            for (int i = 0; i < limit; ++i) {
+                guint8 *in_p = reinterpret_cast<guint8*>(in_data) + i;
+                guint32 in_px = *in_p; in_px <<= 24;
+                guint32 out_px = filter(in_px);
+                *in_p = out_px >> 24;
+            }
+        }
+        cairo_surface_mark_dirty(out);
+        return;
+    }
+
+    if (bppin == 4) {
+        if (bppout == 4) {
+            // bppin == 4, bppout == 4
+            if (fast_path) {
+                #if HAVE_OPENMP
+                #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+                #endif
+                for (int i = 0; i < limit; ++i) {
+                    *(out_data + i) = filter(*(in_data + i));
+                }
+            } else {
+                #if HAVE_OPENMP
+                #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+                #endif
+                for (int i = 0; i < h; ++i) {
+                    guint32 *in_p = in_data + i * stridein/4;
+                    guint32 *out_p = out_data + i * strideout/4;
+                    for (int j = 0; j < w; ++j) {
+                        *out_p = filter(*in_p);
+                        ++in_p; ++out_p;
+                    }
+                }
+            }
+        } else {
+            // bppin == 4, bppout == 1
+            // we use this path with COLORMATRIX_LUMINANCETOALPHA
+            #if HAVE_OPENMP
+            #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+            #endif
+            for (int i = 0; i < h; ++i) {
+                guint32 *in_p = in_data + i * stridein/4;
+                guint8 *out_p = reinterpret_cast<guint8*>(out_data) + i * strideout;
+                for (int j = 0; j < w; ++j) {
+                    guint32 out_px = filter(*in_p);
+                    *out_p = out_px >> 24;
+                    ++in_p; ++out_p;
+                }
+            }
+        }
+    } else if (bppout == 1) {
+        // bppin == 1, bppout == 1
+        if (fast_path) {
+            #if HAVE_OPENMP
+            #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+            #endif
+            for (int i = 0; i < limit; ++i) {
+                guint8 *in_p = reinterpret_cast<guint8*>(in_data) + i;
+                guint8 *out_p = reinterpret_cast<guint8*>(out_data) + i;
+                guint32 in_px = *in_p; in_px <<= 24;
+                guint32 out_px = filter(in_px);
+                *out_p = out_px >> 24;
+            }
+        } else {
+            #if HAVE_OPENMP
+            #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+            #endif
+            for (int i = 0; i < h; ++i) {
+                guint8 *in_p = reinterpret_cast<guint8*>(in_data) + i * stridein;
+                guint8 *out_p = reinterpret_cast<guint8*>(out_data) + i * strideout;
+                for (int j = 0; j < w; ++j) {
+                    guint32 in_px = *in_p; in_px <<= 24;
+                    guint32 out_px = filter(in_px);
+                    *out_p = out_px >> 24;
+                    ++in_p; ++out_p;
+                }
+            }
+        }
+    } else {
+        // bppin == 1, bppout == 4
+        // used in COLORMATRIX_MATRIX when in is NR_FILTER_SOURCEALPHA
+        if (fast_path) {
+            #if HAVE_OPENMP
+            #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+            #endif
+            for (int i = 0; i < limit; ++i) {
+                guint8 in_p = reinterpret_cast<guint8*>(in_data)[i];
+                out_data[i] = filter(guint32(in_p) << 24);
+            }
+        } else {
+            #if HAVE_OPENMP
+            #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+            #endif
+            for (int i = 0; i < h; ++i) {
+                guint8 *in_p = reinterpret_cast<guint8*>(in_data) + i * stridein;
+                guint32 *out_p = out_data + i * strideout/4;
+                for (int j = 0; j < w; ++j) {
+                    out_p[j] = filter(guint32(in_p[j]) << 24);
+                }
+            }
+        }
+    }
+    cairo_surface_mark_dirty(out);
+}
+
+
+/**
+ * Synthesize surface pixels based on their position.
+ * This template accepts a functor that gets called with the x and y coordinates of the pixels,
+ * given as integers.
+ * @param out       Output surface
+ * @param out_area  The region of the output surface that should be synthesized
+ * @param synth     Synthesis functor
+ */
+template <typename Synth>
+void ink_cairo_surface_synthesize(cairo_surface_t *out, cairo_rectangle_t const &out_area, Synth synth)
+{
+    // ASSUMPTIONS
+    // 1. Cairo ARGB32 surface strides are always divisible by 4
+    // 2. We can only receive CAIRO_FORMAT_ARGB32 or CAIRO_FORMAT_A8 surfaces
+
+    int w = out_area.width;
+    int h = out_area.height;
+    int strideout = cairo_image_surface_get_stride(out);
+    int bppout = cairo_image_surface_get_format(out) == CAIRO_FORMAT_A8 ? 1 : 4;
+    // NOTE: fast path is not used, because we would need 2 divisions to get pixel indices
+
+    unsigned char *out_data = cairo_image_surface_get_data(out);
+
+    #if HAVE_OPENMP
+    int limit = w * h;
+    int numOfThreads = get_num_filter_threads();
+    #endif
+
+    if (bppout == 4) {
+        #if HAVE_OPENMP
+        #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+        #endif
+        for (int i = out_area.y; i < h; ++i) {
+            guint32 *out_p = reinterpret_cast<guint32*>(out_data + i * strideout);
+            for (int j = out_area.x; j < w; ++j) {
+                *out_p = synth(j, i);
+                ++out_p;
+            }
+        }
+    } else {
+        // bppout == 1
+        #if HAVE_OPENMP
+        #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(numOfThreads)
+        #endif
+        for (int i = out_area.y; i < h; ++i) {
+            guint8 *out_p = out_data + i * strideout;
+            for (int j = out_area.x; j < w; ++j) {
+                guint32 out_px = synth(j, i);
+                *out_p = out_px >> 24;
+                ++out_p;
+            }
+        }
+    }
+    cairo_surface_mark_dirty(out);
+}
+
+template <typename Synth>
+void ink_cairo_surface_synthesize(cairo_surface_t *out, Synth synth)
+{
+    int w = cairo_image_surface_get_width(out);
+    int h = cairo_image_surface_get_height(out);
+
+    cairo_rectangle_t area;
+    area.x = 0;
+    area.y = 0;
+    area.width = w;
+    area.height = h;
+
+    ink_cairo_surface_synthesize(out, area, synth);
+}
+
+struct SurfaceSynth {
+    SurfaceSynth(cairo_surface_t *surface)
+        : _px(cairo_image_surface_get_data(surface))
+        , _w(cairo_image_surface_get_width(surface))
+        , _h(cairo_image_surface_get_height(surface))
+        , _stride(cairo_image_surface_get_stride(surface))
+        , _alpha(cairo_surface_get_content(surface) == CAIRO_CONTENT_ALPHA)
+    {
+        cairo_surface_flush(surface);
+    }
+
+    guint32 pixelAt(int x, int y) const {
+        if (_alpha) {
+            unsigned char *px = _px + y*_stride + x;
+            return *px << 24;
+        } else {
+            unsigned char *px = _px + y*_stride + x*4;
+            return *reinterpret_cast<guint32*>(px);
+        }
+    }
+    guint32 alphaAt(int x, int y) const {
+        if (_alpha) {
+            unsigned char *px = _px + y*_stride + x;
+            return *px;
+        } else {
+            unsigned char *px = _px + y*_stride + x*4;
+            guint32 p = *reinterpret_cast<guint32*>(px);
+            return (p & 0xff000000) >> 24;
+        }
+    }
+
+    // retrieve a pixel value with bilinear interpolation
+    guint32 pixelAt(double x, double y) const {
+        if (_alpha) {
+            return alphaAt(x, y) << 24;
+        }
+
+        double xf = floor(x), yf = floor(y);
+        int xi = xf, yi = yf;
+        guint32 xif = round((x - xf) * 255), yif = round((y - yf) * 255);
+        guint32 p00, p01, p10, p11;
+
+        unsigned char *pxi = _px + yi*_stride + xi*4;
+        guint32 *pxu = reinterpret_cast<guint32*>(pxi);
+        guint32 *pxl = reinterpret_cast<guint32*>(pxi + _stride);
+        p00 = *pxu;  p10 = *(pxu + 1);
+        p01 = *pxl;  p11 = *(pxl + 1);
+
+        guint32 comp[4];
+
+        for (unsigned i = 0; i < 4; ++i) {
+            guint32 shift = i*8;
+            guint32 mask = 0xff << shift;
+            guint32 c00 = (p00 & mask) >> shift;
+            guint32 c10 = (p10 & mask) >> shift;
+            guint32 c01 = (p01 & mask) >> shift;
+            guint32 c11 = (p11 & mask) >> shift;
+
+            guint32 iu = (255-xif) * c00 + xif * c10;
+            guint32 il = (255-xif) * c01 + xif * c11;
+            comp[i] = (255-yif) * iu + yif * il;
+            comp[i] = (comp[i] + (255*255/2)) / (255*255);
+        }
+
+        guint32 result = comp[0] | (comp[1] << 8) | (comp[2] << 16) | (comp[3] << 24);
+        return result;
+    }
+
+    // retrieve an alpha value with bilinear interpolation
+    guint32 alphaAt(double x, double y) const {
+        double xf = floor(x), yf = floor(y);
+        int xi = xf, yi = yf;
+        guint32 xif = round((x - xf) * 255), yif = round((y - yf) * 255);
+        guint32 p00, p01, p10, p11;
+        if (_alpha) {
+            unsigned char *pxu = _px + yi*_stride + xi;
+            unsigned char *pxl = pxu + _stride;
+            p00 = *pxu;  p10 = *(pxu + 1);
+            p01 = *pxl;  p11 = *(pxl + 1);
+        } else {
+            unsigned char *pxi = _px + yi*_stride + xi*4;
+            guint32 *pxu = reinterpret_cast<guint32*>(pxi);
+            guint32 *pxl = reinterpret_cast<guint32*>(pxi + _stride);
+            p00 = (*pxu & 0xff000000) >> 24;  p10 = (*(pxu + 1) & 0xff000000) >> 24;
+            p01 = (*pxl & 0xff000000) >> 24;  p11 = (*(pxl + 1) & 0xff000000) >> 24;
+        }
+        guint32 iu = (255-xif) * p00 + xif * p10;
+        guint32 il = (255-xif) * p01 + xif * p11;
+        guint32 result = (255-yif) * iu + yif * il;
+        result = (result + (255*255/2)) / (255*255);
+        return result;
+    }
+
+    // compute surface normal at given coordinates using 3x3 Sobel gradient filter
+    NR::Fvector surfaceNormalAt(int x, int y, double scale) const {
+        // Below there are some multiplies by zero. They will be optimized out.
+        // Do not remove them, because they improve readability.
+        // NOTE: fetching using alphaAt is slightly lazy.
+        NR::Fvector normal;
+        double fx = -scale/255.0, fy = -scale/255.0;
+        normal[Z_3D] = 1.0;
+        if (G_UNLIKELY(x == 0)) {
+            // leftmost column
+            if (G_UNLIKELY(y == 0)) {
+                // upper left corner
+                fx *= (2.0/3.0);
+                fy *= (2.0/3.0);
+                double p00 = alphaAt(x,y),   p10 = alphaAt(x+1, y),
+                       p01 = alphaAt(x,y+1), p11 = alphaAt(x+1, y+1);
+                normal[X_3D] =
+                    -2.0 * p00 +2.0 * p10
+                    -1.0 * p01 +1.0 * p11;
+                normal[Y_3D] = 
+                    -2.0 * p00 -1.0 * p10
+                    +2.0 * p01 +1.0 * p11;
+            } else if (G_UNLIKELY(y == (_h - 1))) {
+                // lower left corner
+                fx *= (2.0/3.0);
+                fy *= (2.0/3.0);
+                double p00 = alphaAt(x,y-1), p10 = alphaAt(x+1, y-1),
+                       p01 = alphaAt(x,y  ), p11 = alphaAt(x+1, y);
+                normal[X_3D] =
+                    -1.0 * p00 +1.0 * p10
+                    -2.0 * p01 +2.0 * p11;
+                normal[Y_3D] = 
+                    -2.0 * p00 -1.0 * p10
+                    +2.0 * p01 +1.0 * p11;
+            } else {
+                // leftmost column
+                fx *= (1.0/2.0);
+                fy *= (1.0/3.0);
+                double p00 = alphaAt(x, y-1), p10 = alphaAt(x+1, y-1),
+                       p01 = alphaAt(x, y  ), p11 = alphaAt(x+1, y  ),
+                       p02 = alphaAt(x, y+1), p12 = alphaAt(x+1, y+1);
+                normal[X_3D] =
+                    -1.0 * p00 +1.0 * p10
+                    -2.0 * p01 +2.0 * p11
+                    -1.0 * p02 +1.0 * p12;
+                normal[Y_3D] =
+                    -2.0 * p00 -1.0 * p10
+                    +0.0 * p01 +0.0 * p11 // this will be optimized out
+                    +2.0 * p02 +1.0 * p12;
+            }
+        } else if (G_UNLIKELY(x == (_w - 1))) {
+            // rightmost column
+            if (G_UNLIKELY(y == 0)) {
+                // top right corner
+                fx *= (2.0/3.0);
+                fy *= (2.0/3.0);
+                double p00 = alphaAt(x-1,y),   p10 = alphaAt(x, y),
+                       p01 = alphaAt(x-1,y+1), p11 = alphaAt(x, y+1);
+                normal[X_3D] =
+                    -2.0 * p00 +2.0 * p10
+                    -1.0 * p01 +1.0 * p11;
+                normal[Y_3D] = 
+                    -1.0 * p00 -2.0 * p10
+                    +1.0 * p01 +2.0 * p11;
+            } else if (G_UNLIKELY(y == (_h - 1))) {
+                // bottom right corner
+                fx *= (2.0/3.0);
+                fy *= (2.0/3.0);
+                double p00 = alphaAt(x-1,y-1), p10 = alphaAt(x, y-1),
+                       p01 = alphaAt(x-1,y  ), p11 = alphaAt(x, y);
+                normal[X_3D] =
+                    -1.0 * p00 +1.0 * p10
+                    -2.0 * p01 +2.0 * p11;
+                normal[Y_3D] = 
+                    -1.0 * p00 -2.0 * p10
+                    +1.0 * p01 +2.0 * p11;
+            } else {
+                // rightmost column
+                fx *= (1.0/2.0);
+                fy *= (1.0/3.0);
+                double p00 = alphaAt(x-1, y-1), p10 = alphaAt(x, y-1),
+                       p01 = alphaAt(x-1, y  ), p11 = alphaAt(x, y  ),
+                       p02 = alphaAt(x-1, y+1), p12 = alphaAt(x, y+1);
+                normal[X_3D] =
+                    -1.0 * p00 +1.0 * p10
+                    -2.0 * p01 +2.0 * p11
+                    -1.0 * p02 +1.0 * p12;
+                normal[Y_3D] =
+                    -1.0 * p00 -2.0 * p10
+                    +0.0 * p01 +0.0 * p11
+                    +1.0 * p02 +2.0 * p12;
+            }
+        } else {
+            // interior
+            if (G_UNLIKELY(y == 0)) {
+                // top row
+                fx *= (1.0/3.0);
+                fy *= (1.0/2.0);
+                double p00 = alphaAt(x-1, y  ), p10 = alphaAt(x, y  ), p20 = alphaAt(x+1, y  ),
+                       p01 = alphaAt(x-1, y+1), p11 = alphaAt(x, y+1), p21 = alphaAt(x+1, y+1);
+                normal[X_3D] =
+                    -2.0 * p00 +0.0 * p10 +2.0 * p20
+                    -1.0 * p01 +0.0 * p11 +1.0 * p21;
+                normal[Y_3D] =
+                    -1.0 * p00 -2.0 * p10 -1.0 * p20
+                    +1.0 * p01 +2.0 * p11 +1.0 * p21;
+            } else if (G_UNLIKELY(y == (_h - 1))) {
+                // bottom row
+                fx *= (1.0/3.0);
+                fy *= (1.0/2.0);
+                double p00 = alphaAt(x-1, y-1), p10 = alphaAt(x, y-1), p20 = alphaAt(x+1, y-1),
+                       p01 = alphaAt(x-1, y  ), p11 = alphaAt(x, y  ), p21 = alphaAt(x+1, y  );
+                normal[X_3D] =
+                    -1.0 * p00 +0.0 * p10 +1.0 * p20
+                    -2.0 * p01 +0.0 * p11 +2.0 * p21;
+                normal[Y_3D] =
+                    -1.0 * p00 -2.0 * p10 -1.0 * p20
+                    +1.0 * p01 +2.0 * p11 +1.0 * p21;
+            } else {
+                // interior pixels
+                // note: p11 is actually unused, so we don't fetch its value
+                fx *= (1.0/4.0);
+                fy *= (1.0/4.0);
+                double p00 = alphaAt(x-1, y-1), p10 = alphaAt(x, y-1), p20 = alphaAt(x+1, y-1),
+                       p01 = alphaAt(x-1, y  ), p11 = 0.0,             p21 = alphaAt(x+1, y  ),
+                       p02 = alphaAt(x-1, y+1), p12 = alphaAt(x, y+1), p22 = alphaAt(x+1, y+1);
+                normal[X_3D] =
+                    -1.0 * p00 +0.0 * p10 +1.0 * p20
+                    -2.0 * p01 +0.0 * p11 +2.0 * p21
+                    -1.0 * p02 +0.0 * p12 +1.0 * p22;
+                normal[Y_3D] =
+                    -1.0 * p00 -2.0 * p10 -1.0 * p20
+                    +0.0 * p01 +0.0 * p11 +0.0 * p21
+                    +1.0 * p02 +2.0 * p12 +1.0 * p22;
+            }
+        }
+        normal[X_3D] *= fx;
+        normal[Y_3D] *= fy;
+        NR::normalize_vector(normal);
+        return normal;
+    }
+
+    unsigned char *_px;
+    int _w, _h, _stride;
+    bool _alpha;
+};
+
+// Some helpers for pixel manipulation
+G_GNUC_CONST inline gint32
+pxclamp(gint32 v, gint32 low, gint32 high) {
+    // NOTE: it is possible to write a "branchless" clamping operation.
+    // However, it will be slower than this function, because the code below
+    // is compiled to conditional moves.
+    if (v < low) return low;
+    if (v > high) return high;
+    return v;
+}
+
+#endif
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/cairo-utils.cpp b/src/display/cairo-utils.cpp
new file mode 100644
index 0000000..21ffb79
--- /dev/null
+++ b/src/display/cairo-utils.cpp
@@ -0,0 +1,1934 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Helper functions to use cairo with inkscape
+ *
+ * Copyright (C) 2007 bulia byak
+ * Copyright (C) 2008 Johan Engelen
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ *
+ */
+
+#include "display/cairo-utils.h"
+
+#include <2geom/affine.h>
+#include <2geom/curves.h>
+#include <2geom/path-sink.h>
+#include <2geom/path.h>
+#include <2geom/pathvector.h>
+#include <2geom/point.h>
+#include <2geom/sbasis-to-bezier.h>
+#include <2geom/transforms.h>
+#include <atomic>
+#include <boost/algorithm/string.hpp>
+#include <boost/operators.hpp>
+#include <boost/optional/optional.hpp>
+#include <gdk-pixbuf/gdk-pixbuf.h>
+#include <glib/gstdio.h>
+#include <glibmm/fileutils.h>
+#include <stdexcept>
+
+#include "cairo-templates.h"
+#include "color.h"
+#include "document.h"
+#include "helper/pixbuf-ops.h"
+#include "preferences.h"
+#include "ui/util.h"
+#include "util/scope_exit.h"
+#include "util/units.h"
+
+#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 17, 6)
+#define CAIRO_HAS_HAIRLINE
+#endif
+
+/**
+ * Key for cairo_surface_t to keep track of current color interpolation value
+ * Only the address of the structure is used, it is never initialized. See:
+ * http://www.cairographics.org/manual/cairo-Types.html#cairo-user-data-key-t
+ */
+static cairo_user_data_key_t ink_color_interpolation_key;
+
+namespace Inkscape {
+
+/* The class below implement the following hack:
+ * 
+ * The pixels formats of Cairo and GdkPixbuf are different.
+ * GdkPixbuf accesses pixels as bytes, alpha is not premultiplied,
+ * and successive bytes of a single pixel contain R, G, B and A components.
+ * Cairo accesses pixels as 32-bit ints, alpha is premultiplied,
+ * and each int contains as 0xAARRGGBB, accessed with bitwise operations.
+ *
+ * In other words, on a little endian system, a GdkPixbuf will contain:
+ *   char *data = "rgbargbargba...."
+ *   int *data = { 0xAABBGGRR, 0xAABBGGRR, 0xAABBGGRR, ... }
+ * while a Cairo image surface will contain:
+ *   char *data = "bgrabgrabgra...."
+ *   int *data = { 0xAARRGGBB, 0xAARRGGBB, 0xAARRGGBB, ... }
+ *
+ * It is possible to convert between these two formats (almost) losslessly.
+ * Some color information from partially transparent regions of the image
+ * is lost, but the result when displaying this image will remain the same.
+ *
+ * The class allows interoperation between GdkPixbuf
+ * and Cairo surfaces without creating a copy of the image.
+ * This is implemented by creating a GdkPixbuf and a Cairo image surface
+ * which share their data. Depending on what is needed at a given time,
+ * the pixels are converted in place to the Cairo or the GdkPixbuf format.
+ */
+
+/** Create a pixbuf from a Cairo surface.
+ * The constructor takes ownership of the passed surface,
+ * so it should not be destroyed. */
+Pixbuf::Pixbuf(cairo_surface_t *s)
+    : _pixbuf(gdk_pixbuf_new_from_data(
+        cairo_image_surface_get_data(s), GDK_COLORSPACE_RGB, TRUE, 8,
+        cairo_image_surface_get_width(s), cairo_image_surface_get_height(s),
+        cairo_image_surface_get_stride(s),
+        ink_cairo_pixbuf_cleanup, s))
+    , _surface(s)
+    , _mod_time(0)
+    , _pixel_format(PF_CAIRO)
+    , _cairo_store(true)
+{}
+
+/** Create a pixbuf from a GdkPixbuf.
+ * The constructor takes ownership of the passed GdkPixbuf reference,
+ * so it should not be unrefed. */
+Pixbuf::Pixbuf(GdkPixbuf *pb)
+    : _pixbuf(pb)
+    , _surface(nullptr)
+    , _mod_time(0)
+    , _pixel_format(PF_GDK)
+    , _cairo_store(false)
+{
+    _forceAlpha();
+    _surface = cairo_image_surface_create_for_data(
+        gdk_pixbuf_get_pixels(_pixbuf), CAIRO_FORMAT_ARGB32,
+        gdk_pixbuf_get_width(_pixbuf), gdk_pixbuf_get_height(_pixbuf), gdk_pixbuf_get_rowstride(_pixbuf));
+}
+
+Pixbuf::Pixbuf(Inkscape::Pixbuf const &other)
+    : _pixbuf(gdk_pixbuf_copy(other._pixbuf))
+    , _surface(cairo_image_surface_create_for_data(
+        gdk_pixbuf_get_pixels(_pixbuf), CAIRO_FORMAT_ARGB32,
+        gdk_pixbuf_get_width(_pixbuf), gdk_pixbuf_get_height(_pixbuf), gdk_pixbuf_get_rowstride(_pixbuf)))
+    , _mod_time(other._mod_time)
+    , _path(other._path)
+    , _pixel_format(other._pixel_format)
+    , _cairo_store(false)
+{}
+
+Pixbuf::~Pixbuf()
+{
+    if (!_cairo_store) {
+        cairo_surface_destroy(_surface);
+    }
+    g_object_unref(_pixbuf);
+}
+
+#if !GDK_PIXBUF_CHECK_VERSION(2, 41, 0)
+/**
+ * Incremental file read introduced to workaround
+ * https://gitlab.gnome.org/GNOME/gdk-pixbuf/issues/70
+ */
+static bool _workaround_issue_70__gdk_pixbuf_loader_write( //
+    GdkPixbufLoader *loader, guchar *decoded, gsize decoded_len, GError **error)
+{
+    bool success = true;
+    gsize bytes_left = decoded_len;
+    gsize secret_limit = 0xffff;
+    guchar *decoded_head = decoded;
+    while (bytes_left && success) {
+        gsize bytes = (bytes_left > secret_limit) ? secret_limit : bytes_left;
+        success = gdk_pixbuf_loader_write(loader, decoded_head, bytes, error);
+        decoded_head += bytes;
+        bytes_left -= bytes;
+    }
+
+    return success;
+}
+#define gdk_pixbuf_loader_write _workaround_issue_70__gdk_pixbuf_loader_write
+#endif
+
+/**
+ * Create a new Pixbuf with the image cropped to the given area.
+ */
+Pixbuf *Pixbuf::cropTo(const Geom::IntRect &area) const
+{
+    GdkPixbuf *copy = nullptr;
+    auto source = _pixbuf;
+    if (_pixel_format == PF_CAIRO) {
+        // This copies twice, but can be run on const, which is useful.
+        copy = gdk_pixbuf_copy(_pixbuf);
+        ensure_pixbuf(copy);
+        source = copy;
+    }
+    auto cropped = gdk_pixbuf_new_subpixbuf(source,
+        area.left(), area.top(), area.width(), area.height());
+    if (copy) {
+        // Clean up our pixbuf copy
+        g_object_unref(copy);
+    }
+    return new Pixbuf(cropped);
+}
+
+Pixbuf *Pixbuf::create_from_data_uri(gchar const *uri_data, double svgdpi)
+{
+    Pixbuf *pixbuf = nullptr;
+
+    bool data_is_image = false;
+    bool data_is_svg = false;
+    bool data_is_base64 = false;
+
+    gchar const *data = uri_data;
+
+    while (*data) {
+        if (strncmp(data,"base64",6) == 0) {
+            /* base64-encoding */
+            data_is_base64 = true;
+            data_is_image = true; // Illustrator produces embedded images without MIME type, so we assume it's image no matter what
+            data += 6;
+        }
+        else if (strncmp(data,"image/png",9) == 0) {
+            /* PNG image */
+            data_is_image = true;
+            data += 9;
+        }
+        else if (strncmp(data,"image/jpg",9) == 0) {
+            /* JPEG image */
+            data_is_image = true;
+            data += 9;
+        }
+        else if (strncmp(data,"image/jpeg",10) == 0) {
+            /* JPEG image */
+            data_is_image = true;
+            data += 10;
+        }
+        else if (strncmp(data,"image/jp2",9) == 0) {
+            /* JPEG2000 image */
+            data_is_image = true;
+            data += 9;
+        }
+        else if (strncmp(data,"image/svg+xml",13) == 0) {
+            /* JPEG2000 image */
+            data_is_svg = true;
+            data_is_image = true;
+            data += 13;
+        }
+        else { /* unrecognized option; skip it */
+            while (*data) {
+                if (((*data) == ';') || ((*data) == ',')) {
+                    break;
+                }
+                data++;
+            }
+        }
+        if ((*data) == ';') {
+            data++;
+            continue;
+        }
+        if ((*data) == ',') {
+            data++;
+            break;
+        }
+    }
+
+    if ((*data) && data_is_image && !data_is_svg && data_is_base64) {
+        GdkPixbufLoader *loader = gdk_pixbuf_loader_new();
+
+        if (!loader) return nullptr;
+
+        gsize decoded_len = 0;
+        guchar *decoded = g_base64_decode(data, &decoded_len);
+
+        if (gdk_pixbuf_loader_write(loader, decoded, decoded_len, nullptr)) {
+            gdk_pixbuf_loader_close(loader, nullptr);
+            GdkPixbuf *buf = gdk_pixbuf_loader_get_pixbuf(loader);
+            if (buf) {
+                g_object_ref(buf);
+                bool has_ori = Pixbuf::get_embedded_orientation(buf) != Geom::identity();
+                buf = Pixbuf::apply_embedded_orientation(buf);
+                pixbuf = new Pixbuf(buf);
+
+                if (!has_ori) {
+                    // We DO NOT want to store the original data if it contains orientation
+                    // data since many exports that will use the surface do not handle it.
+                    // TODO: Preserve the original meta data from the file by stripping out
+                    // orientation but keeping all other aspects of the raster.
+                    GdkPixbufFormat *fmt = gdk_pixbuf_loader_get_format(loader);
+                    gchar *fmt_name = gdk_pixbuf_format_get_name(fmt);
+                    pixbuf->_setMimeData(decoded, decoded_len, fmt_name);
+                    g_free(fmt_name);
+                }
+            } else {
+                g_free(decoded);
+            }
+        } else {
+            g_free(decoded);
+        }
+        g_object_unref(loader);
+    }
+    
+    if ((*data) && data_is_image && data_is_svg && data_is_base64) {
+        gsize decoded_len = 0;
+        guchar *decoded = g_base64_decode(data, &decoded_len);
+        std::unique_ptr<SPDocument> svgDoc(
+            SPDocument::createNewDocFromMem(reinterpret_cast<gchar const *>(decoded), decoded_len, false));
+        // Check the document loaded properly
+        if (!svgDoc || !svgDoc->getRoot()) {
+            return nullptr;
+        }
+        Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+        double dpi = prefs->getDouble("/dialogs/import/defaultxdpi/value", 96.0);
+        if (svgdpi && svgdpi > 0) {
+            dpi = svgdpi;
+        }
+
+        // Get the size of the document
+        Inkscape::Util::Quantity svgWidth = svgDoc->getWidth();
+        Inkscape::Util::Quantity svgHeight = svgDoc->getHeight();
+        const double svgWidth_px = svgWidth.value("px");
+        const double svgHeight_px = svgHeight.value("px");
+        if (svgWidth_px < 0 || svgHeight_px < 0) {
+            g_warning("create_from_data_uri: malformed document: svgWidth_px=%f, svgHeight_px=%f", svgWidth_px,
+                      svgHeight_px);
+            return nullptr;
+        }
+        
+        assert(!pixbuf);
+        Geom::Rect area(0, 0, svgWidth_px, svgHeight_px);
+        pixbuf = sp_generate_internal_bitmap(svgDoc.get(), area, dpi);
+        GdkPixbuf const *buf = pixbuf->getPixbufRaw();
+
+        // Tidy up
+        if (buf == nullptr) {
+            std::cerr << "Pixbuf::create_from_data: failed to load contents: " << std::endl;
+            delete pixbuf;
+            g_free(decoded);
+            return nullptr;
+        } else {
+            pixbuf->_setMimeData(decoded, decoded_len, "svg+xml");
+        }
+    }
+
+    return pixbuf;
+}
+
+Pixbuf *Pixbuf::create_from_file(std::string const &fn, double svgdpi)
+{
+    Pixbuf *pb = nullptr;
+    // test correctness of filename
+    if (!g_file_test(fn.c_str(), G_FILE_TEST_EXISTS)) { 
+        return nullptr;
+    }
+    GStatBuf stdir;
+    int val = g_stat(fn.c_str(), &stdir);
+    if (val == 0 && stdir.st_mode & S_IFDIR){
+        return nullptr;
+    }
+    // we need to load the entire file into memory,
+    // since we'll store it as MIME data
+    gchar *data = nullptr;
+    gsize len = 0;
+    GError *error = nullptr;
+
+    if (g_file_get_contents(fn.c_str(), &data, &len, &error)) {
+
+        if (error != nullptr) {
+            std::cerr << "Pixbuf::create_from_file: " << error->message << std::endl;
+            std::cerr << "   (" << fn << ")" << std::endl;
+            return nullptr;
+        }
+
+        pb = Pixbuf::create_from_buffer(std::move(data), len, svgdpi, fn);
+
+        if (pb) {
+            pb->_mod_time = stdir.st_mtime;
+        }
+    } else {
+        std::cerr << "Pixbuf::create_from_file: failed to get contents: " << fn << std::endl;
+        return nullptr;
+    }
+
+    return pb;
+}
+
+GdkPixbuf *Pixbuf::apply_embedded_orientation(GdkPixbuf *buf)
+{
+    GdkPixbuf *old = buf;
+    buf = gdk_pixbuf_apply_embedded_orientation(buf);
+    g_object_unref(old);
+    return buf;
+}
+
+/**
+ * Gets any available orientation data and returns it as an affine.
+ */
+Geom::Affine Pixbuf::get_embedded_orientation(GdkPixbuf *buf)
+{
+    // See gdk_pixbuf_apply_embedded_orientation in gdk-pixbuf
+    if (auto opt_str = gdk_pixbuf_get_option(buf, "orientation")) {
+        switch ((int)g_ascii_strtoll(opt_str, NULL, 10)) {
+            case 2: // Flip Horz
+                return Geom::Scale(-1, 1);
+            case 3: // +180 Rotate
+                return Geom::Scale(-1, -1);
+            case 4: // Flip Vert
+                return Geom::Scale(1, -1);
+            case 5: // +90 Rotate & Flip Horz
+                return Geom::Rotate(90) * Geom::Scale(-1, 1);
+            case 6: // +90 Rotate
+                return Geom::Rotate(90);
+            case 7: // +90 Rotate * Flip Vert
+                return Geom::Rotate(90) * Geom::Scale(1, -1);
+            case 8: // -90 Rotate
+                return Geom::Rotate(-90);
+            default:
+                break;
+
+        }
+    }
+    return Geom::identity();
+}
+
+Pixbuf *Pixbuf::create_from_buffer(std::string const &buffer, double svgdpi, std::string const &fn)
+{
+#if GLIB_CHECK_VERSION(2,67,3)
+    auto datacopy = (gchar *)g_memdup2(buffer.data(), buffer.size());
+#else
+    auto datacopy = (gchar *)g_memdup(buffer.data(), buffer.size());
+#endif
+    return Pixbuf::create_from_buffer(std::move(datacopy), buffer.size(), svgdpi, fn);
+}
+
+Pixbuf *Pixbuf::create_from_buffer(gchar *&&data, gsize len, double svgdpi, std::string const &fn)
+{
+    bool has_ori = false;
+    Pixbuf *pb = nullptr;
+    GError *error = nullptr;
+    {
+        GdkPixbuf *buf = nullptr;
+        GdkPixbufLoader *loader = nullptr;
+        std::string::size_type idx;
+        idx = fn.rfind('.');
+        bool is_svg = false;    
+        if(idx != std::string::npos)
+        {
+            if (boost::iequals(fn.substr(idx+1).c_str(), "svg")) {
+                std::unique_ptr<SPDocument> svgDoc(SPDocument::createNewDocFromMem(data, len, true, fn.c_str()));
+
+                // Check the document loaded properly
+                if (!svgDoc || !svgDoc->getRoot()) {
+                    return nullptr;
+                }
+
+                Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+                double dpi = prefs->getDouble("/dialogs/import/defaultxdpi/value", 96.0);
+                if (svgdpi && svgdpi > 0) {
+                    dpi = svgdpi;
+                }
+
+                // Get the size of the document
+                Inkscape::Util::Quantity svgWidth = svgDoc->getWidth();
+                Inkscape::Util::Quantity svgHeight = svgDoc->getHeight();
+                const double svgWidth_px = svgWidth.value("px");
+                const double svgHeight_px = svgHeight.value("px");
+                if (svgWidth_px < 0 || svgHeight_px < 0) {
+                    g_warning("create_from_buffer: malformed document: svgWidth_px=%f, svgHeight_px=%f", svgWidth_px,
+                              svgHeight_px);
+                    return nullptr;
+                }
+
+                Geom::Rect area(0, 0, svgWidth_px, svgHeight_px);
+                pb = sp_generate_internal_bitmap(svgDoc.get(), area, dpi);
+                buf = pb->getPixbufRaw();
+
+                // Tidy up
+                if (buf == nullptr) {
+                    delete pb;
+                    return nullptr;
+                }
+                buf = Pixbuf::apply_embedded_orientation(buf);
+                is_svg = true;
+            }
+        }
+        if (!is_svg) {
+            loader = gdk_pixbuf_loader_new();
+            gdk_pixbuf_loader_write(loader, (guchar *) data, len, &error);
+            if (error != nullptr) {
+                std::cerr << "Pixbuf::create_from_file: " << error->message << std::endl;
+                std::cerr << "   (" << fn << ")" << std::endl;
+                g_free(data);
+                g_object_unref(loader);
+                return nullptr;
+            }
+
+            gdk_pixbuf_loader_close(loader, &error);
+            if (error != nullptr) {
+                std::cerr << "Pixbuf::create_from_file: " << error->message << std::endl;
+                std::cerr << "   (" << fn << ")" << std::endl;
+                g_free(data);
+                g_object_unref(loader);
+                return nullptr;
+            }
+            
+            buf = gdk_pixbuf_loader_get_pixbuf(loader);
+            if (buf) {
+                // gdk_pixbuf_loader_get_pixbuf returns a borrowed reference
+                g_object_ref(buf);
+                has_ori = Pixbuf::get_embedded_orientation(buf) != Geom::identity();
+                buf = Pixbuf::apply_embedded_orientation(buf);
+                pb = new Pixbuf(buf);
+            }
+        }
+
+        if (pb) {
+            pb->_path = fn;
+            if (is_svg) {
+                pb->_setMimeData((guchar *) data, len, "svg");
+            } else if(!has_ori) {
+                // We DO NOT want to store the original data if it contains orientation
+                // data since many exports that will use the surface do not handle it.
+                GdkPixbufFormat *fmt = gdk_pixbuf_loader_get_format(loader);
+                gchar *fmt_name = gdk_pixbuf_format_get_name(fmt);
+                pb->_setMimeData((guchar *) data, len, fmt_name);
+                g_free(fmt_name);
+                g_object_unref(loader);
+            }
+        } else {
+            std::cerr << "Pixbuf::create_from_file: failed to load contents: " << fn << std::endl;
+            g_free(data);
+        }
+
+        // TODO: we could also read DPI, ICC profile, gamma correction, and other information
+        // from the file. This can be done by using format-specific libraries e.g. libpng.
+    }
+
+    return pb;
+}
+
+/**
+ * Converts the pixbuf to GdkPixbuf pixel format.
+ * The returned pixbuf can be used e.g. in calls to gdk_pixbuf_save().
+ */
+GdkPixbuf *Pixbuf::getPixbufRaw(bool convert_format)
+{
+    if (convert_format) {
+        ensurePixelFormat(PF_GDK);
+    }
+    return _pixbuf;
+}
+
+GdkPixbuf *Pixbuf::getPixbufRaw() const
+{
+    assert(_pixel_format == PF_GDK);
+    return _pixbuf;
+}
+
+/**
+ * Converts the pixbuf to Cairo pixel format and returns an image surface
+ * which can be used as a source.
+ *
+ * The returned surface is owned by the GdkPixbuf and should not be freed.
+ * Calling this function causes the pixbuf to be unsuitable for use
+ * with GTK drawing functions until ensurePixelFormat(Pixbuf::PIXEL_FORMAT_PIXBUF) is called.
+ */
+cairo_surface_t *Pixbuf::getSurfaceRaw()
+{
+    ensurePixelFormat(PF_CAIRO);
+    return _surface;
+}
+
+cairo_surface_t *Pixbuf::getSurfaceRaw() const
+{
+    assert(_pixel_format == PF_CAIRO);
+    return _surface;
+}
+
+/* Declaring this function in the header requires including <gdkmm/pixbuf.h>,
+ * which stupidly includes <glibmm.h> which in turn pulls in <glibmm/threads.h>.
+ * However, since glib 2.32, <glibmm/threads.h> has to be included before <glib.h>
+ * when compiling with G_DISABLE_DEPRECATED, as we do in non-release builds.
+ * This necessitates spamming a lot of files with #include <glibmm/threads.h>
+ * at the top.
+ *
+ * Since we don't really use gdkmm, do not define this function for now. */
+
+/*
+Glib::RefPtr<Gdk::Pixbuf> Pixbuf::getPixbuf(bool convert_format = true)
+{
+    g_object_ref(_pixbuf);
+    Glib::RefPtr<Gdk::Pixbuf> p(getPixbuf(convert_format));
+    return p;
+}
+*/
+
+Cairo::RefPtr<Cairo::Surface> Pixbuf::getSurface()
+{
+    return Cairo::RefPtr<Cairo::Surface>(new Cairo::Surface(getSurfaceRaw(), false));
+}
+
+/** Retrieves the original compressed data for the surface, if any.
+ * The returned data belongs to the object and should not be freed. */
+guchar const *Pixbuf::getMimeData(gsize &len, std::string &mimetype) const
+{
+    static gchar const *mimetypes[] = {
+        CAIRO_MIME_TYPE_JPEG, CAIRO_MIME_TYPE_JP2, CAIRO_MIME_TYPE_PNG, nullptr };
+    static guint mimetypes_len = g_strv_length(const_cast<gchar**>(mimetypes));
+
+    guchar const *data = nullptr;
+
+    for (guint i = 0; i < mimetypes_len; ++i) {
+        unsigned long len_long = 0;
+        cairo_surface_get_mime_data(const_cast<cairo_surface_t*>(_surface), mimetypes[i], &data, &len_long);
+        if (data != nullptr) {
+			len = len_long;
+            mimetype = mimetypes[i];
+            break;
+        }
+    }
+
+    return data;
+}
+
+int Pixbuf::width() const {
+    return gdk_pixbuf_get_width(const_cast<GdkPixbuf*>(_pixbuf));
+}
+int Pixbuf::height() const {
+    return gdk_pixbuf_get_height(const_cast<GdkPixbuf*>(_pixbuf));
+}
+int Pixbuf::rowstride() const {
+    return gdk_pixbuf_get_rowstride(const_cast<GdkPixbuf*>(_pixbuf));
+}
+guchar const *Pixbuf::pixels() const {
+    return gdk_pixbuf_get_pixels(const_cast<GdkPixbuf*>(_pixbuf));
+}
+guchar *Pixbuf::pixels() {
+    return gdk_pixbuf_get_pixels(_pixbuf);
+}
+void Pixbuf::markDirty() {
+    cairo_surface_mark_dirty(_surface);
+}
+
+void Pixbuf::_forceAlpha()
+{
+    if (gdk_pixbuf_get_has_alpha(_pixbuf)) return;
+
+    GdkPixbuf *old = _pixbuf;
+    _pixbuf = gdk_pixbuf_add_alpha(old, FALSE, 0, 0, 0);
+    g_object_unref(old);
+}
+
+void Pixbuf::_setMimeData(guchar *data, gsize len, Glib::ustring const &format)
+{
+    gchar const *mimetype = nullptr;
+
+    if (format == "jpeg") {
+        mimetype = CAIRO_MIME_TYPE_JPEG;
+    } else if (format == "jpeg2000") {
+        mimetype = CAIRO_MIME_TYPE_JP2;
+    } else if (format == "png") {
+        mimetype = CAIRO_MIME_TYPE_PNG;
+    }
+
+    if (mimetype != nullptr) {
+        cairo_surface_set_mime_data(_surface, mimetype, data, len, g_free, data);
+        //g_message("Setting Cairo MIME data: %s", mimetype);
+    } else {
+        g_free(data);
+        //g_message("Not setting Cairo MIME data: unknown format %s", name.c_str());
+    }
+}
+
+/**
+ * Convert the internal pixel format between CAIRO and GDK formats.
+ */
+void Pixbuf::ensurePixelFormat(PixelFormat fmt)
+{
+    if (fmt == PF_CAIRO && _pixel_format == PF_GDK) {
+        ensure_argb32(_pixbuf);
+        _pixel_format = fmt;
+    } else if (fmt == PF_GDK && _pixel_format == PF_CAIRO) {
+        ensure_pixbuf(_pixbuf);
+        _pixel_format = fmt;
+    } else if (fmt != _pixel_format) {
+        g_assert_not_reached();
+    }
+}
+
+/**
+ * Converts GdkPixbuf's data to premultiplied ARGB.
+ * This function will convert a GdkPixbuf in place into Cairo's native pixel format.
+ * Note that this is a hack intended to save memory. When the pixbuf is in Cairo's format,
+ * using it with GTK will result in corrupted drawings.
+ */
+void Pixbuf::ensure_argb32(GdkPixbuf *pb)
+{
+    convert_pixels_pixbuf_to_argb32(
+        gdk_pixbuf_get_pixels(pb),
+        gdk_pixbuf_get_width(pb),
+        gdk_pixbuf_get_height(pb),
+        gdk_pixbuf_get_rowstride(pb));
+}
+
+/**
+ * Converts GdkPixbuf's data back to its native format.
+ * Once this is done, the pixbuf can be used with GTK again.
+ */
+void Pixbuf::ensure_pixbuf(GdkPixbuf *pb)
+{
+    convert_pixels_argb32_to_pixbuf(
+        gdk_pixbuf_get_pixels(pb),
+        gdk_pixbuf_get_width(pb),
+        gdk_pixbuf_get_height(pb),
+        gdk_pixbuf_get_rowstride(pb));
+}
+
+} // namespace Inkscape
+
+/*
+ * Can be called recursively.
+ * If optimize_stroke == false, the view Rect is not used.
+ */
+static void
+feed_curve_to_cairo(cairo_t *cr, Geom::Curve const &c, Geom::Affine const &trans, Geom::Rect const &view, bool optimize_stroke)
+{
+    using Geom::X;
+    using Geom::Y;
+
+    unsigned order = 0;
+    if (auto b = dynamic_cast<Geom::BezierCurve const*>(&c)) {
+        order = b->order();
+    }
+
+    // handle the three typical curve cases
+    switch (order) {
+    case 1:
+    {
+        Geom::Point end_tr = c.finalPoint() * trans;
+        if (!optimize_stroke) {
+            cairo_line_to(cr, end_tr[0], end_tr[1]);
+        } else {
+            Geom::Rect swept(c.initialPoint()*trans, end_tr);
+            if (swept.intersects(view)) {
+                cairo_line_to(cr, end_tr[0], end_tr[1]);
+            } else {
+                cairo_move_to(cr, end_tr[0], end_tr[1]);
+            }
+        }
+    }
+    break;
+    case 2:
+    {
+        auto quadratic_bezier = static_cast<Geom::QuadraticBezier const*>(&c);
+        std::array<Geom::Point, 3> points;
+        for (int i = 0; i < 3; i++) {
+            points[i] = quadratic_bezier->controlPoint(i) * trans;
+        }
+        // degree-elevate to cubic Bezier, since Cairo doesn't do quadratic Beziers
+        Geom::Point b1 = points[0] + (2./3) * (points[1] - points[0]);
+        Geom::Point b2 = b1 + (1./3) * (points[2] - points[0]);
+        if (!optimize_stroke) {
+            cairo_curve_to(cr, b1[X], b1[Y], b2[X], b2[Y], points[2][X], points[2][Y]);
+        } else {
+            Geom::Rect swept(points[0], points[2]);
+            swept.expandTo(points[1]);
+            if (swept.intersects(view)) {
+                cairo_curve_to(cr, b1[X], b1[Y], b2[X], b2[Y], points[2][X], points[2][Y]);
+            } else {
+                cairo_move_to(cr, points[2][X], points[2][Y]);
+            }
+        }
+    }
+    break;
+    case 3:
+    {
+        auto cubic_bezier = static_cast<Geom::CubicBezier const*>(&c);
+        std::array<Geom::Point, 4> points;
+        for (int i = 0; i < 4; i++) {
+            points[i] = cubic_bezier->controlPoint(i);
+        }
+        //points[0] *= trans; // don't do this one here for fun: it is only needed for optimized strokes
+        points[1] *= trans;
+        points[2] *= trans;
+        points[3] *= trans;
+        if (!optimize_stroke) {
+            cairo_curve_to(cr, points[1][X], points[1][Y], points[2][X], points[2][Y], points[3][X], points[3][Y]);
+        } else {
+            points[0] *= trans;  // didn't transform this point yet
+            Geom::Rect swept(points[0], points[3]);
+            swept.expandTo(points[1]);
+            swept.expandTo(points[2]);
+            if (swept.intersects(view)) {
+                cairo_curve_to(cr, points[1][X], points[1][Y], points[2][X], points[2][Y], points[3][X], points[3][Y]);
+            } else {
+                cairo_move_to(cr, points[3][X], points[3][Y]);
+            }
+        }
+    }
+    break;
+    default:
+    {
+        if (Geom::EllipticalArc const *arc = dynamic_cast<Geom::EllipticalArc const*>(&c)) {
+            if (arc->isChord()) {
+                Geom::Point endPoint(arc->finalPoint());
+                cairo_line_to(cr, endPoint[0], endPoint[1]);
+            } else {
+                Geom::Affine xform = arc->unitCircleTransform() * trans;
+                // Don't draw anything if the angle is borked
+                if(std::isnan(arc->initialAngle()) || std::isnan(arc->finalAngle())) {
+                    g_warning("Bad angle while drawing EllipticalArc");
+                    break;
+                }
+
+                // Apply the transformation to the current context
+                auto cm = geom_to_cairo(xform);
+
+                cairo_save(cr);
+                cairo_transform(cr, &cm);
+
+                // Draw the circle
+                if (arc->sweep()) {
+                    cairo_arc(cr, 0, 0, 1, arc->initialAngle(), arc->finalAngle());
+                } else {
+                    cairo_arc_negative(cr, 0, 0, 1, arc->initialAngle(), arc->finalAngle());
+                }
+                // Revert the current context
+                cairo_restore(cr);
+            }
+        } else {
+            // handles sbasis as well as all other curve types
+            // this is very slow
+            Geom::Path sbasis_path = Geom::cubicbezierpath_from_sbasis(c.toSBasis(), 0.1);
+
+            // recurse to convert the new path resulting from the sbasis to svgd
+            for (const auto & iter : sbasis_path) {
+                feed_curve_to_cairo(cr, iter, trans, view, optimize_stroke);
+            }
+        }
+    }
+    break;
+    }
+}
+
+
+/** Feeds path-creating calls to the cairo context translating them from the Path */
+static void
+feed_path_to_cairo (cairo_t *ct, Geom::Path const &path)
+{
+    if (path.empty())
+        return;
+
+    cairo_move_to(ct, path.initialPoint()[0], path.initialPoint()[1] );
+
+    for (Geom::Path::const_iterator cit = path.begin(); cit != path.end_open(); ++cit) {
+        feed_curve_to_cairo(ct, *cit, Geom::identity(), Geom::Rect(), false); // optimize_stroke is false, so the view rect is not used
+    }
+
+    if (path.closed()) {
+        cairo_close_path(ct);
+    }
+}
+
+/** Feeds path-creating calls to the cairo context translating them from the Path, with the given transform and shift */
+static void
+feed_path_to_cairo (cairo_t *ct, Geom::Path const &path, Geom::Affine trans, Geom::OptRect area, bool optimize_stroke, double stroke_width)
+{
+    if (!area)
+        return;
+    if (path.empty())
+        return;
+
+    // Transform all coordinates to coords within "area"
+    Geom::Point shift = area->min();
+    Geom::Rect view = *area;
+    view.expandBy (stroke_width);
+    view = view * (Geom::Affine)Geom::Translate(-shift);
+    //  Pass transformation to feed_curve, so that we don't need to create a whole new path.
+    Geom::Affine transshift(trans * Geom::Translate(-shift));
+
+    Geom::Point initial = path.initialPoint() * transshift;
+    cairo_move_to(ct, initial[0], initial[1] );
+
+    for(Geom::Path::const_iterator cit = path.begin(); cit != path.end_open(); ++cit) {
+        feed_curve_to_cairo(ct, *cit, transshift, view, optimize_stroke);
+    }
+
+    if (path.closed()) {
+        if (!optimize_stroke) {
+            cairo_close_path(ct);
+        } else {
+            cairo_line_to(ct, initial[0], initial[1]);
+            /* We cannot use cairo_close_path(ct) here because some parts of the path may have been
+               clipped and not drawn (maybe the before last segment was outside view area), which 
+               would result in closing the "subpath" after the last interruption, not the entire path.
+
+               However, according to cairo documentation:
+               The behavior of cairo_close_path() is distinct from simply calling cairo_line_to() with the equivalent coordinate
+               in the case of stroking. When a closed sub-path is stroked, there are no caps on the ends of the sub-path. Instead,
+               there is a line join connecting the final and initial segments of the sub-path. 
+
+               The correct fix will be possible when cairo introduces methods for moving without
+               ending/starting subpaths, which we will use for skipping invisible segments; then we
+               will be able to use cairo_close_path here. This issue also affects ps/eps/pdf export,
+               see bug 168129
+            */
+        }
+    }
+}
+
+/** Feeds path-creating calls to the cairo context translating them from the PathVector, with the given transform and shift
+ *  One must have done cairo_new_path(ct); before calling this function. */
+void
+feed_pathvector_to_cairo (cairo_t *ct, Geom::PathVector const &pathv, Geom::Affine trans, Geom::OptRect area, bool optimize_stroke, double stroke_width)
+{
+    if (!area)
+        return;
+    if (pathv.empty())
+        return;
+
+    for(const auto & it : pathv) {
+        feed_path_to_cairo(ct, it, trans, area, optimize_stroke, stroke_width);
+    }
+}
+
+/** Feeds path-creating calls to the cairo context translating them from the PathVector
+ *  One must have done cairo_new_path(ct); before calling this function. */
+void
+feed_pathvector_to_cairo (cairo_t *ct, Geom::PathVector const &pathv)
+{
+    if (pathv.empty())
+        return;
+
+    for(const auto & it : pathv) {
+        feed_path_to_cairo(ct, it);
+    }
+}
+
+/*
+ * Pulls out the last cairo path context and reconstitutes it
+ * into a local geom path vector for inkscape use.
+ *
+ * @param ct - The cairo context
+ *
+ * @returns an optioal Geom::PathVector object
+ */
+std::optional<Geom::PathVector> extract_pathvector_from_cairo(cairo_t *ct)
+{
+    cairo_path_t *path = cairo_copy_path(ct);
+    if (!path)
+        return std::nullopt;
+
+    auto path_freer = scope_exit([&] { cairo_path_destroy(path); });
+
+    Geom::PathBuilder res;
+    auto end = &path->data[path->num_data];
+    for (auto p = &path->data[0]; p < end; p += p->header.length) {
+        switch (p->header.type) {
+            case CAIRO_PATH_MOVE_TO:
+                if (p->header.length != 2)
+                    return std::nullopt;
+                res.moveTo(Geom::Point(p[1].point.x, p[1].point.y));
+                break;
+
+            case CAIRO_PATH_LINE_TO:
+                if (p->header.length != 2)
+                    return std::nullopt;
+                res.lineTo(Geom::Point(p[1].point.x, p[1].point.y));
+                break;
+
+            case CAIRO_PATH_CURVE_TO:
+                if (p->header.length != 4)
+                    return std::nullopt;
+                res.curveTo(Geom::Point(p[1].point.x, p[1].point.y), Geom::Point(p[2].point.x, p[2].point.y),
+                            Geom::Point(p[3].point.x, p[3].point.y));
+                break;
+
+            case CAIRO_PATH_CLOSE_PATH:
+                if (p->header.length != 1)
+                    return std::nullopt;
+                res.closePath();
+                break;
+            default:
+                return std::nullopt;
+        }
+    }
+
+    res.flush();
+    return res.peek();
+}
+
+static std::atomic<int> num_filter_threads = 4;
+
+int get_num_filter_threads()
+{
+    return num_filter_threads.load(std::memory_order_relaxed);
+}
+
+void set_num_filter_threads(int n)
+{
+    num_filter_threads.store(n, std::memory_order_relaxed);
+}
+
+SPColorInterpolation
+get_cairo_surface_ci(cairo_surface_t *surface) {
+    void* data = cairo_surface_get_user_data( surface, &ink_color_interpolation_key );
+    if( data != nullptr ) {
+        return (SPColorInterpolation)GPOINTER_TO_INT( data );
+    } else {
+        return SP_CSS_COLOR_INTERPOLATION_AUTO;
+    }
+}
+
+/** Set the color_interpolation_value for a Cairo surface.
+ *  Transform the surface between sRGB and linearRGB if necessary. */
+void
+set_cairo_surface_ci(cairo_surface_t *surface, SPColorInterpolation ci) {
+
+    if( cairo_surface_get_content( surface ) != CAIRO_CONTENT_ALPHA ) {
+
+        SPColorInterpolation ci_in = get_cairo_surface_ci( surface );
+
+        if( ci_in == SP_CSS_COLOR_INTERPOLATION_SRGB &&
+            ci    == SP_CSS_COLOR_INTERPOLATION_LINEARRGB ) {
+            ink_cairo_surface_srgb_to_linear( surface );
+        }
+        if( ci_in == SP_CSS_COLOR_INTERPOLATION_LINEARRGB &&
+            ci    == SP_CSS_COLOR_INTERPOLATION_SRGB ) {
+            ink_cairo_surface_linear_to_srgb( surface );
+        }
+
+        cairo_surface_set_user_data(surface, &ink_color_interpolation_key, GINT_TO_POINTER (ci), nullptr);
+    }
+}
+
+void
+copy_cairo_surface_ci(cairo_surface_t *in, cairo_surface_t *out) {
+    cairo_surface_set_user_data(out, &ink_color_interpolation_key, cairo_surface_get_user_data(in, &ink_color_interpolation_key), nullptr);
+}
+
+void
+ink_cairo_set_source_rgba32(cairo_t *ct, guint32 rgba)
+{
+    cairo_set_source_rgba(ct, SP_RGBA32_R_F(rgba), SP_RGBA32_G_F(rgba), SP_RGBA32_B_F(rgba), SP_RGBA32_A_F(rgba));
+}
+
+void
+ink_cairo_set_source_color(cairo_t *ct, SPColor const &c, double opacity)
+{
+    cairo_set_source_rgba(ct, c.v.c[0], c.v.c[1], c.v.c[2], opacity);
+}
+
+void ink_matrix_to_2geom(Geom::Affine &m, cairo_matrix_t const &cm)
+{
+    m[0] = cm.xx;
+    m[2] = cm.xy;
+    m[4] = cm.x0;
+    m[1] = cm.yx;
+    m[3] = cm.yy;
+    m[5] = cm.y0;
+}
+
+void ink_matrix_to_cairo(cairo_matrix_t &cm, Geom::Affine const &m)
+{
+    cm.xx = m[0];
+    cm.xy = m[2];
+    cm.x0 = m[4];
+    cm.yx = m[1];
+    cm.yy = m[3];
+    cm.y0 = m[5];
+}
+
+void
+ink_cairo_transform(cairo_t *ct, Geom::Affine const &m)
+{
+    cairo_matrix_t cm;
+    ink_matrix_to_cairo(cm, m);
+    cairo_transform(ct, &cm);
+}
+
+void
+ink_cairo_pattern_set_matrix(cairo_pattern_t *cp, Geom::Affine const &m)
+{
+    cairo_matrix_t cm;
+    ink_matrix_to_cairo(cm, m);
+    cairo_pattern_set_matrix(cp, &cm);
+}
+
+void
+ink_cairo_set_hairline(cairo_t *ct)
+{
+#ifdef CAIRO_HAS_HAIRLINE
+    cairo_set_hairline(ct, true);
+#else
+    // As a backup, use a device unit of 1
+    double x = 1.0, y = 0.0;
+    cairo_device_to_user_distance(ct, &x, &y);
+    cairo_set_line_width(ct, std::hypot(x, y));
+#endif
+}
+
+void ink_cairo_set_dither(cairo_surface_t *surface, bool enabled)
+{
+#ifdef CAIRO_HAS_DITHER
+    cairo_image_surface_set_dither(surface, enabled ? CAIRO_DITHER_BEST : CAIRO_DITHER_NONE);
+#endif
+}
+
+/**
+ * Create an exact copy of a surface.
+ * Creates a surface that has the same type, content type, dimensions and contents
+ * as the specified surface.
+ */
+cairo_surface_t *
+ink_cairo_surface_copy(cairo_surface_t *s)
+{
+    cairo_surface_t *ns = ink_cairo_surface_create_identical(s);
+
+    if (cairo_surface_get_type(s) == CAIRO_SURFACE_TYPE_IMAGE) {
+        // use memory copy instead of using a Cairo context
+        cairo_surface_flush(s);
+        int stride = cairo_image_surface_get_stride(s);
+        int h = cairo_image_surface_get_height(s);
+        memcpy(cairo_image_surface_get_data(ns), cairo_image_surface_get_data(s), stride * h);
+        cairo_surface_mark_dirty(ns);
+    } else {
+        // generic implementation
+        cairo_t *ct = cairo_create(ns);
+        cairo_set_source_surface(ct, s, 0, 0);
+        cairo_set_operator(ct, CAIRO_OPERATOR_SOURCE);
+        cairo_paint(ct);
+        cairo_destroy(ct);
+    }
+
+    return ns;
+}
+
+/**
+ * Create an exact copy of an image surface.
+ */
+Cairo::RefPtr<Cairo::ImageSurface>
+ink_cairo_surface_copy(Cairo::RefPtr<Cairo::ImageSurface> surface )
+{
+    int width  = surface->get_width();
+    int height = surface->get_height();
+    int stride = surface->get_stride();
+    auto new_surface = Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32, width, height); // device scale?
+
+    surface->flush();
+    memcpy(new_surface->get_data(), surface->get_data(), stride * height);
+    new_surface->mark_dirty(); // Clear caches. Mandatory after messing directly with contents.
+
+    return new_surface;
+}
+
+/**
+ * Create a surface that differs only in pixel content.
+ * Creates a surface that has the same type, content type and dimensions
+ * as the specified surface. Pixel contents are not copied.
+ */
+cairo_surface_t *
+ink_cairo_surface_create_identical(cairo_surface_t *s)
+{
+    cairo_surface_t *ns = ink_cairo_surface_create_same_size(s, cairo_surface_get_content(s));
+    cairo_surface_set_user_data(ns, &ink_color_interpolation_key, cairo_surface_get_user_data(s, &ink_color_interpolation_key), nullptr);
+    return ns;
+}
+
+cairo_surface_t *
+ink_cairo_surface_create_same_size(cairo_surface_t *s, cairo_content_t c)
+{
+    // ink_cairo_surface_get_width()/height() returns value in pixels
+    // cairo_surface_create_similar() uses device units
+    double x_scale = 0;
+    double y_scale = 0;
+    cairo_surface_get_device_scale( s, &x_scale, &y_scale );
+
+    assert (x_scale > 0);
+    assert (y_scale > 0);
+
+    cairo_surface_t *ns =
+        cairo_surface_create_similar(s, c,
+                                     ink_cairo_surface_get_width(s)/x_scale,
+                                     ink_cairo_surface_get_height(s)/y_scale);
+    return ns;
+}
+
+/**
+ * Extract the alpha channel into a new surface.
+ * Creates a surface with a content type of CAIRO_CONTENT_ALPHA that contains
+ * the alpha values of pixels from @a s.
+ */
+cairo_surface_t *
+ink_cairo_extract_alpha(cairo_surface_t *s)
+{
+    cairo_surface_t *alpha = ink_cairo_surface_create_same_size(s, CAIRO_CONTENT_ALPHA);
+
+    cairo_t *ct = cairo_create(alpha);
+    cairo_set_source_surface(ct, s, 0, 0);
+    cairo_set_operator(ct, CAIRO_OPERATOR_SOURCE);
+    cairo_paint(ct);
+    cairo_destroy(ct);
+
+    return alpha;
+}
+
+cairo_surface_t *
+ink_cairo_surface_create_output(cairo_surface_t *image, cairo_surface_t *bg)
+{
+    cairo_content_t imgt = cairo_surface_get_content(image);
+    cairo_content_t bgt = cairo_surface_get_content(bg);
+    cairo_surface_t *out = nullptr;
+
+    if (bgt == CAIRO_CONTENT_ALPHA && imgt == CAIRO_CONTENT_ALPHA) {
+        out = ink_cairo_surface_create_identical(bg);
+    } else {
+        out = ink_cairo_surface_create_same_size(bg, CAIRO_CONTENT_COLOR_ALPHA);
+    }
+
+    return out;
+}
+
+void
+ink_cairo_surface_blit(cairo_surface_t *src, cairo_surface_t *dest)
+{
+    if (cairo_surface_get_type(src) == CAIRO_SURFACE_TYPE_IMAGE &&
+        cairo_surface_get_type(dest) == CAIRO_SURFACE_TYPE_IMAGE &&
+        cairo_image_surface_get_format(src) == cairo_image_surface_get_format(dest) &&
+        cairo_image_surface_get_height(src) == cairo_image_surface_get_height(dest) &&
+        cairo_image_surface_get_width(src) == cairo_image_surface_get_width(dest) &&
+        cairo_image_surface_get_stride(src) == cairo_image_surface_get_stride(dest))
+    {
+        // use memory copy instead of using a Cairo context
+        cairo_surface_flush(src);
+        int stride = cairo_image_surface_get_stride(src);
+        int h = cairo_image_surface_get_height(src);
+        memcpy(cairo_image_surface_get_data(dest), cairo_image_surface_get_data(src), stride * h);
+        cairo_surface_mark_dirty(dest);
+    } else {
+        // generic implementation
+        cairo_t *ct = cairo_create(dest);
+        cairo_set_source_surface(ct, src, 0, 0);
+        cairo_set_operator(ct, CAIRO_OPERATOR_SOURCE);
+        cairo_paint(ct);
+        cairo_destroy(ct);
+    }
+}
+
+/**
+ * Return width in pixels.
+ */
+int
+ink_cairo_surface_get_width(cairo_surface_t *surface)
+{
+    // For now only image surface is handled.
+    // Later add others, e.g. cairo-gl
+    assert(cairo_surface_get_type(surface) == CAIRO_SURFACE_TYPE_IMAGE);
+    return cairo_image_surface_get_width(surface);
+}
+
+/**
+ * Return height in pixels.
+ */
+int
+ink_cairo_surface_get_height(cairo_surface_t *surface)
+{
+    assert(cairo_surface_get_type(surface) == CAIRO_SURFACE_TYPE_IMAGE);
+    return cairo_image_surface_get_height(surface);
+}
+
+static int ink_cairo_surface_average_color_internal(cairo_surface_t *surface, double &rf, double &gf, double &bf, double &af)
+{
+    rf = gf = bf = af = 0.0;
+    cairo_surface_flush(surface);
+    int width = cairo_image_surface_get_width(surface);
+    int height = cairo_image_surface_get_height(surface);
+    int stride = cairo_image_surface_get_stride(surface);
+    unsigned char *data = cairo_image_surface_get_data(surface);
+
+    /* TODO convert this to OpenMP somehow */
+    for (int y = 0; y < height; ++y, data += stride) {
+        for (int x = 0; x < width; ++x) {
+            guint32 px = *reinterpret_cast<guint32*>(data + 4*x);
+            EXTRACT_ARGB32(px, a,r,g,b)
+            rf += r / 255.0;
+            gf += g / 255.0;
+            bf += b / 255.0;
+            af += a / 255.0;
+        }
+    }
+    return width * height;
+}
+
+guint32 ink_cairo_surface_average_color(cairo_surface_t *surface)
+{
+    double rf,gf,bf,af;
+    ink_cairo_surface_average_color_premul(surface, rf,gf,bf,af);
+    guint32 r = round(rf * 255);
+    guint32 g = round(gf * 255);
+    guint32 b = round(bf * 255);
+    guint32 a = round(af * 255);
+    ASSEMBLE_ARGB32(px, a,r,g,b);
+    return px;
+}
+// We extract colors from pattern background, if we need to extract sometimes from a gradient we can add
+// a extra parameter with the spot number and use cairo_pattern_get_color_stop_rgba
+// also if the pattern is a image we can pass a boolean like solid = false to get the color by image average ink_cairo_surface_average_color
+guint32 ink_cairo_pattern_get_argb32(cairo_pattern_t *pattern)
+{
+    double red = 0;
+    double green = 0;
+    double blue = 0;
+    double alpha = 0;
+    auto status = cairo_pattern_get_rgba(pattern, &red, &green, &blue, &alpha);
+    if (status != CAIRO_STATUS_PATTERN_TYPE_MISMATCH) {
+        // in ARGB32 format
+        return SP_RGBA32_F_COMPOSE(alpha, red, green, blue);
+    }
+        
+    cairo_surface_t *surface;
+    status = cairo_pattern_get_surface (pattern, &surface);
+    if (status != CAIRO_STATUS_PATTERN_TYPE_MISMATCH) {
+        // first pixel only
+        auto *pxbsurface =  cairo_image_surface_get_data(surface);
+        return *reinterpret_cast<guint32 const *>(pxbsurface);
+    }
+    return 0;
+}
+
+void ink_cairo_surface_average_color(cairo_surface_t *surface, double &r, double &g, double &b, double &a)
+{
+    int count = ink_cairo_surface_average_color_internal(surface, r,g,b,a);
+
+    r /= a;
+    g /= a;
+    b /= a;
+    a /= count;
+
+    r = CLAMP(r, 0.0, 1.0);
+    g = CLAMP(g, 0.0, 1.0);
+    b = CLAMP(b, 0.0, 1.0);
+    a = CLAMP(a, 0.0, 1.0);
+}
+
+void ink_cairo_surface_average_color_premul(cairo_surface_t *surface, double &r, double &g, double &b, double &a)
+{
+    int count = ink_cairo_surface_average_color_internal(surface, r,g,b,a);
+
+    r /= count;
+    g /= count;
+    b /= count;
+    a /= count;
+
+    r = CLAMP(r, 0.0, 1.0);
+    g = CLAMP(g, 0.0, 1.0);
+    b = CLAMP(b, 0.0, 1.0);
+    a = CLAMP(a, 0.0, 1.0);
+}
+
+static guint32 srgb_to_linear( const guint32 c, const guint32 a ) {
+
+    const guint32 c1 = unpremul_alpha( c, a );
+
+    double cc = c1/255.0;
+
+    if( cc < 0.04045 ) {
+        cc /= 12.92;
+    } else {
+        cc = pow( (cc+0.055)/1.055, 2.4 );
+    }
+    cc *= 255.0;
+
+    const guint32 c2 = (int)cc;
+
+    return premul_alpha( c2, a );
+}
+
+static guint32 linear_to_srgb( const guint32 c, const guint32 a ) {
+
+    const guint32 c1 = unpremul_alpha( c, a );
+
+    double cc = c1/255.0;
+
+    if( cc < 0.0031308 ) {
+        cc *= 12.92;
+    } else {
+        cc = pow( cc, 1.0/2.4 )*1.055-0.055;
+    }
+    cc *= 255.0;
+
+    const guint32 c2 = (int)cc;
+
+    return premul_alpha( c2, a );
+}
+
+static uint32_t srgb_to_linear_argb32(uint32_t in)
+{
+    EXTRACT_ARGB32(in, a, r, g, b);
+    if (a != 0) {
+        r = srgb_to_linear(r, a);
+        g = srgb_to_linear(g, a);
+        b = srgb_to_linear(b, a);
+    }
+    ASSEMBLE_ARGB32(out, a, r, g, b);
+    return out;
+}
+
+int ink_cairo_surface_srgb_to_linear(cairo_surface_t *surface)
+{
+    cairo_surface_flush(surface);
+    int width = cairo_image_surface_get_width(surface);
+    int height = cairo_image_surface_get_height(surface);
+
+    ink_cairo_surface_filter(surface, surface, srgb_to_linear_argb32);
+
+    return width * height;
+}
+
+static uint32_t linear_to_srgb_argb32(uint32_t in)
+{
+    EXTRACT_ARGB32(in, a, r, g, b);
+    if (a != 0) {
+        r = linear_to_srgb(r, a);
+        g = linear_to_srgb(g, a);
+        b = linear_to_srgb(b, a);
+    }
+    ASSEMBLE_ARGB32(out, a, r, g, b);
+    return out;
+}
+
+SPBlendMode ink_cairo_operator_to_css_blend(cairo_operator_t cairo_operator)
+{
+    // All of the blend modes are implemented in Cairo as of 1.10.
+    // For a detailed description, see:
+    // http://cairographics.org/operators/
+
+    switch (cairo_operator) {
+        case CAIRO_OPERATOR_MULTIPLY:
+            return SP_CSS_BLEND_MULTIPLY;
+        case CAIRO_OPERATOR_SCREEN:
+            return SP_CSS_BLEND_SCREEN;
+        case CAIRO_OPERATOR_DARKEN:
+            return SP_CSS_BLEND_DARKEN;
+        case CAIRO_OPERATOR_LIGHTEN:
+            return SP_CSS_BLEND_LIGHTEN;
+        case CAIRO_OPERATOR_OVERLAY:
+            return SP_CSS_BLEND_OVERLAY;
+        case CAIRO_OPERATOR_COLOR_DODGE:
+            return SP_CSS_BLEND_COLORDODGE;
+        case CAIRO_OPERATOR_COLOR_BURN:
+            return SP_CSS_BLEND_COLORBURN;
+        case CAIRO_OPERATOR_HARD_LIGHT:
+            return SP_CSS_BLEND_HARDLIGHT;
+        case CAIRO_OPERATOR_SOFT_LIGHT:
+            return SP_CSS_BLEND_SOFTLIGHT;
+        case CAIRO_OPERATOR_DIFFERENCE:
+            return SP_CSS_BLEND_DIFFERENCE;
+        case CAIRO_OPERATOR_EXCLUSION:
+            return SP_CSS_BLEND_EXCLUSION;
+        case CAIRO_OPERATOR_HSL_HUE:
+            return SP_CSS_BLEND_HUE;
+        case CAIRO_OPERATOR_HSL_SATURATION:
+            return SP_CSS_BLEND_SATURATION;
+        case CAIRO_OPERATOR_HSL_COLOR:
+            return SP_CSS_BLEND_COLOR;
+        case CAIRO_OPERATOR_HSL_LUMINOSITY:
+            return SP_CSS_BLEND_LUMINOSITY;
+        case CAIRO_OPERATOR_OVER:
+            return SP_CSS_BLEND_NORMAL;
+        default:
+            return SP_CSS_BLEND_NORMAL;
+    }
+}
+
+cairo_operator_t ink_css_blend_to_cairo_operator(SPBlendMode css_blend)
+{
+    // All of the blend modes are implemented in Cairo as of 1.10.
+    // For a detailed description, see:
+    // http://cairographics.org/operators/
+
+    switch (css_blend) {
+        case SP_CSS_BLEND_MULTIPLY:
+            return CAIRO_OPERATOR_MULTIPLY;
+        case SP_CSS_BLEND_SCREEN:
+            return CAIRO_OPERATOR_SCREEN;
+        case SP_CSS_BLEND_DARKEN:
+            return CAIRO_OPERATOR_DARKEN;
+        case SP_CSS_BLEND_LIGHTEN:
+            return CAIRO_OPERATOR_LIGHTEN;
+        case SP_CSS_BLEND_OVERLAY:
+            return CAIRO_OPERATOR_OVERLAY;
+        case SP_CSS_BLEND_COLORDODGE:
+            return CAIRO_OPERATOR_COLOR_DODGE;
+        case SP_CSS_BLEND_COLORBURN:
+            return CAIRO_OPERATOR_COLOR_BURN;
+        case SP_CSS_BLEND_HARDLIGHT:
+            return CAIRO_OPERATOR_HARD_LIGHT;
+        case SP_CSS_BLEND_SOFTLIGHT:
+            return CAIRO_OPERATOR_SOFT_LIGHT;
+        case SP_CSS_BLEND_DIFFERENCE:
+            return CAIRO_OPERATOR_DIFFERENCE;
+        case SP_CSS_BLEND_EXCLUSION:
+            return CAIRO_OPERATOR_EXCLUSION;
+        case SP_CSS_BLEND_HUE:
+            return CAIRO_OPERATOR_HSL_HUE;
+        case SP_CSS_BLEND_SATURATION:
+            return CAIRO_OPERATOR_HSL_SATURATION;
+        case SP_CSS_BLEND_COLOR:
+            return CAIRO_OPERATOR_HSL_COLOR;
+        case SP_CSS_BLEND_LUMINOSITY:
+            return CAIRO_OPERATOR_HSL_LUMINOSITY;
+        case SP_CSS_BLEND_NORMAL:
+            return CAIRO_OPERATOR_OVER;
+        default:
+            g_error("Invalid SPBlendMode %d", css_blend);
+            return CAIRO_OPERATOR_OVER;
+    }
+}
+
+int ink_cairo_surface_linear_to_srgb(cairo_surface_t *surface)
+{
+    cairo_surface_flush(surface);
+    int width = cairo_image_surface_get_width(surface);
+    int height = cairo_image_surface_get_height(surface);
+
+    ink_cairo_surface_filter(surface, surface, linear_to_srgb_argb32);
+
+    return width * height;
+}
+
+cairo_pattern_t *
+ink_cairo_pattern_create_checkerboard(guint32 rgba, bool use_alpha)
+{
+    int const w = 6;
+    int const h = 6;
+
+    double r = SP_RGBA32_R_F(rgba);
+    double g = SP_RGBA32_G_F(rgba);
+    double b = SP_RGBA32_B_F(rgba);
+
+    float hsl[3];
+    SPColor::rgb_to_hsl_floatv(hsl, r, g, b);    
+    hsl[2] += hsl[2] < 0.08 ? 0.08 : -0.08; // 0.08 = 0.77-0.69, the original checkerboard colors.
+
+    float rgb2[3];
+    SPColor::hsl_to_rgb_floatv(rgb2, hsl[0], hsl[1], hsl[2]);
+
+    cairo_surface_t *s = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 2*w, 2*h);
+
+    cairo_t *ct = cairo_create(s);
+    cairo_set_operator(ct, CAIRO_OPERATOR_SOURCE);
+    cairo_set_source_rgb(ct, r, g, b);
+    cairo_paint(ct);
+    cairo_set_source_rgb(ct, rgb2[0], rgb2[1], rgb2[2]);
+    cairo_rectangle(ct, 0, 0, w, h);
+    cairo_rectangle(ct, w, h, w, h);
+    cairo_fill(ct);
+    if (use_alpha) {
+        // use alpha to show opacity cover checkerboard
+        double a = SP_RGBA32_A_F(rgba);
+        if (a > 0.0) {
+            cairo_set_operator(ct, CAIRO_OPERATOR_OVER);
+            cairo_rectangle(ct, 0, 0, 2 * w, 2 * h);
+            cairo_set_source_rgba(ct, r, g, b, a);
+            cairo_fill(ct);
+        }
+    }
+    cairo_destroy(ct);
+
+    cairo_pattern_t *p = cairo_pattern_create_for_surface(s);
+    cairo_pattern_set_extend(p, CAIRO_EXTEND_REPEAT);
+    cairo_pattern_set_filter(p, CAIRO_FILTER_NEAREST);
+
+    cairo_surface_destroy(s);
+    return p;
+}
+
+
+/** 
+ * Draw drop shadow around the 'rect' with given 'size' and 'color'; shadow extends to the right and bottom of rect.
+ */
+void ink_cairo_draw_drop_shadow(const Cairo::RefPtr<Cairo::Context> &ctx, const Geom::Rect& rect, double size, guint32 color, double color_alpha) {
+    // draw fake drop shadow built from gradients
+    const auto r = SP_RGBA32_R_F(color);
+    const auto g = SP_RGBA32_G_F(color);
+    const auto b = SP_RGBA32_B_F(color);
+    const auto a = color_alpha;
+    const Geom::Point corners[] = { rect.corner(0), rect.corner(1), rect.corner(2), rect.corner(3) };
+    // space for gradient shadow
+    double sw = size;
+    double half = sw / 2;
+    using Geom::X;
+    using Geom::Y;
+    // 8 gradients total: 4 sides + 4 corners
+    auto grad_top    = Cairo::LinearGradient::create(0, corners[0][Y] + half, 0, corners[0][Y] - half);
+    auto grad_right  = Cairo::LinearGradient::create(corners[1][X], 0, corners[1][X] + sw, 0);
+    auto grad_bottom = Cairo::LinearGradient::create(0, corners[2][Y], 0, corners[2][Y] + sw);
+    auto grad_left   = Cairo::LinearGradient::create(corners[0][X] + half, 0, corners[0][X] - half, 0);
+    auto grad_btm_right = Cairo::RadialGradient::create(corners[2][X], corners[2][Y], 0, corners[2][X], corners[2][Y], sw);
+    auto grad_top_right = Cairo::RadialGradient::create(corners[1][X], corners[1][Y] + half, 0, corners[1][X], corners[1][Y] + half, sw);
+    auto grad_btm_left  = Cairo::RadialGradient::create(corners[3][X] + half, corners[3][Y], 0, corners[3][X] + half, corners[3][Y], sw);
+    auto grad_top_left  = Cairo::RadialGradient::create(corners[0][X], corners[0][Y], 0, corners[0][X], corners[0][Y], half);
+    const int N = 15; // number of gradient stops; stops used to make it non-linear
+    // using easing function here: (exp(a*(1-t)) - 1) / (exp(a) - 1);
+    // it has a nice property of growing from 0 to 1 for t in [0..1]
+    const auto A = 4.0; // this coefficient changes how steep the curve is and controls shadow drop-off
+    const auto denominator = exp(A) - 1;
+    for (int i = 0; i <= N; ++i) {
+        auto pos = static_cast<double>(i) / N;
+        // exponential decay for drop shadow - long tail, with values from 100% down to 0% opacity
+        auto t = 1 - pos; // reverse 't' so alpha drops from 1 to 0
+        auto alpha = (exp(A * t) - 1) / denominator;
+        grad_top->add_color_stop_rgba(pos, r, g, b, alpha * a);
+        grad_bottom->add_color_stop_rgba(pos, r, g, b, alpha * a);
+        grad_right->add_color_stop_rgba(pos, r, g, b, alpha * a);
+        grad_left->add_color_stop_rgba(pos, r, g, b, alpha * a);
+        grad_btm_right->add_color_stop_rgba(pos, r, g, b, alpha * a);
+        grad_top_right->add_color_stop_rgba(pos, r, g, b, alpha * a);
+        grad_btm_left->add_color_stop_rgba(pos, r, g, b, alpha * a);
+        // this left/top corner is just a silver of the shadow: half of it is "hidden" beneath the page
+        if (pos >= 0.5) {
+            grad_top_left->add_color_stop_rgba(2 * (pos - 0.5), r, g, b, alpha * a);
+        }
+    }
+
+    // shadow at the top (faint)
+    ctx->rectangle(corners[0][X], corners[0][Y] - half, std::max(corners[1][X] - corners[0][X], 0.0), half);
+    ctx->set_source(grad_top);
+    ctx->fill();
+
+    // right side
+    ctx->rectangle(corners[1][X], corners[1][Y] + half, sw, std::max(corners[2][Y] - corners[1][Y] - half, 0.0));
+    ctx->set_source(grad_right);
+    ctx->fill();
+
+    // bottom side
+    ctx->rectangle(corners[0][X] + half, corners[2][Y], std::max(corners[1][X] - corners[0][X] - half, 0.0), sw);
+    ctx->set_source(grad_bottom);
+    ctx->fill();
+
+    // left side (faint)
+    ctx->rectangle(corners[0][X] - half, corners[0][Y], half, std::max(corners[2][Y] - corners[1][Y], 0.0));
+    ctx->set_source(grad_left);
+    ctx->fill();
+
+    // bottom corners
+    ctx->rectangle(corners[2][X], corners[2][Y], sw, sw);
+    ctx->set_source(grad_btm_right);
+    ctx->fill();
+
+    ctx->rectangle(corners[3][X] - half, corners[3][Y], std::min(sw, rect.width() + half), sw);
+    ctx->set_source(grad_btm_left);
+    ctx->fill();
+
+    // top corners
+    ctx->rectangle(corners[1][X], corners[1][Y] - half, sw, std::min(sw, rect.height() + half));
+    ctx->set_source(grad_top_right);
+    ctx->fill();
+
+    ctx->rectangle(corners[0][X] - half, corners[0][Y] - half, half, half);
+    ctx->set_source(grad_top_left);
+    ctx->fill();
+}
+
+/**
+ * Converts the Cairo surface to a GdkPixbuf pixel format,
+ * without allocating extra memory.
+ *
+ * This function is intended mainly for creating previews displayed by GTK.
+ * For loading images for display on the canvas, use the Inkscape::Pixbuf object.
+ *
+ * The returned GdkPixbuf takes ownership of the passed surface reference,
+ * so it should NOT be freed after calling this function.
+ */
+GdkPixbuf *ink_pixbuf_create_from_cairo_surface(cairo_surface_t *s)
+{
+    guchar *pixels = cairo_image_surface_get_data(s);
+    int w = cairo_image_surface_get_width(s);
+    int h = cairo_image_surface_get_height(s);
+    int rs = cairo_image_surface_get_stride(s);
+
+    convert_pixels_argb32_to_pixbuf(pixels, w, h, rs);
+
+    GdkPixbuf *pb = gdk_pixbuf_new_from_data(
+        pixels, GDK_COLORSPACE_RGB, TRUE, 8,
+        w, h, rs, ink_cairo_pixbuf_cleanup, s);
+
+    return pb;
+}
+
+/**
+ * Cleanup function for GdkPixbuf.
+ * This function should be passed as the GdkPixbufDestroyNotify parameter
+ * to gdk_pixbuf_new_from_data when creating a GdkPixbuf backed by
+ * a Cairo surface.
+ */
+void ink_cairo_pixbuf_cleanup(guchar * /*pixels*/, void *data)
+{
+    cairo_surface_t *surface = static_cast<cairo_surface_t*>(data);
+    cairo_surface_destroy(surface);
+}
+
+/* The following two functions use "from" instead of "to", because when you write:
+   val1 = argb32_from_pixbuf(val1);
+   the name of the format is closer to the value in that format. */
+
+guint32 argb32_from_pixbuf(guint32 c)
+{
+    uint32_t a;
+    if constexpr (G_BYTE_ORDER == G_LITTLE_ENDIAN) {
+        a = (c & 0xff000000) >> 24;
+    } else {
+        a = (c & 0x000000ff);
+    }
+
+    if (a == 0) {
+        return 0;
+    }
+
+    // extract color components
+    uint32_t r, g, b;
+    if constexpr (G_BYTE_ORDER == G_LITTLE_ENDIAN) {
+        r = (c & 0x000000ff);
+        g = (c & 0x0000ff00) >> 8;
+        b = (c & 0x00ff0000) >> 16;
+    } else {
+        r = (c & 0xff000000) >> 24;
+        g = (c & 0x00ff0000) >> 16;
+        b = (c & 0x0000ff00) >> 8;
+    }
+
+    // premultiply
+    r = premul_alpha(r, a);
+    b = premul_alpha(b, a);
+    g = premul_alpha(g, a);
+
+    // combine into output
+    return (a << 24) | (r << 16) | (g << 8) | b;
+}
+
+/**
+ * Convert one pixel from ARGB to GdkPixbuf format.
+ *
+ * @param c ARGB color
+ * @param bgcolor Color to use if c.alpha is zero (bgcolor.alpha is ignored)
+ */
+guint32 pixbuf_from_argb32(guint32 c, guint32 bgcolor)
+{
+    guint32 a = (c & 0xff000000) >> 24;
+    if (a == 0) {
+        assert(c == 0);
+        c = bgcolor;
+    }
+
+    // extract color components
+    guint32 r = (c & 0x00ff0000) >> 16;
+    guint32 g = (c & 0x0000ff00) >> 8;
+    guint32 b = (c & 0x000000ff);
+
+    if (a != 0) {
+        r = unpremul_alpha(r, a);
+        g = unpremul_alpha(g, a);
+        b = unpremul_alpha(b, a);
+    }
+
+    // combine into output
+    if constexpr (G_BYTE_ORDER == G_LITTLE_ENDIAN) {
+        return r | (g << 8) | (b << 16) | (a << 24);
+    } else {
+        return (r << 24) | (g << 16) | (b << 8) | a;
+    }
+}
+
+/**
+ * Convert pixel data from GdkPixbuf format to ARGB.
+ * This will convert pixel data from GdkPixbuf format to Cairo's native pixel format.
+ * This involves premultiplying alpha and shuffling around the channels.
+ * Pixbuf data must have an alpha channel, otherwise the results are undefined
+ * (usually a segfault).
+ */
+void
+convert_pixels_pixbuf_to_argb32(guchar *data, int w, int h, int stride)
+{
+    if (!data || w < 1 || h < 1 || stride < 1) {
+        return;
+    }
+
+    for (size_t i = 0; i < h; ++i) {
+        guint32 *px = reinterpret_cast<guint32*>(data + i*stride);
+        for (size_t j = 0; j < w; ++j) {
+            *px = argb32_from_pixbuf(*px);
+            ++px;
+        }
+    }
+}
+
+/**
+ * Convert pixel data from ARGB to GdkPixbuf format.
+ * This will convert pixel data from GdkPixbuf format to Cairo's native pixel format.
+ * This involves premultiplying alpha and shuffling around the channels.
+ */
+void
+convert_pixels_argb32_to_pixbuf(guchar *data, int w, int h, int stride, guint32 bgcolor)
+{
+    if (!data || w < 1 || h < 1 || stride < 1) {
+        return;
+    }
+    for (size_t i = 0; i < h; ++i) {
+        guint32 *px = reinterpret_cast<guint32*>(data + i*stride);
+        for (size_t j = 0; j < w; ++j) {
+            *px = pixbuf_from_argb32(*px, bgcolor);
+            ++px;
+        }
+    }
+}
+
+guint32 argb32_from_rgba(guint32 in)
+{
+    guint32 r, g, b, a;
+    a = (in & 0x000000ff);
+    r = premul_alpha((in & 0xff000000) >> 24, a);
+    g = premul_alpha((in & 0x00ff0000) >> 16, a);
+    b = premul_alpha((in & 0x0000ff00) >> 8,  a);
+    ASSEMBLE_ARGB32(px, a, r, g, b)
+    return px;
+}
+
+
+/**
+ * Convert one pixel from ARGB to GdkPixbuf format.
+ *
+ * @param c RGBA color
+ */
+guint32 rgba_from_argb32(guint32 c)
+{
+    guint32 a = (c & 0xff000000) >> 24;
+    guint32 r = (c & 0x00ff0000) >> 16;
+    guint32 g = (c & 0x0000ff00) >> 8;
+    guint32 b = (c & 0x000000ff);
+
+    if (a != 0) {
+        r = unpremul_alpha(r, a);
+        g = unpremul_alpha(g, a);
+        b = unpremul_alpha(b, a);
+    }
+
+    // combine into output
+    guint32 o = (r << 24) | (g << 16) | (b << 8) | (a);
+
+    return o;
+}
+
+/**
+ * Converts a pixbuf to a PNG data structure.
+ * For 8-but RGBA png, this is like copying.
+ *
+ */
+const guchar* pixbuf_to_png(guchar const**rows, guchar* px, int num_rows, int num_cols, int stride, int color_type, int bit_depth)
+{
+    int n_fields = 1 + (color_type&2) + (color_type&4)/4;
+    const guchar* new_data = (const guchar*)malloc(((n_fields * bit_depth * num_cols + 7)/8) * num_rows);
+    char* ptr = (char*) new_data;
+    // Used when we write image data smaller than one byte (for instance in
+    // black and white images where 1px = 1bit). Only possible with greyscale.
+    int pad = 0;
+    for (int row = 0; row < num_rows; ++row) {
+        rows[row] = (const guchar*)ptr;
+        for (int col = 0; col < num_cols; ++col) {
+            guint32 *pixel = reinterpret_cast<guint32*>(px + row*stride)+col;
+
+            guint64 pix3 = (*pixel & 0xff000000) >> 24;
+            guint64 pix2 = (*pixel & 0x00ff0000) >> 16;
+            guint64 pix1 = (*pixel & 0x0000ff00) >> 8;
+            guint64 pix0 = (*pixel & 0x000000ff);
+
+            uint64_t a, r, g, b;
+            if constexpr (G_BYTE_ORDER == G_LITTLE_ENDIAN) {
+                a = pix3;
+                b = pix2;
+                g = pix1;
+                r = pix0;
+            } else {
+                r = pix3;
+                g = pix2;
+                b = pix1;
+                a = pix0;
+            }
+
+            // One of possible rgb to greyscale formulas. This one is called "luminance", "luminosity" or "luma" 
+            guint16 gray = (guint16)((guint32)((0.2126*(r<<24) + 0.7152*(g<<24) + 0.0722*(b<<24)))>>16); 
+            
+            if (color_type & 2) { // RGB or RGBA
+                // for 8bit->16bit transition, I take the FF -> FFFF convention (multiplication by 0x101). 
+                // If you prefer FF -> FF00 (multiplication by 0x100), remove the <<8, <<24, <<40 and <<56
+                // for little-endian, and remove the <<0, <<16, <<32 and <<48 for big-endian.
+                if (color_type & 4) { // RGBA
+                    if (bit_depth == 8)
+                        *((guint32*)ptr) = *pixel; 
+                    else 
+                        // This uses the samples in the order they appear in pixel rather than
+                        // normalised to abgr or rgba in order to make it endian agnostic,
+                        // exploiting the symmetry of the expression (0x101 is the same in both
+                        // endiannesses and each sample is multiplied by that).
+                        *((guint64*)ptr) = (guint64)((pix3<<56)+(pix3<<48)+(pix2<<40)+(pix2<<32)+(pix1<<24)+(pix1<<16)+(pix0<<8)+(pix0));
+                } else { // RGB
+                    if (bit_depth == 8) {
+                        *ptr = r;
+                        *(ptr+1) = g;
+                        *(ptr+2) = b;
+                    } else {
+                        *((guint16*)ptr) = (r<<8)+r;
+                        *((guint16*)(ptr+2)) = (g<<8)+g;
+                        *((guint16*)(ptr+4)) = (b<<8)+b;
+                    }
+                }
+            } else { // Grayscale
+                if (bit_depth == 16) {
+                    if constexpr (G_BYTE_ORDER == G_LITTLE_ENDIAN) {
+                        *(guint16*)ptr = ((gray & 0xff00)>>8) + ((gray & 0x00ff)<<8);
+                    } else {
+                        *(guint16*)ptr = gray;
+                    }
+                    // For 8bit->16bit this mirrors RGB(A), multiplying by
+                    // 0x101; if you prefer multiplying by 0x100, remove the
+                    // <<8 for little-endian, and remove the unshifted value
+                    // for big-endian.
+                    if (color_type & 4) // Alpha channel
+                        *((guint16*)(ptr+2)) = a + (a<<8);
+                } else if (bit_depth == 8) {
+                    *ptr = guint8(gray >> 8);
+                    if (color_type & 4) // Alpha channel
+                        *((guint8*)(ptr+1)) = a;
+                } else {
+                    if (!pad) *ptr=0;
+                    // In PNG numbers are stored left to right, but in most significant bits first, so the first one processed is the ``big'' mask, etc.
+                    int realpad = 8 - bit_depth - pad;
+                    *ptr += guint8((gray >> (16-bit_depth))<<realpad); // Note the "+="
+                    if (color_type & 4) // Alpha channel
+                        *(ptr+1) += guint8((a >> (8-bit_depth))<<(bit_depth + realpad));
+                }
+            }
+
+            pad += bit_depth*n_fields;
+            ptr += pad/8;
+            pad %= 8;
+        }
+        // Align bytes on rows
+        if (pad) {
+            pad = 0;
+            ptr++;
+        }
+    }
+    return new_data; 
+}
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/cairo-utils.h b/src/display/cairo-utils.h
new file mode 100644
index 0000000..fb1e3fd
--- /dev/null
+++ b/src/display/cairo-utils.h
@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Cairo integration helpers.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2010 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef SEEN_INKSCAPE_DISPLAY_CAIRO_UTILS_H
+#define SEEN_INKSCAPE_DISPLAY_CAIRO_UTILS_H
+
+#include <2geom/forward.h>
+#include <cairomm/cairomm.h>
+#include "style.h"
+
+struct SPColor;
+typedef struct _GdkPixbuf GdkPixbuf;
+
+void ink_cairo_pixbuf_cleanup(unsigned char *, void *);
+
+namespace Inkscape {
+
+/** Class to hold image data for raster images.
+ * Allows easy interoperation with GdkPixbuf and Cairo. */
+class Pixbuf {
+public:
+    enum PixelFormat {
+        PF_CAIRO = 1,
+        PF_GDK = 2,
+        PF_LAST
+    };
+
+    explicit Pixbuf(cairo_surface_t *s);
+    explicit Pixbuf(GdkPixbuf *pb);
+    Pixbuf(Inkscape::Pixbuf const &other);
+    ~Pixbuf();
+
+    Pixbuf *cropTo(const Geom::IntRect &area) const;
+
+    GdkPixbuf *getPixbufRaw(bool convert_format = true);
+    GdkPixbuf *getPixbufRaw() const;
+
+    cairo_surface_t *getSurfaceRaw();
+    cairo_surface_t *getSurfaceRaw() const;
+    Cairo::RefPtr<Cairo::Surface> getSurface();
+
+    int width() const;
+    int height() const;
+    int rowstride() const;
+    guchar const *pixels() const;
+    guchar *pixels();
+    void markDirty();
+
+    bool hasMimeData() const;
+    guchar const *getMimeData(gsize &len, std::string &mimetype) const;
+    std::string const &originalPath() const { return _path; }
+    time_t modificationTime() const { return _mod_time; }
+
+    PixelFormat pixelFormat() const { return _pixel_format; }
+    void ensurePixelFormat(PixelFormat fmt);
+    static void ensure_pixbuf(GdkPixbuf *pb);
+    static void ensure_argb32(GdkPixbuf *pb);
+
+    static Pixbuf *create_from_data_uri(gchar const *uri, double svgdpi = 0);
+    static Pixbuf *create_from_file(std::string const &fn, double svgddpi = 0);
+    static Pixbuf *create_from_buffer(std::string const &, double svgddpi = 0, std::string const &fn = "");
+
+  private:
+    static Pixbuf *create_from_buffer(gchar *&&, gsize, double svgddpi = 0, std::string const &fn = "");
+    static Geom::Affine get_embedded_orientation(GdkPixbuf *buf);
+    static GdkPixbuf *apply_embedded_orientation(GdkPixbuf *buf);
+
+    void _ensurePixelsARGB32();
+    void _ensurePixelsPixbuf();
+    void _forceAlpha();
+    void _setMimeData(guchar *data, gsize len, Glib::ustring const &format);
+
+    GdkPixbuf *_pixbuf;
+    cairo_surface_t *_surface;
+    time_t _mod_time;
+    std::string _path;
+    PixelFormat _pixel_format;
+    bool _cairo_store;
+};
+
+} // namespace Inkscape
+
+// Atomic accessors to global variable governing number of filter threads.
+int  get_num_filter_threads();
+void set_num_filter_threads(int);
+
+SPColorInterpolation get_cairo_surface_ci(cairo_surface_t *surface);
+void set_cairo_surface_ci(cairo_surface_t *surface, SPColorInterpolation cif);
+void copy_cairo_surface_ci(cairo_surface_t *in, cairo_surface_t *out);
+void convert_cairo_surface_ci(cairo_surface_t *surface, SPColorInterpolation cif);
+
+void ink_cairo_set_source_color(cairo_t *ct, SPColor const &color, double opacity);
+void ink_cairo_set_source_rgba32(cairo_t *ct, guint32 rgba);
+void ink_cairo_transform(cairo_t *ct, Geom::Affine const &m);
+void ink_cairo_pattern_set_matrix(cairo_pattern_t *cp, Geom::Affine const &m);
+void ink_cairo_set_hairline(cairo_t *ct);
+void ink_cairo_set_dither(cairo_surface_t *surface, bool enabled);
+
+void ink_matrix_to_2geom(Geom::Affine &, cairo_matrix_t const &);
+void ink_matrix_to_cairo(cairo_matrix_t &, Geom::Affine const &);
+cairo_operator_t ink_css_blend_to_cairo_operator(SPBlendMode blend_mode);
+SPBlendMode ink_cairo_operator_to_css_blend(cairo_operator_t cairo_operator);
+cairo_surface_t *ink_cairo_surface_copy(cairo_surface_t *s);
+Cairo::RefPtr<Cairo::ImageSurface> ink_cairo_surface_copy(Cairo::RefPtr<Cairo::ImageSurface> surface);
+cairo_surface_t *ink_cairo_surface_create_identical(cairo_surface_t *s);
+cairo_surface_t *ink_cairo_surface_create_same_size(cairo_surface_t *s, cairo_content_t c);
+cairo_surface_t *ink_cairo_extract_alpha(cairo_surface_t *s);
+cairo_surface_t *ink_cairo_surface_create_output(cairo_surface_t *image, cairo_surface_t *bg);
+void ink_cairo_surface_blit(cairo_surface_t *src, cairo_surface_t *dest);
+int ink_cairo_surface_get_width(cairo_surface_t *surface);
+int ink_cairo_surface_get_height(cairo_surface_t *surface);
+guint32 ink_cairo_surface_average_color(cairo_surface_t *surface);
+guint32 ink_cairo_pattern_get_argb32(cairo_pattern_t *pattern);
+void ink_cairo_surface_average_color(cairo_surface_t *surface, double &r, double &g, double &b, double &a);
+void ink_cairo_surface_average_color_premul(cairo_surface_t *surface, double &r, double &g, double &b, double &a);
+
+double srgb_to_linear( const double c );
+int ink_cairo_surface_srgb_to_linear(cairo_surface_t *surface);
+int ink_cairo_surface_linear_to_srgb(cairo_surface_t *surface);
+
+cairo_pattern_t *ink_cairo_pattern_create_checkerboard(guint32 rgba = 0xC4C4C4FF, bool use_alpha = false);
+// draw drop shadow around the 'rect' with given 'size' and 'color'; shadow extends to the right and bottom of rect
+void ink_cairo_draw_drop_shadow(const Cairo::RefPtr<Cairo::Context> &ctx, const Geom::Rect& rect, double size, guint32 color, double color_alpha);
+
+GdkPixbuf *ink_pixbuf_create_from_cairo_surface(cairo_surface_t *s);
+void convert_pixels_pixbuf_to_argb32(guchar *data, int w, int h, int rs);
+void convert_pixels_argb32_to_pixbuf(guchar *data, int w, int h, int rs, guint32 bgcolor=0);
+
+G_GNUC_CONST guint32 argb32_from_pixbuf(guint32 in);
+G_GNUC_CONST guint32 pixbuf_from_argb32(guint32 in, guint32 bgcolor=0);
+const guchar* pixbuf_to_png(guchar const**rows, guchar* px, int nrows, int ncols, int stride, int color_type, int bit_depth);
+
+/** Convert a pixel in 0xRRGGBBAA format to Cairo ARGB32 format. */
+G_GNUC_CONST guint32 argb32_from_rgba(guint32 in);
+/** Convert a pixel in 0xAARRGGBB format to 0xRRGGBBAA format. */
+G_GNUC_CONST guint32 rgba_from_argb32(guint32 in);
+
+
+G_GNUC_CONST inline guint32
+premul_alpha(const guint32 color, const guint32 alpha)
+{
+    const guint32 temp = alpha * color + 128;
+    return (temp + (temp >> 8)) >> 8;
+}
+G_GNUC_CONST inline guint32
+unpremul_alpha(const guint32 color, const guint32 alpha)
+{
+    if (color >= alpha)
+        return 0xff;
+    return (255 * color + alpha/2) / alpha;
+}
+
+// TODO: move those to 2Geom
+void feed_pathvector_to_cairo (cairo_t *ct, Geom::PathVector const &pathv, Geom::Affine trans, Geom::OptRect area, bool optimize_stroke, double stroke_width);
+void feed_pathvector_to_cairo (cairo_t *ct, Geom::PathVector const &pathv);
+
+std::optional<Geom::PathVector> extract_pathvector_from_cairo(cairo_t *ct);
+
+#define EXTRACT_ARGB32(px,a,r,g,b) \
+    guint32 a, r, g, b; \
+    a = ((px) & 0xff000000) >> 24; \
+    r = ((px) & 0x00ff0000) >> 16; \
+    g = ((px) & 0x0000ff00) >> 8;  \
+    b = ((px) & 0x000000ff);
+
+#define ASSEMBLE_ARGB32(px,a,r,g,b) \
+    guint32 px = (a << 24) | (r << 16) | (g << 8) | b;
+
+inline double srgb_to_linear( const double c ) {
+    if( c < 0.04045 ) {
+        return c / 12.92;
+    } else {
+        return pow( (c+0.055)/1.055, 2.4 );
+    }
+}
+
+
+namespace Inkscape {
+
+namespace Display
+{
+
+inline void ExtractARGB32(guint32 px, guint32 &a, guint32 &r, guint32 &g, guint &b)
+{
+    a = ((px) & 0xff000000) >> 24;
+    r = ((px) & 0x00ff0000) >> 16;
+    g = ((px) & 0x0000ff00) >> 8;
+    b = ((px) & 0x000000ff);
+}
+
+inline void ExtractRGB32(guint32 px, guint32 &r, guint32 &g, guint &b)
+{
+    r = ((px) & 0x00ff0000) >> 16;
+    g = ((px) & 0x0000ff00) >> 8;
+    b = ((px) & 0x000000ff);
+}
+
+inline guint AssembleARGB32(guint32 a, guint32 r, guint32 g, guint32 b)
+{
+    return (a << 24) | (r << 16) | (g << 8) | b;
+}
+
+} // namespace Display
+
+} // namespace Inkscape
+
+#endif // SEEN_INKSCAPE_DISPLAY_CAIRO_UTILS_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/control/README b/src/display/control/README
new file mode 100644
index 0000000..680f0bf
--- /dev/null
+++ b/src/display/control/README
@@ -0,0 +1,112 @@
+
+This directory contains code for handling on-canvas editing objects as
+well as document display.
+
+Historically, the code originates from GnomeCanvas but at this point it
+has been completely rewritten for Inkscape's needs.
+
+One can think of a CanvasItem as a light-weight widget. There is a
+selection mechanism based on an item's position and a method to handle
+events. The selection mechanism is currently very simplistic,
+selecting the top-most item whose bounding box contains the
+cursor. Probably as a result, many items do not use these capabilities
+with external code replacing this functionality (e.g CanvasItemQuad,
+CanvasItemCurve).
+
+Points are stored as document coordinates. They are converted to
+screen coordinates by multiplying by the document to window affine.
+When an object's geometry changes, it must call request_update() to
+flag that its bounds need to be recalculated (_need_update =
+true). This will also cause all ancestors to also be marked and
+finally the Canvas. Before picking or drawing, all bounds must be
+up-to-date. (Changing the Canvas affine will also require bounds to be
+recalculated.) This mechanism ensures that bounds are correct in the
+most efficient manner. If only the style is changed (without geometric
+ramifications) then call canvas->redraw_area() to trigger a redraw.
+
+CanvasItemGroup keeps a list of child items using a Boost intrusive
+list. The pointers between nodes are kept inside the items. This
+allows for quick deletion by avoiding the need to search through the
+list to find the item to delete. This is important when a path
+contains hundress of nodes. However, a Boost intrusive list cannot be
+used with C++ smart pointers. Deleting an item can be done by either
+calling CanvasItemGroup::remove(CanvasItem*) or by directly deleting
+the item. Deleting a CanvasItemGroup will delete it and all of its
+children.
+
+
+Contents (x == pickable):
+
+* CanvasItem:             Abstract base class.
+* CanvasItemBPath:     x  An item representing a Bezier path.
+* CanvasItemCatchall:  x  An infinite item, for capturing left-over events.
+* CanvasItemCtrl:      x  An item representing a control point (knot, node, etc.).
+* CanvasItemCurve:        A single Bezier curve item (line or cubic). Not pickable!
+* CanvasItemDrawing:   x  The SVG drawing.
+* CanvasItemGrid:         Base class for snapping grids.
+* CanvasItemGroup:     x  An item that contains other items.
+* CanvasItemGuideline: x  A guideline for snapping.
+* CanvasItemQuad:         An object defined by four points (only used by Text tool).
+* CanvasItemRect:         An axis aligned rectangle item.
+* CanvasItemRotate:    x  For previewing the rotation of the canvas.
+* CanvasItemText:         A text item.
+
+* CanvasItemEnum:         All the enums you'll want to use!
+* CanvasItemBuffer:       A class that wraps a Cairo buffer for drawing.
+
+Classes here that use CanvasItem's:
+
+* CanvasGridXY:           A Cartesian grid for snapping.
+* CanvasGridAxonom        An Axonometric grid for snapping.
+* SnapIndicator:          A class for showing a snap possibility on canvas.
+* TemporaryItem:          A class to manage the lifetime of a temporary CanvasItem.
+* TemporaryItemList:      A class to track TemporaryItem's.
+
+
+Notes:
+
+CanvasItemCtrl (a.k.a. "Node", "Knot", "Handle", "Dragger", "Ctrl", "Mouse Grab", "Control Point")
+
+  Used by several groups of classes:
+
+  * Knot
+  ** KnotHolderEntity
+  *** live_effects/...
+  *** KnotHolder: Contains one or more KnotHolderEntity's.
+      Example: an object's fill and stroke gradients could have
+      overlapping knot-entities and are moved together via the knot holder.
+  **** shape-editor-knotholders.cpp
+       Classes derived from KnotHolder which contain classes derived from KnotHolderEntity for
+       editing shapes.
+  **** ShapeEditor contains two KnotHolders, one for shapes, one for LPE's.
+
+  ** ui/tools/tool-base.h
+  ** seltrans.h,.cpp
+  ** display/snap-indicator.h
+  ** gradient-drag.cpp
+  ** vanishing-point.h
+
+
+  * ControlPoint, SelectorPoint, SelectableControlPoint, Handle, Node, CurveDragPoint, TransformHandle, plus
+    auxiliary classes (manipulator...).
+  * drag-anchor
+  * pen-tool
+  * measure-tool
+  * guide-line
+  * snap-indicator
+
+
+TODO:
+
+Move files that use CanvasItem's to more appropriate places.
+
+All files that use CanvasItem's in src directory:
+* Move rubberband.h/.cpp to src/ui
+* Move gradient-drag to src/ui
+* Move selcue* to src/ui
+* Move seltrans* to src/ui
+* Move vanishing-point to src/ui
+* Move snap code to src/ui/snap display/snap-indicator.h/.cpp snap.h etc.
+
+See also src/ui/tool and src/ui/knot.
+
diff --git a/src/display/control/canvas-item-bpath.cpp b/src/display/control/canvas-item-bpath.cpp
new file mode 100644
index 0000000..d99588e
--- /dev/null
+++ b/src/display/control/canvas-item-bpath.cpp
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * A class to represent a Bezier path.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCanvasBPath
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "canvas-item-bpath.h"
+
+#include "color.h" // SP_RGBA_x_F
+#include "display/curve.h"
+#include "display/cairo-utils.h"
+#include "helper/geom.h" // bounds_exact_transformed()
+
+namespace Inkscape {
+
+/**
+ * Create a null control bpath.
+ */
+CanvasItemBpath::CanvasItemBpath(CanvasItemGroup *group)
+    : CanvasItem(group)
+{
+    _name = "CanvasItemBpath:Null";
+    _pickable = true; // For now, everyone gets events from this class!
+}
+
+/**
+ * Create a control bpath. Path is in document coordinates.
+ */
+CanvasItemBpath::CanvasItemBpath(CanvasItemGroup *group, Geom::PathVector path, bool phantom_line)
+    : CanvasItem(group)
+    , _path(std::move(path))
+    , _phantom_line(phantom_line)
+{
+    _name = "CanvasItemBpath";
+    _pickable = true; // For now, everyone gets events from this class!
+    request_update(); // Render immediately or temporary bpaths won't show.
+}
+
+/**
+ * Set a control bpath. Curve is in document coordinates.
+ */
+void CanvasItemBpath::set_bpath(SPCurve const *curve, bool phantom_line)
+{
+    set_bpath(curve ? curve->get_pathvector() : Geom::PathVector(), phantom_line);
+}
+
+/**
+ * Set a control bpath. Path is in document coordinates.
+ */
+void CanvasItemBpath::set_bpath(Geom::PathVector path, bool phantom_line)
+{
+    defer([=, path = std::move(path)] () mutable {
+        _path = std::move(path);
+        _phantom_line = phantom_line;
+        request_update();
+    });
+}
+
+/**
+ * Set the fill color and fill rule.
+ */
+void CanvasItemBpath::set_fill(uint32_t fill, SPWindRule fill_rule)
+{
+    defer([=] {
+        if (_fill == fill && _fill_rule == fill_rule) return;
+        _fill = fill;
+        _fill_rule = fill_rule;
+        request_redraw();
+    });
+}
+
+void CanvasItemBpath::set_dashes(std::vector<double> &&dashes)
+{
+    defer([=, dashes = std::move(dashes)] () mutable {
+        _dashes = std::move(dashes);
+    });
+}
+
+/**
+ * Set the stroke width
+ */
+void CanvasItemBpath::set_stroke_width(double width)
+{
+    defer([=] {
+        if (_stroke_width == width) return;
+        _stroke_width = width;
+        request_redraw();
+    });
+}
+
+/**
+ * Returns distance between point in canvas units and nearest point on bpath.
+ */
+double CanvasItemBpath::closest_distance_to(Geom::Point const &p) const
+{
+    double d = Geom::infinity();
+
+    // Convert p to document coordinates (quicker than converting path to canvas units).
+    Geom::Point p_doc = p * affine().inverse();
+    _path.nearestTime(p_doc, &d);
+    d *= affine().descrim(); // Uniform scaling and rotation only.
+
+    return d;
+}
+
+/**
+ * Returns true if point p (in canvas units) is within tolerance (canvas units) distance of bpath.
+ */
+bool CanvasItemBpath::contains(Geom::Point const &p, double tolerance)
+{
+    if (tolerance == 0) {
+        tolerance = 1; // Need a minimum tolerance value or always returns false.
+    }
+
+    // Check for 'inside' a filled bpath if a fill is being used.
+    if ((_fill & 0xff) != 0) {
+        Geom::Point p_doc = p * affine().inverse();
+        if (_path.winding(p_doc) % 2 != 0) {
+            return true;
+        }
+    }
+
+    // Otherwise see how close we are to the outside line.
+    return closest_distance_to(p) < tolerance;
+}
+
+/**
+ * Update and redraw control bpath.
+ */
+void CanvasItemBpath::_update(bool)
+{
+    // Queue redraw of old area (erase previous content).
+    request_redraw();
+
+    if (_path.empty()) {
+        _bounds = {};
+        return;
+    }
+
+    _bounds = expandedBy(bounds_exact_transformed(_path, affine()), 2);
+
+    // Queue redraw of new area
+    request_redraw();
+}
+
+/**
+ * Render bpath to screen via Cairo.
+ */
+void CanvasItemBpath::_render(Inkscape::CanvasItemBuffer &buf) const
+{
+    bool do_fill   = (_fill   & 0xff) != 0; // Not invisible.
+    bool do_stroke = (_stroke & 0xff) != 0; // Not invisible.
+
+    if (!do_fill && !do_stroke) {
+        // Both fill and stroke invisible.
+        return;
+    }
+
+    buf.cr->save();
+
+    // Setup path
+    buf.cr->set_tolerance(0.5);
+    buf.cr->begin_new_path();
+
+    feed_pathvector_to_cairo(buf.cr->cobj(), _path, affine(), buf.rect,
+                             /* optimize_stroke */ !do_fill, 1);
+
+    // Do fill
+    if (do_fill) {
+        buf.cr->set_source_rgba(SP_RGBA32_R_F(_fill), SP_RGBA32_G_F(_fill),
+                                SP_RGBA32_B_F(_fill), SP_RGBA32_A_F(_fill));
+        buf.cr->set_fill_rule(_fill_rule == SP_WIND_RULE_EVENODD ?
+                               Cairo::FILL_RULE_EVEN_ODD : Cairo::FILL_RULE_WINDING);
+        buf.cr->fill_preserve();
+    }
+
+    // Do stroke
+    if (do_stroke) {
+
+        if (!_dashes.empty()) {
+            buf.cr->set_dash(_dashes, 0.0); // 0.0 is offset
+        }
+
+        if (_phantom_line) {
+            buf.cr->set_source_rgba(1.0, 1.0, 1.0, 0.25);
+            buf.cr->set_line_width(2.0);
+            buf.cr->stroke_preserve();
+        }
+
+        buf.cr->set_source_rgba(SP_RGBA32_R_F(_stroke), SP_RGBA32_G_F(_stroke),
+                                SP_RGBA32_B_F(_stroke), SP_RGBA32_A_F(_stroke));
+        buf.cr->set_line_width(_stroke_width);
+        buf.cr->stroke();
+
+    } else {
+        buf.cr->begin_new_path(); // Clears path
+    }
+
+    buf.cr->restore();
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-bpath.h b/src/display/control/canvas-item-bpath.h
new file mode 100644
index 0000000..3b87579
--- /dev/null
+++ b/src/display/control/canvas-item-bpath.h
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_CANVAS_ITEM_BPATH_H
+#define SEEN_CANVAS_ITEM_BPATH_H
+
+/**
+ * A class to represent a Bezier path.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCanvasBPath
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <2geom/transforms.h>
+#include <2geom/pathvector.h>
+
+#include "canvas-item.h"
+
+#include "style-enums.h" // Fill rule
+
+class SPCurve;
+
+namespace Inkscape {
+
+class CanvasItemBpath final : public CanvasItem
+{
+public:
+    CanvasItemBpath(CanvasItemGroup *group);
+    CanvasItemBpath(CanvasItemGroup *group, Geom::PathVector path, bool phantom_line = false);
+
+    // Geometry
+    void set_bpath(SPCurve const *curve, bool phantom_line = false);
+    void set_bpath(Geom::PathVector path, bool phantom_line = false);
+
+    double closest_distance_to(Geom::Point const &p) const;
+
+    // Selection
+    bool contains(Geom::Point const &p, double tolerance = 0) override;
+
+    // Properties
+    void set_fill(uint32_t rgba, SPWindRule fill_rule);
+    void set_dashes(std::vector<double> &&dashes);
+    void set_stroke_width(double width);
+
+protected:
+    ~CanvasItemBpath() override = default;
+
+    void _update(bool propagate) override;
+    void _render(Inkscape::CanvasItemBuffer &buf) const override;
+
+    // Geometry
+    Geom::PathVector _path;
+
+    // Properties
+    SPWindRule _fill_rule = SP_WIND_RULE_EVENODD;
+    std::vector<double> _dashes;
+    bool _phantom_line = false;
+    double _stroke_width = 1.0;
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_ITEM_BPATH_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-buffer.h b/src/display/control/canvas-item-buffer.h
new file mode 100644
index 0000000..a66cb4c
--- /dev/null
+++ b/src/display/control/canvas-item-buffer.h
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_CANVAS_ITEM_BUFFER_H
+#define SEEN_CANVAS_ITEM_BUFFER_H
+
+/**
+ * Buffer for rendering canvas items.
+ */
+
+/*
+ * Author:
+ *   See git history.
+ *
+ * Copyright (C) 2020 Authors
+ *
+ * Rewrite of SPCanvasBuf.
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ *
+ */
+
+#include <2geom/rect.h>
+#include <cairomm/context.h>
+
+namespace Inkscape {
+
+/**
+ * Class used when rendering canvas items.
+ */
+struct CanvasItemBuffer
+{
+    Geom::IntRect rect;
+    int device_scale; // For high DPI monitors.
+    Cairo::RefPtr<Cairo::Context> cr;
+    bool outline_pass;
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_ITEM_BUFFER_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-catchall.cpp b/src/display/control/canvas-item-catchall.cpp
new file mode 100644
index 0000000..e6fbd47
--- /dev/null
+++ b/src/display/control/canvas-item-catchall.cpp
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * A class to catch events after everyone else has had a go.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCanvasAcetate.
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "canvas-item-catchall.h"
+
+namespace Inkscape {
+
+/**
+ * Create an null control catchall.
+ */
+CanvasItemCatchall::CanvasItemCatchall(CanvasItemGroup *group)
+    : CanvasItem(group)
+{
+    _name = "CanvasItemCatchall";
+    _pickable = true; // Duh! That's the purpose of this class!
+}
+
+/**
+ * Returns true if point p (in canvas units) is within tolerance (canvas units) distance of catchall.
+ */
+bool CanvasItemCatchall::contains(Geom::Point const &p, double tolerance)
+{
+    return true; // We contain every place!
+}
+
+/**
+ * Update and redraw control catchall.
+ */
+void CanvasItemCatchall::_update(bool)
+{
+    _bounds = Geom::Rect(-Geom::infinity(), -Geom::infinity(), Geom::infinity(), Geom::infinity());
+}
+
+/**
+ * Render catchall to screen via Cairo.
+ */
+void CanvasItemCatchall::_render(Inkscape::CanvasItemBuffer &buf) const
+{
+    // Do nothing! (Needed as CanvasItem is abstract.)
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-catchall.h b/src/display/control/canvas-item-catchall.h
new file mode 100644
index 0000000..6e0270a
--- /dev/null
+++ b/src/display/control/canvas-item-catchall.h
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_CANVAS_ITEM_CATCHALL_H
+#define SEEN_CANVAS_ITEM_CATCHALL_H
+
+/**
+ * A class to catch events after everyone else has had a go.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCanvasAcetate.
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "canvas-item.h"
+
+namespace Inkscape {
+
+class CanvasItemCatchall final : public CanvasItem
+{
+public:
+    CanvasItemCatchall(CanvasItemGroup *group);
+
+    // Selection
+    bool contains(Geom::Point const &p, double tolerance) override;
+
+protected:
+    ~CanvasItemCatchall() override = default;
+
+    void _update(bool propagate) override;
+    void _render(Inkscape::CanvasItemBuffer &buf) const override;
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_ITEM_CATCHALL_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-context.cpp b/src/display/control/canvas-item-context.cpp
new file mode 100644
index 0000000..99afdc4
--- /dev/null
+++ b/src/display/control/canvas-item-context.cpp
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "canvas-item-context.h"
+#include "canvas-item-group.h"
+
+namespace Inkscape {
+
+CanvasItemContext::CanvasItemContext(UI::Widget::Canvas *canvas)
+    : _canvas(canvas)
+    , _root(new CanvasItemGroup(this))
+{
+}
+
+CanvasItemContext::~CanvasItemContext()
+{
+    delete _root;
+}
+
+void CanvasItemContext::snapshot()
+{
+    assert(!_snapshotted);
+    _snapshotted = true;
+}
+
+void CanvasItemContext::unsnapshot()
+{
+    assert(_snapshotted);
+    _snapshotted = false;
+    _funclog();
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-context.h b/src/display/control/canvas-item-context.h
new file mode 100644
index 0000000..117110a
--- /dev/null
+++ b/src/display/control/canvas-item-context.h
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * The context in which a single CanvasItem tree exists. Holds the root node and common state.
+ */
+#ifndef SEEN_CANVAS_ITEM_CONTEXT_H
+#define SEEN_CANVAS_ITEM_CONTEXT_H
+
+#include <2geom/affine.h>
+#include "util/funclog.h"
+
+namespace Inkscape {
+
+namespace UI::Widget { class Canvas; }
+class CanvasItemGroup;
+
+class CanvasItemContext
+{
+public:
+    CanvasItemContext(UI::Widget::Canvas *canvas);
+    CanvasItemContext(CanvasItemContext const &) = delete;
+    CanvasItemContext &operator=(CanvasItemContext const &) = delete;
+    ~CanvasItemContext();
+
+    // Structure
+    UI::Widget::Canvas *canvas() const { return _canvas; }
+    CanvasItemGroup *root() const { return _root; }
+
+    // Geometry
+    Geom::Affine const &affine() const { return _affine; }
+    void setAffine(Geom::Affine const &affine) { _affine = affine; }
+
+    // Snapshotting
+    void snapshot();
+    void unsnapshot();
+    bool snapshotted() const { return _snapshotted; }
+
+    template<typename F>
+    void defer(F &&f) { _snapshotted ? _funclog.emplace(std::forward<F>(f)) : f(); }
+
+private:
+    // Structure
+    UI::Widget::Canvas *_canvas;
+    CanvasItemGroup *_root;
+
+    // Geometry
+    Geom::Affine _affine;
+
+    // Snapshotting
+    char _cacheline_separator[127];
+
+    bool _snapshotted = false;
+    Util::FuncLog _funclog;
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_ITEM_CONTEXT_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-ctrl.cpp b/src/display/control/canvas-item-ctrl.cpp
new file mode 100644
index 0000000..e0dcd90
--- /dev/null
+++ b/src/display/control/canvas-item-ctrl.cpp
@@ -0,0 +1,1181 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * A class to represent a control node.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCtrl
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <2geom/transforms.h>
+
+#include "canvas-item-ctrl.h"
+#include "helper/geom.h"
+
+#include "preferences.h"         // Default size. 
+#include "display/cairo-utils.h" // argb32_from_rgba()
+
+#include "ui/widget/canvas.h"
+
+namespace Inkscape {
+
+/**
+ * Create a null control node.
+ */
+CanvasItemCtrl::CanvasItemCtrl(CanvasItemGroup *group)
+    : CanvasItem(group)
+{
+    _name = "CanvasItemCtrl:Null";
+    _pickable = true; // Everybody gets events from this class!
+}
+
+/**
+ * Create a control ctrl. Shape auto-set by type.
+ */
+CanvasItemCtrl::CanvasItemCtrl(CanvasItemGroup *group, CanvasItemCtrlType type)
+    : CanvasItem(group)
+    , _type(type)
+{
+    _name = "CanvasItemCtrl:Type_" + std::to_string(_type);
+    _pickable = true; // Everybody gets events from this class!
+
+    // Use _type to set default values:
+    set_shape_default();
+    set_size_default();
+}
+
+/**
+ * Create a control ctrl. Point is in document coordinates.
+ */
+CanvasItemCtrl::CanvasItemCtrl(CanvasItemGroup *group, CanvasItemCtrlType type, Geom::Point const &p)
+    : CanvasItemCtrl(group, type)
+{
+    _position = p;
+    request_update();
+}
+
+/**
+ * Create a control ctrl.
+ */
+CanvasItemCtrl::CanvasItemCtrl(CanvasItemGroup *group, CanvasItemCtrlShape shape)
+    : CanvasItem(group)
+    , _shape(shape)
+    , _type(CANVAS_ITEM_CTRL_TYPE_DEFAULT)
+{
+    _name = "CanvasItemCtrl:Shape_" + std::to_string(_shape);
+    _pickable = true; // Everybody gets events from this class!
+}
+
+/**
+ * Create a control ctrl. Point is in document coordinates.
+ */
+CanvasItemCtrl::CanvasItemCtrl(CanvasItemGroup *group, CanvasItemCtrlShape shape, Geom::Point const &p)
+    : CanvasItemCtrl(group, shape)
+{
+    _position = p;
+}
+
+/**
+ * Set the position. Point is in document coordinates.
+ */
+void CanvasItemCtrl::set_position(Geom::Point const &position)
+{
+    // std::cout << "CanvasItemCtrl::set_ctrl: " << _name << ": " << position << std::endl;
+    defer([=] {
+        if (_position == position) return;
+        _position = position;
+        request_update();
+    });
+}
+
+/**
+ * Returns distance between point in canvas units and position of ctrl.
+ */
+double CanvasItemCtrl::closest_distance_to(Geom::Point const &p) const
+{
+    // TODO: Different criteria for different shapes.
+    return Geom::distance(p, _position * affine());
+}
+
+/**
+ * If tolerance is zero, returns true if point p (in canvas units) is inside bounding box,
+ * else returns true if p (in canvas units) is within tolerance (canvas units) distance of ctrl.
+ * The latter assumes ctrl center anchored.
+ */
+bool CanvasItemCtrl::contains(Geom::Point const &p, double tolerance)
+{
+    // TODO: Different criteria for different shapes.
+    if (!_bounds) return false;
+    if (tolerance == 0) {
+        return _bounds->interiorContains(p);
+    } else {
+        return closest_distance_to(p) <= tolerance;
+    }
+}
+
+static auto angle_of(Geom::Affine const &affine)
+{
+    return std::atan2(affine[1], affine[0]);
+}
+
+/**
+ * Update and redraw control ctrl.
+ */
+void CanvasItemCtrl::_update(bool)
+{
+    // Queue redraw of old area (erase previous content).
+    request_redraw();
+
+    // Setting the position to (inf, inf) to hide it is a pervasive hack we need to support.
+    if (!_position.isFinite()) {
+        _bounds = {};
+        return;
+    }
+
+    // Width and height are always odd.
+    assert(_width % 2 == 1);
+    assert(_height % 2 == 1);
+
+    // Get half width and height, rounded down.
+    int const w_half = _width / 2;
+    int const h_half = _height / 2;
+
+    // Set _angle, and compute adjustment for anchor.
+    int dx = 0;
+    int dy = 0;
+
+    switch (_shape) {
+        case CANVAS_ITEM_CTRL_SHAPE_DARROW:
+        case CANVAS_ITEM_CTRL_SHAPE_SARROW:
+        case CANVAS_ITEM_CTRL_SHAPE_CARROW:
+        case CANVAS_ITEM_CTRL_SHAPE_SALIGN:
+        case CANVAS_ITEM_CTRL_SHAPE_CALIGN:
+        {
+            double angle = _anchor * M_PI_4 + angle_of(affine());
+            double const half = _width / 2.0;
+
+            dx = -(half + 2) * cos(angle); // Add a bit to prevent tip from overlapping due to rounding errors.
+            dy = -(half + 2) * sin(angle);
+
+            switch (_shape) {
+                case CANVAS_ITEM_CTRL_SHAPE_CARROW:
+                    angle += 5 * M_PI_4;
+                    break;
+
+                case CANVAS_ITEM_CTRL_SHAPE_SARROW:
+                    angle += M_PI_2;
+                    break;
+
+                case CANVAS_ITEM_CTRL_SHAPE_SALIGN:
+                    dx = -(half / 2 + 2) * cos(angle);
+                    dy = -(half / 2 + 2) * sin(angle);
+                    angle -= M_PI_2;
+                    break;
+
+                case CANVAS_ITEM_CTRL_SHAPE_CALIGN:
+                    angle -= M_PI_4;
+                    dx = (half / 2 + 2) * ( sin(angle) - cos(angle));
+                    dy = (half / 2 + 2) * (-sin(angle) - cos(angle));
+                    break;
+
+                default:
+                    break;
+            }
+
+            if (_angle != angle) {
+                _angle = angle;
+                _built.reset();
+            }
+
+            break;
+        }
+
+        case CANVAS_ITEM_CTRL_SHAPE_PIVOT:
+        case CANVAS_ITEM_CTRL_SHAPE_MALIGN: {
+            double const angle = angle_of(affine());
+            if (_angle != angle) {
+                _angle = angle;
+                _built.reset();
+            }
+            break;
+        }
+
+        default:
+            switch (_anchor) {
+                case SP_ANCHOR_N:
+                case SP_ANCHOR_CENTER:
+                case SP_ANCHOR_S:
+                    break;
+
+                case SP_ANCHOR_NW:
+                case SP_ANCHOR_W:
+                case SP_ANCHOR_SW:
+                    dx = w_half;
+                    break;
+
+                case SP_ANCHOR_NE:
+                case SP_ANCHOR_E:
+                case SP_ANCHOR_SE:
+                    dx = -w_half;
+                    break;
+            }
+
+            switch (_anchor) {
+                case SP_ANCHOR_W:
+                case SP_ANCHOR_CENTER:
+                case SP_ANCHOR_E:
+                    break;
+
+                case SP_ANCHOR_NW:
+                case SP_ANCHOR_N:
+                case SP_ANCHOR_NE:
+                    dy = h_half;
+                    break;
+
+                case SP_ANCHOR_SW:
+                case SP_ANCHOR_S:
+                case SP_ANCHOR_SE:
+                    dy = -h_half;
+                    break;
+            }
+            break;
+    }
+
+    auto const pt = Geom::IntPoint(-w_half, -h_half) + Geom::IntPoint(dx, dy) + (_position * affine()).floor();
+    _bounds = Geom::IntRect(pt, pt + Geom::IntPoint(_width, _height));
+
+    // Queue redraw of new area
+    request_redraw();
+}
+
+static inline uint32_t compose_xor(uint32_t bg, uint32_t fg, uint32_t a)
+{
+    uint32_t c = bg * (255 - a) + (((bg ^ ~fg) + (bg >> 2) - (bg > 127 ? 63 : 0)) & 255) * a;
+    return (c + 127) / 255;
+}
+
+/**
+ * Render ctrl to screen via Cairo.
+ */
+void CanvasItemCtrl::_render(CanvasItemBuffer &buf) const
+{
+    _built.init([&, this] {
+        build_cache(buf.device_scale);
+    });
+
+    Geom::Point c = _bounds->min() - buf.rect.min();
+    int x = c.x(); // Must be pixel aligned.
+    int y = c.y();
+
+    buf.cr->save();
+
+    // This code works regardless of source type.
+
+    // 1. Copy the affected part of output to a temporary surface
+
+    // Size in device pixels. Does not set device scale.
+    int width  = _width  * buf.device_scale;
+    int height = _height * buf.device_scale;
+    auto work = Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32, width, height);
+    cairo_surface_set_device_scale(work->cobj(), buf.device_scale, buf.device_scale); // No C++ API!
+
+    auto cr = Cairo::Context::create(work);
+    cr->translate(-_bounds->left(), -_bounds->top());
+    cr->set_source(buf.cr->get_target(), buf.rect.left(), buf.rect.top());
+    cr->paint();
+    // static int a = 0;
+    // std::string name0 = "ctrl0_" + _name + "_" + std::to_string(a++) + ".png";
+    // work->write_to_png(name0);
+
+    // 2. Composite the control on a temporary surface
+    work->flush();
+    int strideb = work->get_stride();
+    unsigned char *pxb = work->get_data();
+
+    // this code allow background become isolated from rendering so we can do things like outline overlay
+    uint32_t backcolor = get_canvas()->get_effective_background();
+    uint32_t *p = _cache.get();
+    for (int i = 0; i < height; ++i) {
+        auto pb = reinterpret_cast<uint32_t*>(pxb + i * strideb);
+        for (int j = 0; j < width; ++j) {
+            uint32_t base = *pb;
+            uint32_t cc = *p++;
+            uint32_t ac = cc & 0xff;
+            if (*pb == 0 && cc != 0) {
+                base = backcolor;
+            }
+            if (ac == 0 && cc != 0) {
+                *pb++ = argb32_from_rgba(cc | 0x000000ff);
+            } else if (ac == 0) {
+                *pb++ = base;
+            } else if (
+                _mode == CANVAS_ITEM_CTRL_MODE_XOR || 
+                _mode == CANVAS_ITEM_CTRL_MODE_GRAYSCALED_XOR ||
+                _mode == CANVAS_ITEM_CTRL_MODE_DESATURATED_XOR) 
+            {
+                EXTRACT_ARGB32(base, ab,rb,gb,bb)
+                // here we get canvas color and if color to draw
+                // has opacity, we override base colors
+                // flattenig canvas color
+                EXTRACT_ARGB32(backcolor, abb,rbb,gbb,bbb)
+                if (abb != ab) {
+                    rb = (ab/255.0) * rb + (1-(ab/255.0)) * rbb;
+                    gb = (ab/255.0) * gb + (1-(ab/255.0)) * gbb;
+                    bb = (ab/255.0) * bb + (1-(ab/255.0)) * bbb;
+                    ab = 255;
+                }
+                uint32_t ro = compose_xor(rb, (cc & 0xff000000) >> 24, ac);
+                uint32_t go = compose_xor(gb, (cc & 0x00ff0000) >> 16, ac);
+                uint32_t bo = compose_xor(bb, (cc & 0x0000ff00) >>  8, ac);
+                if (_mode == CANVAS_ITEM_CTRL_MODE_GRAYSCALED_XOR ||
+                    _mode == CANVAS_ITEM_CTRL_MODE_DESATURATED_XOR) {
+                    uint32_t gray = ro * 0.299 + go * 0.587 + bo * 0.114;
+                    if (_mode == CANVAS_ITEM_CTRL_MODE_DESATURATED_XOR) {
+                        double f = 0.85; // desaturate by 15%
+                        double p = sqrt(ro * ro * 0.299 + go * go *  0.587 + bo * bo * 0.114);
+                        ro = p + (ro - p) * f;
+                        go = p + (go - p) * f;
+                        bo = p + (bo - p) * f;
+                    } else {
+                        ro = gray;
+                        go = gray;
+                        bo = gray;
+                    }
+                }
+                ASSEMBLE_ARGB32(px, ab,ro,go,bo)
+                *pb++ = px;
+            } else {
+                *pb++ = argb32_from_rgba(cc | 0x000000ff);
+            }
+        }
+    }
+    work->mark_dirty();
+    // std::string name1 = "ctrl1_" + _name + "_" + std::to_string(a) + ".png";
+    // work->write_to_png(name1);
+
+    // 3. Replace the affected part of output with contents of temporary surface
+    buf.cr->set_source(work, x, y);
+
+    buf.cr->rectangle(x, y, _width, _height);
+    buf.cr->clip();
+    buf.cr->set_operator(Cairo::OPERATOR_SOURCE);
+    buf.cr->paint();
+    buf.cr->restore();
+}
+
+void CanvasItemCtrl::set_fill(uint32_t fill)
+{
+    defer([=] {
+        if (_fill == fill) return;
+        _fill = fill;
+        _built.reset();
+        request_redraw();
+    });
+}
+
+void CanvasItemCtrl::set_stroke(uint32_t stroke)
+{
+    defer([=] {
+        if (_stroke == stroke) return;
+        _stroke = stroke;
+        _built.reset();
+        request_redraw();
+    });
+}
+
+void CanvasItemCtrl::set_shape(CanvasItemCtrlShape shape)
+{
+    defer([=] {
+        if (_shape == shape) return;
+        _shape = shape;
+        _built.reset();
+        request_update(); // Geometry could change
+    });
+}
+
+void CanvasItemCtrl::set_shape_default()
+{
+    switch (_type) {
+        case CANVAS_ITEM_CTRL_TYPE_ADJ_HANDLE:
+            _shape = CANVAS_ITEM_CTRL_SHAPE_DARROW;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_ADJ_SKEW:
+            _shape = CANVAS_ITEM_CTRL_SHAPE_SARROW;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_ADJ_ROTATE:
+            _shape = CANVAS_ITEM_CTRL_SHAPE_CARROW;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_ADJ_CENTER:
+            _shape = CANVAS_ITEM_CTRL_SHAPE_PIVOT;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_ADJ_SALIGN:
+            _shape = CANVAS_ITEM_CTRL_SHAPE_SALIGN;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_ADJ_CALIGN:
+            _shape = CANVAS_ITEM_CTRL_SHAPE_CALIGN;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_ADJ_MALIGN:
+            _shape = CANVAS_ITEM_CTRL_SHAPE_MALIGN;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_NODE_AUTO:
+        case CANVAS_ITEM_CTRL_TYPE_ROTATE:
+        case CANVAS_ITEM_CTRL_TYPE_MARGIN:
+            _shape = CANVAS_ITEM_CTRL_SHAPE_CIRCLE;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_CENTER:
+            _shape = CANVAS_ITEM_CTRL_SHAPE_PLUS;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_SHAPER:
+        case CANVAS_ITEM_CTRL_TYPE_LPE:
+        case CANVAS_ITEM_CTRL_TYPE_NODE_CUSP:
+            _shape = CANVAS_ITEM_CTRL_SHAPE_DIAMOND;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_POINT:
+            _shape = CANVAS_ITEM_CTRL_SHAPE_CROSS;
+            break;
+
+        default:
+            _shape = CANVAS_ITEM_CTRL_SHAPE_SQUARE;
+    }
+}
+
+void CanvasItemCtrl::set_mode(CanvasItemCtrlMode mode)
+{
+    defer([=] {
+        if (_mode == mode) return;
+        _mode = mode;
+        _built.reset();
+        request_update();
+    });
+}
+
+void CanvasItemCtrl::set_pixbuf(Glib::RefPtr<Gdk::Pixbuf> pixbuf)
+{
+    defer([=, pixbuf = std::move(pixbuf)] () mutable {
+        if (_pixbuf != pixbuf) return;
+        _pixbuf = std::move(pixbuf);
+        _width = _pixbuf->get_width();
+        _height = _pixbuf->get_height();
+        _built.reset();
+        request_update();
+    });
+}
+
+// Nominally width == height == size except possibly for pixmaps.
+void CanvasItemCtrl::set_size(int size)
+{
+    defer([=] {
+        if (_pixbuf) {
+            // std::cerr << "CanvasItemCtrl::set_size: Attempting to set size on pixbuf control!" << std::endl;
+            return;
+        }
+        if (_width == size + _extra && _height == size + _extra) return;
+        _width  = size + _extra;
+        _height = size + _extra;
+        _built.reset();
+        request_update(); // Geometry change
+    });
+}
+
+void CanvasItemCtrl::set_size_via_index(int size_index)
+{
+    // Size must always be an odd number to center on pixel.
+
+    if (size_index < 1 || size_index > 15) {
+        std::cerr << "CanvasItemCtrl::set_size_via_index: size_index out of range!" << std::endl;
+        size_index = 3;
+    }
+
+    int size = 0;
+    switch (_type) {
+        case CANVAS_ITEM_CTRL_TYPE_ADJ_HANDLE:
+        case CANVAS_ITEM_CTRL_TYPE_ADJ_SKEW:
+            size = size_index * 2 + 7;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_ADJ_ROTATE:
+        case CANVAS_ITEM_CTRL_TYPE_ADJ_CENTER:
+            size = size_index * 2 + 9; // 2 larger than HANDLE/SKEW
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_ADJ_SALIGN:
+        case CANVAS_ITEM_CTRL_TYPE_ADJ_CALIGN:
+        case CANVAS_ITEM_CTRL_TYPE_ADJ_MALIGN:
+            size = size_index * 4 + 5; // Needs to be larger to allow for rotating.
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_POINT:
+        case CANVAS_ITEM_CTRL_TYPE_ROTATE:
+        case CANVAS_ITEM_CTRL_TYPE_MARGIN:
+        case CANVAS_ITEM_CTRL_TYPE_CENTER:
+        case CANVAS_ITEM_CTRL_TYPE_SIZER:
+        case CANVAS_ITEM_CTRL_TYPE_SHAPER:
+        case CANVAS_ITEM_CTRL_TYPE_LPE:
+        case CANVAS_ITEM_CTRL_TYPE_NODE_AUTO:
+        case CANVAS_ITEM_CTRL_TYPE_NODE_CUSP:
+            size = size_index * 2 + 5;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_NODE_SMOOTH:
+        case CANVAS_ITEM_CTRL_TYPE_NODE_SYMETRICAL:
+            size = size_index * 2 + 3;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_INVISIPOINT:
+            size = 1;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_ANCHOR: // vanishing point for 3D box and anchor for pencil
+            size = size_index * 2 + 1;
+            break;
+
+        case CANVAS_ITEM_CTRL_TYPE_DEFAULT:
+            size = size_index * 2 + 1;
+            break;
+
+        default:
+            g_warning("set_size_via_index: missing case for handle type: %d", static_cast<int>(_type));
+            size = size_index * 2 + 1;
+            break;
+    }
+
+    set_size(size);
+}
+
+void CanvasItemCtrl::set_size_default()
+{
+    int size = Preferences::get()->getIntLimited("/options/grabsize/value", 3, 1, 15);
+    set_size_via_index(size);
+}
+
+void CanvasItemCtrl::set_size_extra(int extra)
+{
+    defer([=] {
+        if (_extra == extra || _pixbuf) return; // Don't enlarge pixbuf!
+        _width  += extra - _extra;
+        _height += extra - _extra;
+        _extra = extra;
+        _built.reset();
+        request_update(); // Geometry change
+    });
+}
+
+void CanvasItemCtrl::set_type(CanvasItemCtrlType type)
+{
+    defer([=] {
+        if (_type == type) return;
+        _type = type;
+
+        // Use _type to set default values.
+        set_shape_default();
+        set_size_default();
+        _built.reset();
+        request_update(); // Possible geometry change
+    });
+}
+
+void CanvasItemCtrl::set_angle(double angle)
+{
+    defer([=] {
+        if (_angle == angle) return;
+        _angle = angle;
+        _built.reset();
+        request_update(); // Geometry change
+    });
+}
+
+void CanvasItemCtrl::set_anchor(SPAnchorType anchor)
+{
+    defer([=] {
+        if (_anchor == anchor) return;
+        _anchor = anchor;
+        request_update(); // Geometry change
+    });
+}
+
+// ---------- Protected ----------
+
+static void draw_darrow(Cairo::RefPtr<Cairo::Context> const &cr, double size)
+{
+    // Find points, starting from tip of one arrowhead, working clockwise.
+    /*   1        4
+        ╱│        │╲
+       ╱ └────────┘ ╲
+     0╱  2        3  ╲5
+      ╲  8        7  ╱
+       ╲ ┌────────┐ ╱
+        ╲│9      6│╱
+    */
+
+    // Length of arrowhead (not including stroke).
+    double delta = (size-1)/4.0; // Use unscaled width.
+
+    // Tip of arrow (0)
+    double tip_x = 0.5;          // At edge, allow room for stroke.
+    double tip_y = size/2.0;     // Center, assuming width == height.
+
+    // Outer corner (1)
+    double out_x = tip_x + delta;
+    double out_y = tip_y - delta;
+
+    // Inner corner (2)
+    double in_x = out_x;
+    double in_y = out_y + (delta/2.0);
+
+    double x0 = tip_x;                double y0 = tip_y;
+    double x1 = out_x;                double y1 = out_y;
+    double x2 = in_x;                 double y2 = in_y;
+    double x3 = size - in_x;          double y3 = in_y;
+    double x4 = size - out_x;         double y4 = out_y;
+    double x5 = size - tip_x;         double y5 = tip_y;
+    double x6 = size - out_x;         double y6 = size - out_y;
+    double x7 = size - in_x;          double y7 = size - in_y;
+    double x8 = in_x;                 double y8 = size - in_y;
+    double x9 = out_x;                double y9 = size - out_y;
+
+    // Draw arrow
+    cr->move_to(x0, y0);
+    cr->line_to(x1, y1);
+    cr->line_to(x2, y2);
+    cr->line_to(x3, y3);
+    cr->line_to(x4, y4);
+    cr->line_to(x5, y5);
+    cr->line_to(x6, y6);
+    cr->line_to(x7, y7);
+    cr->line_to(x8, y8);
+    cr->line_to(x9, y9);
+    cr->close_path();
+}
+
+static void draw_carrow(Cairo::RefPtr<Cairo::Context> const &cr, double size)
+{
+    // Length of arrowhead (not including stroke).
+    double delta = (size-3)/4.0; // Use unscaled width.
+
+    // Tip of arrow
+    double tip_x =         1.5;  // Edge, allow room for stroke when rotated.
+    double tip_y = delta + 1.5;
+
+    // Outer corner (1)
+    double out_x = tip_x + delta;
+    double out_y = tip_y - delta;
+
+    // Inner corner (2)
+    double in_x = out_x;
+    double in_y = out_y + (delta/2.0);
+
+    double x0 = tip_x;                double y0 = tip_y;
+    double x1 = out_x;                double y1 = out_y;
+    double x2 = in_x;                 double y2 = in_y;
+    double x3 = size - in_y;        //double y3 = size - in_x;
+    double x4 = size - out_y;         double y4 = size - out_x;
+    double x5 = size - tip_y;         double y5 = size - tip_x;
+    double x6 = x5 - delta;           double y6 = y4;
+    double x7 = x5 - delta/2.0;       double y7 = y4;
+    double x8 = x1;                 //double y8 = y0 + delta/2.0;
+    double x9 = x1;                   double y9 = y0 + delta;
+
+    // Draw arrow
+    cr->move_to(x0, y0);
+    cr->line_to(x1, y1);
+    cr->line_to(x2, y2);
+    cr->arc(x1, y4, x3-x2, 3.0*M_PI/2.0, 0);
+    cr->line_to(x4, y4);
+    cr->line_to(x5, y5);
+    cr->line_to(x6, y6);
+    cr->line_to(x7, y7);
+    cr->arc_negative(x1, y4, x7-x8, 0, 3.0*M_PI/2.0);
+    cr->line_to(x9, y9);
+    cr->close_path();
+}
+
+static void draw_triangle(Cairo::RefPtr<Cairo::Context> const &cr, double size)
+{
+    // Construct an arrowhead (triangle)
+    double s = size/2.0;
+    double wcos = s * cos( M_PI/6 );
+    double hsin = s * sin( M_PI/6 );    
+    // Construct a smaller arrow head for fill.
+    Geom::Point p1f(1, s);
+    Geom::Point p2f(s + wcos - 1, s + hsin);
+    Geom::Point p3f(s + wcos - 1, s - hsin);
+    // Draw arrow
+    cr->move_to(p1f[0], p1f[1]);
+    cr->line_to(p2f[0], p2f[1]);
+    cr->line_to(p3f[0], p3f[1]);
+    cr->close_path();
+}
+
+static void draw_triangle_angled(Cairo::RefPtr<Cairo::Context> const &cr, double size)
+{
+    // Construct an arrowhead (triangle) of half size.
+    double s = size/2.0;
+    double wcos = s * cos( M_PI/9 );
+    double hsin = s * sin( M_PI/9 );
+    Geom::Point p1f(s + 1, s);
+    Geom::Point p2f(s + wcos - 1, s + hsin - 1);
+    Geom::Point p3f(s + wcos - 1, s - (hsin - 1));
+    // Draw arrow
+    cr->move_to(p1f[0], p1f[1]);
+    cr->line_to(p2f[0], p2f[1]);
+    cr->line_to(p3f[0], p3f[1]);
+    cr->close_path();
+}
+
+static void draw_pivot(Cairo::RefPtr<Cairo::Context> const &cr, double size)
+{
+    double delta4 = (size-5)/4.0; // Keep away from edge or will clip when rotating.
+    double delta8 = delta4/2;
+
+    // Line start
+    double center = size/2.0;
+
+    cr->move_to (center - delta8, center - 2*delta4 - delta8);
+    cr->rel_line_to ( delta4,  0     );
+    cr->rel_line_to ( 0,       delta4);
+
+    cr->rel_line_to ( delta4,  delta4);
+
+    cr->rel_line_to ( delta4,  0     );
+    cr->rel_line_to ( 0,       delta4);
+    cr->rel_line_to (-delta4,  0     );
+
+    cr->rel_line_to (-delta4,  delta4);
+
+    cr->rel_line_to ( 0,       delta4);
+    cr->rel_line_to (-delta4,  0     );
+    cr->rel_line_to ( 0,      -delta4);
+
+    cr->rel_line_to (-delta4, -delta4);
+
+    cr->rel_line_to (-delta4,  0     );
+    cr->rel_line_to ( 0,      -delta4);
+    cr->rel_line_to ( delta4,  0     );
+
+    cr->rel_line_to ( delta4, -delta4);
+    cr->close_path();
+
+    cr->begin_new_sub_path();
+    cr->arc_negative(center, center, delta4, 0, -2 * M_PI);
+}
+
+static void draw_salign(Cairo::RefPtr<Cairo::Context> const &cr, double size)
+{
+    // Triangle pointing at line.
+
+    // Basic units.
+    double delta4 = (size-1)/4.0; // Use unscaled width.
+    double delta8 = delta4/2;
+    if (delta8 < 2) {
+        // Keep a minimum gap of at least one pixel (after stroking).
+        delta8 = 2;
+    }
+
+    // Tip of triangle
+    double tip_x = size/2.0; // Center (also rotation point).
+    double tip_y = size/2.0;
+
+    // Corner triangle position.
+    double outer = size/2.0 - delta4;
+
+    // Outer line position
+    double oline = size/2.0 + (int)delta4;
+
+    // Inner line position
+    double iline = size/2.0 + (int)delta8;
+
+    // Draw triangle
+    cr->move_to(tip_x,           tip_y);
+    cr->line_to(outer,           outer);
+    cr->line_to(size - outer,    outer);
+    cr->close_path();
+
+    // Draw line
+    cr->move_to(outer,           iline);
+    cr->line_to(size - outer,    iline);
+    cr->line_to(size - outer,    oline);
+    cr->line_to(outer,           oline);
+    cr->close_path();
+}
+
+static void draw_calign(Cairo::RefPtr<Cairo::Context> const &cr, double size)
+{
+    // Basic units.
+    double delta4 = (size-1)/4.0; // Use unscaled width.
+    double delta8 = delta4/2;
+    if (delta8 < 2) {
+        // Keep a minimum gap of at least one pixel (after stroking).
+        delta8 = 2;
+    }
+
+    // Tip of triangle
+    double tip_x = size/2.0; // Center (also rotation point).
+    double tip_y = size/2.0;
+
+    // Corner triangle position.
+    double outer = size/2.0 - delta8 - delta4;
+
+    // End of line positin
+    double eline = size/2.0 - delta8;
+
+    // Outer line position
+    double oline = size/2.0 + (int)delta4;
+
+    // Inner line position
+    double iline = size/2.0 + (int)delta8;
+
+    // Draw triangle
+    cr->move_to(tip_x,           tip_y);
+    cr->line_to(outer,           tip_y);
+    cr->line_to(tip_x,           outer);
+    cr->close_path();
+
+    // Draw line
+    cr->move_to(iline,           iline);
+    cr->line_to(iline,           eline);
+    cr->line_to(oline,           eline);
+    cr->line_to(oline,           oline);
+    cr->line_to(eline,           oline);
+    cr->line_to(eline,           iline);
+    cr->close_path();
+}
+
+static void draw_malign(Cairo::RefPtr<Cairo::Context> const &cr, double size)
+{
+    // Basic units.
+    double delta4 = (size-1)/4.0; // Use unscaled width.
+    double delta8 = delta4/2;
+    if (delta8 < 2) {
+        // Keep a minimum gap of at least one pixel (after stroking).
+        delta8 = 2;
+    }
+
+    // Tip of triangle
+    double tip_0 = size/2.0;
+    double tip_1 = size/2.0 - delta8;
+
+    // Draw triangles
+    cr->move_to(tip_0,           tip_1);
+    cr->line_to(tip_0 - delta4,  tip_1 - delta4);
+    cr->line_to(tip_0 + delta4,  tip_1 - delta4);
+    cr->close_path();
+
+    cr->move_to(size - tip_1,           tip_0);
+    cr->line_to(size - tip_1 + delta4,  tip_0 - delta4);
+    cr->line_to(size - tip_1 + delta4,  tip_0 + delta4);
+    cr->close_path();
+
+    cr->move_to(size - tip_0,           size - tip_1);
+    cr->line_to(size - tip_0 + delta4,  size - tip_1 + delta4);
+    cr->line_to(size - tip_0 - delta4,  size - tip_1 + delta4);
+    cr->close_path();
+
+    cr->move_to(tip_1,           tip_0);
+    cr->line_to(tip_1 - delta4,  tip_0 + delta4);
+    cr->line_to(tip_1 - delta4,  tip_0 - delta4);
+    cr->close_path();
+}
+
+void CanvasItemCtrl::build_cache(int device_scale) const
+{
+    if (_width < 2 || _height < 2) {
+        return; // Nothing to render
+    }
+
+    if (_shape != CANVAS_ITEM_CTRL_SHAPE_BITMAP) {
+        if (_width % 2 == 0 || _height % 2 == 0) {
+            std::cerr << "CanvasItemCtrl::build_cache: Width and/or height not odd integer! "
+                      << _name << ":  width: " << _width << "  height: " << _height << std::endl;
+        }
+    }
+
+    // Get memory for cache.
+    int width  = _width  * device_scale;  // Not unsigned or math errors occur!
+    int height = _height * device_scale;
+    int size = width * height;
+
+    _cache = std::make_unique<uint32_t[]>(size);
+    auto p = _cache.get();
+
+    switch (_shape) {
+        case CANVAS_ITEM_CTRL_SHAPE_SQUARE:
+            // Actually any rectanglular shape.
+            for (int i = 0; i < width; ++i) {
+                for (int j = 0; j < width; ++j) {
+                    if (i + 1 > device_scale && device_scale < width  - i &&
+                        j + 1 > device_scale && device_scale < height - j)
+                    {
+                        *p++ = _fill;
+                    } else {
+                        *p++ = _stroke;
+                    }
+                }
+            }
+            break;
+
+        case CANVAS_ITEM_CTRL_SHAPE_DIAMOND: {
+            // Assume width == height.
+            int m = (width+1)/2;
+
+            for (int i = 0; i < width; ++i) {
+                for (int j = 0; j < height; ++j) {
+                    if (          i  +           j  > m-1+device_scale &&
+                         (width-1-i) +           j  > m-1+device_scale &&
+                         (width-1-i) + (height-1-j) > m-1+device_scale &&
+                                i    + (height-1-j) > m-1+device_scale ) {
+                        *p++ = _fill;
+                    } else
+                    if (          i  +           j  > m-2 &&
+                         (width-1-i) +           j  > m-2 &&
+                         (width-1-i) + (height-1-j) > m-2 &&
+                                i    + (height-1-j) > m-2 ) {
+                        *p++ = _stroke;
+                    } else {
+                        *p++ = 0;
+                    }
+                }
+            }
+            break;
+        }
+
+        case CANVAS_ITEM_CTRL_SHAPE_CIRCLE: {
+            // Assume width == height.
+            double rs  = width/2.0;
+            double rs2 = rs*rs;
+            double rf  = rs-device_scale;
+            double rf2 = rf*rf;
+
+            for (int i = 0; i < width; ++i) {
+                for (int j = 0; j < height; ++j) {
+
+                    double rx = i - (width /2.0) + 0.5;
+                    double ry = j - (height/2.0) + 0.5;
+                    double r2 = rx*rx + ry*ry;
+
+                    if (r2 < rf2) {
+                        *p++ = _fill;
+                    } else if (r2 < rs2) {
+                        *p++ = _stroke;
+                    } else {
+                        *p++ = 0;
+                    }
+                }
+            }
+            break;
+        }
+
+        case CANVAS_ITEM_CTRL_SHAPE_CROSS:
+            // Actually an 'X'.
+            for (int y = 0; y < height; y++) {
+                for (int x = 0; x < width; x++) {
+                    if ( abs(x - y)             < device_scale ||
+                         abs(width - 1 - x - y) < device_scale  ) {
+                        *p++ = _stroke;
+                    } else {
+                        *p++ = 0;
+                    }
+                }
+            }
+            break;
+
+        case CANVAS_ITEM_CTRL_SHAPE_PLUS:
+            // Actually an '+'.
+            for (int y = 0; y < height; y++) {
+                for (int x = 0; x < width; x++) {
+                    if ( std::abs(x-width/2)   < device_scale ||
+                         std::abs(y-height/2)  < device_scale  ) {
+                        *p++ = _stroke;
+                    } else {
+                        *p++ = 0;
+                    }
+                }
+            }
+            break;
+        case CANVAS_ITEM_CTRL_SHAPE_TRIANGLE:        //triangle optionaly rotated
+        case CANVAS_ITEM_CTRL_SHAPE_TRIANGLE_ANGLED: // triangle with pointing to center of  knot and rotated this way
+        case CANVAS_ITEM_CTRL_SHAPE_DARROW:          // Double arrow
+        case CANVAS_ITEM_CTRL_SHAPE_SARROW:          // Same shape as darrow but rendered rotated 90 degrees.
+        case CANVAS_ITEM_CTRL_SHAPE_CARROW:          // Double corner arrow
+        case CANVAS_ITEM_CTRL_SHAPE_PIVOT:           // Fancy "plus"
+        case CANVAS_ITEM_CTRL_SHAPE_SALIGN:          // Side align (triangle pointing toward line)
+        case CANVAS_ITEM_CTRL_SHAPE_CALIGN:          // Corner align (triangle pointing into "L")
+        case CANVAS_ITEM_CTRL_SHAPE_MALIGN:          // Middle align (four triangles poining inward)
+        {
+            double size = _width; // Use unscaled width.
+
+            auto work = Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32, device_scale * size, device_scale * size);
+            cairo_surface_set_device_scale(work->cobj(), device_scale, device_scale); // No C++ API!
+            auto cr = Cairo::Context::create(work);
+
+            // Rotate around center
+            cr->translate( size/2.0,  size/2.0);
+            cr->rotate(_angle);
+            cr->translate(-size/2.0, -size/2.0);
+
+            // Construct path
+            bool triangles = _shape == CANVAS_ITEM_CTRL_SHAPE_TRIANGLE_ANGLED || _shape == CANVAS_ITEM_CTRL_SHAPE_TRIANGLE;
+            switch (_shape) {
+                case CANVAS_ITEM_CTRL_SHAPE_DARROW:
+                case CANVAS_ITEM_CTRL_SHAPE_SARROW:
+                    draw_darrow(cr, size);
+                    break;
+
+                case CANVAS_ITEM_CTRL_SHAPE_TRIANGLE:
+                    draw_triangle(cr, size);
+                    break;
+
+                case CANVAS_ITEM_CTRL_SHAPE_TRIANGLE_ANGLED:
+                    draw_triangle_angled(cr, size);
+                    break;
+
+                case CANVAS_ITEM_CTRL_SHAPE_CARROW:
+                    draw_carrow(cr, size);
+                    break;
+
+                case CANVAS_ITEM_CTRL_SHAPE_PIVOT:
+                    draw_pivot(cr, size);
+                    break;
+
+                case CANVAS_ITEM_CTRL_SHAPE_SALIGN:
+                    draw_salign(cr, size);
+                    break;
+
+                case CANVAS_ITEM_CTRL_SHAPE_CALIGN:
+                    draw_calign(cr, size);
+                    break;
+
+                case CANVAS_ITEM_CTRL_SHAPE_MALIGN:
+                    draw_malign(cr, size);
+                    break;
+
+                default:
+                    // Shouldn't happen
+                    break;
+            }
+
+            // Fill and stroke.
+            cr->set_source_rgba(SP_RGBA32_R_F(_fill),
+                                SP_RGBA32_G_F(_fill),
+                                SP_RGBA32_B_F(_fill),
+                                SP_RGBA32_A_F(_fill));
+            cr->fill_preserve();
+            cr->set_source_rgba(SP_RGBA32_R_F(_stroke),
+                                SP_RGBA32_G_F(_stroke),
+                                SP_RGBA32_B_F(_stroke),
+                                SP_RGBA32_A_F(_stroke));
+            cr->set_line_width(1);
+            cr->stroke();
+
+            // Copy to buffer.
+            work->flush();
+            int strideb = work->get_stride();
+            unsigned char* pxb = work->get_data();
+            auto p = _cache.get();
+            for (int i = 0; i < device_scale * size; ++i) {
+                auto pb = reinterpret_cast<uint32_t*>(pxb + i * strideb);
+                for (int j = 0; j < width; ++j) {
+
+                    if (triangles) {
+                        *p++ = rgba_from_argb32(*pb);
+                    } else {
+                        uint32_t color = 0x0;
+
+                        // Need to un-premultiply alpha and change order argb -> rgba.
+                        uint32_t alpha = (*pb & 0xff000000) >> 24;
+                        if (alpha == 0x0) {
+                            color = 0x0;
+                        } else {
+                            uint32_t rgb = unpremul_alpha(*pb & 0xffffff, alpha);
+                            color = (rgb << 8) + alpha;
+                        }
+                        *p++ = color;
+                    }
+                    pb++;
+                }
+            }
+            break;
+        }
+
+        case CANVAS_ITEM_CTRL_SHAPE_BITMAP:
+        {
+            if (_pixbuf) {
+                unsigned char* px = _pixbuf->get_pixels();
+                unsigned int   rs = _pixbuf->get_rowstride();
+                for (int y = 0; y < height/device_scale; y++){
+                    for (int x = 0; x < width/device_scale; x++) {
+                        unsigned char *s = px + rs*y + 4*x;
+                        uint32_t color;
+                        if (s[3] < 0x80) {
+                            color = 0;
+                        } else if (s[0] < 0x80) {
+                            color = _stroke;
+                        } else {
+                            color = _fill;
+                        }
+
+                        // Fill in device_scale x device_scale block
+                        for (int i = 0; i < device_scale; ++i) {
+                            for (int j = 0; j < device_scale; ++j) {
+                                auto p = _cache.get() +
+                                    (x * device_scale + i) +            // Column
+                                    (y * device_scale + j) * width;     // Row
+                                *p = color;
+                            }
+                        }
+                    }
+                }
+            } else {
+                std::cerr << "CanvasItemCtrl::build_cache: No bitmap!" << std::endl;
+                auto p = _cache.get();
+                for (int y = 0; y < height/device_scale; y++){
+                    for (int x = 0; x < width/device_scale; x++) {
+                        if (x == y) {
+                            *p++ = 0xffff0000;
+                        } else {
+                            *p++ = 0;
+                        }
+                    }
+                }
+            }
+            break;
+        }
+
+        case CANVAS_ITEM_CTRL_SHAPE_IMAGE:
+            std::cerr << "CanvasItemCtrl::build_cache: image: UNIMPLEMENTED" << std::endl;
+            break;
+
+        default:
+            std::cerr << "CanvasItemCtrl::build_cache: unhandled shape!" << std::endl;
+            break;
+    }
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-ctrl.h b/src/display/control/canvas-item-ctrl.h
new file mode 100644
index 0000000..6c072a2
--- /dev/null
+++ b/src/display/control/canvas-item-ctrl.h
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_CANVAS_ITEM_CTRL_H
+#define SEEN_CANVAS_ITEM_CTRL_H
+
+/**
+ * A class to represent a control node.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCtrl
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <memory>
+#include <2geom/point.h>
+#include <gdk-pixbuf/gdk-pixbuf.h>
+
+#include "canvas-item.h"
+#include "canvas-item-enums.h"
+
+#include "enums.h" // SP_ANCHOR_X
+#include "display/initlock.h"
+
+namespace Inkscape {
+
+class CanvasItemCtrl : public CanvasItem
+{
+public:
+    CanvasItemCtrl(CanvasItemGroup *group);
+    CanvasItemCtrl(CanvasItemGroup *group, CanvasItemCtrlType type);
+    CanvasItemCtrl(CanvasItemGroup *group, CanvasItemCtrlType type, Geom::Point const &p);
+    CanvasItemCtrl(CanvasItemGroup *group, CanvasItemCtrlShape shape);
+    CanvasItemCtrl(CanvasItemGroup *group, CanvasItemCtrlShape shape, Geom::Point const &p);
+
+    // Geometry
+    void set_position(Geom::Point const &position);
+
+    double closest_distance_to(Geom::Point const &p) const;
+
+    // Selection
+    bool contains(Geom::Point const &p, double tolerance = 0) override;
+
+    // Properties
+    void set_fill(uint32_t rgba) override;
+    void set_stroke(uint32_t rgba) override;
+    void set_shape(CanvasItemCtrlShape shape);
+    void set_shape_default(); // Use type to determine shape.
+    void set_mode(CanvasItemCtrlMode mode);
+    void set_mode_default();
+    void set_size(int size);
+    virtual void set_size_via_index(int size_index);
+    void set_size_default(); // Use preference and type to set size.
+    void set_size_extra(int extra); // Used to temporary increase size of ctrl.
+    void set_anchor(SPAnchorType anchor);
+    void set_angle(double angle);
+    void set_type(CanvasItemCtrlType type);
+    void set_pixbuf(Glib::RefPtr<Gdk::Pixbuf> pixbuf);
+ 
+protected:
+    ~CanvasItemCtrl() override = default;
+
+    void _update(bool propagate) override;
+    void _render(Inkscape::CanvasItemBuffer &buf) const override;
+
+    void build_cache(int device_scale) const;
+
+    // Geometry
+    Geom::Point _position;
+
+    // Display
+    InitLock _built;
+    mutable std::unique_ptr<uint32_t[]> _cache;
+
+    // Properties
+    CanvasItemCtrlType  _type  = CANVAS_ITEM_CTRL_TYPE_DEFAULT;
+    CanvasItemCtrlShape _shape = CANVAS_ITEM_CTRL_SHAPE_SQUARE;
+    CanvasItemCtrlMode  _mode  = CANVAS_ITEM_CTRL_MODE_XOR;
+    int _width  = 5; // Nominally width == height == size... unless we use a pixmap.
+    int _height = 5;
+    int _extra  = 0; // Used to temporarily increase size.
+    double _angle = 0; // Used for triangles, could be used for arrows.
+    SPAnchorType _anchor = SP_ANCHOR_CENTER;
+    Glib::RefPtr<Gdk::Pixbuf> _pixbuf;
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_ITEM_CTRL_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-curve.cpp b/src/display/control/canvas-item-curve.cpp
new file mode 100644
index 0000000..c37c1a0
--- /dev/null
+++ b/src/display/control/canvas-item-curve.cpp
@@ -0,0 +1,207 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * A class to represent a single Bezier control curve, either a line or a cubic Bezier.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCtrlLine and SPCtrlCurve
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <2geom/bezier-curve.h>
+
+#include "canvas-item-curve.h"
+
+#include "color.h" // SP_RGBA_x_F
+
+#include "helper/geom.h"
+#include "ui/widget/canvas.h"
+
+namespace Inkscape {
+
+/**
+ * Create an null control curve.
+ */
+CanvasItemCurve::CanvasItemCurve(CanvasItemGroup *group)
+    : CanvasItem(group)
+{
+    _name = "CanvasItemCurve:Null";
+}
+
+/**
+ * Create a linear control curve. Points are in document coordinates.
+ */
+CanvasItemCurve::CanvasItemCurve(CanvasItemGroup *group, Geom::Point const &p0, Geom::Point const &p1)
+    : CanvasItem(group)
+    , _curve(std::make_unique<Geom::LineSegment>(p0, p1))
+{
+    _name = "CanvasItemCurve:Line";
+}
+
+/**
+ * Create a cubic Bezier control curve. Points are in document coordinates.
+ */
+CanvasItemCurve::CanvasItemCurve(CanvasItemGroup *group,
+                                 Geom::Point const &p0, Geom::Point const &p1,
+                                 Geom::Point const &p2, Geom::Point const &p3)
+    : CanvasItem(group)
+    , _curve(std::make_unique<Geom::CubicBezier>(p0, p1, p2, p3))
+{
+    _name = "CanvasItemCurve:CubicBezier";
+}
+
+/**
+ * Set a linear control curve. Points are in document coordinates.
+ */
+void CanvasItemCurve::set_coords(Geom::Point const &p0, Geom::Point const &p1)
+{
+    defer([=] {
+        _name = "CanvasItemCurve:Line";
+        _curve = std::make_unique<Geom::LineSegment>(p0, p1);
+        request_update();
+    });
+}
+
+/**
+ * Set a cubic Bezier control curve. Points are in document coordinates.
+ */
+void CanvasItemCurve::set_coords(Geom::Point const &p0, Geom::Point const &p1, Geom::Point const &p2, Geom::Point const &p3)
+{
+    defer([=] {
+        _name = "CanvasItemCurve:CubicBezier";
+        _curve = std::make_unique<Geom::CubicBezier>(p0, p1, p2, p3);
+        request_update();
+    });
+}
+
+/**
+ * Set stroke width.
+ */
+void CanvasItemCurve::set_width(int width)
+{
+    defer([=] {
+        if (_width == width) return;
+        _width = width;
+        request_update();
+    });
+}
+
+/**
+ * Set background stroke alpha.
+ */
+void CanvasItemCurve::set_bg_alpha(float alpha)
+{
+    defer([=] {
+        if (bg_alpha == alpha) return;
+        bg_alpha = alpha;
+        request_update();
+    });
+}
+
+/**
+ * Returns distance between point in canvas units and nearest point on curve.
+ */
+double CanvasItemCurve::closest_distance_to(Geom::Point const &p) const
+{
+    double d = Geom::infinity();
+    if (_curve) {
+        Geom::BezierCurve curve = *_curve;
+        curve *= affine(); // Document to canvas.
+        Geom::Point n = curve.pointAt(curve.nearestTime(p));
+        d = Geom::distance(p, n);
+    }
+    return d;
+}
+
+/**
+ * Returns true if point p (in canvas units) is within tolerance (canvas units) distance of curve.
+ */
+bool CanvasItemCurve::contains(Geom::Point const &p, double tolerance)
+{
+    return closest_distance_to(p) <= tolerance;
+}
+
+/**
+ * Update and redraw control curve.
+ */
+void CanvasItemCurve::_update(bool)
+{
+    // Queue redraw of old area (erase previous content).
+    request_redraw(); // This is actually never useful as curves are always deleted
+    // and recreated when a node is moved! But keep it in case we change that.
+
+    if (!_curve || _curve->isDegenerate()) {
+        _bounds = {};
+        return; // No curve! Can happen - see node.h.
+    }
+
+    // Tradeoff between updating a larger area (typically twice for Beziers?) vs computation time for bounds.
+    _bounds = expandedBy(_curve->boundsExact() * affine(), 2); // Room for stroke.
+
+    // Queue redraw of new area
+    request_redraw();
+}
+
+/**
+ * Render curve to screen via Cairo.
+ */
+void CanvasItemCurve::_render(Inkscape::CanvasItemBuffer &buf) const
+{
+    assert(_curve); // Not called if _curve is null, since _bounds would be null.
+
+    // Todo: Transform, rather than copy.
+    Geom::BezierCurve curve = *_curve;
+    curve *= affine();                          // Document to canvas.
+    curve *= Geom::Translate(-buf.rect.min());  // Canvas to screen.
+
+    buf.cr->save();
+
+    buf.cr->begin_new_path();
+
+    if (curve.size() == 2) {
+        // Line
+        buf.cr->move_to(curve[0].x(), curve[0].y());
+        buf.cr->line_to(curve[1].x(), curve[1].y());
+    } else {
+        // Curve
+        buf.cr->move_to(curve[0].x(), curve[0].y());
+        buf.cr->curve_to(curve[1].x(), curve[1].y(),  curve[2].x(), curve[2].y(),  curve[3].x(), curve[3].y());
+    }
+
+    buf.cr->set_source_rgba(1.0, 1.0, 1.0, bg_alpha);
+    buf.cr->set_line_width(background_width);
+    buf.cr->stroke_preserve();
+
+    buf.cr->set_source_rgba(SP_RGBA32_R_F(_stroke), SP_RGBA32_G_F(_stroke), SP_RGBA32_B_F(_stroke), SP_RGBA32_A_F(_stroke));
+    buf.cr->set_line_width(_width);
+    buf.cr->stroke();
+
+    // Uncomment to show bounds
+    // Geom::Rect bounds = _bounds;
+    // bounds.expandBy(-1);
+    // bounds -= buf.rect.min();
+    // buf.cr->set_source_rgba(1.0, 0.0, 0.0, 1.0);
+    // buf.cr->rectangle(bounds.min().x(), bounds.min().y(), bounds.width(), bounds.height());
+    // buf.cr->stroke();
+
+    buf.cr->restore();
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-curve.h b/src/display/control/canvas-item-curve.h
new file mode 100644
index 0000000..8e1f9b5
--- /dev/null
+++ b/src/display/control/canvas-item-curve.h
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_CANVAS_ITEM_CURVE_H
+#define SEEN_CANVAS_ITEM_CURVE_H
+
+/**
+ * A class to represent a single Bezier control curve.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCtrlLine and SPCtrlCurve
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <memory>
+#include <2geom/path.h>
+
+#include "canvas-item.h"
+
+namespace Inkscape {
+
+class CanvasItemCurve final : public CanvasItem
+{
+public:
+    CanvasItemCurve(CanvasItemGroup *group);
+    CanvasItemCurve(CanvasItemGroup *group, Geom::Point const &p0, Geom::Point const &p1);
+    CanvasItemCurve(CanvasItemGroup *group, Geom::Point const &p0, Geom::Point const &p1,
+                                            Geom::Point const &p2, Geom::Point const &p3);
+
+    // Geometry
+    void set_coords(Geom::Point const &p0, Geom::Point const &p1);
+    void set_coords(Geom::Point const &p0, Geom::Point const &p1, Geom::Point const &p2, Geom::Point const &p3);
+    void set_width(int width);
+    void set_bg_alpha(float alpha);
+    bool is_line() const { return _curve->size() == 2; }
+
+    double closest_distance_to(Geom::Point const &p) const;
+
+    // Selection
+    bool contains(Geom::Point const &p, double tolerance = 0) override;
+ 
+protected:
+    ~CanvasItemCurve() override = default;
+
+    void _update(bool propagate) override;
+    void _render(Inkscape::CanvasItemBuffer &buf) const override;
+
+    // Display
+    std::unique_ptr<Geom::BezierCurve> _curve;
+
+    int _width = 1;
+    int background_width = 3; // this should be an odd number so that the background appears on both the sides of the curve.
+    float bg_alpha = 0.5f;
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_ITEM_CURVE_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-drawing.cpp b/src/display/control/canvas-item-drawing.cpp
new file mode 100644
index 0000000..cfa527a
--- /dev/null
+++ b/src/display/control/canvas-item-drawing.cpp
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * A class to render the SVG drawing.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of _SPCanvasArena.
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "canvas-item-drawing.h"
+
+#include "desktop.h"
+
+#include "display/drawing.h"
+#include "display/drawing-context.h"
+#include "display/drawing-item.h"
+#include "display/drawing-group.h"
+
+#include "helper/geom.h"
+#include "ui/widget/canvas.h"
+#include "ui/modifiers.h"
+
+namespace Inkscape {
+
+/**
+ * Create the drawing. One per window!
+ */
+CanvasItemDrawing::CanvasItemDrawing(CanvasItemGroup *group)
+    : CanvasItem(group)
+{
+    _name = "CanvasItemDrawing";
+    _pickable = true;
+
+    _drawing = std::make_unique<Drawing>(this);
+    auto root = new DrawingGroup(*_drawing);
+    root->setPickChildren(true);
+    _drawing->setRoot(root);
+}
+
+/**
+ * Returns true if point p (in canvas units) is inside some object in drawing.
+ */
+bool CanvasItemDrawing::contains(Geom::Point const &p, double tolerance)
+{
+    if (tolerance != 0) {
+        std::cerr << "CanvasItemDrawing::contains: Non-zero tolerance not implemented!" << std::endl;
+    }
+
+    _picked_item = _drawing->pick(p, _drawing->cursorTolerance(), _sticky * DrawingItem::PICK_STICKY | _pick_outline * DrawingItem::PICK_OUTLINE);
+
+    if (_picked_item) {
+        // This will trigger a signal that is handled by our event handler. Seems a bit of a
+        // round-about way of doing things but it matches what other pickable canvas-item classes do.
+        return true;
+    }
+
+    return false;
+}
+
+/**
+ * Update and redraw drawing.
+ */
+void CanvasItemDrawing::_update(bool)
+{
+    // Undo y-axis flip. This should not be here!!!!
+    auto new_drawing_affine = affine();
+    if (auto desktop = get_canvas()->get_desktop()) {
+        new_drawing_affine = desktop->doc2dt() * new_drawing_affine;
+    }
+
+    bool affine_changed = _drawing_affine != new_drawing_affine;
+    if (affine_changed) {
+        _drawing_affine = new_drawing_affine;
+    }
+
+    _drawing->update(Geom::IntRect::infinite(), _drawing_affine, DrawingItem::STATE_ALL, affine_changed * DrawingItem::STATE_ALL);
+
+    _bounds = expandedBy(_drawing->root()->drawbox(), 1); // Avoid aliasing artifacts
+
+    // Todo: This should be managed elsewhere.
+    if (_cursor) {
+        /* Mess with enter/leave notifiers */
+        DrawingItem *new_drawing_item = _drawing->pick(_c, _delta, _sticky * DrawingItem::PICK_STICKY | _pick_outline * DrawingItem::PICK_OUTLINE);
+        if (_active_item != new_drawing_item) {
+
+            GdkEventCrossing ec;
+            ec.window = get_canvas()->get_window()->gobj();
+            ec.send_event = true;
+            ec.subwindow = ec.window;
+            ec.time = GDK_CURRENT_TIME;
+            ec.x = _c.x();
+            ec.y = _c.y();
+
+            /* fixme: Why? */
+            if (_active_item) {
+                ec.type = GDK_LEAVE_NOTIFY;
+                _drawing_event_signal.emit((GdkEvent *) &ec, _active_item);
+            }
+
+            _active_item = new_drawing_item;
+
+            if (_active_item) {
+                ec.type = GDK_ENTER_NOTIFY;
+                _drawing_event_signal.emit((GdkEvent *) &ec, _active_item);
+            }
+        }
+    }
+}
+
+/**
+ * Render drawing to screen via Cairo.
+ */
+void CanvasItemDrawing::_render(Inkscape::CanvasItemBuffer &buf) const
+{
+    auto dc = Inkscape::DrawingContext(buf.cr->cobj(), buf.rect.min());
+    _drawing->render(dc, buf.rect, buf.outline_pass * DrawingItem::RENDER_OUTLINE);
+}
+
+/**
+ * Handle events directed at the drawing. We first attempt to handle them here.
+ */
+bool CanvasItemDrawing::handle_event(GdkEvent *event)
+{
+    bool retval = false;
+    
+    switch (event->type) {
+        case GDK_ENTER_NOTIFY:
+            if (!_cursor) {
+                if (_active_item) {
+                    std::cerr << "CanvasItemDrawing::event_handler: cursor entered drawing with an active item!" << std::endl;
+                }
+                _cursor = true;
+
+                /* TODO ... event -> arena transform? */
+                _c = Geom::Point(event->crossing.x, event->crossing.y);
+
+                _active_item = _drawing->pick(_c, _drawing->cursorTolerance(), _sticky * DrawingItem::PICK_STICKY | _pick_outline * DrawingItem::PICK_OUTLINE);
+                retval = _drawing_event_signal.emit(event, _active_item);
+            }
+            break;
+
+        case GDK_LEAVE_NOTIFY:
+            if (_cursor) {
+                retval = _drawing_event_signal.emit(event, _active_item);
+                _active_item = nullptr;
+                _cursor = false;
+            }
+            break;
+
+        case GDK_MOTION_NOTIFY:
+        {
+            /* TODO ... event -> arena transform? */
+            _c = Geom::Point(event->motion.x, event->motion.y);
+
+            auto new_drawing_item = _drawing->pick(_c, _drawing->cursorTolerance(), _sticky * DrawingItem::PICK_STICKY | _pick_outline * DrawingItem::PICK_OUTLINE);
+            if (_active_item != new_drawing_item) {
+
+                GdkEventCrossing ec;
+                ec.window = event->motion.window;
+                ec.send_event = event->motion.send_event;
+                ec.subwindow = event->motion.window;
+                ec.time = event->motion.time;
+                ec.x = event->motion.x;
+                ec.y = event->motion.y;
+
+                /* fixme: What is wrong? */
+                if (_active_item) {
+                    ec.type = GDK_LEAVE_NOTIFY;
+                    retval = _drawing_event_signal.emit((GdkEvent *) &ec, _active_item);
+                }
+
+                _active_item = new_drawing_item;
+
+                if (_active_item) {
+                    ec.type = GDK_ENTER_NOTIFY;
+                    retval = _drawing_event_signal.emit((GdkEvent *) &ec, _active_item);
+                }
+            }
+            retval = retval || _drawing_event_signal.emit(event, _active_item);
+            break;
+        }
+
+        case GDK_SCROLL:
+        {
+            if (Modifiers::Modifier::get(Modifiers::Type::CANVAS_ZOOM)->active(event->scroll.state)) {
+                /* Zoom is emitted by the canvas as well, ignore here */
+                return false;
+            }
+            retval = _drawing_event_signal.emit(event, _active_item);
+            break;
+        }
+
+        default:
+            /* Just send event */
+            retval = _drawing_event_signal.emit(event, _active_item);
+            break;
+    }
+
+    return retval;
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-drawing.h b/src/display/control/canvas-item-drawing.h
new file mode 100644
index 0000000..f3fd494
--- /dev/null
+++ b/src/display/control/canvas-item-drawing.h
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_CANVAS_ITEM_DRAWING_H
+#define SEEN_CANVAS_ITEM_DRAWING_H
+
+/**
+ * A class to render the SVG drawing.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of _SPCanvasArena.
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <sigc++/sigc++.h>
+
+
+#include "canvas-item.h"
+
+namespace Inkscape {
+
+class Drawing;
+class DrawingItem;
+class Updatecontext;
+
+class CanvasItemDrawing final : public CanvasItem
+{
+public:
+    CanvasItemDrawing(CanvasItemGroup *group);
+
+    // Selection
+    bool contains(Geom::Point const &p, double tolerance = 0) override;
+
+    // Display
+    Inkscape::Drawing *get_drawing() { return _drawing.get(); }
+
+    // Drawing items
+    void set_active(Inkscape::DrawingItem *active) { _active_item = active; }
+    Inkscape::DrawingItem *get_active() { return _active_item; }
+
+    // Events
+    bool handle_event(GdkEvent *event) override;
+    void set_sticky(bool sticky) { _sticky = sticky; }
+    void set_pick_outline(bool pick_outline) { _pick_outline = pick_outline; }
+
+    // Signals
+    sigc::connection connect_drawing_event(sigc::slot<bool (GdkEvent*, Inkscape::DrawingItem *)> slot) {
+        return _drawing_event_signal.connect(slot);
+    }
+
+protected:
+    ~CanvasItemDrawing() override = default;
+
+    void _update(bool propagate) override;
+    void _render(Inkscape::CanvasItemBuffer &buf) const override;
+
+    // Selection
+    Geom::Point _c;
+    double _delta = Geom::infinity();
+    Inkscape::DrawingItem *_active_item = nullptr;
+    Inkscape::DrawingItem *_picked_item = nullptr;
+
+    // Display
+    std::unique_ptr<Inkscape::Drawing> _drawing;
+    Geom::Affine _drawing_affine;
+
+    // Events
+    bool _cursor = false;
+    bool _sticky = false; // Pick anything, even if hidden.
+    bool _pick_outline = false;
+
+    // Signals
+    sigc::signal<bool (GdkEvent*, Inkscape::DrawingItem *)> _drawing_event_signal;
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_ITEM_DRAWING_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-enums.h b/src/display/control/canvas-item-enums.h
new file mode 100644
index 0000000..ab173f3
--- /dev/null
+++ b/src/display/control/canvas-item-enums.h
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Enums for CanvasItems.
+ */
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ */
+
+#ifndef SEEN_CANVAS_ITEM_ENUMS_H
+#define SEEN_CANVAS_ITEM_ENUMS_H
+
+namespace Inkscape {
+
+enum CanvasItemColor {
+    CANVAS_ITEM_PRIMARY,
+    CANVAS_ITEM_SECONDARY,
+    CANVAS_ITEM_TERTIARY
+};
+
+enum CanvasItemCtrlShape {
+    CANVAS_ITEM_CTRL_SHAPE_SQUARE,
+    CANVAS_ITEM_CTRL_SHAPE_DIAMOND,
+    CANVAS_ITEM_CTRL_SHAPE_CIRCLE,
+    CANVAS_ITEM_CTRL_SHAPE_TRIANGLE,
+    CANVAS_ITEM_CTRL_SHAPE_CROSS,
+    CANVAS_ITEM_CTRL_SHAPE_PLUS,
+    CANVAS_ITEM_CTRL_SHAPE_PIVOT,  // Fancy "plus"
+    CANVAS_ITEM_CTRL_SHAPE_DARROW, // Double headed arrow.
+    CANVAS_ITEM_CTRL_SHAPE_SARROW, // Double headed arrow, rotated (skew).
+    CANVAS_ITEM_CTRL_SHAPE_CARROW, // Double headed curved arrow.
+    CANVAS_ITEM_CTRL_SHAPE_SALIGN, // Side alignment.
+    CANVAS_ITEM_CTRL_SHAPE_CALIGN, // Corner alignment.
+    CANVAS_ITEM_CTRL_SHAPE_MALIGN, // Center (middle) alignment.
+    CANVAS_ITEM_CTRL_SHAPE_BITMAP,
+    CANVAS_ITEM_CTRL_SHAPE_IMAGE,
+    CANVAS_ITEM_CTRL_SHAPE_LINE,
+    CANVAS_ITEM_CTRL_SHAPE_TRIANGLE_ANGLED,
+};
+
+// Applies to control points.
+enum CanvasItemCtrlType {
+    CANVAS_ITEM_CTRL_TYPE_DEFAULT,
+    CANVAS_ITEM_CTRL_TYPE_ADJ_HANDLE, // Stretch & Scale
+    CANVAS_ITEM_CTRL_TYPE_ADJ_SKEW,
+    CANVAS_ITEM_CTRL_TYPE_ADJ_ROTATE,
+    CANVAS_ITEM_CTRL_TYPE_ADJ_CENTER,
+    CANVAS_ITEM_CTRL_TYPE_ADJ_SALIGN,
+    CANVAS_ITEM_CTRL_TYPE_ADJ_CALIGN,
+    CANVAS_ITEM_CTRL_TYPE_ADJ_MALIGN,
+    CANVAS_ITEM_CTRL_TYPE_ANCHOR,
+    CANVAS_ITEM_CTRL_TYPE_POINT,
+    CANVAS_ITEM_CTRL_TYPE_ROTATE,
+    CANVAS_ITEM_CTRL_TYPE_MARGIN,
+    CANVAS_ITEM_CTRL_TYPE_CENTER,
+    CANVAS_ITEM_CTRL_TYPE_SIZER,
+    CANVAS_ITEM_CTRL_TYPE_SHAPER,
+    CANVAS_ITEM_CTRL_TYPE_LPE,
+    CANVAS_ITEM_CTRL_TYPE_NODE_AUTO,
+    CANVAS_ITEM_CTRL_TYPE_NODE_CUSP,
+    CANVAS_ITEM_CTRL_TYPE_NODE_SMOOTH,
+    CANVAS_ITEM_CTRL_TYPE_NODE_SYMETRICAL,
+    CANVAS_ITEM_CTRL_TYPE_INVISIPOINT
+};
+
+enum CanvasItemCtrlMode {
+    CANVAS_ITEM_CTRL_MODE_COLOR,
+    CANVAS_ITEM_CTRL_MODE_XOR,
+    CANVAS_ITEM_CTRL_MODE_DESATURATED_XOR,
+    CANVAS_ITEM_CTRL_MODE_GRAYSCALED_XOR
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_ITEM_ENUMS_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-grid.cpp b/src/display/control/canvas-item-grid.cpp
new file mode 100644
index 0000000..2c14ae2
--- /dev/null
+++ b/src/display/control/canvas-item-grid.cpp
@@ -0,0 +1,522 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of GridCanvasItem.
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <2geom/line.h>
+
+#include "canvas-item-grid.h"
+#include "color.h"
+#include "helper/geom.h"
+
+enum Dim3 { X, Y, Z };
+
+static int calculate_scaling_factor(double length, int major)
+{
+    int multiply = 1;
+    int step = std::max(major, 1);
+    int watchdog = 0;
+
+    while (length * multiply < 8.0 && watchdog < 100) {
+        multiply *= step;
+        // First pass, go up to the major line spacing, then keep increasing by two.
+        step = 2;
+        watchdog++;
+    }
+
+    return multiply;
+}
+
+namespace Inkscape {
+
+/**
+ * Create a null control grid.
+ */
+CanvasItemGrid::CanvasItemGrid(CanvasItemGroup *group)
+    : CanvasItem(group)
+    , _origin(0, 0)
+    , _spacing(1, 1)
+    , _minor_color(GRID_DEFAULT_MINOR_COLOR)
+    , _major_color(GRID_DEFAULT_MAJOR_COLOR)
+    , _major_line_interval(5)
+    , _dotted(false)
+{
+    _no_emp_when_zoomed_out = Preferences::get()->getBool("/options/grids/no_emphasize_when_zoomedout");
+    _pref_tracker = Preferences::PreferencesObserver::create("/options/grids/no_emphasize_when_zoomedout", [this] (auto &entry) {
+        set_no_emp_when_zoomed_out(entry.getBool());
+    });
+
+    request_update();
+}
+
+/**
+ * Returns true if point p (in canvas units) is within tolerance (canvas units) distance of grid.
+ */
+bool CanvasItemGrid::contains(Geom::Point const &p, double tolerance)
+{
+    return false; // We're not pickable!
+}
+
+// Find the signed distance of a point to a line. The distance is negative if
+// the point lies to the left of the line considering the line's versor.
+static double signed_distance(Geom::Point const &point, Geom::Line const &line)
+{
+    return Geom::cross(point - line.initialPoint(), line.versor());
+}
+
+// Find intersections of line with rectangle. There should be zero or two.
+// If line is degenerate with rectangle side, two corner points are returned.
+static std::vector<Geom::Point> intersect_line_rectangle(Geom::Line const &line, Geom::Rect const &rect)
+{
+    std::vector<Geom::Point> intersections;
+    for (int i = 0; i < 4; ++i) {
+        Geom::LineSegment side(rect.corner(i), rect.corner((i + 1) % 4));
+        try {
+            if (auto oc = Geom::intersection(line, side)) {
+                intersections.emplace_back(line.pointAt(oc->ta));
+            }
+        } catch (Geom::InfiniteSolutions const &) {
+            return { side.pointAt(0), side.pointAt(1) };
+        }
+    }
+    return intersections;
+}
+
+void CanvasItemGrid::set_origin(Geom::Point const &point)
+{
+    defer([=] {
+        if (_origin == point) return;
+        _origin = point;
+        request_update();
+    });
+}
+
+void CanvasItemGrid::set_major_color(uint32_t color)
+{
+    defer([=] {
+        if (_major_color == color) return;
+        _major_color = color;
+        request_update();
+    });
+}
+
+void CanvasItemGrid::set_minor_color(uint32_t color)
+{
+    defer([=] {
+        if (_minor_color == color) return;
+        _minor_color = color;
+        request_update();
+    });
+}
+
+void CanvasItemGrid::set_dotted(bool dotted)
+{
+    defer([=] {
+        if (_dotted == dotted) return;
+        _dotted = dotted;
+        request_update();
+    });
+}
+
+void CanvasItemGrid::set_spacing(Geom::Point const &point)
+{
+    defer([=] {
+        if (_spacing == point) return;
+        _spacing = point;
+        request_update();
+    });
+}
+
+void CanvasItemGrid::set_major_line_interval(int n)
+{
+    if (n < 1) return;
+    defer([=] {
+        if (_major_line_interval == n) return;
+        _major_line_interval = n;
+        request_update();
+    });
+}
+
+void CanvasItemGrid::set_no_emp_when_zoomed_out(bool noemp)
+{
+    if (_no_emp_when_zoomed_out != noemp) {
+        _no_emp_when_zoomed_out = noemp;
+        request_redraw();
+    }
+}
+
+/** ====== Rectangular Grid  ====== **/
+
+CanvasItemGridXY::CanvasItemGridXY(Inkscape::CanvasItemGroup *group)
+    : CanvasItemGrid(group)
+{
+    _name = "CanvasItemGridXY";
+}
+
+void CanvasItemGridXY::_update(bool)
+{
+    _bounds = Geom::Rect(-Geom::infinity(), -Geom::infinity(), Geom::infinity(), Geom::infinity());
+
+    // Queue redraw of grid area
+    ow = _origin * affine();
+    sw[0] = Geom::Point(_spacing[0], 0) * affine().withoutTranslation();
+    sw[1] = Geom::Point(0, _spacing[1]) * affine().withoutTranslation();
+
+    // Find suitable grid spacing for display
+    for (int dim : {0, 1}) {
+        int const scaling_factor = calculate_scaling_factor(sw[dim].length(), _major_line_interval);
+        sw[dim] *= scaling_factor;
+        scaled[dim] = scaling_factor > 1;
+    }
+
+    request_redraw();
+}
+
+void CanvasItemGridXY::_render(Inkscape::CanvasItemBuffer &buf) const
+{
+    // no_emphasize_when_zoomedout determines color (minor or major) when only major grid lines/dots shown.
+    uint32_t empcolor = ((scaled[Geom::X] || scaled[Geom::Y]) && _no_emp_when_zoomed_out) ? _minor_color : _major_color;
+    uint32_t color = _minor_color;
+
+    buf.cr->save();
+    buf.cr->translate(-buf.rect.left(), -buf.rect.top());
+    buf.cr->set_line_width(1.0);
+    buf.cr->set_line_cap(Cairo::LINE_CAP_SQUARE);
+
+    // Add a 2px margin to the buffer rectangle to avoid missing intersections (in case of rounding errors, and due to adding 0.5 below)
+    auto const buf_rect_with_margin = expandedBy(buf.rect, 2);
+
+    for (int dim : {0, 1}) {
+        int const nrm = dim ^ 0x1;
+
+        // Construct an axis line through origin with direction normal to grid spacing.
+        Geom::Line axis = Geom::Line::from_origin_and_vector(ow, sw[dim]);
+        Geom::Line orth = Geom::Line::from_origin_and_vector(ow, sw[nrm]);
+
+        double spacing = sw[nrm].length(); // Spacing between grid lines.
+        double dash    = sw[dim].length(); // Total length of dash pattern.
+
+        // Find the minimum and maximum distances of the buffer corners from axis.
+        double min =  Geom::infinity();
+        double max = -Geom::infinity();
+        for (int c = 0; c < 4; ++c) {
+
+            // We need signed distance... lib2geom offers only positive distance.
+            double distance = signed_distance(buf_rect_with_margin.corner(c), axis);
+
+            // Correct it for coordinate flips (inverts handedness).
+            if (Geom::cross(axis.vector(), orth.vector()) > 0) {
+                distance = -distance;
+            }
+
+            min = std::min(min, distance);
+            max = std::max(max, distance);
+        }
+        int start = std::floor(min / spacing);
+        int stop  = std::floor(max / spacing);
+
+        // Loop over grid lines that intersected buf rectangle.
+        for (int j = start + 1; j <= stop; ++j) {
+
+            Geom::Line grid_line = Geom::make_parallel_line(ow + j * sw[nrm], axis);
+
+            std::vector<Geom::Point> x = intersect_line_rectangle(grid_line, buf_rect_with_margin);
+
+            // If we have two intersections, grid line intersects buffer rectangle.
+            if (x.size() == 2) {
+                // Make sure lines are always drawn in the same direction (or dashes misplaced).
+                Geom::Line vector(x[0], x[1]);
+                if (Geom::dot(vector.vector(), axis.vector()) < 0.0) {
+                    std::swap(x[0], x[1]);
+                }
+
+                // Set up line. Need to use floor()+0.5 such that Cairo will draw us lines with a width of a single pixel, without any aliasing.
+                // For this we need to position the lines at exactly half pixels, see https://www.cairographics.org/FAQ/#sharp_lines
+                // Must be consistent with the pixel alignment of the guide lines, see CanvasItemGridXY::render(), and the drawing of the rulers
+                buf.cr->move_to(floor(x[0].x()) + 0.5, floor(x[0].y()) + 0.5);
+                buf.cr->line_to(floor(x[1].x()) + 0.5, floor(x[1].y()) + 0.5);
+
+                // Determine whether to draw with the emphasis color.
+                bool const noemp = !scaled[dim] && j % _major_line_interval != 0;
+
+                // Set dash pattern and color.
+                if (_dotted) {
+                    // alpha needs to be larger than in the line case to maintain a similar
+                    // visual impact but setting it to the maximal value makes the dots
+                    // dominant in some cases. Solution, increase the alpha by a factor of
+                    // 4. This then allows some user adjustment.
+                    uint32_t _empdot = (empcolor & 0xff) << 2;
+                    if (_empdot > 0xff)
+                        _empdot = 0xff;
+                    _empdot += (empcolor & 0xffffff00);
+
+                    uint32_t _colordot = (color & 0xff) << 2;
+                    if (_colordot > 0xff)
+                        _colordot = 0xff;
+                    _colordot += (color & 0xffffff00);
+
+                    // Dash pattern must use spacing from orthogonal direction.
+                    // Offset is to center dash on orthogonal lines.
+                    double offset = std::fmod(signed_distance(x[0], orth), sw[dim].length());
+                    if (Geom::cross(axis.vector(), orth.vector()) > 0) {
+                        offset = -offset;
+                    }
+
+                    std::vector<double> dashes;
+                    if (noemp) {
+                        // Minor lines
+                        dashes.push_back(1.0);
+                        dashes.push_back(dash - 1.0);
+                        offset -= 0.5;
+                        buf.cr->set_source_rgba(SP_RGBA32_R_F(_colordot), SP_RGBA32_G_F(_colordot),
+                                                SP_RGBA32_B_F(_colordot), SP_RGBA32_A_F(_colordot));
+                    } else {
+                        // Major lines
+                        dashes.push_back(3.0);
+                        dashes.push_back(dash - 3.0);
+                        offset -= 1.5; // Center dash on intersection.
+                        buf.cr->set_source_rgba(SP_RGBA32_R_F(_empdot), SP_RGBA32_G_F(_empdot),
+                                                SP_RGBA32_B_F(_empdot), SP_RGBA32_A_F(_empdot));
+                    }
+
+                    buf.cr->set_line_cap(Cairo::LINE_CAP_BUTT);
+                    buf.cr->set_dash(dashes, -offset);
+
+                } else {
+                    // Solid lines
+                    uint32_t col = noemp ? color : empcolor;
+                    buf.cr->set_source_rgba(SP_RGBA32_R_F(col), SP_RGBA32_G_F(col),
+                                            SP_RGBA32_B_F(col), SP_RGBA32_A_F(col));
+                }
+
+                buf.cr->stroke();
+
+            } else {
+                std::cerr << "CanvasItemGridXY::render: Grid line doesn't intersect!" << std::endl;
+            }
+        }
+    }
+
+    buf.cr->restore();
+}
+
+/** ========= Axonometric Grids ======== */
+
+/*
+ * Current limits are: one axis (y-axis) is always vertical. The other two
+ * axes are bound to a certain range of angles. The z-axis always has an angle
+ * smaller than 90 degrees (measured from horizontal, 0 degrees being a line extending
+ * to the right). The x-axis will always have an angle between 0 and 90 degrees.
+ */
+CanvasItemGridAxonom::CanvasItemGridAxonom(Inkscape::CanvasItemGroup *group)
+    : CanvasItemGrid(group)
+{
+    _name = "CanvasItemGridAxonom";
+
+    angle_deg[X] = 30.0;
+    angle_deg[Y] = 30.0;
+    angle_deg[Z] = 0.0;
+
+    angle_rad[X] = Geom::rad_from_deg(angle_deg[X]);
+    angle_rad[Y] = Geom::rad_from_deg(angle_deg[Y]);
+    angle_rad[Z] = Geom::rad_from_deg(angle_deg[Z]);
+
+    tan_angle[X] = std::tan(angle_rad[X]);
+    tan_angle[Y] = std::tan(angle_rad[Y]);
+    tan_angle[Z] = std::tan(angle_rad[Z]);
+}
+
+void CanvasItemGridAxonom::_update(bool)
+{
+    _bounds = Geom::Rect(-Geom::infinity(), -Geom::infinity(), Geom::infinity(), Geom::infinity());
+
+    ow = _origin * affine();
+    lyw = _spacing.y() * affine().descrim();
+
+    int const scaling_factor = calculate_scaling_factor(lyw, _major_line_interval);
+    lyw *= scaling_factor;
+    scaled = scaling_factor > 1;
+
+    spacing_ylines = lyw / (tan_angle[X] + tan_angle[Z]);
+    lxw_x          = Geom::are_near(tan_angle[X], 0) ? Geom::infinity() : lyw / tan_angle[X];
+    lxw_z          = Geom::are_near(tan_angle[Z], 0) ? Geom::infinity() : lyw / tan_angle[Z];
+
+    if (_major_line_interval == 0) {
+        scaled = true;
+    }
+
+    request_redraw();
+}
+
+// expects value given to be in degrees
+void CanvasItemGridAxonom::set_angle_x(double deg)
+{
+    defer([=] {
+        angle_deg[X] = std::clamp(deg, 0.0, 89.0); // setting to 90 and values close cause extreme slowdowns
+        angle_rad[X] = Geom::rad_from_deg(angle_deg[X]);
+        tan_angle[X] = std::tan(angle_rad[X]);
+        request_update();
+    });
+}
+
+// expects value given to be in degrees
+void CanvasItemGridAxonom::set_angle_z(double deg)
+{
+    defer([=] {
+        angle_deg[Z] = std::clamp(deg, 0.0, 89.0); // setting to 90 and values close cause extreme slowdowns
+        angle_rad[Z] = Geom::rad_from_deg(angle_deg[Z]);
+        tan_angle[Z] = std::tan(angle_rad[Z]);
+        request_update();
+    });
+}
+
+static void drawline(Inkscape::CanvasItemBuffer &buf, int x0, int y0, int x1, int y1, uint32_t rgba)
+{
+    buf.cr->move_to(0.5 + x0, 0.5 + y0);
+    buf.cr->line_to(0.5 + x1, 0.5 + y1);
+    buf.cr->set_source_rgba(SP_RGBA32_R_F(rgba), SP_RGBA32_G_F(rgba),
+                            SP_RGBA32_B_F(rgba), SP_RGBA32_A_F(rgba));
+    buf.cr->stroke();
+}
+
+static void vline(Inkscape::CanvasItemBuffer &buf, int x, int ys, int ye, uint32_t rgba)
+{
+    if (x < buf.rect.left() || x >= buf.rect.right())
+        return;
+
+    buf.cr->move_to(0.5 + x, 0.5 + ys);
+    buf.cr->line_to(0.5 + x, 0.5 + ye);
+    buf.cr->set_source_rgba(SP_RGBA32_R_F(rgba), SP_RGBA32_G_F(rgba),
+                            SP_RGBA32_B_F(rgba), SP_RGBA32_A_F(rgba));
+    buf.cr->stroke();
+}
+
+/**
+ * This function calls Cairo to render a line on a particular canvas buffer.
+ * Coordinates are interpreted as SCREENcoordinates
+ */
+void CanvasItemGridAxonom::_render(Inkscape::CanvasItemBuffer &buf) const
+{
+    // Set correct coloring, depending preference (when zoomed out, always major coloring or minor coloring)
+    uint32_t empcolor = (scaled && _no_emp_when_zoomed_out) ? _minor_color : _major_color;
+    uint32_t color = _minor_color;
+
+    buf.cr->save();
+    buf.cr->translate(-buf.rect.left(), -buf.rect.top());
+    buf.cr->set_line_width(1.0);
+    buf.cr->set_line_cap(Cairo::LINE_CAP_SQUARE);
+
+    // gc = gridcoordinates (the coordinates calculated from the grids origin 'grid->ow'.
+    // sc = screencoordinates ( for example "buf.rect.left()" is in screencoordinates )
+    // bc = buffer patch coordinates (x=0 on left side of page, y=0 on bottom of page)
+
+    // tl = topleft
+    auto const buf_tl_gc = buf.rect.min() - ow;
+
+    // render the three separate line groups representing the main-axes
+
+    // x-axis always goes from topleft to bottomright. (0,0) - (1,1)
+    double const xintercept_y_bc = (buf_tl_gc.x() * tan_angle[X]) - buf_tl_gc.y();
+    double const xstart_y_sc = (xintercept_y_bc - std::floor(xintercept_y_bc / lyw) * lyw) + buf.rect.top();
+    int const xlinestart = std::round((xstart_y_sc - buf_tl_gc.x() * tan_angle[X] - ow.y()) / lyw);
+    int xlinenum = xlinestart;
+
+    // lines starting on left side.
+    for (double y = xstart_y_sc; y < buf.rect.bottom(); y += lyw, xlinenum++) {
+        int const x0 = buf.rect.left();
+        int const y0 = round(y);
+        int x1 = x0 + round((buf.rect.bottom() - y) / tan_angle[X]);
+        int y1 = buf.rect.bottom();
+        if (Geom::are_near(tan_angle[X], 0)) {
+            x1 = buf.rect.right();
+            y1 = y0;
+        }
+
+        bool const noemp = !scaled && xlinenum % _major_line_interval != 0;
+        drawline(buf, x0, y0, x1, y1, noemp ? color : empcolor);
+    }
+
+    // lines starting from top side
+    if (!Geom::are_near(tan_angle[X], 0)) {
+        double const xstart_x_sc = buf.rect.left() + (lxw_x - (xstart_y_sc - buf.rect.top()) / tan_angle[X]);
+        xlinenum = xlinestart-1;
+        for (double x = xstart_x_sc; x < buf.rect.right(); x += lxw_x, xlinenum--) {
+            int const y0 = buf.rect.top();
+            int const y1 = buf.rect.bottom();
+            int const x0 = round(x);
+            int const x1 = x0 + round((y1 - y0) / tan_angle[X]);
+
+            bool const noemp = !scaled && xlinenum % _major_line_interval != 0;
+            drawline(buf, x0, y0, x1, y1, noemp ? color : empcolor);
+        }
+    }
+
+    // y-axis lines (vertical)
+    double const ystart_x_sc = floor (buf_tl_gc[Geom::X] / spacing_ylines) * spacing_ylines + ow[Geom::X];
+    int const  ylinestart = round((ystart_x_sc - ow[Geom::X]) / spacing_ylines);
+    int ylinenum = ylinestart;
+    for (double x = ystart_x_sc; x < buf.rect.right(); x += spacing_ylines, ylinenum++) {
+        int const x0 = floor(x); // sp_grid_vline will add 0.5 again, so we'll pre-emptively use floor()
+        // instead of round() to avoid biasing the vertical lines to the right by half a pixel; see
+        // CanvasItemGridXY::render() for more details
+        bool const noemp = !scaled && ylinenum % _major_line_interval != 0;
+        vline(buf, x0, buf.rect.top(), buf.rect.bottom() - 1, noemp ? color : empcolor);
+    }
+
+    // z-axis always goes from bottomleft to topright. (0,1) - (1,0)
+    double const zintercept_y_bc = (buf_tl_gc.x() * -tan_angle[Z]) - buf_tl_gc.y();
+    double const zstart_y_sc = (zintercept_y_bc - std::floor(zintercept_y_bc / lyw) * lyw) + buf.rect.top();
+    int const  zlinestart = std::round((zstart_y_sc + buf_tl_gc.x() * tan_angle[Z] - ow.y()) / lyw);
+    int zlinenum = zlinestart;
+    // lines starting from left side
+    double next_y = zstart_y_sc;
+    for (double y = zstart_y_sc; y < buf.rect.bottom(); y += lyw, zlinenum++, next_y = y) {
+        int const x0 = buf.rect.left();
+        int const y0 = round(y);
+        int x1 = x0 + round((y - buf.rect.top()) / tan_angle[Z]);
+        int y1 = buf.rect.top();
+        if (Geom::are_near(tan_angle[Z], 0)) {
+            x1 = buf.rect.right();
+            y1 = y0;
+        }
+
+        bool const noemp = !scaled && zlinenum % _major_line_interval != 0;
+        drawline(buf, x0, y0, x1, y1, noemp ? color : empcolor);
+    }
+
+    // draw lines from bottom-up
+    if (!Geom::are_near(tan_angle[Z], 0)) {
+        double const zstart_x_sc = buf.rect.left() + (next_y - buf.rect.bottom()) / tan_angle[Z];
+        for (double x = zstart_x_sc; x < buf.rect.right(); x += lxw_z, zlinenum++) {
+            int const y0 = buf.rect.bottom();
+            int const y1 = buf.rect.top();
+            int const x0 = round(x);
+            int const x1 = x0 + round(buf.rect.height() / tan_angle[Z]);
+
+            bool const noemp = !scaled && zlinenum % _major_line_interval != 0;
+            drawline(buf, x0, y0, x1, y1, noemp ? color : empcolor);
+        }
+    }
+
+    buf.cr->restore();
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-grid.h b/src/display/control/canvas-item-grid.h
new file mode 100644
index 0000000..3e8bc28
--- /dev/null
+++ b/src/display/control/canvas-item-grid.h
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of GridCanvasItem.
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+#ifndef SEEN_CANVAS_ITEM_GRID_H
+#define SEEN_CANVAS_ITEM_GRID_H
+
+#include <cstdint>
+#include <2geom/point.h>
+
+#include "canvas-item.h"
+#include "preferences.h"
+
+uint32_t constexpr GRID_DEFAULT_MAJOR_COLOR = 0x0099e54d;
+uint32_t constexpr GRID_DEFAULT_MINOR_COLOR = 0x0099e526;
+
+namespace Inkscape {
+
+class CanvasItemGrid : public CanvasItem
+{
+public:
+    CanvasItemGrid(CanvasItemGroup *group);
+
+    // Selection
+    bool contains(Geom::Point const &p, double tolerance = 0) override;
+
+    // Properties
+    void set_major_color(uint32_t color);
+    void set_minor_color(uint32_t color);
+    void set_origin(Geom::Point const &point);
+    void set_spacing(Geom::Point const &point);
+    void set_dotted(bool b);
+    void set_major_line_interval(int n);
+    void set_no_emp_when_zoomed_out(bool noemp);
+
+protected:
+    ~CanvasItemGrid() override = default;
+
+    bool _dotted;
+
+    Geom::Point _origin;
+
+    Geom::Point _spacing; /**< Spacing between elements of the grid */
+
+    int _major_line_interval;
+    bool _no_emp_when_zoomed_out;
+    uint32_t _major_color;
+    uint32_t _minor_color;
+
+private:
+    std::unique_ptr<Preferences::PreferencesObserver> _pref_tracker;
+};
+
+/** Canvas Item for rectangular grids */
+class CanvasItemGridXY final : public CanvasItemGrid
+{
+public:
+    CanvasItemGridXY(CanvasItemGroup *group);
+
+protected:
+    friend class GridSnapperXY;
+
+    void _update(bool propagate) override;
+    void _render(CanvasItemBuffer &buf) const override;
+
+    bool scaled[2];    /**< Whether the grid is in scaled mode, which can
+                            be different in the X or Y direction, hence two
+                            variables */
+    Geom::Point ow;      /**< Transformed origin by the affine for the zoom */
+    Geom::Point sw[2];   /**< Transformed spacing by the affine for the zoom */
+};
+
+/** Canvas Item for axonometric grids */
+class CanvasItemGridAxonom final : public CanvasItemGrid
+{
+public:
+    CanvasItemGridAxonom(CanvasItemGroup *group);
+
+    // Properties
+    void set_angle_x(double value);
+    void set_angle_z(double value);
+
+protected:
+    friend class GridSnapperAxonom;
+
+    void _update(bool propagate) override;
+    void _render(CanvasItemBuffer &buf) const override;
+
+    bool scaled;          /**< Whether the grid is in scaled mode */
+
+    double angle_deg[3];  /**< Angle of each axis (note that angle[2] == 0) */
+    double angle_rad[3];  /**< Angle of each axis (note that angle[2] == 0) */
+    double tan_angle[3];  /**< tan(angle[.]) */
+
+    double lyw   = 1.0;     /**< Transformed length y by the affine for the zoom */
+    double lxw_x = 1.0;
+    double lxw_z = 1.0;
+    double spacing_ylines = 1.0;
+
+    Geom::Point ow;         /**< Transformed origin by the affine for the zoom */
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_ITEM_GRID_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-group.cpp b/src/display/control/canvas-item-group.cpp
new file mode 100644
index 0000000..93193c3
--- /dev/null
+++ b/src/display/control/canvas-item-group.cpp
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * A CanvasItem that contains other CanvasItem's.
+ */
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCanvasGroup
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <boost/range/adaptor/reversed.hpp>
+#include "canvas-item-group.h"
+
+constexpr bool DEBUG_LOGGING = false;
+
+namespace Inkscape {
+
+CanvasItemGroup::CanvasItemGroup(CanvasItemGroup *group)
+    : CanvasItem(group)
+{
+    _name = "CanvasItemGroup";
+    _pickable = true; // For now all groups are pickable... look into turning this off for some groups (e.g. temp).
+}
+
+CanvasItemGroup::CanvasItemGroup(CanvasItemContext *context)
+    : CanvasItem(context)
+{
+    _name = "CanvasItemGroup:Root";
+    _pickable = true; // see above
+}
+
+CanvasItemGroup::~CanvasItemGroup()
+{
+    items.clear_and_dispose([] (auto c) { delete c; });
+}
+
+void CanvasItemGroup::_update(bool propagate)
+{
+    _bounds = {};
+
+    // Update all children and calculate new bounds.
+    for (auto &item : items) {
+        item.update(propagate);
+        _bounds |= item.get_bounds();
+    }
+}
+
+void CanvasItemGroup::_mark_net_invisible()
+{
+    if (!_net_visible) {
+        return;
+    }
+    _net_visible = false;
+    _need_update = false;
+    for (auto &item : items) {
+        item._mark_net_invisible();
+    }
+    _bounds = {};
+}
+
+void CanvasItemGroup::visit_page_rects(std::function<void(Geom::Rect const &)> const &f) const
+{
+    for (auto &item : items) {
+        if (!item.is_visible()) continue;
+        item.visit_page_rects(f);
+    }
+}
+
+void CanvasItemGroup::_render(Inkscape::CanvasItemBuffer &buf) const
+{
+    for (auto &item : items) {
+        item.render(buf);
+    }
+}
+
+// Return last visible and pickable item that contains point.
+// SPCanvasGroup returned distance but it was not used.
+CanvasItem *CanvasItemGroup::pick_item(Geom::Point const &p)
+{
+    if constexpr (DEBUG_LOGGING) {
+        std::cout << "CanvasItemGroup::pick_item:" << std::endl;
+        std::cout << "  PICKING: In group: " << _name << "  bounds: " << _bounds << std::endl;
+    }
+
+    for (auto &item : boost::adaptors::reverse(items)) {
+        if constexpr (DEBUG_LOGGING) std::cout << "    PICKING: Checking: " << item.get_name() << "  bounds: " << item.get_bounds() << std::endl;
+
+        if (item.is_visible() && item.is_pickable() && item.contains(p)) {
+            if (auto group = dynamic_cast<CanvasItemGroup*>(&item)) {
+                if (auto ret = group->pick_item(p)) {
+                    return ret;
+                }
+            } else {
+                return &item;
+            }
+        }
+    }
+
+    return nullptr;
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-group.h b/src/display/control/canvas-item-group.h
new file mode 100644
index 0000000..4ab5884
--- /dev/null
+++ b/src/display/control/canvas-item-group.h
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_CANVAS_ITEM_GROUP_H
+#define SEEN_CANVAS_ITEM_GROUP_H
+
+/**
+ * A CanvasItem that contains other CanvasItems.
+ */
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCanvasGroup
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "canvas-item.h"
+
+namespace Inkscape {
+
+class CanvasItemGroup final : public CanvasItem
+{
+public:
+    CanvasItemGroup(CanvasItemGroup *group);
+    CanvasItemGroup(CanvasItemContext *context);
+
+    // Geometry
+    void visit_page_rects(std::function<void(Geom::Rect const &)> const &) const override;
+
+    // Selection
+    CanvasItem *pick_item(Geom::Point const &p);
+
+protected:
+    friend class CanvasItem; // access to items
+    friend class CanvasItemContext; // access to destructor
+
+    ~CanvasItemGroup() override;
+
+    void _update(bool propagate) override;
+    void _mark_net_invisible() override;
+    void _render(Inkscape::CanvasItemBuffer &buf) const override;
+
+    /**
+     * Type for linked list storing CanvasItems.
+     * Used to speed deletion when a group contains a large number of items (as in nodes for a complex path).
+     */
+    using CanvasItemList = boost::intrusive::list<
+        Inkscape::CanvasItem,
+        boost::intrusive::member_hook<Inkscape::CanvasItem, boost::intrusive::list_member_hook<>,
+                                      &Inkscape::CanvasItem::member_hook>>;
+
+    CanvasItemList items;
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_ITEM_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-guideline.cpp b/src/display/control/canvas-item-guideline.cpp
new file mode 100644
index 0000000..7cefc2b
--- /dev/null
+++ b/src/display/control/canvas-item-guideline.cpp
@@ -0,0 +1,312 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * A class to represent a control guide line.
+ */
+
+/*
+ * Authors:
+ *   Tavmjong Bah       - Rewrite of SPGuideLine
+ *   Rafael Siejakowski - Tweaks to handle appearance
+ *
+ * Copyright (C) 2020-2022 the Authors.
+ *
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <2geom/line.h>
+
+#include "canvas-item-guideline.h"
+#include "canvas-item-ctrl.h"
+
+#include "desktop.h" // Canvas orientation so label is orientated correctly.
+#include "ui/widget/canvas.h"
+
+namespace Inkscape {
+
+/**
+ * Create a control guide line. Points are in document units.
+ */
+CanvasItemGuideLine::CanvasItemGuideLine(CanvasItemGroup *group, Glib::ustring label,
+                                         Geom::Point const &origin, Geom::Point const &normal)
+    : CanvasItem(group)
+    , _origin(origin)
+    , _normal(normal)
+    , _label(std::move(label))
+{
+    _name = "CanvasItemGuideLine:" + _label;
+    _pickable = true; // For now, everybody gets events from this class!
+
+    // Control to move guide line.
+    _origin_ctrl = make_canvasitem<CanvasItemGuideHandle>(group, _origin, this);
+    _origin_ctrl->set_name("CanvasItemGuideLine:Ctrl:" + _label);
+    _origin_ctrl->set_size_default();
+    _origin_ctrl->set_pickable(true); // The handle will also react to dragging
+    set_locked(false); // Init _origin_ctrl shape and stroke.
+}
+
+/**
+ * Sets origin of guide line (place where handle is located).
+ */
+void CanvasItemGuideLine::set_origin(Geom::Point const &origin)
+{
+    if (_origin != origin) {
+        _origin = origin;
+        _origin_ctrl->set_position(_origin);
+        request_update();
+    }
+}
+
+/**
+ * Sets orientation of guide line.
+ */
+void CanvasItemGuideLine::set_normal(Geom::Point const &normal)
+{
+    if (_normal != normal) {
+        _normal = normal;
+        request_update();
+    }
+}
+
+/**
+ * Sets the inverted nature of the line
+ */
+void CanvasItemGuideLine::set_inverted(bool inverted)
+{
+    if (_inverted != inverted) {
+        _inverted = inverted;
+        request_update();
+    }
+}
+
+/**
+ * Returns distance between point in canvas units and nearest point on guideLine.
+ */
+double CanvasItemGuideLine::closest_distance_to(Geom::Point const &p)
+{
+    // Maybe store guide as a Geom::Line?
+    auto guide = Geom::Line::from_origin_and_vector(_origin, Geom::rot90(_normal));
+    guide *= affine();
+    return Geom::distance(p, guide);
+}
+
+/**
+ * Returns true if point p (in canvas units) is within tolerance (canvas units) distance of guideLine (or 1 if tolerance is zero).
+ */
+bool CanvasItemGuideLine::contains(Geom::Point const &p, double tolerance)
+{
+    if (tolerance == 0) {
+        tolerance = 1; // Can't pick of zero!
+    }
+
+    return closest_distance_to(p) < tolerance;
+}
+
+/**
+ * Returns the pointer to the origin control (the "dot")
+ */
+CanvasItemGuideHandle* CanvasItemGuideLine::dot() const
+{
+    return _origin_ctrl.get();
+}
+
+/**
+ * Update and redraw control guideLine.
+ */
+void CanvasItemGuideLine::_update(bool)
+{
+    // Required when rotating canvas
+    _bounds = Geom::Rect(-Geom::infinity(), -Geom::infinity(), Geom::infinity(), Geom::infinity());
+
+    // Queue redraw of new area (and old too).
+    request_redraw();
+}
+
+/**
+ * Render guideLine to screen via Cairo.
+ */
+void CanvasItemGuideLine::_render(Inkscape::CanvasItemBuffer &buf) const
+{
+    // Document to canvas
+    Geom::Point const normal = _normal * affine().withoutTranslation(); // Direction only
+    Geom::Point const origin = _origin * affine();
+
+    /* Need to use floor()+0.5 such that Cairo will draw us lines with a width of a single pixel,
+     * without any aliasing. For this we need to position the lines at exactly half pixels, see
+     * https://www.cairographics.org/FAQ/#sharp_lines
+     * Must be consistent with the pixel alignment of the grid lines, see CanvasXYGrid::Render(),
+     * and the drawing of the rulers.
+     * Lastly, the origin control is also pixel-aligned and we want to visually cut through its
+     * exact center.
+     */
+    Geom::Point const aligned_origin = origin.floor() + Geom::Point(0.5, 0.5);
+
+    // Set up the Cairo rendering context
+    auto ctx = buf.cr;
+    ctx->save();
+    ctx->translate(-buf.rect.left(), -buf.rect.top()); // Canvas to screen
+    ctx->set_source_rgba(SP_RGBA32_R_F(_stroke), SP_RGBA32_G_F(_stroke),
+                         SP_RGBA32_B_F(_stroke), SP_RGBA32_A_F(_stroke));
+    ctx->set_line_width(1);
+
+    if (_inverted) {
+        // operator not available in cairo C++ bindings
+        cairo_set_operator(ctx->cobj(), CAIRO_OPERATOR_DIFFERENCE);
+    }
+
+    if (!_label.empty()) { // Render text label
+        ctx->save();
+        ctx->translate(aligned_origin.x(), aligned_origin.y());
+
+        auto desktop = get_canvas()->get_desktop();
+        ctx->rotate(atan2(normal.cw()) + M_PI * (desktop && desktop->is_yaxisdown() ? 1 : 0));
+        ctx->translate(0, -(_origin_ctrl->radius() + LABEL_SEP)); // Offset by dot radius + 2
+        ctx->move_to(0, 0);
+        ctx->show_text(_label);
+        ctx->restore();
+    }
+
+    // Draw guide.
+    // Special case: horizontal and vertical lines (easier calculations)
+
+    // Don't use isHorizontal()/isVertical() as they test only exact matches.
+    if (Geom::are_near(normal.y(), 0.0)) {
+        // Vertical
+        double const position = aligned_origin.x();
+        ctx->move_to(position, buf.rect.top()    + 0.5);
+        ctx->line_to(position, buf.rect.bottom() - 0.5);
+    } else if (Geom::are_near(normal.x(), 0.0)) {
+        // Horizontal
+        double position = aligned_origin.y();
+        ctx->move_to(buf.rect.left()  + 0.5, position);
+        ctx->line_to(buf.rect.right() - 0.5, position);
+    } else {
+        // Angled
+        Geom::Line line = Geom::Line::from_origin_and_vector(aligned_origin, Geom::rot90(normal));
+
+        // Find intersections of the line with buf rectangle. There should be zero or two.
+        std::vector<Geom::Point> intersections;
+        for (unsigned i = 0; i < 4; ++i) {
+            Geom::LineSegment side(buf.rect.corner(i), buf.rect.corner((i+1)%4));
+            try {
+                Geom::OptCrossing oc = Geom::intersection(line, side);
+                if (oc) {
+                    intersections.push_back(line.pointAt(oc->ta));
+                }
+            } catch (Geom::InfiniteSolutions const &) {
+                // Shouldn't happen as we have already taken care of horizontal/vertical guides.
+                std::cerr << "CanvasItemGuideLine::render: Error: Infinite intersections." << std::endl;
+            }
+        }
+
+        if (intersections.size() == 2) {
+            double const x0 = intersections[0].x();
+            double const x1 = intersections[1].x();
+            double const y0 = intersections[0].y();
+            double const y1 = intersections[1].y();
+            ctx->move_to(x0, y0);
+            ctx->line_to(x1, y1);
+        }
+    }
+    ctx->stroke();
+
+    ctx->restore();
+}
+
+void CanvasItemGuideLine::set_visible(bool visible)
+{
+    CanvasItem::set_visible(visible);
+    _origin_ctrl->set_visible(visible);
+}
+
+void CanvasItemGuideLine::set_stroke(uint32_t color)
+{
+    // Make sure the fill of the control is the same as the stroke
+    // of the guide-line:
+    _origin_ctrl->set_fill(color);
+    CanvasItem::set_stroke(color);
+}
+
+void CanvasItemGuideLine::set_label(Glib::ustring &&label)
+{
+    defer([=, label = std::move(label)] () mutable {
+        if (_label == label) return;
+        _label = std::move(label);
+        request_update();
+    });
+}
+
+void CanvasItemGuideLine::set_locked(bool locked)
+{
+    defer([=] {
+        if (_locked == locked) return;
+        _locked = locked;
+        if (_locked) {
+            _origin_ctrl->set_shape(CANVAS_ITEM_CTRL_SHAPE_CROSS);
+            _origin_ctrl->set_stroke(CONTROL_LOCKED_COLOR);
+            _origin_ctrl->set_fill(0x00000000);   // no fill
+        } else {
+            _origin_ctrl->set_shape(CANVAS_ITEM_CTRL_SHAPE_CIRCLE);
+            _origin_ctrl->set_stroke(0x00000000); // no stroke
+            _origin_ctrl->set_fill(_stroke);      // fill the control with this guide's color
+        }
+    });
+}
+
+//===============================================================================================
+
+/**
+ * @brief Create a handle ("dot") along a guide line
+ * @param group - the associated canvas item group
+ * @param pos   - position
+ * @param line  - pointer to the corresponding guide line
+ */
+CanvasItemGuideHandle::CanvasItemGuideHandle(CanvasItemGroup *group,
+                                             Geom::Point const &pos,
+                                             CanvasItemGuideLine* line)
+    : CanvasItemCtrl(group, CANVAS_ITEM_CTRL_SHAPE_CIRCLE, pos)
+    , _my_line(line) // Save a pointer to our guide line
+{
+}
+
+/**
+ * Return the radius of the handle dot
+ */
+double CanvasItemGuideHandle::radius() const
+{
+    return 0.5 * static_cast<double>(_width); // radius is half the width
+}
+
+/**
+ * Update the size of the handle based on the index from Preferences
+ */
+void CanvasItemGuideHandle::set_size_via_index(int index)
+{
+    double const r = static_cast<double>(index) * SCALE;
+    unsigned long const rounded_diameter = std::lround(r * 2.0); // diameter is twice the radius
+    unsigned long size = rounded_diameter | 0x1; // make sure the size is always odd
+    if (size < MINIMUM_SIZE) {
+        size = MINIMUM_SIZE;
+    }
+    defer([=] {
+        if (_width == size) return;
+        _width = size;
+        _height = size;
+        _built.reset();
+        request_update();
+        _my_line->request_update();
+    });
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-guideline.h b/src/display/control/canvas-item-guideline.h
new file mode 100644
index 0000000..424fb27
--- /dev/null
+++ b/src/display/control/canvas-item-guideline.h
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_CANVAS_ITEM_GUIDELINE_H
+#define SEEN_CANVAS_ITEM_GUIDELINE_H
+
+/**
+ * A class to represent a control guide line.
+ */
+
+/*
+ * Authors:
+ *   Tavmjong Bah       - Rewrite of SPGuideLine
+ *   Rafael Siejakowski - Tweaks to handle appearance
+ *
+ * Copyright (C) 2020-2022 the Authors.
+ *
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <glibmm/ustring.h>
+
+#include <2geom/point.h>
+#include <2geom/transforms.h>
+
+#include "canvas-item.h"
+#include "canvas-item-ctrl.h"
+#include "canvas-item-ptr.h"
+
+namespace Inkscape {
+
+class CanvasItemGuideHandle;
+
+class CanvasItemGuideLine final : public CanvasItem
+{
+public:
+    CanvasItemGuideLine(CanvasItemGroup *group, Glib::ustring label, Geom::Point const &origin, Geom::Point const &normal);
+
+    // Geometry
+    void set_origin(Geom::Point const &origin);
+    void set_normal(Geom::Point const &normal);
+    double closest_distance_to(Geom::Point const &p);
+
+    // Selection
+    bool contains(Geom::Point const &p, double tolerance = 0) override;
+
+    // Properties
+    void set_visible(bool visible) override;
+    void set_stroke(uint32_t color) override;
+    void set_label(Glib::ustring &&label);
+    void set_locked(bool locked);
+    void set_inverted(bool inverted);
+ 
+    // Getters
+    CanvasItemGuideHandle *dot() const;
+
+protected:
+    ~CanvasItemGuideLine() override = default;
+
+    void _update(bool propagate) override;
+    void _render(Inkscape::CanvasItemBuffer &buf) const override;
+
+    Geom::Point _origin;
+    Geom::Point _normal = Geom::Point(0, 1);
+    Glib::ustring _label;
+    bool _locked = true; // Flipped in constructor to trigger init of _origin_ctrl.
+    bool _inverted = false;
+    CanvasItemPtr<CanvasItemGuideHandle> _origin_ctrl;
+
+    static constexpr uint32_t CONTROL_LOCKED_COLOR = 0x00000080; // RGBA black semitranslucent
+    static constexpr double LABEL_SEP = 2.0; // Distance between the label and the origin control
+};
+
+// A handle ("dot") serving as draggable origin control
+class CanvasItemGuideHandle final : public CanvasItemCtrl
+{
+public:
+    CanvasItemGuideHandle(CanvasItemGroup *group, Geom::Point const &pos, CanvasItemGuideLine *line);
+    double radius() const;
+    void set_size_via_index(int index) override;
+
+protected:
+    ~CanvasItemGuideHandle() override = default;
+
+    CanvasItemGuideLine *_my_line; // The guide line we belong to
+
+    // static data
+    static constexpr double   SCALE        = 0.55; // handle size relative to an auto-smooth node
+    static constexpr unsigned MINIMUM_SIZE = 7;    // smallest handle size, must be an odd int
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_ITEM_GUIDELINE_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-ptr.h b/src/display/control/canvas-item-ptr.h
new file mode 100644
index 0000000..b8c198c
--- /dev/null
+++ b/src/display/control/canvas-item-ptr.h
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_CANVAS_ITEM_PTR_H
+#define SEEN_CANVAS_ITEM_PTR_H
+
+/*
+ * An entirely analogous file to display/drawing-item-ptr.h.
+ */
+
+#include <memory>
+#include <type_traits>
+
+namespace Inkscape { class CanvasItem; }
+
+/// Deleter object which calls the unlink() method of CanvasItem.
+struct CanvasItemUnlinkDeleter
+{
+    template <typename T>
+    void operator()(T *t)
+    {
+        static_assert(std::is_base_of_v<Inkscape::CanvasItem, T>);
+        t->unlink();
+    }
+};
+
+/// Smart pointer used to hold CanvasItems, like std::unique_ptr.
+template <typename T>
+using CanvasItemPtr = std::unique_ptr<T, CanvasItemUnlinkDeleter>;
+
+/// Convienence function to create a CanvasItemPtr, like std::make_unique.
+template <typename T, typename... Args>
+auto make_canvasitem(Args&&... args)
+{
+    return CanvasItemPtr<T>(new T(std::forward<Args>(args)...));
+};
+
+#endif // SEEN_CANVAS_ITEM_PTR_H
diff --git a/src/display/control/canvas-item-quad.cpp b/src/display/control/canvas-item-quad.cpp
new file mode 100644
index 0000000..06914de
--- /dev/null
+++ b/src/display/control/canvas-item-quad.cpp
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * A class to represent a control quadrilateral. Used to highlight selected text.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCtrlQuadr
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cassert>
+
+#include "canvas-item-quad.h"
+
+#include "color.h" // SP_RGBA_x_F
+#include "helper/geom.h"
+
+namespace Inkscape {
+
+/**
+ * Create an null control quad.
+ */
+CanvasItemQuad::CanvasItemQuad(CanvasItemGroup *group)
+    : CanvasItem(group)
+{
+    _name = "CanvasItemQuad:Null";
+}
+
+/**
+ * Create a control quad. Points are in document coordinates.
+ */
+CanvasItemQuad::CanvasItemQuad(CanvasItemGroup *group,
+                               Geom::Point const &p0, Geom::Point const &p1,
+                               Geom::Point const &p2, Geom::Point const &p3)
+    : CanvasItem(group)
+    , _p0(p0)
+    , _p1(p1)
+    , _p2(p2)
+    , _p3(p3)
+{
+    _name = "CanvasItemQuad";
+}
+
+/**
+ * Set a control quad. Points are in document coordinates.
+ */
+void CanvasItemQuad::set_coords(Geom::Point const &p0, Geom::Point const &p1, Geom::Point const &p2, Geom::Point const &p3)
+{
+    defer([=] {
+        _p0 = p0;
+        _p1 = p1;
+        _p2 = p2;
+        _p3 = p3;
+        request_update();
+    });
+}
+
+/**
+ * Returns true if point p (in canvas units) is within tolerance (canvas units) distance of quad.
+ */
+bool CanvasItemQuad::contains(Geom::Point const &p, double tolerance)
+{
+    if (tolerance != 0) {
+        std::cerr << "CanvasItemQuad::contains: Non-zero tolerance not implemented!" << std::endl;
+    }
+
+    Geom::Point p0 = _p0 * affine();
+    Geom::Point p1 = _p1 * affine();
+    Geom::Point p2 = _p2 * affine();
+    Geom::Point p3 = _p3 * affine();
+
+    // From 2geom rotated-rect.cpp
+    return
+        Geom::cross(p1 - p0, p - p0) >= 0 &&
+        Geom::cross(p2 - p1, p - p1) >= 0 &&
+        Geom::cross(p3 - p2, p - p2) >= 0 &&
+        Geom::cross(p0 - p3, p - p3) >= 0;
+}
+
+/**
+ * Update and redraw control quad.
+ */
+void CanvasItemQuad::_update(bool)
+{
+    if (_p0 == _p1 || _p1 == _p2 || _p2 == _p3 || _p3 == _p0) {
+        _bounds = {};
+        return; // Not quad or not initialized.
+    }
+
+    // Queue redraw of old area (erase previous content).
+    request_redraw(); // This is actually never useful as quads are always deleted
+    // and recreated when a node is moved! But keep it in case we change that.
+
+    _bounds = expandedBy(bounds_of(_p0, _p1, _p2, _p3) * affine(), 2); // Room for anti-aliasing effects.
+
+    // Queue redraw of new area
+    request_redraw();
+}
+
+/**
+ * Render quad to screen via Cairo.
+ */
+void CanvasItemQuad::_render(Inkscape::CanvasItemBuffer &buf) const
+{
+    // Document to canvas
+    Geom::Point p0 = _p0 * affine();
+    Geom::Point p1 = _p1 * affine();
+    Geom::Point p2 = _p2 * affine();
+    Geom::Point p3 = _p3 * affine();
+
+    // Canvas to screen
+    p0 *= Geom::Translate(-buf.rect.min());
+    p1 *= Geom::Translate(-buf.rect.min());
+    p2 *= Geom::Translate(-buf.rect.min());
+    p3 *= Geom::Translate(-buf.rect.min());
+
+    buf.cr->save();
+
+    buf.cr->begin_new_path();
+
+    buf.cr->move_to(p0.x(), p0.y());
+    buf.cr->line_to(p1.x(), p1.y());
+    buf.cr->line_to(p2.x(), p2.y());
+    buf.cr->line_to(p3.x(), p3.y());
+    buf.cr->close_path();
+
+    if (_inverted) {
+        cairo_set_operator(buf.cr->cobj(), CAIRO_OPERATOR_DIFFERENCE);
+    }
+
+    buf.cr->set_source_rgba(SP_RGBA32_R_F(_fill), SP_RGBA32_G_F(_fill),
+                            SP_RGBA32_B_F(_fill), SP_RGBA32_A_F(_fill));
+    buf.cr->fill_preserve();
+
+    buf.cr->set_line_width(1);
+    buf.cr->set_source_rgba(SP_RGBA32_R_F(_stroke), SP_RGBA32_G_F(_stroke),
+                            SP_RGBA32_B_F(_stroke), SP_RGBA32_A_F(_stroke));
+    buf.cr->stroke_preserve();
+    buf.cr->begin_new_path();
+
+    buf.cr->restore();
+}
+
+void CanvasItemQuad::set_inverted(bool inverted)
+{
+    defer([=] {
+        if (_inverted == inverted) return;
+        _inverted = inverted;
+        request_redraw();
+    });
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-quad.h b/src/display/control/canvas-item-quad.h
new file mode 100644
index 0000000..deb8e46
--- /dev/null
+++ b/src/display/control/canvas-item-quad.h
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_CANVAS_ITEM_QUAD_H
+#define SEEN_CANVAS_ITEM_QUAD_H
+
+/**
+ * A class to represent a control quadrilateral. Used to highlight selected text.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCtrlQuadr
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <2geom/point.h>
+#include <2geom/transforms.h>
+
+#include "canvas-item.h"
+
+namespace Inkscape {
+
+class CanvasItemQuad final : public CanvasItem
+{
+public:
+    CanvasItemQuad(CanvasItemGroup *group);
+    CanvasItemQuad(CanvasItemGroup *group, Geom::Point const &p0, Geom::Point const &p1,
+                                           Geom::Point const &p2, Geom::Point const &p3);
+
+    // Geometry
+    void set_coords(Geom::Point const &p0, Geom::Point const &p1, Geom::Point const &p2, Geom::Point const &p3);
+
+    // Selection
+    bool contains(Geom::Point const &p, double tolerance = 0) override;
+
+    void set_inverted(bool inverted);
+
+protected:
+    ~CanvasItemQuad() override = default;
+
+    void _update(bool propagate) override;
+    void _render(Inkscape::CanvasItemBuffer &buf) const override;
+
+    Geom::Point _p0;
+    Geom::Point _p1;
+    Geom::Point _p2;
+    Geom::Point _p3;
+
+    bool _inverted = false;
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_ITEM_QUAD_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-rect.cpp b/src/display/control/canvas-item-rect.cpp
new file mode 100644
index 0000000..0204cdf
--- /dev/null
+++ b/src/display/control/canvas-item-rect.cpp
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * A class to represent a control rectangle. Used for rubberband selector, page outline, etc.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of CtrlRect
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cairo/cairo.h>
+
+#include "canvas-item-rect.h"
+
+#include "display/cairo-utils.h"
+#include "color.h"    // SP_RGBA_x_F
+#include "helper/geom.h"
+#include "inkscape.h"
+#include "ui/util.h"
+#include "ui/widget/canvas.h"
+
+namespace Inkscape {
+
+/**
+ * Create an null control rect.
+ */
+CanvasItemRect::CanvasItemRect(CanvasItemGroup *group)
+    : CanvasItem(group)
+{
+    _name = "CanvasItemRect:Null";
+}
+
+/**
+ * Create a control rect. Point are in document coordinates.
+ */
+CanvasItemRect::CanvasItemRect(CanvasItemGroup *group, Geom::Rect const &rect)
+    : CanvasItem(group)
+    , _rect(rect)
+{
+    _name = "CanvasItemRect";
+}
+
+/**
+ * Set a control rect. Points are in document coordinates.
+ */
+void CanvasItemRect::set_rect(Geom::Rect const &rect)
+{
+    defer([=] {
+        if (_rect == rect) return;
+        _rect = rect;
+        request_update();
+    });
+}
+
+/**
+ * Run a callback for each rectangle that should be filled and painted in the background.
+ */
+void CanvasItemRect::visit_page_rects(std::function<void(Geom::Rect const &)> const &f) const
+{
+    if (_is_page && _fill != 0) {
+        f(_rect);
+    }
+}
+
+/**
+ * Returns true if point p (in canvas units) is within tolerance (canvas units) distance of rect.
+ * Non-zero tolerance not implemented! Is valid for a rotated canvas.
+ */
+bool CanvasItemRect::contains(Geom::Point const &p, double tolerance)
+{
+    if (tolerance != 0) {
+        std::cerr << "CanvasItemRect::contains: Non-zero tolerance not implemented!" << std::endl;
+    }
+
+    return _rect.contains(p * affine().inverse());
+}
+
+/**
+ * Update and redraw control rect.
+ */
+void CanvasItemRect::_update(bool)
+{
+    // Queue redraw of old area (erase previous content).
+    request_redraw();
+
+    // Enlarge bbox by twice shadow size (to allow for shadow on any side with a 45deg rotation).
+    _bounds = _rect;
+    // note: add shadow size before applying transformation, since get_shadow_size accounts for scale
+    if (_shadow_width > 0 && !_dashed) {
+        _bounds->expandBy(2 * get_shadow_size());
+    }
+    *_bounds *= affine();
+    _bounds->expandBy(2); // Room for stroke.
+
+    // Queue redraw of new area
+    request_redraw();
+}
+
+/**
+ * Render rect to screen via Cairo.
+ */
+void CanvasItemRect::_render(Inkscape::CanvasItemBuffer &buf) const
+{
+    // Are we axis aligned?
+    auto const &aff = affine();
+    bool const axis_aligned = (Geom::are_near(aff[1], 0) && Geom::are_near(aff[2], 0))
+                           || (Geom::are_near(aff[0], 0) && Geom::are_near(aff[3], 0));
+
+    // If so, then snap the rectangle to the pixel grid.
+    auto rect = _rect;
+    if (axis_aligned) {
+        rect = (floor(_rect * aff) + Geom::Point(0.5, 0.5)) * aff.inverse();
+    }
+
+    buf.cr->save();
+    buf.cr->translate(-buf.rect.left(), -buf.rect.top());
+
+    if (_inverted) {
+        cairo_set_operator(buf.cr->cobj(), CAIRO_OPERATOR_DIFFERENCE);
+    }
+
+    // Draw shadow first. Shadow extends under rectangle to reduce aliasing effects. Canvas draws page shadows in OpenGL mode.
+    if (_shadow_width > 0 && !_dashed && !(_is_page && get_canvas()->get_opengl_enabled())) {
+        // There's only one UI knob to adjust border and shadow color, so instead of using border color
+        // transparency as is, it is boosted by this function, since shadow attenuates it.
+        auto const alpha = (std::exp(-3 * SP_RGBA32_A_F(_shadow_color)) - 1) / (std::exp(-3) - 1);
+
+        // Flip shadow upside-down if y-axis is inverted.
+        auto doc2dt = Geom::identity();
+        if (auto desktop = get_canvas()->get_desktop()) {
+            doc2dt = desktop->doc2dt();
+        }
+
+        buf.cr->save();
+        buf.cr->transform(geom_to_cairo(doc2dt * aff));
+        ink_cairo_draw_drop_shadow(buf.cr, rect * doc2dt, get_shadow_size(), _shadow_color, alpha);
+        buf.cr->restore();
+    }
+
+    // Get the points we need transformed into window coordinates.
+    buf.cr->begin_new_path();
+    for (int i = 0; i < 4; ++i) {
+        auto pt = rect.corner(i) * aff;
+        buf.cr->line_to(pt.x(), pt.y());
+    }
+    buf.cr->close_path();
+
+    // Draw border.
+    static std::valarray<double> dashes = {4.0, 4.0};
+    if (_dashed) {
+        buf.cr->set_dash(dashes, -0.5);
+    }
+    buf.cr->set_line_width(1);
+    // we maybe have painted the background, back to "normal" compositing
+    buf.cr->set_source_rgba(SP_RGBA32_R_F(_stroke), SP_RGBA32_G_F(_stroke),
+                            SP_RGBA32_B_F(_stroke), SP_RGBA32_A_F(_stroke));
+    buf.cr->stroke_preserve();
+
+    // Highlight the border by drawing it in _shadow_color.
+    if (_shadow_width == 1 && _dashed) {
+        buf.cr->set_dash(dashes, 3.5); // Dash offset by dash length.
+        buf.cr->set_source_rgba(SP_RGBA32_R_F(_shadow_color), SP_RGBA32_G_F(_shadow_color),
+                                SP_RGBA32_B_F(_shadow_color), SP_RGBA32_A_F(_shadow_color));
+        buf.cr->stroke_preserve();
+    }
+
+    buf.cr->begin_new_path(); // Clear path or get weird artifacts.
+
+    // Uncomment to show bounds
+    // Geom::Rect bounds = _bounds;
+    // bounds.expandBy(-1);
+    // bounds -= buf.rect.min();
+    // buf.cr->set_source_rgba(1.0, 0.0, _shadow_width / 3.0, 1.0);
+    // buf.cr->rectangle(bounds.min().x(), bounds.min().y(), bounds.width(), bounds.height());
+    // buf.cr->stroke();
+
+    buf.cr->restore();
+}
+
+void CanvasItemRect::set_is_page(bool is_page)
+{
+    defer([=] {
+        if (_is_page == is_page) return;
+        _is_page = is_page;
+        request_redraw();
+    });
+}
+
+void CanvasItemRect::set_fill(uint32_t fill)
+{
+    if (fill != _fill && _is_page) get_canvas()->set_page(fill);
+    CanvasItem::set_fill(fill);
+}
+
+void CanvasItemRect::set_dashed(bool dashed)
+{
+    defer([=] {
+        if (_dashed == dashed) return;
+        _dashed = dashed;
+        request_redraw();
+    });
+}
+
+void CanvasItemRect::set_inverted(bool inverted)
+{
+    defer([=] {
+        if (_inverted == inverted) return;
+        _inverted = inverted;
+        request_redraw();
+    });
+}
+
+void CanvasItemRect::set_shadow(uint32_t color, int width)
+{
+    defer([=] {
+        if (_shadow_color == color && _shadow_width == width) return;
+        _shadow_color = color;
+        _shadow_width = width;
+        request_redraw();
+        if (_is_page) get_canvas()->set_border(_shadow_width > 0 ? color : 0x0);
+    });
+}
+
+double CanvasItemRect::get_shadow_size() const
+{
+    // gradient drop shadow needs much more room than solid one, so inflating the size;
+    // fudge factor of 6 used to make sizes baked in svg documents work as steps:
+    // typical value of 2 will work out to 12 pixels which is a narrow shadow (b/c of exponential fall of)
+    auto size = _shadow_width * 6;
+    if (size < 0) {
+        size = 0;
+    } else if (size > 120) {
+        // arbitrarily selected max size, so Cairo gradient doesn't blow up if document has bogus shadow values
+        size = 120;
+    }
+    auto scale = affine().descrim();
+
+    // calculate space for gradient shadow; if divided by 'scale' it would be zoom independent (fixed in size);
+    // if 'scale' is not used, drop shadow will be getting smaller with document zoom;
+    // here hybrid approach is used: "unscaling" with square root of scale allows shadows to diminish
+    // more slowly at small zoom levels (so it's still perceptible) and grow more slowly at high mag (where it doesn't matter, b/c it's typically off-screen)
+    return size / (scale > 0 ? sqrt(scale) : 1);
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-rect.h b/src/display/control/canvas-item-rect.h
new file mode 100644
index 0000000..4f67734
--- /dev/null
+++ b/src/display/control/canvas-item-rect.h
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_CANVAS_ITEM_RECT_H
+#define SEEN_CANVAS_ITEM_RECT_H
+
+/**
+ * A class to represent a control rectangle. Used for rubberband selector, page outline, etc.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of CtrlRect
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <memory>
+#include <2geom/path.h>
+
+#include "canvas-item.h"
+
+namespace Inkscape {
+
+class CanvasItemRect final : public CanvasItem
+{
+public:
+    CanvasItemRect(CanvasItemGroup *group);
+    CanvasItemRect(CanvasItemGroup *group, Geom::Rect const &rect);
+
+    // Geometry
+    void set_rect(Geom::Rect const &rect);
+    void visit_page_rects(std::function<void(Geom::Rect const &)> const &) const override;
+
+    // Selection
+    bool contains(Geom::Point const &p, double tolerance = 0) override;
+
+    // Properties
+    void set_is_page(bool is_page);
+    void set_fill(uint32_t color) override;
+    void set_dashed(bool dash = true);
+    void set_inverted(bool inverted = false);
+    void set_shadow(uint32_t color, int width);
+ 
+protected:
+    ~CanvasItemRect() override = default;
+
+    void _update(bool propagate) override;
+    void _render(Inkscape::CanvasItemBuffer &buf) const override;
+
+    // Geometry
+    double get_shadow_size() const;
+
+    Geom::Rect _rect;
+    bool _is_page = false;
+    bool _dashed = false;
+    bool _inverted = false;
+    int _shadow_width = 0;
+    uint32_t _shadow_color = 0x0;
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_ITEM_RECT_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-text.cpp b/src/display/control/canvas-item-text.cpp
new file mode 100644
index 0000000..5049543
--- /dev/null
+++ b/src/display/control/canvas-item-text.cpp
@@ -0,0 +1,303 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * A class to represent a control textrilateral. Used to highlight selected text.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCtrlTextr
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "canvas-item-text.h"
+
+#include <cmath>
+#include <utility> // std::move
+#include <glibmm/i18n.h>
+
+#include "color.h" // SP_RGBA_x_F
+
+#include "ui/util.h"
+
+namespace Inkscape {
+
+/**
+ * Create a null control text.
+ */
+CanvasItemText::CanvasItemText(CanvasItemGroup *group)
+    : CanvasItem(group)
+{
+    _name = "CanvasItemText";
+    _fill = 0x33337fff; // Override CanvasItem default.
+}
+
+/**
+ * Create a control text. Point are in document coordinates.
+ */
+CanvasItemText::CanvasItemText(CanvasItemGroup *group, Geom::Point const &p, Glib::ustring text, bool scaled)
+    : CanvasItem(group)
+    , _p(p)
+    , _text(std::move(text))
+    , _scaled(scaled)
+{
+    _name = "CanvasItemText";
+    _fill = 0x33337fff; // Override CanvasItem default.
+
+    request_update();
+}
+
+/**
+ * Set a text position. Position is in document coordinates.
+ */
+void CanvasItemText::set_coord(Geom::Point const &p)
+{
+    defer([=] {
+        if (_p == p) return;
+        _p = p;
+        request_update();
+    });
+}
+
+/**
+ * Set a text position. Position is in document coordinates.
+ */
+void CanvasItemText::set_bg_radius(double rad)
+{
+    defer([=] {
+        if (_bg_rad == rad) return;
+        _bg_rad = rad;
+        request_update();
+    });
+}
+
+/**
+ * Returns true if point p (in canvas units) is within tolerance (canvas units) distance of text.
+ */
+bool CanvasItemText::contains(Geom::Point const &p, double tolerance)
+{
+    return false; // We never select text.
+}
+
+/**
+ * Update and redraw control text.
+ */
+void CanvasItemText::_update(bool)
+{
+    // Queue redraw of old area (erase previous content).
+    request_redraw();
+
+    // Point needs to be scaled manually if not cairo scaling
+    Geom::Point p = _scaled ? _p : _p * affine();
+
+    // Measure text size
+    _text_box = load_text_extents();
+
+    // Offset relative to requested point
+    double offset_x = -(_anchor_position.x() * _text_box.width());
+    double offset_y = -(_anchor_position.y() * _text_box.height());
+    offset_x += p.x() + _adjust_offset.x();
+    offset_y += p.y() + _adjust_offset.y();
+    _text_box *= Geom::Translate(Geom::Point(offset_x, offset_y).floor());
+
+    // Pixel alignment of background. Avoid aliasing artifacts on redraw.
+    _text_box = _text_box.roundOutwards();
+
+    // Don't apply affine here, to keep text at the same size in screen coords.
+    _bounds = _text_box;
+    if (_scaled && _bounds) {
+        *_bounds *= affine();
+        _bounds = _bounds->roundOutwards();
+    }
+
+    // Queue redraw of new area
+    request_redraw();
+}
+
+/**
+ * Render text to screen via Cairo.
+ */
+void CanvasItemText::_render(Inkscape::CanvasItemBuffer &buf) const
+{
+    buf.cr->save();
+
+    // Screen to desktop coords.
+    buf.cr->translate(-buf.rect.left(), -buf.rect.top());
+
+    if (_scaled) {
+        // Convert from canvas space to document space
+        buf.cr->transform(geom_to_cairo(affine()));
+    }
+
+    double x = _text_box.min().x();
+    double y = _text_box.min().y();
+    double w = _text_box.width();
+    double h = _text_box.height();
+
+    // Background
+    if (_use_background) {
+        if (_bg_rad == 0.0) {
+            buf.cr->rectangle(x, y, w, h);
+        } else {
+            double radius = _bg_rad * (std::min(w ,h) / 2);
+            buf.cr->arc(x + w - radius, y + radius, radius, -M_PI_2, 0);
+            buf.cr->arc(x + w - radius, y + h - radius, radius, 0, M_PI_2);
+            buf.cr->arc(x + radius, y + h - radius, radius, M_PI_2, M_PI);
+            buf.cr->arc(x + radius, y + radius, radius, M_PI, 3*M_PI_2);
+        }
+        buf.cr->set_line_width(2);
+        buf.cr->set_source_rgba(SP_RGBA32_R_F(_background), SP_RGBA32_G_F(_background),
+                                SP_RGBA32_B_F(_background), SP_RGBA32_A_F(_background));
+        buf.cr->fill();
+    }
+
+    // Center the text inside the draw background box
+    auto bx = x + w / 2.0;
+    auto by = y + h / 2.0 + 1;
+    buf.cr->move_to(int(bx - _text_size.x_bearing - _text_size.width/2.0),
+                    int(by - _text_size.y_bearing - _text_extent.height/2.0));
+
+    buf.cr->select_font_face(_fontname, Cairo::FONT_SLANT_NORMAL, Cairo::FONT_WEIGHT_NORMAL);
+    buf.cr->set_font_size(_fontsize);
+    buf.cr->text_path(_text);
+    buf.cr->set_source_rgba(SP_RGBA32_R_F(_fill), SP_RGBA32_G_F(_fill),
+                            SP_RGBA32_B_F(_fill), SP_RGBA32_A_F(_fill));
+    buf.cr->fill();
+    buf.cr->restore();
+}
+
+void CanvasItemText::set_text(Glib::ustring text)
+{
+    defer([=, text = std::move(text)] () mutable {
+        if (_text == text) return;
+        _text = std::move(text);
+        request_update(); // Might be larger than before!
+    });
+}
+
+void CanvasItemText::set_fontsize(double fontsize)
+{
+    defer([=] {
+        if (_fontsize == fontsize) return;
+        _fontsize = fontsize;
+        request_update(); // Might be larger than before!
+    });
+}
+
+/**
+ * Load the sizes of the text extent using the given font.
+ */
+Geom::Rect CanvasItemText::load_text_extents()
+{
+    auto surface = Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32, 1, 1);
+    auto context = Cairo::Context::create(surface);
+    context->select_font_face(_fontname, Cairo::FONT_SLANT_NORMAL, Cairo::FONT_WEIGHT_NORMAL);
+    context->set_font_size(_fontsize);
+    context->get_text_extents(_text, _text_size);
+
+    if (_fixed_line) {
+        // TRANSLATORS: This is a set of letters to test for font ascender and descenders.
+        context->get_text_extents(_("lg1p$"), _text_extent);
+    } else {
+        _text_extent = _text_size;
+    }
+
+    return Geom::Rect::from_xywh(0, 0,
+                                 _text_size.x_advance + _border * 2,
+                                 _text_extent.height + _border * 2);
+}
+
+void CanvasItemText::set_background(uint32_t background)
+{
+    defer([=] {
+        if (_background != background) {
+            _background = background;
+            request_redraw();
+        }
+        _use_background = true;
+    });
+}
+
+/**
+ * Set the anchor point, x and y between 0.0 and 1.0.
+ */
+void CanvasItemText::set_anchor(Geom::Point const &anchor_pt)
+{
+    defer([=] {
+        if (_anchor_position == anchor_pt) return;
+        _anchor_position = anchor_pt;
+        request_update();
+    });
+}
+
+void CanvasItemText::set_adjust(Geom::Point const &adjust_pt)
+{
+    defer([=] {
+        if (_adjust_offset == adjust_pt) return;
+        _adjust_offset = adjust_pt;
+        request_update();
+    });
+}
+
+void CanvasItemText::set_fixed_line(bool fixed_line)
+{
+    defer([=] {
+        if (_fixed_line == fixed_line) return;
+        _fixed_line = fixed_line;
+        request_update();
+    });
+}
+
+void CanvasItemText::set_border(double border)
+{
+    defer([=] {
+        if (_border == border) return;
+        _border = border;
+        request_update();
+    });
+}
+
+} // namespace Inkscape
+
+/* FROM: http://lists.cairographics.org/archives/cairo-bugs/2009-March/003014.html
+  - Glyph surfaces: In most font rendering systems, glyph surfaces
+    have an origin at (0,0) and a bounding box that is typically
+    represented as (x_bearing,y_bearing,width,height).  Depending on
+    which way y progresses in the system, y_bearing may typically be
+    negative (for systems similar to cairo, with origin at top left),
+    or be positive (in systems like PDF with origin at bottom left).
+    No matter which is the case, it is important to note that
+    (x_bearing,y_bearing) is the coordinates of top-left of the glyph
+    relative to the glyph origin.  That is, for example:
+
+    Scaled-glyph space:
+
+      (x_bearing,y_bearing) <-- negative numbers
+         +----------------+
+         |      .         |
+         |      .         |
+         |......(0,0) <---|-- glyph origin
+         |                |
+         |                |
+         +----------------+
+                  (width+x_bearing,height+y_bearing)
+
+    Note the similarity of the origin to the device space.  That is
+    exactly how we use the device_offset to represent scaled glyphs:
+    to use the device-space origin as the glyph origin.
+*/
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item-text.h b/src/display/control/canvas-item-text.h
new file mode 100644
index 0000000..a3ad4f4
--- /dev/null
+++ b/src/display/control/canvas-item-text.h
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_CANVAS_ITEM_TEXT_H
+#define SEEN_CANVAS_ITEM_TEXT_H
+
+/**
+ * A class to represent on-screen text.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCanvasText.
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <2geom/point.h>
+#include <2geom/transforms.h>
+
+#include <glibmm/ustring.h>
+
+#include "canvas-item.h"
+
+namespace Inkscape {
+
+class CanvasItemText final : public CanvasItem
+{
+public:
+    CanvasItemText(CanvasItemGroup *group);
+    CanvasItemText(CanvasItemGroup *group, Geom::Point const &p, Glib::ustring text, bool scaled = false);
+
+    // Geometry
+    void set_coord(Geom::Point const &p);
+    void set_bg_radius(double rad);
+
+    // Selection
+    bool contains(Geom::Point const &p, double tolerance = 0) override;
+
+    // Properties
+    void set_text(Glib::ustring text);
+    void set_fontsize(double fontsize);
+    void set_border(double border);
+    void set_background(uint32_t background);
+    void set_anchor(Geom::Point const &anchor_pt);
+    void set_adjust(Geom::Point const &adjust_pt);
+    void set_fixed_line(bool fixed_line);
+
+protected:
+    ~CanvasItemText() override = default;
+
+    void _update(bool propagate) override;
+    void _render(Inkscape::CanvasItemBuffer &buf) const override;
+
+    Geom::Point _p;  // Position of text (not box around text).
+    Cairo::TextExtents _text_extent;
+    Cairo::TextExtents _text_size;
+    Geom::Point _anchor_position;
+    Geom::Point _adjust_offset;
+    Geom::Rect _text_box;
+    Glib::ustring _text;
+    std::string _fontname = "sans-serif";
+    double _fontsize = 10;
+    double _border = 3;
+    double _bg_rad = 0;
+    uint32_t _background = 0x0000007f;
+    bool _use_background = false;
+    bool _fixed_line = false; // Correction for font heights
+    bool _scaled = false;
+
+    Geom::Rect load_text_extents();
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_ITEM_TEXT_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item.cpp b/src/display/control/canvas-item.cpp
new file mode 100644
index 0000000..984d24d
--- /dev/null
+++ b/src/display/control/canvas-item.cpp
@@ -0,0 +1,334 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * Abstract base class for on-canvas control items.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCanvasItem
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "canvas-item.h"
+#include "canvas-item-group.h"
+#include "canvas-item-ctrl.h"
+
+#include "ui/widget/canvas.h"
+
+constexpr bool DEBUG_LOGGING = false;
+constexpr bool DEBUG_BOUNDS = false;
+
+namespace Inkscape {
+
+CanvasItem::CanvasItem(CanvasItemContext *context)
+    : _context(context)
+    , _parent(nullptr)
+{
+    if constexpr (DEBUG_LOGGING) std::cout << "CanvasItem: create root " << get_name() << std::endl;
+    request_update();
+}
+
+CanvasItem::CanvasItem(CanvasItemGroup *parent)
+    : _context(parent->_context)
+    , _parent(parent)
+{
+    if constexpr (DEBUG_LOGGING) std::cout << "CanvasItem: add " << get_name() << " to " << parent->get_name() << " " << parent->items.size() << std::endl;
+    defer([=] {
+        parent->items.push_back(*this);
+        request_update();
+    });
+}
+
+void CanvasItem::unlink()
+{
+    defer([=] {
+        // Clear canvas of item.
+        request_redraw();
+
+        // Remove from parent.
+        if (_parent) {
+            if constexpr (DEBUG_LOGGING) std::cout << "CanvasItem: remove " << get_name() << " from " << _parent->get_name() << " " << _parent->items.size() << std::endl;
+            auto it = _parent->items.iterator_to(*this);
+            assert(it != _parent->items.end());
+            _parent->items.erase(it);
+            _parent->request_update();
+        } else {
+            if constexpr (DEBUG_LOGGING) std::cout << "CanvasItem: destroy root " << get_name() << std::endl;
+        }
+
+        delete this;
+    });
+}
+
+CanvasItem::~CanvasItem()
+{
+    // Clear any pointers to this object in canvas.
+    get_canvas()->canvas_item_destructed(this);
+}
+
+bool CanvasItem::is_descendant_of(CanvasItem const *ancestor) const
+{
+    auto item = this;
+    while (item) {
+        if (item == ancestor) {
+            return true;
+        }
+        item = item->_parent;
+    }
+    return false;
+}
+
+void CanvasItem::set_z_position(int zpos)
+{
+    if (!_parent) {
+        std::cerr << "CanvasItem::set_z_position: No parent!" << std::endl;
+        return;
+    }
+
+    defer([=] {
+        _parent->items.erase(_parent->items.iterator_to(*this));
+
+        if (zpos <= 0) {
+            _parent->items.push_front(*this);
+        } else if (zpos >= _parent->items.size() - 1) {
+            _parent->items.push_back(*this);
+        } else {
+            auto it = _parent->items.begin();
+            std::advance(it, zpos);
+            _parent->items.insert(it, *this);
+        }
+    });
+}
+
+void CanvasItem::raise_to_top()
+{
+    if (!_parent) {
+        std::cerr << "CanvasItem::raise_to_top: No parent!" << std::endl;
+        return;
+    }
+
+    defer([=] {
+        _parent->items.erase(_parent->items.iterator_to(*this));
+        _parent->items.push_back(*this);
+    });
+}
+
+void CanvasItem::lower_to_bottom()
+{
+    if (!_parent) {
+        std::cerr << "CanvasItem::lower_to_bottom: No parent!" << std::endl;
+        return;
+    }
+
+    defer([=] {
+        _parent->items.erase(_parent->items.iterator_to(*this));
+        _parent->items.push_front(*this);
+    });
+}
+
+// Indicate geometry changed and bounds needs recalculating.
+void CanvasItem::request_update()
+{
+    if (_need_update || !_visible) {
+        return;
+    }
+
+    _need_update = true;
+
+    if (_parent) {
+        _parent->request_update();
+    } else {
+        get_canvas()->request_update();
+    }
+}
+
+void CanvasItem::update(bool propagate)
+{
+    if (!_visible) {
+        _mark_net_invisible();
+        return;
+    }
+
+    bool reappearing = !_net_visible;
+    _net_visible = true;
+
+    if (!_need_update && !reappearing && !propagate) {
+        return;
+    }
+
+    _need_update = false;
+
+    // Get new bounds
+    _update(propagate);
+
+    if (reappearing) {
+        request_redraw();
+    }
+}
+
+void CanvasItem::_mark_net_invisible()
+{
+    if (!_net_visible) {
+        return;
+    }
+    _net_visible = false;
+    _need_update = false;
+    request_redraw();
+    _bounds = {};
+}
+
+// Grab all events!
+void CanvasItem::grab(Gdk::EventMask event_mask, Glib::RefPtr<Gdk::Cursor> const &cursor)
+{
+    if constexpr (DEBUG_LOGGING) std::cout << "CanvasItem::grab: " << _name << std::endl;
+
+    auto canvas = get_canvas();
+
+    // Don't grab if we already have a grabbed item!
+    if (canvas->get_grabbed_canvas_item()) {
+        return;
+    }
+
+    gtk_grab_add(GTK_WIDGET(canvas->gobj()));
+
+    canvas->set_grabbed_canvas_item(this, event_mask);
+    canvas->set_current_canvas_item(this); // So that all events go to grabbed item.
+}
+
+void CanvasItem::ungrab()
+{
+    if constexpr (DEBUG_LOGGING) std::cout << "CanvasItem::ungrab: " << _name << std::endl;
+
+    auto canvas = get_canvas();
+
+    if (canvas->get_grabbed_canvas_item() != this) {
+        return; // Sanity check
+    }
+
+    canvas->set_grabbed_canvas_item(nullptr, (Gdk::EventMask)0); // Zero mask
+
+    gtk_grab_remove(GTK_WIDGET(canvas->gobj()));
+}
+
+void CanvasItem::render(CanvasItemBuffer &buf) const
+{
+    if (_visible && _bounds && _bounds->interiorIntersects(buf.rect)) {
+        _render(buf);
+        if constexpr (DEBUG_BOUNDS) {
+            auto bounds = *_bounds;
+            bounds.expandBy(-1);
+            bounds -= buf.rect.min();
+            buf.cr->set_source_rgba(1.0, 0.0, 0.0, 1.0);
+            buf.cr->rectangle(bounds.min().x(), bounds.min().y(), bounds.width(), bounds.height());
+            buf.cr->stroke();
+        }
+    }
+}
+
+/*
+ * The main invariant of the invisibility system is
+ *
+ *     x needs update and is visible  ==>  parent(x) needs update or is invisible
+ *
+ * When x belongs to the visible subtree, meaning it and all its parents are visible,
+ * this condition reduces to
+ *
+ *     x needs update  ==>  parent(x) needs update
+ *
+ * Thus within the visible subtree, the subset of nodes that need updating forms a subtree.
+ *
+ * In the update() function, we only walk this latter subtree.
+ */
+
+void CanvasItem::set_visible(bool visible)
+{
+    defer([=] {
+        if (_visible == visible) return;
+        if (_visible) {
+            request_update();
+            _visible = false;
+        } else {
+            _visible = true;
+            _need_update = false;
+            request_update();
+        }
+    });
+}
+
+void CanvasItem::request_redraw()
+{
+    // Queue redraw request
+    if (_bounds) {
+        get_canvas()->redraw_area(*_bounds);
+    }
+}
+
+void CanvasItem::set_fill(uint32_t fill)
+{
+    defer([=] {
+        if (_fill == fill) return;
+        _fill = fill;
+        request_redraw();
+    });
+}
+
+void CanvasItem::set_stroke(uint32_t stroke)
+{
+    defer([=] {
+        if (_stroke == stroke) return;
+        _stroke = stroke;
+        request_redraw();
+    });
+}
+
+void CanvasItem::update_canvas_item_ctrl_sizes(int size_index)
+{
+    if (auto ctrl = dynamic_cast<CanvasItemCtrl*>(this)) {
+        // We can't use set_size_default as the preference file is updated ->after<- the signal is emitted!
+        ctrl->set_size_via_index(size_index);
+    } else if (auto group = dynamic_cast<CanvasItemGroup*>(this)) {
+        for (auto &item : group->items) {
+            item.update_canvas_item_ctrl_sizes(size_index);
+        }
+    }
+}
+
+void CanvasItem::canvas_item_print_tree(int level, int zorder) const
+{
+    if (level == 0) {
+        std::cout << "Canvas Item Tree" << std::endl;
+    }
+
+    std::cout << "CC: ";
+    for (int i = 0; i < level; ++i) {
+        std::cout << "  ";
+    }
+
+    std::cout << zorder << ": " << _name << std::endl;
+
+    if (auto group = dynamic_cast<Inkscape::CanvasItemGroup const*>(this)) {
+        int i = 0;
+        for (auto &item : group->items) {
+            item.canvas_item_print_tree(level + 1, i);
+            i++;
+        }
+    }
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-item.h b/src/display/control/canvas-item.h
new file mode 100644
index 0000000..fc34176
--- /dev/null
+++ b/src/display/control/canvas-item.h
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_CANVAS_ITEM_H
+#define SEEN_CANVAS_ITEM_H
+
+/**
+ * Abstract base class for on-canvas control items.
+ */
+
+/*
+ * Author:
+ *   Tavmjong Bah
+ *
+ * Copyright (C) 2020 Tavmjong Bah
+ *
+ * Rewrite of SPCanvasItem
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ *
+ * A note about coordinates:
+ *
+ *   1. Canvas items are constructed using document (SVG) coordinates.
+ *   2. Calculations are made in canvas units, which is equivalent of SVG units multiplied by zoom factor.
+ *      This is true for bounds and closest distance calculations.
+ *   3  Drawing is done in screen units which is the same as canvas units but translated.
+ *   The document and canvas origins overlap.
+ *   The affine contains only scaling and rotating components.
+ */
+
+#include <cstdint>
+#include <boost/intrusive/list.hpp>
+#include <2geom/rect.h>
+#include <sigc++/sigc++.h>
+
+#include <gdkmm/device.h> // Gdk::EventMask
+#include <gdk/gdk.h>  // GdkEvent
+
+#include "canvas-item-enums.h"
+#include "canvas-item-buffer.h"
+#include "canvas-item-context.h"
+
+class SPItem;
+
+namespace Inkscape {
+
+inline constexpr uint32_t CANVAS_ITEM_COLORS[] = { 0x0000ff7f, 0xff00007f, 0xffff007f };
+
+namespace UI::Widget { class Canvas; }
+class CanvasItemGroup;
+
+class CanvasItem
+{
+public:
+    CanvasItem(CanvasItemContext *context);
+    CanvasItem(CanvasItemGroup *parent);
+    CanvasItem(CanvasItem const &) = delete;
+    CanvasItem &operator=(CanvasItem const &) = delete;
+    void unlink();
+
+    // Structure
+    UI::Widget::Canvas *get_canvas() const { return _context->canvas(); }
+    CanvasItemGroup *get_parent() const { return _parent; }
+    bool is_descendant_of(CanvasItem const *ancestor) const;
+
+    // Z Position
+    void set_z_position(int zpos);
+    void raise_to_top();    // Move to top of group (last entry).
+    void lower_to_bottom(); // Move to bottom of group (first entry).
+
+    // Geometry
+    void request_update();
+    void update(bool propagate);
+    virtual void visit_page_rects(std::function<void(Geom::Rect const &)> const &) const {}
+    Geom::OptRect const &get_bounds() const { return _bounds; }
+
+    // Selection
+    virtual bool contains(Geom::Point const &p, double tolerance = 0) { return _bounds && _bounds->interiorContains(p); }
+    void grab(Gdk::EventMask event_mask, Glib::RefPtr<Gdk::Cursor> const & = {});
+    void ungrab();
+
+    // Display
+    void render(Inkscape::CanvasItemBuffer &buf) const;
+    bool is_visible() const { return _visible; }
+    virtual void set_visible(bool visible);
+    void show() { set_visible(true); }
+    void hide() { set_visible(false); }
+    void request_redraw(); // queue redraw request
+
+    // Properties
+    virtual void set_fill(uint32_t rgba);
+    void set_fill(CanvasItemColor color) { set_fill(CANVAS_ITEM_COLORS[color]); }
+    virtual void set_stroke(uint32_t rgba);
+    void set_stroke(CanvasItemColor color) { set_stroke(CANVAS_ITEM_COLORS[color]); }
+    void set_name(std::string &&name) { _name = std::move(name); }
+    std::string const &get_name() const { return _name; }
+    void update_canvas_item_ctrl_sizes(int size_index);
+
+    // Events
+    void set_pickable(bool pickable) { _pickable = pickable; }
+    bool is_pickable() const { return _pickable; }
+    sigc::connection connect_event(sigc::slot<bool(GdkEvent*)> const &slot) {
+        return _event_signal.connect(slot);
+    }
+    virtual bool handle_event(GdkEvent *event) {
+        return _event_signal.emit(event); // Default just emits event.
+    }
+
+    // Recursively print CanvasItem tree.
+    void canvas_item_print_tree(int level = 0, int zorder = 0) const;
+
+    // Boost linked list member hook, speeds deletion.
+    boost::intrusive::list_member_hook<> member_hook;
+
+protected:
+    friend class CanvasItemGroup;
+
+    virtual ~CanvasItem();
+
+    // Structure
+    CanvasItemContext *_context;
+    CanvasItemGroup *_parent;
+
+    // Geometry
+    Geom::OptRect _bounds;
+    bool _need_update = false;
+    Geom::Affine const &affine() const { return _context->affine(); }
+    virtual void _update(bool propagate) = 0;
+    virtual void _mark_net_invisible();
+
+    // Display
+    bool _visible = true;
+    bool _net_visible = true;
+    virtual void _render(Inkscape::CanvasItemBuffer &buf) const = 0;
+
+    // Selection
+    bool _pickable = false; // Most items are just for display and are not pickable!
+
+    // Properties
+    uint32_t _fill    = CANVAS_ITEM_COLORS[CANVAS_ITEM_SECONDARY];
+    uint32_t _stroke  = CANVAS_ITEM_COLORS[CANVAS_ITEM_PRIMARY];
+    std::string _name; // For debugging
+
+    // Events
+    sigc::signal<bool (GdkEvent*)> _event_signal;
+
+    // Snapshotting
+    template<typename F>
+    void defer(F &&f) { _context->defer(std::forward<F>(f)); }
+};
+
+} // namespace Inkscape
+
+// Todo: Move to lib2geom.
+inline auto &operator<<(std::ostream &s, Geom::OptRect const &rect)
+{
+    return rect ? (s << *rect) : (s << "(empty)");
+}
+
+#endif // SEEN_CANVAS_ITEM_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-page.cpp b/src/display/control/canvas-page.cpp
new file mode 100644
index 0000000..5fa337d
--- /dev/null
+++ b/src/display/control/canvas-page.cpp
@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Inkscape pages implementation
+ *
+ * Authors:
+ *   Martin Owens <doctormo@geek-2.com>
+ *
+ * Copyright (C) 2021 Martin Owens
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "canvas-page.h"
+#include "canvas-item-rect.h"
+#include "canvas-item-text.h"
+#include "color.h"
+
+namespace Inkscape {
+
+CanvasPage::CanvasPage() = default;
+
+CanvasPage::~CanvasPage() = default;
+
+/**
+ * Add the page canvas to the given canvas item groups (canvas view is implicit)
+ */
+void CanvasPage::add(Geom::Rect size, CanvasItemGroup *background_group, CanvasItemGroup *border_group)
+{
+    // Foreground 'border'
+    if (auto item = new CanvasItemRect(border_group, size)) {
+        item->set_name("foreground");
+        item->set_is_page(true);
+        canvas_items.emplace_back(item);
+    }
+
+    // Background rectangle 'fill'
+    if (auto item = new CanvasItemRect(background_group, size)) {
+        item->set_name("background");
+        item->set_is_page(true);
+        item->set_dashed(false);
+        item->set_inverted(false);
+        item->set_stroke(0x00000000);
+        canvas_items.emplace_back(item);
+    }
+
+    if (auto item = new CanvasItemRect(border_group, size)) {
+        item->set_name("margin");
+        item->set_dashed(false);
+        item->set_inverted(false);
+        item->set_stroke(_margin_color);
+        canvas_items.emplace_back(item);
+    }
+
+    if (auto item = new CanvasItemRect(border_group, size)) {
+        item->set_name("bleed");
+        item->set_dashed(false);
+        item->set_inverted(false);
+        item->set_stroke(_bleed_color);
+        canvas_items.emplace_back(item);
+    }
+
+    if (auto label = new CanvasItemText(border_group, Geom::Point(0, 0), "{Page Label}")) {
+        label->set_fixed_line(false);
+        canvas_items.emplace_back(label);
+    }
+}
+/**
+ * Hide the page in the given canvas widget.
+ */
+void CanvasPage::remove(UI::Widget::Canvas *canvas)
+{
+    g_assert(canvas != nullptr);
+    for (auto it = canvas_items.begin(); it != canvas_items.end();) {
+        if (canvas == (*it)->get_canvas()) {
+            it = canvas_items.erase(it);
+        } else {
+            ++it;
+        }
+    }
+}
+
+void CanvasPage::show()
+{
+    for (auto &item : canvas_items) {
+        item->show();
+    }
+}
+
+void CanvasPage::hide()
+{
+    for (auto &item : canvas_items) {
+        item->hide();
+    }
+}
+
+void CanvasPage::set_guides_visible(bool show) {
+    for (auto& item: canvas_items) {
+        if (item->get_name() == "margin" || item->get_name() == "bleed") {
+            item->set_visible(show);
+        }
+    }
+}
+
+/**
+ * Update the visual representation of a page on screen.
+ *
+ * @param size - The size of the page in desktop units
+ * @param txt - An optional label for the page
+ * @param outline - Disable normal rendering and show as an outline.
+ */
+void CanvasPage::update(Geom::Rect size, Geom::OptRect margin, Geom::OptRect bleed, const char *txt, bool outline)
+{
+    // Put these in the preferences?
+    bool border_on_top = _border_on_top;
+    guint32 shadow_color = _border_color; // there's no separate shadow color in the UI, border color is used
+    guint32 select_color = 0x000000cc;
+    guint32 border_color = _border_color;
+    guint32 margin_color = _margin_color;
+    guint32 bleed_color = _bleed_color;
+
+    // This is used when showing the viewport as *not a page* it's mostly
+    // never used as the first page is normally the viewport too.
+    if (outline) {
+        border_on_top = false;
+        _shadow_size = 0;
+        border_color = select_color;
+    }
+
+    for (auto &item : canvas_items) {
+        if (auto rect = dynamic_cast<CanvasItemRect *>(item.get())) {
+            if (rect->get_name() == "margin") {
+                rect->set_stroke(margin_color);
+                bool vis = margin && *margin != size;
+                rect->set_visible(vis);
+                if (vis) {
+                    rect->set_rect(*margin);
+                }
+                continue;
+            }
+            if (rect->get_name() == "bleed") {
+                rect->set_stroke(bleed_color);
+                bool vis = bleed && *bleed != size;
+                rect->set_visible(vis);
+                if (vis) {
+                    rect->set_rect(*bleed);
+                }
+                continue;
+            }
+
+            rect->set_rect(size);
+
+            bool is_foreground = (rect->get_name() == "foreground");
+            // This will put the border on the background OR foreground layer as needed.
+            if (is_foreground == border_on_top) {
+                rect->show();
+                rect->set_stroke(is_selected ? select_color : border_color);
+            } else {
+                rect->hide();
+                rect->set_stroke(0x0);
+            }
+            // This undoes the hide for the background rect, and additionally gives it a fill and shadow.
+            if (!is_foreground) {
+                rect->show();
+/*
+                if (_checkerboard) {
+                    // draw checkerboard pattern, ignore alpha (background color doesn't support it)
+                    rect->set_background_checkerboard(_background_color, false);
+                }
+                else {
+                    // Background color does not support transparency; draw opaque pages
+                    rect->set_background(_background_color | 0xff);
+                }
+*/
+                rect->set_fill(_background_color);
+                rect->set_shadow(shadow_color, _shadow_size);
+            } else {
+                rect->set_fill(0x0);
+                rect->set_shadow(0x0, 0);
+            }
+        } else if (auto label = dynamic_cast<CanvasItemText *>(item.get())) {
+            _updateTextItem(label, size, txt ? txt : "");
+        }
+    }
+}
+
+/**
+ * Update the page's textual label.
+ */
+void CanvasPage::_updateTextItem(CanvasItemText *label, Geom::Rect page, std::string txt)
+{
+    // Default style for the label
+    int fontsize = 10.0;
+    uint32_t foreground = 0xffffffff;
+    uint32_t background = 0x00000099;
+    uint32_t selected = 0x0e5bf199;
+    Geom::Point anchor(0.0, 1.0);
+    Geom::Point coord = page.corner(0);
+    double radius = 0.2;
+
+    // Change the colors for whiter/lighter backgrounds
+    unsigned char luminance = SP_RGBA32_LUMINANCE(_canvas_color);
+    if (luminance < 0x88) {
+        foreground = 0x000000ff;
+        background = 0xffffff99;
+        selected = 0x50afe7ff;
+    }
+
+    if (_label_style == "below") {
+        radius = 1.0;
+        fontsize = 14.0;
+        anchor = Geom::Point(0.5, -0.2);
+        coord = Geom::Point(page.midpoint()[Geom::X], page.bottom());
+
+        if (!txt.empty()) {
+            std::string bullet = is_selected ? " \u2022 " : "   ";
+            txt = bullet + txt + bullet;
+        }
+    }
+
+    label->set_fontsize(fontsize);
+    label->set_fill(foreground);
+    label->set_background(is_selected ? selected : background);
+    label->set_bg_radius(radius);
+    label->set_anchor(anchor);
+    label->set_coord(coord);
+    label->set_visible(!txt.empty());
+    label->set_text(std::move(txt));
+    label->set_border(4.0);
+}
+
+bool CanvasPage::setOnTop(bool on_top)
+{
+    if (on_top != _border_on_top) {
+        _border_on_top = on_top;
+        return true;
+    }
+    return false;
+}
+
+bool CanvasPage::setShadow(int shadow)
+{
+    if (_shadow_size != shadow) {
+        _shadow_size = shadow;
+        return true;
+    }
+    return false;
+}
+
+bool CanvasPage::setPageColor(uint32_t border, uint32_t bg, uint32_t canvas, uint32_t margin, uint32_t bleed)
+{
+    if (border != _border_color || bg != _background_color || canvas != _canvas_color) {
+        _border_color = border;
+        _background_color = bg;
+        _canvas_color = canvas;
+        _margin_color = margin;
+        _bleed_color = bleed;
+        return true;
+    }
+    return false;
+}
+
+bool CanvasPage::setLabelStyle(const std::string &style)
+{
+    if (style != _label_style) {
+        _label_style = style;
+        return true;
+    }
+    return false;
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-page.h b/src/display/control/canvas-page.h
new file mode 100644
index 0000000..e3227bf
--- /dev/null
+++ b/src/display/control/canvas-page.h
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * 
+ *//*
+ * Authors:
+ *   Martin Owens 2021
+ * 
+ * Copyright (C) 2021 Martin Owens
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+#ifndef SEEN_CANVAS_PAGE_H
+#define SEEN_CANVAS_PAGE_H
+
+#include <2geom/rect.h>
+#include <glib.h>
+#include <vector>
+
+#include "canvas-item-ptr.h"
+
+namespace Inkscape {
+namespace UI::Widget { class Canvas; }
+
+class CanvasItemGroup;
+class CanvasItemText;
+
+class CanvasPage
+{
+public:
+    CanvasPage();
+    ~CanvasPage();
+
+    void update(Geom::Rect size, Geom::OptRect margin, Geom::OptRect bleed, const char *txt, bool outline = false);
+    void add(Geom::Rect size, CanvasItemGroup *background_group, CanvasItemGroup *foreground_group);
+    void remove(UI::Widget::Canvas *canvas);
+    void show();
+    void hide();
+    void set_guides_visible(bool show);
+
+    bool setOnTop(bool on_top);
+    bool setShadow(int shadow);
+    bool setPageColor(uint32_t border, uint32_t bg, uint32_t canvas, uint32_t margin, uint32_t bleed);
+    bool setLabelStyle(const std::string &style);
+
+    bool is_selected = false;
+private:
+    void _updateTextItem(CanvasItemText *label, Geom::Rect page, std::string txt);
+
+    // This may make this look like a CanvasItemGroup, but it's not one. This
+    // isn't a collection of items, but a set of items in multiple Canvases.
+    // Each item can belong in either a foreground or background group.
+    std::vector<CanvasItemPtr<CanvasItem>> canvas_items;
+
+    int _shadow_size = 0;
+    bool _border_on_top = true;
+    uint32_t _background_color = 0xffffffff;
+    uint32_t _border_color = 0x00000040;
+    uint32_t _canvas_color = 0xffffffff;
+    uint32_t _margin_color = 0x1699d771; // Blue'ish
+    uint32_t _bleed_color = 0xbe310e62; // Red'ish
+
+    std::string _label_style = "default";
+};
+
+} // namespace Inkscape
+
+#endif // SEEN_CANVAS_PAGE_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/control/canvas-temporary-item-list.cpp b/src/display/control/canvas-temporary-item-list.cpp
new file mode 100644
index 0000000..6ff516d
--- /dev/null
+++ b/src/display/control/canvas-temporary-item-list.cpp
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Provides a class that can contain active TemporaryItem's on a desktop
+ * Code inspired by message-stack.cpp
+ *
+ * Authors:
+ *   Johan Engelen
+ *
+ * Copyright (C) Johan Engelen 2008 <j.b.c.engelen@utwente.nl>
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <algorithm>
+#include "canvas-temporary-item.h"
+#include "canvas-temporary-item-list.h"
+
+namespace Inkscape {
+namespace Display {
+
+TemporaryItemList::~TemporaryItemList()
+{
+    // delete all items in list so the timeouts are removed
+    for (auto tempitem : itemlist) {
+        delete tempitem;
+    }
+    itemlist.clear();
+}
+
+// Note that TemporaryItem or TemporaryItemList is responsible for deletion and such, so this return pointer can safely be ignored.
+TemporaryItem *TemporaryItemList::add_item(CanvasItem *item, int lifetime_msecs)
+{
+    // beware of strange things happening due to very short timeouts
+    TemporaryItem *tempitem;
+    if (lifetime_msecs == 0)
+        tempitem = new TemporaryItem(item, 0);
+    else {
+        tempitem = new TemporaryItem(item, lifetime_msecs);
+        tempitem->signal_timeout.connect([this] (auto tempitem) { itemlist.remove(tempitem); });
+        // no need to delete the item, it does that itself after signal_timeout.emit() completes
+    }
+
+    itemlist.emplace_back(tempitem);
+    return tempitem;
+}
+
+void TemporaryItemList::delete_item(TemporaryItem *tempitem)
+{
+    // check if the item is in the list, if so, delete it. (in other words, don't wait for the item to delete itself)
+    auto it = std::find_if(itemlist.begin(), itemlist.end(), [=] (auto *item) {
+        return item == tempitem;
+    });
+
+    if (it != itemlist.end()) {
+        itemlist.erase(it);
+        delete tempitem;
+    }
+}
+
+} // namespace Display
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-temporary-item-list.h b/src/display/control/canvas-temporary-item-list.h
new file mode 100644
index 0000000..1321cbf
--- /dev/null
+++ b/src/display/control/canvas-temporary-item-list.h
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef INKSCAPE_CANVAS_TEMPORARY_ITEM_LIST_H
+#define INKSCAPE_CANVAS_TEMPORARY_ITEM_LIST_H
+
+/*
+ * Authors:
+ *   Johan Engelen
+ *
+ * Copyright (C) Johan Engelen 2008 <j.b.c.engelen@utwente.nl>
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <list>
+
+class SPDesktop;
+
+namespace Inkscape {
+
+class CanvasItem;
+
+namespace Display {
+
+class TemporaryItem;
+
+/**
+ * Provides a class that can contain active TemporaryItems on a desktop.
+ */
+class TemporaryItemList final
+{
+public:
+    TemporaryItemList() = default;
+    TemporaryItemList(TemporaryItemList const &) = delete;
+    TemporaryItemList &operator=(TemporaryItemList const &) = delete;
+    ~TemporaryItemList();
+
+    TemporaryItem* add_item(CanvasItem *item, int lifetime_msecs);
+    void           delete_item(TemporaryItem *tempitem);
+
+protected:
+    std::list<TemporaryItem *> itemlist; ///< List of temp items.
+};
+
+} // namespace Display
+} // namespace Inkscape
+
+#endif // INKSCAPE_CANVAS_TEMPORARY_ITEM_LIST_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-temporary-item.cpp b/src/display/control/canvas-temporary-item.cpp
new file mode 100644
index 0000000..d95ad21
--- /dev/null
+++ b/src/display/control/canvas-temporary-item.cpp
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Provides a class that can contain active TemporaryItem's on a desktop
+ * When the object is deleted, it also deletes the canvasitem it contains!
+ * This object should be created/managed by a TemporaryItemList.
+ * After its lifetime, it fires the timeout signal, afterwards *it deletes itself*.
+ *
+ * (part of code inspired by message-stack.cpp)
+ *
+ * Authors:
+ *   Johan Engelen
+ *
+ * Copyright (C) Johan Engelen 2008 <j.b.c.engelen@utwente.nl>
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <glibmm/main.h>
+
+#include "canvas-temporary-item.h"
+#include "canvas-item.h"
+
+namespace Inkscape {
+namespace Display {
+
+TemporaryItem::TemporaryItem(CanvasItem *item, int lifetime_msecs)
+    : canvasitem(std::move(item))
+{
+    // Zero lifetime means stay forever, so do not add timeout event.
+    if (lifetime_msecs > 0) {
+        timeout_conn = Glib::signal_timeout().connect([this] {
+            signal_timeout.emit(this);
+            delete this;
+            return false;
+        }, lifetime_msecs);
+    }
+}
+
+TemporaryItem::~TemporaryItem() = default;
+
+} // namespace Display
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/canvas-temporary-item.h b/src/display/control/canvas-temporary-item.h
new file mode 100644
index 0000000..4ce2787
--- /dev/null
+++ b/src/display/control/canvas-temporary-item.h
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef INKSCAPE_CANVAS_TEMPORARY_ITEM_H
+#define INKSCAPE_CANVAS_TEMPORARY_ITEM_H
+
+/*
+ * Authors:
+ *   Johan Engelen
+ *
+ * Copyright (C) Johan Engelen 2008 <j.b.c.engelen@utwente.nl>
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <sigc++/signal.h>
+#include <sigc++/connection.h>
+#include "display/control/canvas-item-ptr.h"
+#include "helper/auto-connection.h"
+
+namespace Inkscape {
+
+class CanvasItem;
+
+namespace Display {
+
+/**
+ * Provides a class to put a canvasitem temporarily on-canvas.
+ */
+class TemporaryItem final
+{
+public:
+    TemporaryItem(CanvasItem *item, int lifetime_msecs);
+    TemporaryItem(TemporaryItem const &) = delete;
+    TemporaryItem &operator=(TemporaryItem const &) = delete;
+    ~TemporaryItem();
+
+    sigc::signal<void (TemporaryItem *)> signal_timeout;
+
+protected:
+    friend class TemporaryItemList;
+
+    CanvasItemPtr<CanvasItem> canvasitem; ///< The item we are holding on to.
+    auto_connection timeout_conn;
+};
+
+} //namespace Display
+} //namespace Inkscape
+
+#endif // INKSCAPE_CANVAS_TEMPORARY_ITEM_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/control/snap-indicator.cpp b/src/display/control/snap-indicator.cpp
new file mode 100644
index 0000000..8672d88
--- /dev/null
+++ b/src/display/control/snap-indicator.cpp
@@ -0,0 +1,648 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Provides a class that shows a temporary indicator on the canvas of where the snap was, and what kind of snap
+ *
+ * Authors:
+ *   Johan Engelen
+ *   Diederik van Lierop
+ *
+ * Copyright (C) Johan Engelen 2009 <j.b.c.engelen@utwente.nl>
+ * Copyright (C) Diederik van Lierop 2010 - 2012 <mail@diedenrezi.nl>
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <glibmm/i18n.h>
+#include <string>
+#include <iomanip>
+#include <unordered_map>
+
+#include "snap-indicator.h"
+
+#include "desktop.h"
+#include "enums.h"
+#include "preferences.h"
+#include "util/units.h"
+#include "document.h"
+
+
+#include "canvas-item-ctrl.h"
+#include "canvas-item-rect.h"
+#include "canvas-item-text.h"
+#include "canvas-item-curve.h"
+
+#include "ui/tools/measure-tool.h"
+
+#define DISTANCE_BG_RADIUS 0.3
+
+namespace Inkscape {
+namespace Display {
+
+static std::map<SnapSourceType, Glib::ustring> source2string = {
+    {SNAPSOURCE_UNDEFINED, _("UNDEFINED")},
+    {SNAPSOURCE_BBOX_CORNER, _("Bounding box corner")},
+    {SNAPSOURCE_BBOX_MIDPOINT, _("Bounding box midpoint")},
+    {SNAPSOURCE_BBOX_EDGE_MIDPOINT, _("Bounding box side midpoint")},
+    {SNAPSOURCE_NODE_SMOOTH, _("Smooth node")},
+    {SNAPSOURCE_NODE_CUSP, _("Cusp node")},
+    {SNAPSOURCE_LINE_MIDPOINT, _("Line midpoint")},
+    {SNAPSOURCE_PATH_INTERSECTION, _("Path intersection")},
+    {SNAPSOURCE_RECT_CORNER, _("Corner")},
+    {SNAPSOURCE_CONVEX_HULL_CORNER, _("Convex hull corner")},
+    {SNAPSOURCE_ELLIPSE_QUADRANT_POINT, _("Quadrant point")},
+    {SNAPSOURCE_NODE_HANDLE, _("Handle")},
+    {SNAPSOURCE_GUIDE, _("Guide")},
+    {SNAPSOURCE_GUIDE_ORIGIN, _("Guide origin")},
+    {SNAPSOURCE_ROTATION_CENTER, _("Object rotation center")},
+    {SNAPSOURCE_OBJECT_MIDPOINT, _("Object midpoint")},
+    {SNAPSOURCE_IMG_CORNER, _("Corner")},
+    {SNAPSOURCE_TEXT_ANCHOR, _("Text anchor")},
+    {SNAPSOURCE_OTHER_HANDLE, _("Handle")},
+    {SNAPSOURCE_GRID_PITCH, _("Multiple of grid spacing")},
+    {SNAPSOURCE_PAGE_CORNER, _("Page corner")},
+    {SNAPSOURCE_PAGE_CENTER, _("Page center")},
+};
+
+static std::map<SnapTargetType, Glib::ustring> target2string = {
+    {SNAPTARGET_UNDEFINED, _("UNDEFINED")},
+    {SNAPTARGET_BBOX_CORNER, _("bounding box corner")},
+    {SNAPTARGET_BBOX_EDGE, _("bounding box side")},
+    {SNAPTARGET_BBOX_EDGE_MIDPOINT, _("bounding box side midpoint")},
+    {SNAPTARGET_BBOX_MIDPOINT, _("bounding box midpoint")},
+    {SNAPTARGET_NODE_SMOOTH, _("smooth node")},
+    {SNAPTARGET_NODE_CUSP, _("cusp node")},
+    {SNAPTARGET_LINE_MIDPOINT, _("line midpoint")},
+    {SNAPTARGET_PATH, _("path")},
+    {SNAPTARGET_PATH_PERPENDICULAR, _("path (perpendicular)")},
+    {SNAPTARGET_PATH_TANGENTIAL, _("path (tangential)")},
+    {SNAPTARGET_PATH_INTERSECTION, _("path intersection")},
+    {SNAPTARGET_PATH_GUIDE_INTERSECTION, _("guide-path intersection")},
+    {SNAPTARGET_PATH_CLIP, _("clip-path")},
+    {SNAPTARGET_PATH_MASK, _("mask-path")},
+    {SNAPTARGET_ELLIPSE_QUADRANT_POINT, _("quadrant point")},
+    {SNAPTARGET_RECT_CORNER, _("corner")},
+    {SNAPTARGET_GRID, _("grid line")},
+    {SNAPTARGET_GRID_INTERSECTION, _("grid intersection")},
+    {SNAPTARGET_GRID_PERPENDICULAR, _("grid line (perpendicular)")},
+    {SNAPTARGET_GUIDE, _("guide")},
+    {SNAPTARGET_GUIDE_INTERSECTION, _("guide intersection")},
+    {SNAPTARGET_GUIDE_ORIGIN, _("guide origin")},
+    {SNAPTARGET_GUIDE_PERPENDICULAR, _("guide (perpendicular)")},
+    {SNAPTARGET_GRID_GUIDE_INTERSECTION, _("grid-guide intersection")},
+    {SNAPTARGET_PAGE_EDGE_BORDER, _("page border")},
+    {SNAPTARGET_PAGE_EDGE_CORNER, _("page corner")},
+    {SNAPTARGET_PAGE_EDGE_CENTER, _("page center")},
+    {SNAPTARGET_PAGE_MARGIN_BORDER, _("page margin border")},
+    {SNAPTARGET_PAGE_MARGIN_CORNER, _("page margin corner")},
+    {SNAPTARGET_PAGE_MARGIN_CENTER, _("page margin center")},
+    {SNAPTARGET_PAGE_BLEED_BORDER, _("page bleed border")},
+    {SNAPTARGET_PAGE_BLEED_CORNER, _("page bleed corner")},
+    {SNAPTARGET_OBJECT_MIDPOINT, _("object midpoint")},
+    {SNAPTARGET_IMG_CORNER, _("corner")},
+    {SNAPTARGET_ROTATION_CENTER, _("object rotation center")},
+    {SNAPTARGET_TEXT_ANCHOR, _("text anchor")},
+    {SNAPTARGET_TEXT_BASELINE, _("text baseline")},
+    {SNAPTARGET_CONSTRAINED_ANGLE, _("constrained angle")},
+    {SNAPTARGET_CONSTRAINT, _("constraint")},
+};
+
+SnapIndicator::SnapIndicator(SPDesktop * desktop)
+    :   _snaptarget(nullptr),
+        _snaptarget_tooltip(nullptr),
+        _snaptarget_bbox(nullptr),
+        _snapsource(nullptr),
+        _snaptarget_is_presnap(false),
+        _desktop(desktop)
+{
+}
+
+SnapIndicator::~SnapIndicator()
+{
+    // remove item that might be present
+    remove_snaptarget();
+    remove_snapsource();
+}
+
+void
+SnapIndicator::set_new_snaptarget(Inkscape::SnappedPoint const &p, bool pre_snap)
+{
+    remove_snaptarget(); //only display one snaptarget at a time
+
+    g_assert(_desktop != nullptr);
+
+    if (!p.getSnapped()) {
+        return; // If we haven't snapped, then it is of no use to draw a snapindicator
+    }
+
+    if (p.getTarget() == SNAPTARGET_CONSTRAINT) {
+        // This is not a real snap, although moving along the constraint did affect the mouse pointer's position.
+        // Maybe we should only show a snap indicator when the user explicitly asked for a constraint by pressing ctrl?
+        // We should not show a snap indicator when stretching a selection box, which is also constrained. That would be
+        // too much information.
+        return;
+    }
+
+    bool is_alignment = p.getAlignmentTarget().has_value();
+    bool is_distribution = p.getTarget() & SNAPTARGET_DISTRIBUTION_CATEGORY;
+
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    double scale = prefs->getDouble("/tools/measure/scale", 100.0) / 100.0;
+
+    bool value = prefs->getBool("/options/snapindicator/value", true);
+
+    if (value) {
+        Glib::ustring target_name = _("UNDEFINED");
+        Glib::ustring source_name = _("UNDEFINED");
+
+        if (!is_alignment && !is_distribution) {
+            if (target2string.find(p.getTarget()) == target2string.end())
+                g_warning("Target type %i not present in target2string", p.getTarget());
+
+            if (source2string.find(p.getSource()) == source2string.end())
+                g_warning("Source type %i not present in target2string", p.getSource());
+
+            target_name = _(target2string[p.getTarget()].c_str());
+            source_name = _(source2string[p.getSource()].c_str());
+        }
+        //std::cout << "Snapped " << source_name << " to " << target_name << std::endl;
+
+        remove_snapsource(); // Don't set both the source and target indicators, as these will overlap
+
+        double timeout_val = prefs->getDouble("/options/snapindicatorpersistence/value", 2.0);
+        if (timeout_val < 0.1) {
+            timeout_val = 0.1; // a zero value would mean infinite persistence (i.e. until new snap occurs)
+            // Besides, negatives values would ....?
+        }
+
+        // TODO: should this be a constant or a separate prefrence
+        // we are using the preference of measure tool here.
+        double fontsize = prefs->getDouble("/tools/measure/fontsize", 10.0);
+
+        if (is_distribution) {
+            make_distribution_indicators(p, fontsize, scale);
+        }
+
+        if (is_alignment) {
+            auto color = pre_snap ? 0x7f7f7fff : get_guide_color(p.getAlignmentTargetType());
+            make_alignment_indicator(p.getPoint(), *p.getAlignmentTarget(), color, fontsize, scale);
+            if (p.getAlignmentTargetType() == SNAPTARGET_ALIGNMENT_INTERSECTION) {
+                make_alignment_indicator(p.getPoint(), *p.getAlignmentTarget2(), color, fontsize, scale);
+            }
+        } 
+
+        _snaptarget_is_presnap = pre_snap;
+ 
+        // Display the snap indicator (i.e. the cross)
+        Inkscape::CanvasItemCtrl *ctrl;
+
+        if (!is_alignment && !is_distribution) {
+            // Display snap indicator at snap target
+            ctrl = new Inkscape::CanvasItemCtrl(_desktop->getCanvasTemp(), Inkscape::CANVAS_ITEM_CTRL_SHAPE_CROSS);
+            ctrl->set_size(11);
+            ctrl->set_stroke( pre_snap ? 0x7f7f7fff : 0xff0000ff);
+            ctrl->set_position(p.getPoint());
+
+            _snaptarget = _desktop->add_temporary_canvasitem(ctrl, timeout_val*1000.0);
+            // The snap indicator will be deleted after some time-out, and sp_canvas_item_dispose
+            // will be called. This will set canvas->current_item to NULL if the snap indicator was
+            // the current item, after which any events will go to the root handler instead of any
+            // item handler. Dragging an object which has just snapped might therefore not be possible
+            // without selecting / repicking it again. To avoid this, we make sure here that the
+            // snap indicator will never be picked, and will therefore never be the current item.
+            // Reported bugs:
+            //   - scrolling when hovering above a pre-snap indicator won't work (for example)
+            //     (https://bugs.launchpad.net/inkscape/+bug/522335/comments/8)
+            //   - dragging doesn't work without repicking
+            //     (https://bugs.launchpad.net/inkscape/+bug/1420301/comments/15)
+            ctrl->set_pickable(false);
+
+            // Display the tooltip, which reveals the type of snap source and the type of snap target
+            Glib::ustring tooltip_str;
+            if ( (p.getSource() != SNAPSOURCE_GRID_PITCH) && (p.getTarget() != SNAPTARGET_UNDEFINED) ) {
+                tooltip_str = source_name + _(" to ") + target_name;
+            } else if (p.getSource() != SNAPSOURCE_UNDEFINED) {
+                tooltip_str = source_name;
+            }
+
+
+            if (!tooltip_str.empty()) {
+                Geom::Point tooltip_pos = p.getPoint();
+                if (dynamic_cast<Inkscape::UI::Tools::MeasureTool *>(_desktop->event_context)) {
+                    // Make sure that the snap tooltips do not overlap the ones from the measure tool
+                    tooltip_pos += _desktop->w2d(Geom::Point(0, -3*fontsize));
+                } else {
+                    tooltip_pos += _desktop->w2d(Geom::Point(0, -2*fontsize));
+                }
+
+                auto canvas_tooltip = new Inkscape::CanvasItemText(_desktop->getCanvasTemp(), tooltip_pos, tooltip_str);
+                canvas_tooltip->set_fontsize(fontsize);
+                canvas_tooltip->set_fill(0xffffffff);
+                canvas_tooltip->set_background(pre_snap ? 0x33337f40 : 0x33337f7f);
+
+                _snaptarget_tooltip = _desktop->add_temporary_canvasitem(canvas_tooltip, timeout_val*1000.0);
+            }
+
+            // Display the bounding box, if we snapped to one
+            Geom::OptRect const bbox = p.getTargetBBox();
+            if (bbox) {
+                auto box = new Inkscape::CanvasItemRect(_desktop->getCanvasTemp(), *bbox);
+                box->set_stroke(pre_snap ? 0x7f7f7fff : 0xff0000ff);
+                box->set_dashed(true);
+                box->set_pickable(false); // Is false by default.
+                box->lower_to_bottom();
+                _snaptarget_bbox = _desktop->add_temporary_canvasitem(box, timeout_val*1000.0);
+            }
+        }
+    }
+}
+
+void
+SnapIndicator::remove_snaptarget(bool only_if_presnap)
+{
+    if (only_if_presnap && !_snaptarget_is_presnap) {
+        return;
+    }
+
+    if (_snaptarget) {
+        _desktop->remove_temporary_canvasitem(_snaptarget);
+        _snaptarget = nullptr;
+        _snaptarget_is_presnap = false;
+    }
+
+    if (_snaptarget_tooltip) {
+        _desktop->remove_temporary_canvasitem(_snaptarget_tooltip);
+        _snaptarget_tooltip = nullptr;
+    }
+
+    if (_snaptarget_bbox) {
+        _desktop->remove_temporary_canvasitem(_snaptarget_bbox);
+        _snaptarget_bbox = nullptr;
+    }
+
+    for (auto *item : _alignment_snap_indicators) {
+        _desktop->remove_temporary_canvasitem(item);
+    }
+    _alignment_snap_indicators.clear();
+
+    for (auto *item : _distribution_snap_indicators) {
+        _desktop->remove_temporary_canvasitem(item);
+    }
+    _distribution_snap_indicators.clear();
+}
+
+void
+SnapIndicator::set_new_snapsource(Inkscape::SnapCandidatePoint const &p)
+{
+    remove_snapsource();
+
+    g_assert(_desktop != nullptr); // If this fails, then likely setup() has not been called on the snap manager (see snap.cpp -> setup())
+
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    bool value = prefs->getBool("/options/snapindicator/value", true);
+
+    if (value) {
+        auto ctrl = new Inkscape::CanvasItemCtrl(_desktop->getCanvasTemp(), Inkscape::CANVAS_ITEM_CTRL_SHAPE_CIRCLE);
+        ctrl->set_size(7);
+        ctrl->set_stroke(0xff0000ff);
+        ctrl->set_position(p.getPoint());
+        _snapsource = _desktop->add_temporary_canvasitem(ctrl, 1000);
+    }
+}
+
+void
+SnapIndicator::set_new_debugging_point(Geom::Point const &p)
+{
+    g_assert(_desktop != nullptr);
+    auto ctrl = new Inkscape::CanvasItemCtrl(_desktop->getCanvasTemp(), Inkscape::CANVAS_ITEM_CTRL_SHAPE_DIAMOND);
+    ctrl->set_size(11);
+    ctrl->set_stroke(0x00ff00ff);
+    ctrl->set_position(p);
+    _debugging_points.push_back(_desktop->add_temporary_canvasitem(ctrl, 5000));
+}
+
+void
+SnapIndicator::remove_snapsource()
+{
+    if (_snapsource) {
+        _desktop->remove_temporary_canvasitem(_snapsource);
+        _snapsource = nullptr;
+    }
+}
+
+void
+SnapIndicator::remove_debugging_points()
+{
+    for (std::list<TemporaryItem *>::const_iterator i = _debugging_points.begin(); i != _debugging_points.end(); ++i) {
+        _desktop->remove_temporary_canvasitem(*i);
+    }
+    _debugging_points.clear();
+}
+
+guint32 SnapIndicator::get_guide_color(SnapTargetType t)
+{
+    switch(t) {
+        case SNAPTARGET_ALIGNMENT_BBOX_CORNER:
+        case SNAPTARGET_ALIGNMENT_BBOX_MIDPOINT:
+        case SNAPTARGET_ALIGNMENT_BBOX_EDGE_MIDPOINT:
+            return 0xff0000ff;
+        case SNAPTARGET_ALIGNMENT_PAGE_EDGE_CENTER:
+        case SNAPTARGET_ALIGNMENT_PAGE_EDGE_CORNER:
+        case SNAPTARGET_ALIGNMENT_PAGE_MARGIN_CENTER:
+        case SNAPTARGET_ALIGNMENT_PAGE_MARGIN_CORNER:
+        case SNAPTARGET_ALIGNMENT_PAGE_BLEED_CORNER:
+            return 0x00ff00ff;
+        case SNAPTARGET_ALIGNMENT_HANDLE:
+            return 0x0000ffff;
+        case SNAPTARGET_ALIGNMENT_INTERSECTION:
+            return 0xd13bd1ff;
+        default:
+            g_warning("Alignment guide color not handled %i", t);
+            return 0x000000ff;
+    }
+}
+
+std::pair<Geom::Coord, int> get_y_and_sign(Geom::Rect const &source, Geom::Rect const &target, double const offset)
+{
+    Geom::Coord y;
+    int sign;
+
+    // We add a margin of 5px here to make sure that very small movements of mouse
+    // pointer do not cause the position of distribution indicator to change.
+    if (source.midpoint().y() < target.midpoint().y() + 5) {
+        y = source.max().y() + offset;
+        sign = 1;
+    } else {
+        y = source.min().y() - offset;
+        sign = -1;
+    }
+
+    return {y, sign};
+}
+
+std::pair<Geom::Coord, int> get_x_and_sign(Geom::Rect const &source, Geom::Rect const &target, double const offset)
+{
+    Geom::Coord x;
+    int sign;
+
+    // We add a margin of 5px here to make sure that very small movements of mouse
+    // pointer do not cause the position of distribution indicator to change.
+    if (source.midpoint().x() < target.midpoint().x() + 5) {
+        x = source.max().x() + offset;
+        sign = 1;
+    } else {
+        x = source.min().x() - offset;
+        sign = -1;
+    }
+
+    return {x, sign};
+}
+
+void SnapIndicator::make_alignment_indicator(Geom::Point const &p1, Geom::Point const &p2, guint32 color, double fontsize, double scale)
+{
+    //make sure the line is straight
+    g_assert(p1.x() == p2.x() || p1.y() == p2.y());
+
+    Preferences *prefs = Preferences::get();
+    bool show_distance = prefs->getBool("/options/snapindicatordistance/value", false);
+
+    Inkscape::CanvasItemCurve *line;
+
+    auto ctrl = new Inkscape::CanvasItemCtrl(_desktop->getCanvasTemp(), Inkscape::CANVAS_ITEM_CTRL_SHAPE_CIRCLE);
+    ctrl->set_size(7);
+    ctrl->set_mode(Inkscape::CanvasItemCtrlMode::CANVAS_ITEM_CTRL_MODE_COLOR);
+    ctrl->set_stroke(0xffffffff);
+    ctrl->set_fill(color);
+    ctrl->set_position(p1);
+    ctrl->set_pickable(false);
+    _alignment_snap_indicators.push_back(_desktop->add_temporary_canvasitem(ctrl, 0));
+
+    ctrl = new Inkscape::CanvasItemCtrl(_desktop->getCanvasTemp(), Inkscape::CANVAS_ITEM_CTRL_SHAPE_CIRCLE);
+    ctrl->set_size(7);
+    ctrl->set_mode(Inkscape::CanvasItemCtrlMode::CANVAS_ITEM_CTRL_MODE_COLOR);
+    ctrl->set_stroke(0xffffffff);
+    ctrl->set_fill(color);
+    ctrl->set_position(p2);
+    ctrl->set_pickable(false);
+    _alignment_snap_indicators.push_back(_desktop->add_temporary_canvasitem(ctrl, 0));
+
+    auto dist = Geom::L2(p2 - p1);
+    double offset = (fontsize + 5) / _desktop->current_zoom();
+    if (show_distance && dist > 2 * offset) {
+        auto direction = Geom::unit_vector(p1 - p2);
+        auto text_pos = (p1 + p2)/2;
+
+        Glib::ustring unit_name = _desktop->doc()->getDisplayUnit()->abbr.c_str();
+        if (!unit_name.compare("")) {
+            unit_name = DEFAULT_UNIT_NAME;
+        }
+
+        dist = Inkscape::Util::Quantity::convert(dist, "px", unit_name);
+
+        Glib::ustring distance = Glib::ustring::format(std::fixed, std::setprecision(1), std::noshowpoint, scale*dist);
+        
+        auto text = new Inkscape::CanvasItemText(_desktop->getCanvasTemp(), text_pos, distance);
+        text->set_fontsize(fontsize);
+        text->set_fill(color);
+        text->set_background(0xffffffc8);
+        text->set_bg_radius(DISTANCE_BG_RADIUS);
+        text->set_anchor({0.5, 0.5});
+        _alignment_snap_indicators.push_back(_desktop->add_temporary_canvasitem(text, 0));
+
+        auto temp_point = text_pos + offset*direction;
+        line = new Inkscape::CanvasItemCurve(_desktop->getCanvasTemp(), p1, temp_point);
+        line->set_stroke(color);
+        line->set_bg_alpha(1.0f);
+        _alignment_snap_indicators.push_back(_desktop->add_temporary_canvasitem(line, 0));
+
+        temp_point = text_pos - offset*direction;
+        line = new Inkscape::CanvasItemCurve(_desktop->getCanvasTemp(), temp_point, p2);
+        line->set_stroke(color);
+        line->set_bg_alpha(1.0f);
+        _alignment_snap_indicators.push_back(_desktop->add_temporary_canvasitem(line, 0));
+    } else {
+        line = new Inkscape::CanvasItemCurve(_desktop->getCanvasTemp(), p1, p2);
+        line->set_stroke(color);
+        line->set_bg_alpha(1.0f);
+        _alignment_snap_indicators.push_back(_desktop->add_temporary_canvasitem(line, 0));
+    }
+}
+
+Inkscape::CanvasItemCurve* SnapIndicator::make_stub_line_v(Geom::Point const & p) 
+{
+    Geom::Coord length = 10/_desktop->current_zoom();
+    auto line = new Inkscape::CanvasItemCurve(_desktop->getCanvasTemp(), p + Geom::Point(0, length/2), p - Geom::Point(0, length/2));
+    line->set_stroke(0xff5f1fff);
+    return line;
+}
+
+Inkscape::CanvasItemCurve* SnapIndicator::make_stub_line_h(Geom::Point const & p) 
+{
+    Geom::Coord length = 10/_desktop->current_zoom();
+    auto line = new Inkscape::CanvasItemCurve(_desktop->getCanvasTemp(), p + Geom::Point(length/2, 0), p - Geom::Point(length/2, 0));
+    line->set_stroke(0xff5f1fff);
+    return line;
+}
+
+void SnapIndicator::make_distribution_indicators(SnappedPoint const &p,
+                                                double fontsize,
+                                                double scale)
+{
+    Preferences *prefs = Preferences::get();
+    bool show_distance = prefs->getBool("/options/snapindicatordistance/value", false);
+
+    guint32 color = 0xff5f1fff;
+    guint32 text_fill = 0xffffffff;
+    guint32 text_bg = 0xff5f1fff; //0x33337f7f
+    Geom::Point text_pos;
+    double text_offset = (fontsize * 2);
+    // double line_offset = 5/_desktop->current_zoom();
+    double line_offset = 0;
+
+    Glib::ustring unit_name = _desktop->doc()->getDisplayUnit()->abbr.c_str();
+    if (!unit_name.compare("")) {
+        unit_name = DEFAULT_UNIT_NAME;
+    }
+    auto equal_dist = Inkscape::Util::Quantity::convert(p.getDistributionDistance(), "px", unit_name);
+    Glib::ustring distance = Glib::ustring::format(std::fixed, std::setprecision(1), std::noshowpoint, scale*equal_dist);
+
+    switch (p.getTarget()) {
+        case SNAPTARGET_DISTRIBUTION_Y:
+        case SNAPTARGET_DISTRIBUTION_X:
+        case SNAPTARGET_DISTRIBUTION_RIGHT:
+        case SNAPTARGET_DISTRIBUTION_LEFT:
+        case SNAPTARGET_DISTRIBUTION_UP:
+        case SNAPTARGET_DISTRIBUTION_DOWN: {
+            Geom::Point p1, p2;
+            Inkscape::CanvasItemCurve *point1, *point2;
+
+            for (auto it = p.getBBoxes().begin(); it + 1 != p.getBBoxes().end(); it++) {
+                switch (p.getTarget()) {
+                    case SNAPTARGET_DISTRIBUTION_RIGHT: 
+                    case SNAPTARGET_DISTRIBUTION_LEFT:
+                    case SNAPTARGET_DISTRIBUTION_X: {
+                        auto [y, sign] = get_y_and_sign(*it, *std::next(it), 5/_desktop->current_zoom());
+                        p1 = Geom::Point(it->max().x() + line_offset, y);
+                        p2 = Geom::Point(std::next(it)->min().x() - line_offset, y);
+                        text_pos = (p1 + p2)/2 + _desktop->w2d(Geom::Point(0, sign*text_offset));
+
+                        point1 = make_stub_line_v(p1);
+                        point2 = make_stub_line_v(p2);
+                        break;
+                    }
+
+                    case SNAPTARGET_DISTRIBUTION_DOWN:
+                    case SNAPTARGET_DISTRIBUTION_UP:
+                    case SNAPTARGET_DISTRIBUTION_Y: {
+                        auto [x, sign] = get_x_and_sign(*it, *std::next(it), 5/_desktop->current_zoom());
+                        p1 = Geom::Point(x, it->max().y() + line_offset);
+                        p2 = Geom::Point(x, std::next(it)->min().y() - line_offset);
+                        text_pos = (p1 + p2)/2 + _desktop->w2d(Geom::Point(sign*text_offset, 0));
+
+                        point1 = make_stub_line_h(p1);
+                        point2 = make_stub_line_h(p2);
+                        break;
+                    }
+                }
+
+                _distribution_snap_indicators.push_back(_desktop->add_temporary_canvasitem(point1, 0));
+                _distribution_snap_indicators.push_back(_desktop->add_temporary_canvasitem(point2, 0));
+
+                auto line1 = new Inkscape::CanvasItemCurve(_desktop->getCanvasTemp(), p1, p2);
+                line1->set_stroke(color);
+                line1->set_width(2);
+                _distribution_snap_indicators.push_back(_desktop->add_temporary_canvasitem(line1, 0));
+
+                if (show_distance) {
+                    auto text = new Inkscape::CanvasItemText(_desktop->getCanvasTemp(), text_pos, distance);
+                    text->set_fontsize(fontsize);
+                    text->set_fill(text_fill);
+                    text->set_background(text_bg);
+                    text->set_bg_radius(DISTANCE_BG_RADIUS);
+                    text->set_anchor({0.5, 0.5});
+                    _distribution_snap_indicators.push_back(_desktop->add_temporary_canvasitem(text, 0));
+                }
+            }
+        break;
+        }
+        case SNAPTARGET_DISTRIBUTION_XY: {
+            Geom::Point p1, p2;
+            Inkscape::CanvasItemCurve *point1, *point2;
+
+            auto equal_dist2 = Inkscape::Util::Quantity::convert(p.getDistributionDistance2(), "px", unit_name);
+            Glib::ustring distance2 = Glib::ustring::format(std::fixed, std::setprecision(1), std::noshowpoint, scale*equal_dist2);
+
+            for (auto it = p.getBBoxes().begin(); it + 1 != p.getBBoxes().end(); it++) {
+                auto [y, sign] = get_y_and_sign(*it, *std::next(it), 5/_desktop->current_zoom());
+                p1 = Geom::Point(it->max().x() + line_offset, y);
+                p2 = Geom::Point(std::next(it)->min().x() - line_offset, y);
+                text_pos = (p1 + p2)/2 + _desktop->w2d(Geom::Point(0, sign*text_offset));
+
+                point1 = make_stub_line_v(p1);
+                point2 = make_stub_line_v(p2);
+
+                _distribution_snap_indicators.push_back(_desktop->add_temporary_canvasitem(point1, 0));
+                _distribution_snap_indicators.push_back(_desktop->add_temporary_canvasitem(point2, 0));
+
+                auto line1 = new Inkscape::CanvasItemCurve(_desktop->getCanvasTemp(), p1, p2);
+                line1->set_stroke(color);
+                line1->set_width(2);
+                _distribution_snap_indicators.push_back(_desktop->add_temporary_canvasitem(line1, 0));
+
+                if (show_distance) {
+                    auto text = new Inkscape::CanvasItemText(_desktop->getCanvasTemp(), text_pos, distance);
+                    text->set_fontsize(fontsize);
+                    text->set_fill(text_fill);
+                    text->set_background(text_bg);
+                    text->set_bg_radius(DISTANCE_BG_RADIUS);
+                    text->set_anchor({0.5, 0.5});
+                    _distribution_snap_indicators.push_back(_desktop->add_temporary_canvasitem(text, 0));
+                }
+            }
+
+            for (auto it = p.getBBoxes2().begin(); it + 1 != p.getBBoxes2().end(); it++) {
+                auto [x, sign] = get_x_and_sign(*it, *std::next(it), 5/_desktop->current_zoom());
+                p1 = Geom::Point(x, it->max().y() + line_offset);
+                p2 = Geom::Point(x, std::next(it)->min().y() - line_offset);
+                text_pos = (p1 + p2)/2 + _desktop->w2d(Geom::Point(sign*text_offset, 0));
+
+                point1 = make_stub_line_h(p1);
+                point2 = make_stub_line_h(p2);
+
+                _distribution_snap_indicators.push_back(_desktop->add_temporary_canvasitem(point1, 0));
+                _distribution_snap_indicators.push_back(_desktop->add_temporary_canvasitem(point2, 0));
+
+                auto line1 = new Inkscape::CanvasItemCurve(_desktop->getCanvasTemp(), p1, p2);
+                line1->set_stroke(color);
+                line1->set_width(2);
+                _distribution_snap_indicators.push_back(_desktop->add_temporary_canvasitem(line1, 0));
+
+                if (show_distance) {
+                    auto text = new Inkscape::CanvasItemText(_desktop->getCanvasTemp(), text_pos, distance2);
+                    text->set_fontsize(fontsize);
+                    text->set_fill(text_fill);
+                    text->set_background(text_bg);
+                    text->set_bg_radius(DISTANCE_BG_RADIUS);
+                    text->set_anchor({0.5, 0.5});
+                    _distribution_snap_indicators.push_back(_desktop->add_temporary_canvasitem(text, 0));
+                }
+            }
+
+            break;
+        }
+    }
+}
+
+} //namespace Display
+} /* namespace Inkscape */
+
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=4:softtabstop=4 :
diff --git a/src/display/control/snap-indicator.h b/src/display/control/snap-indicator.h
new file mode 100644
index 0000000..ca4721b
--- /dev/null
+++ b/src/display/control/snap-indicator.h
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef INKSCAPE_DISPLAY_SNAP_INDICATOR_H
+#define INKSCAPE_DISPLAY_SNAP_INDICATOR_H
+
+/**
+ * @file
+ * Provides a class that shows a temporary indicator on the canvas of where the snap was, and what kind of snap
+ */
+/*
+ * Authors:
+ *   Johan Engelen
+ *   Diederik van Lierop
+ *
+ * Copyright (C) Johan Engelen 2008 <j.b.c.engelen@utwente.nl>
+ * Copyright (C) Diederik van Lierop 2010 <mail@diedenrezi.nl>
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "snap-enums.h"
+#include "snapped-point.h"
+#include "display/control/canvas-item-curve.h"
+
+#include <glib.h>
+#include <glibmm/i18n.h>
+
+class SPDesktop;
+
+namespace Inkscape {
+namespace Display {
+
+class TemporaryItem;
+
+class SnapIndicator  {
+public:
+    SnapIndicator(SPDesktop *desktop);
+    virtual ~SnapIndicator();
+
+    void set_new_snaptarget(Inkscape::SnappedPoint const &p, bool pre_snap = false);
+    void remove_snaptarget(bool only_if_presnap = false);
+
+    void set_new_snapsource(Inkscape::SnapCandidatePoint const &p);
+    void remove_snapsource();
+
+    void set_new_debugging_point(Geom::Point const &p);
+    void remove_debugging_points();
+
+protected:
+    TemporaryItem *_snaptarget;
+    TemporaryItem *_snaptarget_tooltip;
+    TemporaryItem *_snaptarget_bbox;
+    TemporaryItem *_snapsource;
+
+    std::list<TemporaryItem *> _alignment_snap_indicators;
+    std::list<TemporaryItem *> _distribution_snap_indicators;
+    std::list<TemporaryItem *> _debugging_points;
+    bool _snaptarget_is_presnap;
+    SPDesktop *_desktop;
+
+private:
+    SnapIndicator(const SnapIndicator&) = delete;
+    SnapIndicator& operator=(const SnapIndicator&) = delete;
+
+    void make_distribution_indicators(SnappedPoint const &p, double fontsize, double scale);
+    void make_alignment_indicator(Geom::Point const &p1, Geom::Point const &p2, guint32 color, double fontsize, double scale);
+    guint32 get_guide_color(SnapTargetType t);
+    Inkscape::CanvasItemCurve* make_stub_line_h(Geom::Point const &p);
+    Inkscape::CanvasItemCurve* make_stub_line_v(Geom::Point const &p);
+};
+
+} //namespace Display
+} //namespace Inkscape
+
+#endif
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/curve.cpp b/src/display/curve.cpp
new file mode 100644
index 0000000..a921cc1
--- /dev/null
+++ b/src/display/curve.cpp
@@ -0,0 +1,624 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * Authors:
+ *   Lauris Kaplinski <lauris@kaplinski.com>
+ *   Johan Engelen
+ *
+ * Copyright (C) 2000 Lauris Kaplinski
+ * Copyright (C) 2000-2001 Ximian, Inc.
+ * Copyright (C) 2002 Lauris Kaplinski
+ * Copyright (C) 2008 Johan Engelen
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/curve.h"
+
+#include <glib.h> // g_error
+#include <2geom/sbasis-geometric.h>
+#include <2geom/sbasis-to-bezier.h>
+#include <2geom/point.h>
+#include "helper/geom.h"
+#include "helper/geom-pathstroke.h"
+
+/**
+ * Routines for SPCurve and for its Geom::PathVector
+ */
+
+SPCurve::SPCurve(Geom::Rect const &rect, bool all_four_sides)
+{
+    moveto(rect.corner(0));
+
+    for (int i = 3; i >= 1; --i) {
+        lineto(rect.corner(i));
+    }
+
+    if (all_four_sides) {
+        // When _constrained_ snapping to a path, the 2geom::SimpleCrosser will be invoked which doesn't consider the closing segment.
+        // of a path. Consequently, in case we want to snap to for example the page border, we must provide all four sides of the
+        // rectangle explicitly
+        lineto(rect.corner(0));
+    } else {
+        // ... instead of just three plus a closing segment
+        closepath();
+    }
+}
+
+void SPCurve::set_pathvector(Geom::PathVector const &new_pathv)
+{
+    _pathv = new_pathv;
+}
+
+Geom::PathVector const &SPCurve::get_pathvector() const
+{
+    return _pathv;
+}
+
+/**
+ * Returns the number of segments of all paths summed.
+ * This count includes the closing line segment of a closed path.
+ */
+size_t SPCurve::get_segment_count() const
+{
+    return _pathv.curveCount();
+}
+
+/**
+ * Returns a list of curves corresponding to the subpaths in \a curve.
+ */
+std::vector<SPCurve> SPCurve::split() const
+{
+    std::vector<SPCurve> result;
+
+    for (auto const &path_it : _pathv) {
+        Geom::PathVector newpathv;
+        newpathv.push_back(path_it);
+        result.emplace_back(std::move(newpathv));
+    }
+
+    return result;
+}
+
+/**
+ * Returns a list of curves of non-overlapping subpath in \a curve.
+ */
+std::vector<SPCurve> SPCurve::split_non_overlapping() const
+{
+    std::vector<SPCurve> result;
+
+    auto curves = Inkscape::split_non_intersecting_paths(Geom::PathVector(_pathv));
+
+    for (auto &curve : curves) {
+        result.emplace_back(std::move(curve));
+    }
+
+    return result;
+}
+
+/**
+ * Transform all paths in curve by matrix.
+ */
+void SPCurve::transform(Geom::Affine const &m)
+{
+    _pathv *= m;
+}
+
+/**
+ * Return a copy of the curve with all paths transformed by matrix.
+ */
+SPCurve SPCurve::transformed(const Geom::Affine &m) const
+{
+    return SPCurve(_pathv * m);
+}
+
+/**
+ * Set curve to empty curve.
+ * In more detail: this clears the internal pathvector from all its paths.
+ */
+void SPCurve::reset()
+{
+    _pathv.clear();
+}
+
+/** Several consecutive movetos are ALLOWED
+ *  Ref: http://www.w3.org/TR/SVG11/implnote.html#PathElementImplementationNotes
+ * (first subitem of the item about zero-length path segments) */
+/**
+ * Calls SPCurve::moveto() with point made of given coordinates.
+ */
+void SPCurve::moveto(double x, double y)
+{
+    moveto(Geom::Point(x, y));
+}
+
+/**
+ * Perform a moveto to a point, thus starting a new subpath.
+ * Point p must be finite.
+ */
+void SPCurve::moveto(Geom::Point const &p)
+{
+    Geom::Path path(p);
+    path.setStitching(true);
+    _pathv.push_back(path);
+}
+
+/**
+ * Adds a line to the current subpath.
+ * Point p must be finite.
+ */
+void SPCurve::lineto(Geom::Point const &p)
+{
+    if (_pathv.empty()) {
+        g_message("SPCurve::lineto - path is empty!");
+    } else {
+        _pathv.back().appendNew<Geom::LineSegment>(p);
+    }
+}
+/**
+ * Calls SPCurve::lineto( Geom::Point(x,y) )
+ */
+void SPCurve::lineto(double x, double y)
+{
+    lineto(Geom::Point(x, y));
+}
+
+/**
+ * Adds a quadratic bezier segment to the current subpath.
+ * All points must be finite.
+ */
+void SPCurve::quadto(Geom::Point const &p1, Geom::Point const &p2)
+{
+    if (_pathv.empty()) {
+        g_message("SPCurve::quadto - path is empty!");
+    } else {
+        _pathv.back().appendNew<Geom::QuadraticBezier>(p1, p2);
+    }
+}
+/**
+ * Calls SPCurve::quadto( Geom::Point(x1,y1), Geom::Point(x2,y2) )
+ * All coordinates must be finite.
+ */
+void SPCurve::quadto(double x1, double y1, double x2, double y2)
+{
+    quadto(Geom::Point(x1, y1), Geom::Point(x2, y2));
+}
+
+/**
+ * Adds a bezier segment to the current subpath.
+ * All points must be finite.
+ */
+void SPCurve::curveto(Geom::Point const &p0, Geom::Point const &p1, Geom::Point const &p2)
+{
+    if (_pathv.empty()) {
+        g_message("SPCurve::curveto - path is empty!");
+    } else {
+        _pathv.back().appendNew<Geom::CubicBezier>(p0, p1, p2);
+    }
+}
+/**
+ * Calls SPCurve::curveto( Geom::Point(x0,y0), Geom::Point(x1,y1), Geom::Point(x2,y2) )
+ * All coordinates must be finite.
+ */
+void SPCurve::curveto(double x0, double y0, double x1, double y1, double x2, double y2)
+{
+    curveto(Geom::Point(x0, y0), Geom::Point(x1, y1), Geom::Point(x2, y2));
+}
+
+/**
+ * Close current subpath by possibly adding a line between start and end.
+ */
+void SPCurve::closepath()
+{
+    if (_pathv.empty()) {
+        g_message("%s - path is empty", __PRETTY_FUNCTION__);
+    } else {
+        _pathv.back().close(true);
+    }
+}
+
+/** Like SPCurve::closepath() but sets the end point of the last subpath
+ *  to the subpath start point instead of adding a new lineto.
+ *
+ *  Used for freehand drawing when the user draws back to the start point.
+ */
+void SPCurve::closepath_current()
+{
+    if (_pathv.back().size() > 0 && dynamic_cast<Geom::LineSegment const *>(&_pathv.back().back_open())) {
+        _pathv.back().erase_last();
+    } else {
+        _pathv.back().setFinal(_pathv.back().initialPoint());
+    }
+    _pathv.back().close(true);
+}
+
+/**
+ * True if no paths are in curve. If it only contains a path with only a moveto, the path is considered NON-empty
+ */
+bool SPCurve::is_empty() const
+{
+    return _pathv.empty();
+}
+
+/**
+ * True if paths are in curve. If it only contains a path with only a moveto, the path is considered as unset FALSE
+ */
+bool SPCurve::is_unset() const
+{
+    return get_segment_count() == 0;
+}
+
+/**
+ * True iff all subpaths are closed.
+ * Returns false if the curve is empty.
+ */
+bool SPCurve::is_closed() const
+{
+    if (is_empty()) {
+        return false;
+    } 
+    
+    for (auto const &it : _pathv) {
+        if (!it.closed()) {
+            return false;
+        }
+    }
+    
+    return true;    
+}
+
+/**
+ * True if both curves are equal
+ */
+bool SPCurve::is_equal(SPCurve const *other) const
+{
+    return other && _pathv == other->get_pathvector();
+}
+
+/**
+ * True if both curves are near
+ */
+bool SPCurve::is_similar(SPCurve const *other, double precision) const
+{
+    return other && pathv_similar(_pathv, other->get_pathvector(), precision);
+}
+
+/**
+ * Return last pathsegment (possibly the closing path segment) of the last path in PathVector or NULL.
+ * If the last path is empty (contains only a moveto), the function returns NULL
+ */
+Geom::Curve const *SPCurve::last_segment() const
+{
+    if (is_empty()) {
+        return nullptr;
+    }
+    if (_pathv.back().empty()) {
+        return nullptr;
+    }
+
+    return &_pathv.back().back_default();
+}
+
+/**
+ * Return last path in PathVector or NULL.
+ */
+Geom::Path const *SPCurve::last_path() const
+{
+    if (is_empty()) {
+        return nullptr;
+    }
+
+    return &_pathv.back();
+}
+
+/**
+ * Return first pathsegment in PathVector or NULL.
+ * equal in functionality to SPCurve::first_bpath()
+ */
+Geom::Curve const *SPCurve::first_segment() const
+{
+    if (is_empty()) {
+        return nullptr;
+    }
+    if (_pathv.front().empty()) {
+        return nullptr;
+    }
+
+    return &_pathv.front().front();
+}
+
+/**
+ * Return first path in PathVector or NULL.
+ */
+Geom::Path const *SPCurve::first_path() const
+{
+    if (is_empty()) {
+        return nullptr;
+    }
+
+    return &_pathv.front();
+}
+
+/**
+ * Return first point of first subpath or nothing when the path is empty.
+ */
+std::optional<Geom::Point> SPCurve::first_point() const
+{
+    if (is_empty()) {
+        return {};
+    }
+
+    return _pathv.front().initialPoint();
+}
+
+/**
+ * Return the second point of first subpath or _movePos if curve too short.
+ * If the pathvector is empty, this returns nothing. If the first path is only a moveto, this method
+ * returns the first point of the second path, if it exists. If there is no 2nd path, it returns the
+ * first point of the first path.
+ */
+std::optional<Geom::Point> SPCurve::second_point() const
+{
+    if (is_empty()) {
+        return {};
+    }
+
+    if (_pathv.front().empty()) {
+        // first path is only a moveto
+        // check if there is second path
+        if (_pathv.size() > 1) {
+            return _pathv[1].initialPoint();
+        } else {
+            return _pathv[0].initialPoint();
+        }
+    }
+
+    return _pathv.front()[0].finalPoint();
+}
+
+/**
+ * Return the second-last point of last subpath or first point when that last subpath has only a moveto.
+ */
+std::optional<Geom::Point> SPCurve::penultimate_point() const
+{
+    if (is_empty()) {
+        return {};
+    }
+
+    Geom::Path const &lastpath = _pathv.back();
+    if (!lastpath.empty()) {
+        return lastpath.back_default().initialPoint();
+    } else {
+        return lastpath.initialPoint();
+    }
+}
+
+/**
+ * Return last point of last subpath or nothing when the curve is empty.
+ * If the last path is only a moveto, then return that point.
+ */
+std::optional<Geom::Point> SPCurve::last_point() const
+{
+    if (is_empty()) {
+        return {};
+    }
+
+    return _pathv.back().finalPoint();
+}
+
+/**
+ * Reverse the direction of all paths.
+ */
+void SPCurve::reverse()
+{
+    _pathv.reverse();
+}
+
+/**
+ * Return a copy with the direction of all paths reversed.
+ */
+SPCurve SPCurve::reversed() const
+{
+    return SPCurve(_pathv.reversed());
+}
+
+/**
+ * Append \a curve2 to \a this.
+ * If \a use_lineto is false, simply add all paths in \a curve2 to \a this;
+ * if \a use_lineto is true, combine \a this's last path and \a curve2's first path and add the rest of the paths in \a curve2 to \a this.
+ */
+void SPCurve::append(SPCurve const &curve2, bool use_lineto)
+{
+    append(curve2._pathv, use_lineto);
+}
+
+void SPCurve::append(Geom::PathVector const &pathv, bool use_lineto)
+{
+    if (pathv.empty()) {
+        return;
+    }
+
+    if (use_lineto) {
+        auto it = pathv.begin();
+        if (!_pathv.empty()) {
+            Geom::Path &lastpath = _pathv.back();
+            lastpath.appendNew<Geom::LineSegment>(it->initialPoint());
+            lastpath.append(*it);
+        } else {
+            _pathv.push_back(*it);
+        }
+
+        for (++it; it != pathv.end(); ++it) {
+            _pathv.push_back(*it);
+        }
+    } else {
+        for (auto const &it : pathv) {
+            _pathv.push_back(it);
+        }
+    }
+}
+
+/**
+ * Append \a c1 to \a this with possible fusing of close endpoints. If the end of this curve and the start of c1 are within tolerance distance,
+ * then the startpoint of c1 is moved to the end of this curve and the first subpath of c1 is appended to the last subpath of this curve.
+ * When one of the curves is empty, this curves path becomes the non-empty path.
+ *
+ * @param tolerance Tolerance for endpoint fusion (applied to x and y separately)
+ * @return False if one of the curves (this curve or the argument curve) is closed, true otherwise.
+ */
+bool SPCurve::append_continuous(SPCurve const &c1, double tolerance)
+{
+    if (is_closed() || c1.is_closed()) {
+        return false;
+    }
+
+    if (c1.is_empty()) {
+        return true;
+    }
+
+    if (this->is_empty()) {
+        _pathv = c1._pathv;
+        return true;
+    }
+
+    if ((fabs(last_point()->x() - c1.first_point()->x()) <= tolerance) &&
+        (fabs(last_point()->y() - c1.first_point()->y()) <= tolerance)) {
+    // c1's first subpath can be appended to this curve's last subpath
+        Geom::PathVector::const_iterator path_it = c1._pathv.begin();
+        Geom::Path & lastpath = _pathv.back();
+
+        Geom::Path newfirstpath(*path_it);
+        newfirstpath.setInitial(lastpath.finalPoint());
+        lastpath.append(newfirstpath);
+
+        for (++path_it; path_it != c1._pathv.end(); ++path_it) {
+            _pathv.push_back(*path_it);
+        }
+
+    } else {
+        append(c1, true);
+    }
+
+    return true;
+}
+
+/**
+ * Remove last segment of curve.
+ */
+void SPCurve::backspace()
+{
+    if (is_empty()) {
+        return;
+    }
+
+    if (!_pathv.back().empty()) {
+        _pathv.back().erase_last();
+        _pathv.back().close(false);
+    }
+}
+
+/**
+ * TODO: add comments about what this method does and what assumptions are made and requirements are put on SPCurve
+ (2:08:18 AM) Johan: basically, i convert the path to pw<d2>
+(2:08:27 AM) Johan: then i calculate an offset path
+(2:08:29 AM) Johan: to move the knots
+(2:08:36 AM) Johan: then i add it
+(2:08:40 AM) Johan: then convert back to path
+If I remember correctly, this moves the firstpoint to new_p0, and the lastpoint to new_p1, and moves all nodes in between according to their arclength (interpolates the movement amount)
+ */
+void SPCurve::stretch_endpoints(Geom::Point const &new_p0, Geom::Point const &new_p1)
+{
+    if (is_empty()) {
+        return;
+    }
+
+    auto const offset0 = new_p0 - *first_point();
+    auto const offset1 = new_p1 - *last_point();
+
+    Geom::Piecewise<Geom::D2<Geom::SBasis>> pwd2 = _pathv.front().toPwSb();
+    Geom::Piecewise<Geom::SBasis> arclength = Geom::arcLengthSb(pwd2);
+    if (arclength.lastValue() <= 0) {
+        g_error("SPCurve::stretch_endpoints - arclength <= 0");
+    }
+    arclength *= 1./arclength.lastValue();
+    auto const A = offset0;
+    auto const B = offset1;
+    Geom::Piecewise<Geom::SBasis> offsetx = (arclength*-1.+1)*A[0] + arclength*B[0];
+    Geom::Piecewise<Geom::SBasis> offsety = (arclength*-1.+1)*A[1] + arclength*B[1];
+    Geom::Piecewise<Geom::D2<Geom::SBasis>> offsetpath = Geom::sectionize(Geom::D2<Geom::Piecewise<Geom::SBasis>>(offsetx, offsety));
+    pwd2 += offsetpath;
+    _pathv = Geom::path_from_piecewise(pwd2, 0.001);
+}
+
+/**
+ *  sets start of first path to new_p0, and end of first path to  new_p1
+ */
+void SPCurve::move_endpoints(Geom::Point const &new_p0, Geom::Point const &new_p1)
+{
+    if (is_empty()) {
+        return;
+    }
+    _pathv.front().setInitial(new_p0);
+    _pathv.front().setFinal(new_p1);
+}
+
+/**
+ * returns the number of nodes in a path, used for statusbar text when selecting an spcurve.
+ * Sum of nodes in all the paths. When a path is closed, and its closing line segment is of zero-length,
+ * this function will not count the closing knot double (so basically ignores the closing line segment when it has zero length)
+ */
+size_t SPCurve::nodes_in_path() const
+{
+    size_t nr = 0;
+
+    for (auto const &it : _pathv) {
+        // if the path does not have any segments, it is a naked moveto,
+        // and therefore any path has at least one valid node
+        size_t psize = std::max<size_t>(1, it.size_closed());
+        nr += psize;
+        if (it.closed() && it.size_closed() > 0) {
+            Geom::Curve const &closingline = it.back_closed();
+            // the closing line segment is always of type
+            // Geom::LineSegment.
+            if (are_near(closingline.initialPoint(), closingline.finalPoint())) {
+                // closingline.isDegenerate() did not work, because it only checks for
+                // *exact* zero length, which goes wrong for relative coordinates and
+                // rounding errors...
+                // the closing line segment has zero-length. So stop before that one!
+                nr -= 1;
+            }
+        }
+    }
+
+    return nr;
+}
+
+/**
+ *  Adds p to the last point (and last handle if present) of the last path
+ */
+void SPCurve::last_point_additive_move(Geom::Point const &p)
+{
+    if (is_empty()) {
+        return;
+    }
+
+    _pathv.back().setFinal(_pathv.back().finalPoint() + p);
+
+    // Move handle as well when the last segment is a cubic bezier segment:
+    // TODO: what to do for quadratic beziers?
+    if (auto const lastcube = dynamic_cast<Geom::CubicBezier const *>(&_pathv.back().back())) {
+        Geom::CubicBezier newcube(*lastcube);
+        newcube.setPoint(2, newcube[2] + p);
+        _pathv.back().replace(--_pathv.back().end(), newcube);
+    }
+}
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:
diff --git a/src/display/curve.h b/src/display/curve.h
new file mode 100644
index 0000000..9e99620
--- /dev/null
+++ b/src/display/curve.h
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * Authors:
+ *   Lauris Kaplinski <lauris@kaplinski.com>
+ *
+ * Copyright (C) 2000 Lauris Kaplinski
+ * Copyright (C) 2000-2001 Ximian, Inc.
+ * Copyright (C) 2002 Lauris Kaplinski
+ * Copyright (C) 2008 Johan Engelen
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef SEEN_DISPLAY_CURVE_H
+#define SEEN_DISPLAY_CURVE_H
+
+#include <2geom/pathvector.h>
+#include <cstddef>
+#include <optional>
+#include <vector>
+#include <utility>
+
+/**
+ * Wrapper around a Geom::PathVector object.
+ */
+class SPCurve {
+public:
+    explicit SPCurve() = default;
+    explicit SPCurve(Geom::PathVector pathv) : _pathv(std::move(pathv)) {}
+    explicit SPCurve(Geom::Rect const &rect, bool all_four_sides = false);
+
+    void set_pathvector(Geom::PathVector const &new_pathv);
+    Geom::PathVector const &get_pathvector() const;
+
+    size_t get_segment_count() const;
+    size_t nodes_in_path() const;
+
+    bool is_empty() const;
+    bool is_unset() const;
+    bool is_closed() const;
+    bool is_equal(SPCurve const *other) const;
+    bool is_similar(SPCurve const *other, double precision = 0.001) const;
+    Geom::Curve const *last_segment() const;
+    Geom::Path const *last_path() const;
+    Geom::Curve const *first_segment() const;
+    Geom::Path const *first_path() const;
+    std::optional<Geom::Point> first_point() const;
+    std::optional<Geom::Point> last_point() const;
+    std::optional<Geom::Point> second_point() const;
+    std::optional<Geom::Point> penultimate_point() const;
+
+    void reset();
+
+    void moveto(Geom::Point const &p);
+    void moveto(double x, double y);
+    void lineto(Geom::Point const &p);
+    void lineto(double x, double y);
+    void quadto(Geom::Point const &p1, Geom::Point const &p2);
+    void quadto(double x1, double y1, double x2, double y2);
+    void curveto(Geom::Point const &p0, Geom::Point const &p1, Geom::Point const &p2);
+    void curveto(double x0, double y0, double x1, double y1, double x2, double y2);
+    void closepath();
+    void closepath_current();
+    void backspace();
+
+    void transform(Geom::Affine const &m);
+    SPCurve transformed(Geom::Affine const &m) const;
+    void stretch_endpoints(Geom::Point const &, Geom::Point const &);
+    void move_endpoints(Geom::Point const &, Geom::Point const &);
+    void last_point_additive_move(Geom::Point const &p);
+
+    void append(Geom::PathVector const &, bool use_lineto = false);
+    void append(SPCurve const &curve2, bool use_lineto = false);
+    bool append_continuous(SPCurve const &c1, double tolerance = 0.0625);
+
+    void reverse();
+    SPCurve reversed() const;
+
+    std::vector<SPCurve> split() const;
+    std::vector<SPCurve> split_non_overlapping() const;
+
+    template <typename T>
+    static std::optional<SPCurve> ptr_to_opt(T const &p)
+    {
+        if (p) {
+            return *p;
+        } else {
+            return {};
+        }
+    }
+
+protected:
+    Geom::PathVector _pathv;
+};
+
+#endif // !SEEN_DISPLAY_CURVE_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8 :
diff --git a/src/display/dither-lock.h b/src/display/dither-lock.h
new file mode 100644
index 0000000..975b91f
--- /dev/null
+++ b/src/display/dither-lock.h
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef INKSCAPE_DISPLAY_DITHER_LOCK_H
+#define INKSCAPE_DISPLAY_DITHER_LOCK_H
+
+#include "drawing-context.h"
+#include "cairo-utils.h"
+
+namespace Inkscape {
+
+/// RAII object for temporarily turning dithering on.
+class DitherLock
+{
+public:
+    DitherLock(DrawingContext &dc, bool on)
+        : _cr(dc.rawTarget())
+        , _on(on)
+    {
+        if (_on) {
+            ink_cairo_set_dither(_cr, true);
+        }
+    }
+
+    ~DitherLock()
+    {
+        if (_on) {
+            ink_cairo_set_dither(_cr, false);
+        }
+    }
+
+private:
+    cairo_surface_t *_cr;
+    bool _on;
+};
+
+} // namespace Inkscape
+
+#endif // INKSCAPE_DISPLAY_DITHER_LOCK_H
diff --git a/src/display/drawing-context.cpp b/src/display/drawing-context.cpp
new file mode 100644
index 0000000..516202b
--- /dev/null
+++ b/src/display/drawing-context.cpp
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Cairo drawing context with Inkscape extensions.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/drawing-context.h"
+#include "display/drawing-surface.h"
+#include "display/cairo-utils.h"
+
+namespace Inkscape {
+
+using Geom::X;
+using Geom::Y;
+
+/**
+ * @class DrawingContext::Save
+ * RAII idiom for saving the state of DrawingContext.
+ */
+
+DrawingContext::Save::Save()
+    : _dc(nullptr)
+{}
+DrawingContext::Save::Save(DrawingContext &dc)
+    : _dc(&dc)
+{
+    _dc->save();
+}
+DrawingContext::Save::~Save()
+{
+    if (_dc) {
+        _dc->restore();
+    }
+}
+void DrawingContext::Save::save(DrawingContext &dc)
+{
+    if (_dc) {
+        // TODO: it might be better to treat this occurrence as a bug
+        _dc->restore();
+    }
+    _dc = &dc;
+    _dc->save();
+}
+
+/**
+ * @class DrawingContext
+ * Minimal wrapper over Cairo.
+ *
+ * This is a wrapper over cairo_t, extended with operations that work
+ * with 2Geom geometrical primitives. Some of this is probably duplicated
+ * in cairo-render-context.cpp, which provides higher level operations
+ * for drawing entire SPObjects when exporting.
+ */
+
+// Uses existing Cairo surface
+DrawingContext::DrawingContext(cairo_t *ct, Geom::Point const &origin)
+    : _ct(ct)
+    , _surface(new DrawingSurface(cairo_get_group_target(ct), origin))
+    , _delete_surface(true)
+    , _restore_context(true)
+{
+    _surface->_has_context = true;
+    cairo_reference(_ct);
+    cairo_save(_ct);
+    cairo_translate(_ct, -origin[Geom::X], -origin[Geom::Y]);
+}
+
+// Uses existing Cairo surface
+DrawingContext::DrawingContext(cairo_surface_t *surface, Geom::Point const &origin)
+    : _ct(nullptr)
+    , _surface(new DrawingSurface(surface, origin))
+    , _delete_surface(true)
+    , _restore_context(false)
+{
+    _surface->_has_context = true;
+    _ct = _surface->createRawContext();
+}
+
+DrawingContext::DrawingContext(DrawingSurface &s)
+    : _ct(s.createRawContext())
+    , _surface(&s)
+    , _delete_surface(false)
+    , _restore_context(false)
+{}
+
+DrawingContext::~DrawingContext()
+{
+    if (_restore_context) {
+        cairo_restore(_ct);
+    }
+    cairo_destroy(_ct);
+    _surface->_has_context = false;
+    if (_delete_surface) {
+        delete _surface;
+    }
+}
+
+void DrawingContext::arc(Geom::Point const &center, double radius, Geom::AngleInterval const &angle)
+{
+    double from = angle.initialAngle();
+    double to = angle.finalAngle();
+    if (to > from) {
+        cairo_arc(_ct, center[X], center[Y], radius, from, to);
+    } else {
+        cairo_arc_negative(_ct, center[X], center[Y], radius, to, from);
+    }
+}
+
+// Applies transform to Cairo surface
+void DrawingContext::transform(Geom::Affine const &trans) {
+    ink_cairo_transform(_ct, trans);
+}
+
+void DrawingContext::path(Geom::PathVector const &pv) {
+    feed_pathvector_to_cairo(_ct, pv);
+}
+
+void DrawingContext::paint(double alpha) {
+    if (alpha == 1.0) cairo_paint(_ct);
+    else cairo_paint_with_alpha(_ct, alpha);
+}
+
+void DrawingContext::setHairline() {
+    ink_cairo_set_hairline(_ct);
+}
+
+void DrawingContext::setSource(guint32 rgba) {
+    ink_cairo_set_source_rgba32(_ct, rgba);
+}
+void DrawingContext::setSource(DrawingSurface *s) {
+    Geom::Point origin = s->origin();
+    cairo_set_source_surface(_ct, s->raw(), origin[X], origin[Y]);
+}
+
+Geom::Rect DrawingContext::targetLogicalBounds() const
+{
+    Geom::Rect ret(_surface->area());
+    return ret;
+}
+
+} // end namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-context.h b/src/display/drawing-context.h
new file mode 100644
index 0000000..ec488ac
--- /dev/null
+++ b/src/display/drawing-context.h
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Cairo drawing context with Inkscape extensions.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef SEEN_INKSCAPE_DISPLAY_DRAWING_CONTEXT_H
+#define SEEN_INKSCAPE_DISPLAY_DRAWING_CONTEXT_H
+
+#include <2geom/rect.h>
+#include <2geom/transforms.h>
+#include <boost/utility.hpp>
+#include <cairo.h>
+typedef unsigned int guint32;
+
+namespace Inkscape {
+
+class DrawingSurface;
+
+class DrawingContext
+    : boost::noncopyable
+{
+public:
+    class Save {
+    public:
+        Save();
+        Save(DrawingContext &dc);
+        ~Save();
+        void save(DrawingContext &dc);
+    private:
+        DrawingContext *_dc;
+    };
+
+    DrawingContext(cairo_t *ct, Geom::Point const &origin);
+    DrawingContext(cairo_surface_t *surface, Geom::Point const &origin);
+    DrawingContext(DrawingSurface &s);
+    ~DrawingContext();
+    
+    void save() { cairo_save(_ct); }
+    void restore() { cairo_restore(_ct); }
+    void pushGroup() { cairo_push_group(_ct); }
+    void pushAlphaGroup() { cairo_push_group_with_content(_ct, CAIRO_CONTENT_ALPHA); }
+    void popGroupToSource() { cairo_pop_group_to_source(_ct); }
+
+    void transform(Geom::Affine const &trans);
+    void translate(Geom::Point const &t) { cairo_translate(_ct, t[Geom::X], t[Geom::Y]); } // todo: take Translate
+    void translate(double dx, double dy) { cairo_translate(_ct, dx, dy); }
+    void scale(Geom::Scale const &s) { cairo_scale(_ct, s[Geom::X], s[Geom::Y]); }
+    void scale(double sx, double sy) { cairo_scale(_ct, sx, sy); }
+    void device_to_user_distance(double &dx, double &dy) { cairo_device_to_user_distance(_ct, &dx, &dy); }
+    void user_to_device_distance(double &dx, double &dy) { cairo_user_to_device_distance(_ct, &dx, &dy); }
+
+    void moveTo(Geom::Point const &p) { cairo_move_to(_ct, p[Geom::X], p[Geom::Y]); }
+    void lineTo(Geom::Point const &p) { cairo_line_to(_ct, p[Geom::X], p[Geom::Y]); }
+    void curveTo(Geom::Point const &p1, Geom::Point const &p2, Geom::Point const &p3) {
+        cairo_curve_to(_ct, p1[Geom::X], p1[Geom::Y], p2[Geom::X], p2[Geom::Y], p3[Geom::X], p3[Geom::Y]);
+    }
+    void arc(Geom::Point const &center, double radius, Geom::AngleInterval const &angle);
+    void closePath() { cairo_close_path(_ct); }
+    void rectangle(Geom::Rect const &r) {
+        cairo_rectangle(_ct, r.left(), r.top(), r.width(), r.height());
+    }
+    void rectangle(Geom::IntRect const &r) {
+        cairo_rectangle(_ct, r.left(), r.top(), r.width(), r.height());
+    }
+    // Used in drawing-text.cpp to overwrite glyphs, which have the opposite path rotation as a regular rect
+    void revrectangle(Geom::Rect const &r) {
+        cairo_move_to (    _ct, r.left(), r.top()      );
+        cairo_rel_line_to (_ct, 0,        r.height()   );
+        cairo_rel_line_to (_ct,           r.width(), 0 );
+        cairo_rel_line_to (_ct, 0,       -r.height()   );
+        cairo_close_path ( _ct);
+    }
+    void revrectangle(Geom::IntRect const &r) {
+        cairo_move_to (    _ct, r.left(), r.top()      );
+        cairo_rel_line_to (_ct, 0,        r.height()   );
+        cairo_rel_line_to (_ct,           r.width(), 0 );
+        cairo_rel_line_to (_ct, 0,       -r.height()   );
+        cairo_close_path ( _ct);
+    }
+    void newPath() { cairo_new_path(_ct); }
+    void newSubpath() { cairo_new_sub_path(_ct); }
+    void path(Geom::PathVector const &pv);
+
+    void paint(double alpha = 1.0);
+    void fill() { cairo_fill(_ct); }
+    void fillPreserve() { cairo_fill_preserve(_ct); }
+    void stroke() { cairo_stroke(_ct); }
+    void strokePreserve() { cairo_stroke_preserve(_ct); }
+    void clip() { cairo_clip(_ct); }
+
+    void setLineWidth(double w) { cairo_set_line_width(_ct, w); }
+    void setHairline();
+    void setLineCap(cairo_line_cap_t cap) { cairo_set_line_cap(_ct, cap); }
+    void setLineJoin(cairo_line_join_t join) { cairo_set_line_join(_ct, join); }
+    void setMiterLimit(double miter) { cairo_set_miter_limit(_ct, miter); }
+    void setFillRule(cairo_fill_rule_t rule) { cairo_set_fill_rule(_ct, rule); }
+    void setOperator(cairo_operator_t op) { cairo_set_operator(_ct, op); }
+    cairo_operator_t getOperator() { return cairo_get_operator(_ct); }
+    void setTolerance(double tol) { cairo_set_tolerance(_ct, tol); }
+    void setSource(cairo_pattern_t *source) { cairo_set_source(_ct, source); }
+    void setSource(cairo_surface_t *surface, double x, double y) {
+        cairo_set_source_surface(_ct, surface, x, y);
+    }
+    void setSource(double r, double g, double b, double a = 1.0) {
+        cairo_set_source_rgba(_ct, r, g, b, a);
+    }
+    void setSource(guint32 rgba);
+    void setSource(DrawingSurface *s);
+
+    void patternSetFilter(cairo_filter_t filter) {
+        cairo_pattern_set_filter(cairo_get_source(_ct), filter);
+    }
+    void patternSetExtend(cairo_extend_t extend) { cairo_pattern_set_extend(cairo_get_source(_ct), extend); }
+
+    Geom::Rect targetLogicalBounds() const;
+
+    cairo_t *raw() { return _ct; }
+    cairo_surface_t *rawTarget() { return cairo_get_group_target(_ct); }
+
+    DrawingSurface *surface() { return _surface; } // Needed to find scale in drawing-item.cpp
+
+private:
+    DrawingContext(cairo_t *ct, DrawingSurface *surface, bool destroy);
+
+    cairo_t *_ct;
+    DrawingSurface *_surface;
+    bool _delete_surface;
+    bool _restore_context;
+
+    friend class DrawingSurface;
+};
+
+} // end namespace Inkscape
+
+#endif // !SEEN_INKSCAPE_DISPLAY_DRAWING_ITEM_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-group.cpp b/src/display/drawing-group.cpp
new file mode 100644
index 0000000..12cbf29
--- /dev/null
+++ b/src/display/drawing-group.cpp
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Group belonging to an SVG drawing element.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "drawing-group.h"
+#include "cairo-utils.h"
+#include "drawing-context.h"
+#include "drawing-surface.h"
+#include "drawing-text.h"
+#include "drawing.h"
+#include "style.h"
+
+namespace Inkscape {
+
+DrawingGroup::DrawingGroup(Drawing &drawing)
+    : DrawingItem(drawing) {}
+
+/**
+ * Set whether the group returns children from pick calls.
+ * Previously this feature was called "transparent groups".
+ */
+void DrawingGroup::setPickChildren(bool pick_children)
+{
+    defer([=] {
+        _pick_children = pick_children;
+    });
+}
+
+/**
+ * Set additional transform for the group.
+ * This is applied after the normal transform and mainly useful for
+ * markers, clipping paths, etc.
+ */
+void DrawingGroup::setChildTransform(Geom::Affine const &transform)
+{
+    defer([=] {
+        auto constexpr EPS = 1e-18;
+        auto current = _child_transform ? *_child_transform : Geom::identity();
+        if (Geom::are_near(transform, current, EPS)) return;
+        _markForRendering();
+        _child_transform = transform.isIdentity(EPS) ? nullptr : std::make_unique<Geom::Affine>(transform);
+        _markForUpdate(STATE_ALL, true);
+    });
+}
+
+unsigned DrawingGroup::_updateItem(Geom::IntRect const &area, UpdateContext const &ctx, unsigned flags, unsigned reset)
+{
+    bool outline = _drawing.renderMode() == RenderMode::OUTLINE || _drawing.outlineOverlay();
+
+    UpdateContext child_ctx(ctx);
+    if (_child_transform) {
+        child_ctx.ctm = *_child_transform * ctx.ctm;
+    }
+
+    _bbox = {};
+
+    for (auto &c : _children) {
+        c.update(area, child_ctx, flags, reset);
+        if (c.visible()) {
+            _bbox.unionWith(outline ? c.bbox() : c.drawbox());
+        }
+        _update_complexity += c.getUpdateComplexity();
+        _contains_unisolated_blend |= c.unisolatedBlend();
+    }
+
+    return STATE_ALL;
+}
+
+unsigned DrawingGroup::_renderItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags, DrawingItem const *stop_at) const
+{
+    if (!stop_at) {
+        // normal rendering
+        for (auto &i : _children) {
+            i.render(dc, rc, area, flags, stop_at);
+        }
+    } else {
+        // background rendering
+        for (auto &i : _children) {
+            if (&i == stop_at) {
+                return RENDER_OK; // do not render the stop_at item at all
+            }
+            if (i.isAncestorOf(stop_at)) {
+                // render its ancestors without masks, opacity or filters
+                i.render(dc, rc, area, flags | RENDER_FILTER_BACKGROUND, stop_at);
+                return RENDER_OK;
+            } else {
+                i.render(dc, rc, area, flags, stop_at);
+            }
+        }
+    }
+    return RENDER_OK;
+}
+
+void DrawingGroup::_clipItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area) const
+{
+    for (auto &i : _children) {
+        i.clip(dc, rc, area);
+    }
+}
+
+DrawingItem *DrawingGroup::_pickItem(Geom::Point const &p, double delta, unsigned flags)
+{
+    for (auto &i : _children) {
+        DrawingItem *picked = i.pick(p, delta, flags);
+        if (picked) {
+            return _pick_children ? picked : this;
+        }
+    }
+    return nullptr;
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-group.h b/src/display/drawing-group.h
new file mode 100644
index 0000000..2c7aab2
--- /dev/null
+++ b/src/display/drawing-group.h
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Group belonging to an SVG drawing element.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef INKSCAPE_DISPLAY_DRAWING_GROUP_H
+#define INKSCAPE_DISPLAY_DRAWING_GROUP_H
+
+#include "display/drawing-item.h"
+
+namespace Inkscape {
+
+class DrawingGroup
+    : public DrawingItem
+{
+public:
+    DrawingGroup(Drawing &drawing);
+    int tag() const override { return tag_of<decltype(*this)>; }
+
+    bool pickChildren() { return _pick_children; }
+    void setPickChildren(bool);
+
+    void setChildTransform(Geom::Affine const &);
+
+protected:
+    ~DrawingGroup() override = default;
+
+    unsigned _updateItem(Geom::IntRect const &area, UpdateContext const &ctx, unsigned flags, unsigned reset) override;
+    unsigned _renderItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags, DrawingItem const *stop_at) const override;
+    void _clipItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area) const override;
+    DrawingItem *_pickItem(Geom::Point const &p, double delta, unsigned flags) override;
+    bool _canClip() const override { return true; }
+
+    std::unique_ptr<Geom::Affine> _child_transform;
+};
+
+} // namespace Inkscape
+
+#endif // INKSCAPE_DISPLAY_DRAWING_GROUP_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-image.cpp b/src/display/drawing-image.cpp
new file mode 100644
index 0000000..e82c8d0
--- /dev/null
+++ b/src/display/drawing-image.cpp
@@ -0,0 +1,270 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Bitmap image belonging to an SVG drawing.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <2geom/bezier-curve.h>
+
+#include "drawing.h"
+#include "drawing-context.h"
+#include "drawing-image.h"
+#include "cairo-utils.h"
+#include "cairo-templates.h"
+
+namespace Inkscape {
+
+DrawingImage::DrawingImage(Drawing &drawing)
+    : DrawingItem(drawing)
+    , style_image_rendering(SP_CSS_IMAGE_RENDERING_AUTO)
+{
+}
+
+void DrawingImage::setPixbuf(std::shared_ptr<Inkscape::Pixbuf const> pixbuf)
+{
+    defer([this, pixbuf = std::move(pixbuf)] () mutable {
+        _pixbuf = std::move(pixbuf);
+        _markForUpdate(STATE_ALL, false);
+    });
+}
+
+void DrawingImage::setScale(double sx, double sy)
+{
+    defer([=] {
+        _scale = Geom::Scale(sx, sy);
+        _markForUpdate(STATE_ALL, false);
+    });
+}
+
+void DrawingImage::setOrigin(Geom::Point const &origin)
+{
+    defer([=] {
+        _origin = origin;
+        _markForUpdate(STATE_ALL, false);
+    });
+}
+
+void DrawingImage::setClipbox(Geom::Rect const &box)
+{
+    defer([=] {
+        _clipbox = box;
+        _markForUpdate(STATE_ALL, false);
+    });
+}
+
+Geom::Rect DrawingImage::bounds() const
+{
+    if (!_pixbuf) return _clipbox;
+
+    double pw = _pixbuf->width();
+    double ph = _pixbuf->height();
+    double vw = pw * _scale[Geom::X];
+    double vh = ph * _scale[Geom::Y];
+    Geom::Point wh(vw, vh);
+    Geom::Rect view(_origin, _origin+wh);
+    Geom::OptRect res = _clipbox & view;
+    Geom::Rect ret = res ? *res : _clipbox;
+
+    return ret;
+}
+
+void DrawingImage::setStyle(SPStyle const *style, SPStyle const *context_style)
+{
+    DrawingItem::setStyle(style, context_style);
+
+    auto image_rendering = SP_CSS_IMAGE_RENDERING_AUTO;
+    if (_style) {
+        image_rendering = _style->image_rendering.computed;
+    }
+
+    defer([=] {
+        style_image_rendering = image_rendering;
+    });
+}
+
+unsigned DrawingImage::_updateItem(Geom::IntRect const &, UpdateContext const &, unsigned, unsigned)
+{
+    // Calculate bbox
+    if (_pixbuf) {
+        Geom::Rect r = bounds() * _ctm;
+        _bbox = r.roundOutwards();
+    } else {
+        _bbox = Geom::OptIntRect();
+    }
+
+    return STATE_ALL;
+}
+
+unsigned DrawingImage::_renderItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &/*area*/, unsigned flags, DrawingItem const */*stop_at*/) const
+{
+    bool const outline = (flags & RENDER_OUTLINE) && !_drawing.imageOutlineMode();
+
+    if (!outline) {
+        if (!_pixbuf) return RENDER_OK;
+
+        Inkscape::DrawingContext::Save save(dc);
+        dc.transform(_ctm);
+        dc.newPath();
+        dc.rectangle(_clipbox);
+        dc.clip();
+
+        dc.translate(_origin);
+        dc.scale(_scale);
+        // const_cast required since Cairo needs to modify the internal refcount variable, but we do not want to give up the
+        // benefits of const for the rest of our code. The underlying object is guaranteed to be non-const, so this is well-defined.
+        // It is also thread-safe to modify the refcount in this way, since Cairo uses atomics internally.
+        dc.setSource(const_cast<cairo_surface_t*>(_pixbuf->getSurfaceRaw()), 0, 0);
+        dc.patternSetExtend(CAIRO_EXTEND_PAD);
+
+        // See: http://www.w3.org/TR/SVG/painting.html#ImageRenderingProperty
+        //      https://drafts.csswg.org/css-images-3/#the-image-rendering
+        //      style.h/style.cpp, cairo-render-context.cpp
+        //
+        // CSS 3 defines:
+        //   'optimizeSpeed' as alias for "pixelated"
+        //   'optimizeQuality' as alias for "smooth"
+        switch (style_image_rendering) {
+            case SP_CSS_IMAGE_RENDERING_OPTIMIZESPEED:
+            case SP_CSS_IMAGE_RENDERING_PIXELATED:
+            // we don't have an implementation for crisp-edges, but it should *not* smooth or blur
+            case SP_CSS_IMAGE_RENDERING_CRISPEDGES:
+                dc.patternSetFilter( CAIRO_FILTER_NEAREST );
+                break;
+            case SP_CSS_IMAGE_RENDERING_AUTO:
+            case SP_CSS_IMAGE_RENDERING_OPTIMIZEQUALITY:
+            default:
+                // In recent Cairo, BEST used Lanczos3, which is prohibitively slow
+                dc.patternSetFilter( CAIRO_FILTER_GOOD );
+                break;
+        }
+
+        // Handle an exceptional case where the greyscale color mode needs to be applied per-image.
+        bool const greyscale_exception = (flags & RENDER_OUTLINE) && _drawing.colorMode() == ColorMode::GRAYSCALE;
+        if (greyscale_exception) {
+            dc.pushGroup();
+        }
+
+        dc.paint();
+
+        if (greyscale_exception) {
+            ink_cairo_surface_filter(dc.rawTarget(), dc.rawTarget(), _drawing.grayscaleMatrix());
+            dc.popGroupToSource();
+            dc.paint();
+        }
+
+    } else { // outline; draw a rect instead
+
+        auto rgba = _drawing.imageOutlineColor();
+
+        {   Inkscape::DrawingContext::Save save(dc);
+            dc.transform(_ctm);
+            dc.newPath();
+
+            Geom::Rect r = bounds();
+            Geom::Point c00 = r.corner(0);
+            Geom::Point c01 = r.corner(3);
+            Geom::Point c11 = r.corner(2);
+            Geom::Point c10 = r.corner(1);
+
+            dc.moveTo(c00);
+            // the box
+            dc.lineTo(c10);
+            dc.lineTo(c11);
+            dc.lineTo(c01);
+            dc.lineTo(c00);
+            // the diagonals
+            dc.lineTo(c11);
+            dc.moveTo(c10);
+            dc.lineTo(c01);
+        }
+
+        dc.setLineWidth(0.5);
+        dc.setSource(rgba);
+        dc.stroke();
+    }
+    return RENDER_OK;
+}
+
+/** Calculates the closest distance from p to the segment a1-a2*/
+static double distance_to_segment(Geom::Point const &p, Geom::Point const &a1, Geom::Point const &a2)
+{
+    Geom::LineSegment l(a1, a2);
+    Geom::Point np = l.pointAt(l.nearestTime(p));
+    return Geom::distance(np, p);
+}
+
+DrawingItem *DrawingImage::_pickItem(Geom::Point const &p, double delta, unsigned flags)
+{
+    if (!_pixbuf) return nullptr;
+
+    bool outline = (flags & PICK_OUTLINE) && !_drawing.imageOutlineMode();
+
+    if (outline) {
+        Geom::Rect r = bounds();
+        Geom::Point pick = p * _ctm.inverse();
+
+        // find whether any side or diagonal is within delta
+        // to do so, iterate over all pairs of corners
+        for (unsigned i = 0; i < 3; ++i) { // for i=3, there is nothing to do
+            for (unsigned j = i+1; j < 4; ++j) {
+                if (distance_to_segment(pick, r.corner(i), r.corner(j)) < delta) {
+                    return this;
+                }
+            }
+        }
+        return nullptr;
+
+    } else {
+        auto pixels = _pixbuf->pixels();
+        int width = _pixbuf->width();
+        int height = _pixbuf->height();
+        size_t rowstride = _pixbuf->rowstride();
+
+        Geom::Point tp = p * _ctm.inverse();
+        Geom::Rect r = bounds();
+
+        if (!r.contains(tp))
+            return nullptr;
+
+        double vw = width * _scale[Geom::X];
+        double vh = height * _scale[Geom::Y];
+        int ix = floor((tp[Geom::X] - _origin[Geom::X]) / vw * width);
+        int iy = floor((tp[Geom::Y] - _origin[Geom::Y]) / vh * height);
+
+        if ((ix < 0) || (iy < 0) || (ix >= width) || (iy >= height))
+            return nullptr;
+
+        auto pix_ptr = pixels + iy * rowstride + ix * 4;
+        // pick if the image is less than 99% transparent
+        guint32 alpha = 0;
+        if (_pixbuf->pixelFormat() == Inkscape::Pixbuf::PF_CAIRO) {
+            guint32 px = *reinterpret_cast<guint32 const *>(pix_ptr);
+            alpha = (px & 0xff000000) >> 24;
+        } else if (_pixbuf->pixelFormat() == Inkscape::Pixbuf::PF_GDK) {
+            alpha = pix_ptr[3];
+        } else {
+            throw std::runtime_error("Unrecognized pixel format");
+        }
+        float alpha_f = (alpha / 255.0f) * _opacity;
+        return alpha_f > 0.01 ? this : nullptr;
+    }
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-image.h b/src/display/drawing-image.h
new file mode 100644
index 0000000..94a8c94
--- /dev/null
+++ b/src/display/drawing-image.h
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Bitmap image belonging to an SVG drawing.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef INKSCAPE_DISPLAY_DRAWING_IMAGE_H
+#define INKSCAPE_DISPLAY_DRAWING_IMAGE_H
+
+#include <memory>
+#include <2geom/transforms.h>
+#include <gdk-pixbuf/gdk-pixbuf.h>
+#include <cairo.h>
+
+#include "display/drawing-item.h"
+
+namespace Inkscape {
+class Pixbuf;
+
+class DrawingImage
+    : public DrawingItem
+{
+public:
+    DrawingImage(Drawing &drawing);
+    int tag() const override { return tag_of<decltype(*this)>; }
+
+    void setStyle(SPStyle const *style, SPStyle const *context_style = nullptr) override;
+
+    void setPixbuf(std::shared_ptr<Inkscape::Pixbuf const> pb);
+    void setScale(double sx, double sy);
+    void setOrigin(Geom::Point const &o);
+    void setClipbox(Geom::Rect const &box);
+    Geom::Rect bounds() const;
+
+protected:
+    ~DrawingImage() override = default;
+
+    unsigned _updateItem(Geom::IntRect const &area, UpdateContext const &ctx, unsigned flags, unsigned reset) override;
+    unsigned _renderItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags, DrawingItem const *stop_at) const override;
+    DrawingItem *_pickItem(Geom::Point const &p, double delta, unsigned flags) override;
+
+    std::shared_ptr<Inkscape::Pixbuf const> _pixbuf;
+
+    SPImageRendering style_image_rendering;
+
+    // TODO: the following three should probably be merged into a new Geom::Viewbox object
+    Geom::Rect _clipbox; ///< for preserveAspectRatio
+    Geom::Point _origin;
+    Geom::Scale _scale;
+};
+
+} // namespace Inkscape
+
+#endif // INKSCAPE_DISPLAY_DRAWING_IMAGE_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-item-ptr.h b/src/display/drawing-item-ptr.h
new file mode 100644
index 0000000..0707567
--- /dev/null
+++ b/src/display/drawing-item-ptr.h
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef INKSCAPE_DISPLAY_DRAWINGITEM_PTR_H
+#define INKSCAPE_DISPLAY_DRAWINGITEM_PTR_H
+
+#include <memory>
+#include <type_traits>
+
+namespace Inkscape { class DrawingItem; }
+
+/**
+ * Deleter object which calls the unlink() method of DrawingItem to schedule deferred destruction.
+ */
+struct UnlinkDeleter
+{
+    template <typename T>
+    void operator()(T *t)
+    {
+        static_assert(std::is_base_of_v<Inkscape::DrawingItem, T>);
+        t->unlink();
+    }
+};
+
+/**
+ * Smart pointer used by the Object Tree to hold items in the Display Tree, like std::unique_ptr.
+ *
+ * Upon deletion, the pointed-to object and its subtree will be destroyed immediately if not currently in use by a snapshot.
+ * Otherwise, destruction is deferred to after the snapshot is released.
+ */
+template <typename T>
+using DrawingItemPtr = std::unique_ptr<T, UnlinkDeleter>;
+
+/**
+ * Convienence function to create a DrawingItemPtr, like std::make_unique.
+ */
+template <typename T, typename... Args>
+auto make_drawingitem(Args&&... args)
+{
+    return DrawingItemPtr<T>(new T(std::forward<Args>(args)...));
+};
+
+#endif // INKSCAPE_DISPLAY_DRAWINGITEM_PTR_H
diff --git a/src/display/drawing-item.cpp b/src/display/drawing-item.cpp
new file mode 100644
index 0000000..57e658b
--- /dev/null
+++ b/src/display/drawing-item.cpp
@@ -0,0 +1,1325 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Canvas item belonging to an SVG drawing element.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <climits>
+
+#include "display/drawing-context.h"
+#include "display/drawing-group.h"
+#include "display/drawing-item.h"
+#include "display/drawing-pattern.h"
+#include "display/drawing-surface.h"
+#include "display/drawing-text.h"
+#include "display/drawing.h"
+
+#include "display/cairo-utils.h"
+#include "display/cairo-templates.h"
+
+#include "display/control/canvas-item-drawing.h"
+#include "ui/widget/canvas.h" // Mark area for redrawing.
+
+#include "nr-filter.h"
+#include "style.h"
+
+#include "object/sp-item.h"
+
+static constexpr auto CACHE_SCORE_THRESHOLD = 50000.0; ///< Do not consider objects for caching below this score.
+
+namespace Inkscape {
+
+struct CacheData
+{
+    mutable std::mutex mutables;
+    mutable std::optional<DrawingCache> surface;
+};
+
+/**
+ * @class DrawingItem
+ * SVG drawing item for display.
+ *
+ * This class represents the renderable portion of the SVG document. Typically this
+ * is created by the SP tree, in particular the invoke_show() virtual function.
+ *
+ * @section ObjectLifetime Object lifetime
+ * Deleting a DrawingItem will cause all of its children to be deleted as well.
+ * This can lead to nasty surprises if you hold references to things
+ * which are children of what is being deleted. Therefore, in the SP tree,
+ * you always need to delete the item views of children before deleting
+ * the view of the parent. Do not call delete on things returned from invoke_show()
+ * - this will cause dangling pointers inside the SPItem and lead to a crash.
+ * Use the corresponding invoke_hide() method.
+ *
+ * Outside of the SP tree, you should not use any references after the root node
+ * has been deleted.
+ */
+
+DrawingItem::DrawingItem(Drawing &drawing)
+    : _drawing(drawing)
+    , _parent(nullptr)
+    , _key(0)
+    , _style(nullptr)
+    , _context_style(nullptr)
+    , _contains_unisolated_blend(false)
+    , style_vector_effect_size(false)
+    , style_vector_effect_rotate(false)
+    , style_vector_effect_fixed(false)
+    , _opacity(1.0)
+    , _clip(nullptr)
+    , _mask(nullptr)
+    , _fill_pattern(nullptr)
+    , _stroke_pattern(nullptr)
+    , _item(nullptr)
+    , _state(0)
+    , _child_type(ChildType::ORPHAN)
+    , _background_new(0)
+    , _background_accumulate(0)
+    , _visible(true)
+    , _sensitive(true)
+    , _cached_persistent(0)
+    , _has_cache_iterator(0)
+    , _propagate_state(0)
+    , _pick_children(0)
+    , _antialias(2)
+    , _isolation(SP_CSS_ISOLATION_AUTO)
+    , _blend_mode(SP_CSS_BLEND_NORMAL)
+{
+}
+
+DrawingItem::~DrawingItem()
+{
+    // Unactivate if active.
+    if (auto itemdrawing = _drawing.getCanvasItemDrawing()) {
+        if (itemdrawing->get_active() == this) {
+            itemdrawing->set_active(nullptr);
+        }
+    } else {
+        // Typically happens, e.g. for any non-Canvas Drawing.
+    }
+
+    // Remove caching candidate entry.
+    if (_has_cache_iterator) {
+        _drawing._candidate_items.erase(_cache_iterator);
+    }
+
+    // Remove from the set of cached items and delete cache.
+    _setCached(false, true);
+
+    _children.clear_and_dispose([] (auto c) { delete c; });
+    delete _clip;
+    delete _mask;
+    delete static_cast<DrawingItem*>(_fill_pattern);
+    delete static_cast<DrawingItem*>(_stroke_pattern);
+}
+
+/// Returns true if item is among the descendants. Will return false if item == this.
+bool DrawingItem::isAncestorOf(DrawingItem const *item) const
+{
+    for (auto c = item->_parent; c; c = c->_parent) {
+        if (c == this) return true;
+    }
+    return false;
+}
+
+bool DrawingItem::unisolatedBlend() const
+{
+    if (_blend_mode != SP_CSS_BLEND_NORMAL) {
+        return true;
+    } else if (_mask || _filter || _opacity < 0.995 || _isolation == SP_CSS_ISOLATION_ISOLATE) {
+        return false;
+    } else {
+        return _contains_unisolated_blend;
+    }
+}
+
+void DrawingItem::appendChild(DrawingItem *item)
+{
+    // Ok to perform non-deferred modification of child, because not part of rendering tree yet.
+    assert(item->_child_type == ChildType::ORPHAN);
+    item->_parent = this;
+    item->_child_type = ChildType::NORMAL;
+
+    defer([=] {
+        _children.push_back(*item);
+
+        // This ensures that _markForUpdate() called on the child will recurse to this item
+        item->_state = STATE_ALL;
+        // Because _markForUpdate recurses through ancestors, we can simply call it
+        // on the just-added child. This has the additional benefit that we do not
+        // rely on the appended child being in the default non-updated state.
+        // We set propagate to true, because the child might have descendants of its own.
+        item->_markForUpdate(STATE_ALL, true);
+    });
+}
+
+void DrawingItem::prependChild(DrawingItem *item)
+{
+    // See appendChild for explanations.
+    assert(item->_child_type == ChildType::ORPHAN);
+    item->_parent = this;
+    item->_child_type = ChildType::NORMAL;
+
+    defer([=] {
+        _children.push_front(*item);
+        item->_state = STATE_ALL;
+        item->_markForUpdate(STATE_ALL, true);
+    });
+}
+
+// Clear this node's ordinary children, deleting them and their descendants without otherwise changing them in any way.
+void DrawingItem::clearChildren()
+{
+    defer([=] {
+        if (_children.empty()) return;
+        _markForRendering();
+        _children.clear_and_dispose([] (auto c) { delete c; });
+        _markForUpdate(STATE_ALL, false);
+    });
+}
+
+void DrawingItem::setTransform(Geom::Affine const &transform)
+{
+    defer([=] {
+        auto constexpr EPS = 1e-18;
+        auto current = _transform ? *_transform : Geom::identity();
+        if (Geom::are_near(transform, current, EPS)) return;
+
+        _markForRendering();
+        _transform = transform.isIdentity(EPS) ? nullptr : std::make_unique<Geom::Affine>(transform);
+        _markForUpdate(STATE_ALL, true);
+    });
+}
+
+void DrawingItem::setOpacity(float opacity)
+{
+    defer([=] {
+        if (opacity == _opacity) return;
+        _opacity = opacity;
+        _markForRendering();
+    });
+}
+
+void DrawingItem::setAntialiasing(unsigned antialias)
+{
+    defer([=] {
+        if (_antialias == antialias) return;
+        _antialias = antialias;
+        _markForRendering();
+    });
+}
+
+void DrawingItem::setIsolation(bool isolation)
+{
+    defer([=] {
+        if (isolation == _isolation) return;
+        _isolation = isolation;
+        _markForRendering();
+    });
+}
+
+void DrawingItem::setBlendMode(SPBlendMode blend_mode)
+{
+    defer([=] {
+        if (blend_mode == _blend_mode) return;
+        _blend_mode = blend_mode;
+        _markForRendering();
+    });
+}
+
+void DrawingItem::setVisible(bool visible)
+{
+    defer([=] {
+        if (visible == _visible) return;
+        _visible = visible;
+        _markForRendering();
+    });
+}
+
+void DrawingItem::setSensitive(bool sensitive)
+{
+    defer([=] { // Must be deferred, since in bitfield.
+        _sensitive = sensitive;
+    });
+}
+
+/**
+ * Enable / disable storing the rendering in memory.
+ * Calling setCached(false, true) will also remove the persistent status
+ */
+void DrawingItem::_setCached(bool cached, bool persistent)
+{
+    static bool const cache_env = getenv("_INKSCAPE_DISABLE_CACHE");
+    if (cache_env) {
+        return;
+    }
+
+    if (persistent) {
+        _cached_persistent = cached && persistent;
+    } else if (_cached_persistent) {
+        return;
+    }
+
+    if (cached == (bool)_cache) {
+        return;
+    }
+
+    if (cached) {
+        _cache = std::make_unique<CacheData>();
+        _drawing._cached_items.insert(this);
+    } else {
+        _cache.reset();
+        _drawing._cached_items.erase(this);
+    }
+}
+
+/**
+ * Process information related to the new style.
+ *
+ * Note: _style is not used by DrawingGlyphs which uses its parent style.
+ */
+void DrawingItem::setStyle(SPStyle const *style, SPStyle const *context_style)
+{
+    // Ok to not defer setting the style pointer, because the pointer itself is only read by SPObject-side code.
+    _style = style;
+    if (context_style) {
+        _context_style = context_style;
+    } else if (_parent) {
+        _context_style = _parent->_context_style;
+    }
+
+    // Copy required information out of style.
+    bool background_new = false;
+    bool vector_effect_size   = false;
+    bool vector_effect_rotate = false;
+    bool vector_effect_fixed  = false;
+    if (style) {
+        background_new = style->enable_background.set && style->enable_background.value == SP_CSS_BACKGROUND_NEW;
+        vector_effect_size   = _style->vector_effect.size;
+        vector_effect_rotate = _style->vector_effect.rotate;
+        vector_effect_fixed  = _style->vector_effect.fixed;
+    }
+
+    // Defer setting the style information on the DrawingItem.
+    defer([=] {
+        _markForRendering();
+
+        if (background_new != _background_new) {
+            _background_new = background_new;
+            _markForUpdate(STATE_BACKGROUND, true);
+        }
+
+        style_vector_effect_size   = vector_effect_size;
+        style_vector_effect_rotate = vector_effect_rotate;
+        style_vector_effect_fixed  = vector_effect_fixed;
+
+        _markForUpdate(STATE_ALL, false);
+    });
+}
+
+/**
+ * Recursively update children style.
+ * The purpose of this call is to update fill and stroke for markers that have elements with
+ * fill/stroke property values of 'context-fill' or 'context-stroke'. Marker styling is not
+ * updated like other 'clones' as marker instances are not included the SP object tree.
+ * Note: this is a virtual function.
+ */
+void DrawingItem::setChildrenStyle(SPStyle const *context_style)
+{
+    _context_style = context_style;
+    for (auto &i : _children) {
+        i.setChildrenStyle(context_style);
+    }
+}
+
+void DrawingItem::setClip(DrawingItem *item)
+{
+    if (item) {
+        assert(item->_child_type == ChildType::ORPHAN);
+        item->_parent = this;
+        item->_child_type = ChildType::CLIP;
+    }
+
+    defer([=] {
+        _markForRendering();
+        delete _clip;
+        _clip = item;
+        _markForUpdate(STATE_ALL, true);
+    });
+}
+
+void DrawingItem::setMask(DrawingItem *item)
+{
+    if (item) {
+        assert(item->_child_type == ChildType::ORPHAN);
+        item->_parent = this;
+        item->_child_type = ChildType::MASK;
+    }
+
+    defer([=] {
+        _markForRendering();
+        delete _mask;
+        _mask = item;
+        _markForUpdate(STATE_ALL, true);
+    });
+}
+
+void DrawingItem::setFillPattern(DrawingPattern *pattern)
+{
+    if (pattern) {
+        assert(pattern->_child_type == ChildType::ORPHAN);
+        pattern->_parent = this;
+        pattern->_child_type = ChildType::FILL;
+    }
+
+    defer([=] {
+        _markForRendering();
+        delete static_cast<DrawingItem*>(_fill_pattern);
+        _fill_pattern = pattern;
+        _markForUpdate(STATE_ALL, false);
+    });
+}
+
+void DrawingItem::setStrokePattern(DrawingPattern *pattern)
+{
+    if (pattern) {
+        assert(pattern->_child_type == ChildType::ORPHAN);
+        pattern->_parent = this;
+        pattern->_child_type = ChildType::STROKE;
+    }
+
+    defer([=] {
+        _markForRendering();
+        delete static_cast<DrawingItem*>(_stroke_pattern);
+        _stroke_pattern = pattern;
+        _markForUpdate(STATE_ALL, false);
+    });
+}
+
+/// Move this item to the given place in the Z order of siblings. Does nothing if the item is not a normal child.
+void DrawingItem::setZOrder(unsigned zorder)
+{
+    if (_child_type != ChildType::NORMAL) return;
+
+    defer([=] {
+        auto it = _parent->_children.iterator_to(*this);
+        _parent->_children.erase(it);
+
+        auto it2 = _parent->_children.begin();
+        std::advance(it2, std::min<unsigned>(zorder, _parent->_children.size()));
+        _parent->_children.insert(it2, *this);
+        _markForRendering();
+    });
+}
+
+void DrawingItem::setItemBounds(Geom::OptRect const &bounds)
+{
+    defer([=] {
+        _item_bbox = bounds;
+    });
+}
+
+void DrawingItem::setFilterRenderer(std::unique_ptr<Filters::Filter> filter)
+{
+    defer([=, filter = std::move(filter)] () mutable {
+        _filter = std::move(filter);
+        _markForRendering();
+    });
+}
+
+/**
+ * Update derived data before operations.
+ * The purpose of this call is to recompute internal data which depends
+ * on the attributes of the object, but is not directly settable by the user.
+ * Precomputing this data speeds up later rendering, because some items
+ * can be omitted.
+ *
+ * Currently this method handles updating the visual and geometric bounding boxes
+ * in pixels, storing the total transformation from item space to the screen
+ * and cache invalidation.
+ *
+ * @param area Area to which the update should be restricted. Only takes effect
+ *             if the bounding box is known.
+ * @param ctx A structure to store cascading state.
+ * @param flags Which internal data should be recomputed. This can be any combination
+ *              of StateFlags.
+ * @param reset State fields that should be reset before processing them. This is
+ *              a means to force a recomputation of internal data even if the item
+ *              considers it up to date. Mainly for internal use, such as
+ *              propagating bounding box recomputation to children when the item's
+ *              transform changes.
+ */
+void DrawingItem::update(Geom::IntRect const &area, UpdateContext const &ctx, unsigned flags, unsigned reset)
+{
+    // We don't need to update what is not visible
+    if (!_visible) {
+        _state = STATE_ALL; // Touch the state for future change to this item
+        return;
+    }
+
+    bool const outline = _drawing.renderMode() == RenderMode::OUTLINE || _drawing.outlineOverlay();
+    bool const filters = _drawing.renderMode() != RenderMode::NO_FILTERS;
+    bool const forcecache = _filter && filters;
+
+    // Set reset flags according to propagation status
+    reset |= _propagate_state;
+    _propagate_state = 0;
+
+    _state &= ~reset; // reset state of this item
+
+    if ((~_state & flags) == 0) return;  // nothing to do
+
+    // TODO this might be wrong
+    if (_state & STATE_BBOX) {
+        // we have up-to-date bbox
+        if (!area.intersects(outline ? _bbox : _drawbox)) return;
+    }
+
+    // compute which elements need an update
+    unsigned to_update = _state ^ flags;
+
+    // this needs to be called before we recurse into children
+    if (to_update & STATE_BACKGROUND) {
+        _background_accumulate = _background_new;
+        if (_child_type == ChildType::NORMAL && _parent->_background_accumulate)
+            _background_accumulate = true;
+    }
+
+    UpdateContext child_ctx(ctx);
+    if (_transform) {
+        child_ctx.ctm = *_transform * ctx.ctm;
+    }
+
+    // Vector effects
+    if (style_vector_effect_fixed) {
+        child_ctx.ctm.setTranslation(Geom::Point(0, 0));
+    }
+
+    if (style_vector_effect_size) {
+        double value = child_ctx.ctm.descrim();
+        if (value > 0.0) {
+            child_ctx.ctm[0] /= value;
+            child_ctx.ctm[1] /= value;
+            child_ctx.ctm[2] /= value;
+            child_ctx.ctm[3] /= value;
+        }
+    }
+
+    if (style_vector_effect_rotate) {
+        double value = child_ctx.ctm.descrim();
+        child_ctx.ctm[0] = value;
+        child_ctx.ctm[1] = 0.0;
+        child_ctx.ctm[2] = 0.0;
+        child_ctx.ctm[3] = value;
+    }
+
+    // Remember the transformation matrix.
+    Geom::Affine ctm_change;
+    bool affine_changed = false;
+    if (!Geom::are_near(_ctm, child_ctx.ctm)) {
+        ctm_change = _ctm.inverse() * child_ctx.ctm;
+        affine_changed = true;
+    }
+    _ctm = child_ctx.ctm;
+
+    bool const totally_invalidated = reset & STATE_TOTAL_INV;
+    if (totally_invalidated) {
+        // Perform work that would have been done by our call to _markForRendering(),
+        // had it not been overshadowed by a totally-invalidating node.
+        if (_cache && _cache->surface) {
+            _cache->surface->markDirty();
+        }
+        _dropPatternCache();
+    }
+
+    // Decide whether this node should be a totally-invalidating node.
+    bool const totally_invalidate = _update_complexity >= 20 && affine_changed;
+    if (totally_invalidate) {
+        reset |= STATE_TOTAL_INV;
+    }
+
+    // Recalculate update complexity; to be recalculated immediately below and by _updateItem().
+    _update_complexity = 1;
+    auto add_complexity_if = [&] (DrawingItem *c) {
+        if (c) {
+            _update_complexity += c->_update_complexity;
+        }
+    };
+    add_complexity_if(_clip);
+    add_complexity_if(_mask);
+    add_complexity_if(_fill_pattern);
+    add_complexity_if(_stroke_pattern);
+
+    // Reset contains_unisolated_blend; to be recalculated by  _updateItem().
+    _contains_unisolated_blend = false;
+
+    // Moved from code that was previously in render().
+    if (forcecache) {
+        _setCached((bool)_cacheRect(), true);
+    }
+
+    // update _bbox and call this function for children
+    _state = _updateItem(area, child_ctx, flags, reset);
+
+    // update drawingitems contained in filter
+    if (_filter) {
+        _filter->update();
+    }
+
+    if (to_update & STATE_BBOX) {
+        // compute drawbox
+        if (_filter && filters) {
+            Geom::OptRect enlarged = _filter->filter_effect_area(_item_bbox);
+            if (enlarged) {
+                *enlarged *= ctm();
+                _drawbox = enlarged->roundOutwards();
+            } else {
+                _drawbox = Geom::OptIntRect();
+            }
+        } else {
+            _drawbox = _bbox;
+        }
+
+        // Clipping
+        if (_clip) {
+            _clip->update(area, child_ctx, flags, reset);
+            if (outline) {
+                _bbox.unionWith(_clip->_bbox);
+            } else {
+                _drawbox.intersectWith(_clip->_bbox);
+            }
+        }
+        // Masking
+        if (_mask) {
+            _mask->update(area, child_ctx, flags, reset);
+            if (outline) {
+                _bbox.unionWith(_mask->_bbox);
+            } else {
+                // for masking, we need full drawbox of mask
+                _drawbox.intersectWith(_mask->_drawbox);
+            }
+        }
+        // Crude fix for outline overlay bbox issues with filtered objects.
+        // (Real solution is to carefully review all bbox/drawbox uses.)
+        if (_drawing.outlineOverlay()) {
+            _bbox |= _drawbox;
+        }
+    }
+    if (to_update & STATE_CACHE) {
+        // Remove old cache iterator.
+        if (_has_cache_iterator) {
+            _drawing._candidate_items.erase(_cache_iterator);
+            _has_cache_iterator = false;
+        }
+
+        // Determine whether this item is cachable.
+        bool isolated = _mask || _filter || _opacity < 0.995
+            || _blend_mode != SP_CSS_BLEND_NORMAL
+            || _isolation == SP_CSS_ISOLATION_ISOLATE
+            || _child_type == ChildType::ROOT;
+        bool cacheable = !_contains_unisolated_blend || isolated;
+
+        // Determine whether to make this item eligible for caching, by creating a cache iterator.
+        double score = _cacheScore();
+        if (score >= CACHE_SCORE_THRESHOLD && cacheable) {
+            CacheRecord cr;
+            cr.score = score;
+            // if _cacheRect() is empty, a negative score will be returned from _cacheScore(),
+            // so this will not execute (cache score threshold must be positive)
+            cr.cache_size = _cacheRect()->area() * 4;
+            cr.item = this;
+            auto it = std::lower_bound(_drawing._candidate_items.begin(), _drawing._candidate_items.end(), cr, std::greater<CacheRecord>());
+            _cache_iterator = _drawing._candidate_items.insert(it, cr);
+            _has_cache_iterator = true;
+        }
+
+        /* Update cache if enabled.
+         * General note: here we only tell the cache how it has to transform
+         * during the render phase. The transformation is deferred because
+         * after the update the item can have its caching turned off,
+         * e.g. because its filter was removed. This way we avoid temporarily
+         * using more memory than the cache budget */
+        if (_cache && _cache->surface) {
+            Geom::OptIntRect cl = _cacheRect();
+            if (_visible && cl && _has_cache_iterator) { // never create cache for invisible items
+                // this takes care of invalidation on transform
+                _cache->surface->scheduleTransform(*cl, ctm_change);
+            } else {
+                // Destroy cache for this item - outside of canvas or invisible.
+                // The opposite transition (invisible -> visible or object
+                // entering the canvas) is handled during the render phase
+                _setCached(false, true);
+            }
+        }
+    }
+
+    if (to_update & STATE_RENDER) {
+        // now that we know drawbox, dirty the corresponding rect on canvas
+        // unless filtered, groups do not need to render by themselves, only their members
+        if (_fill_pattern) {
+            _fill_pattern->update(area, child_ctx, flags, reset);
+        }
+        if (_stroke_pattern) {
+            _stroke_pattern->update(area, child_ctx, flags, reset);
+        }
+        if (!totally_invalidated) {
+            if (!is<DrawingGroup>(this) || (_filter && filters) || totally_invalidate) {
+                _markForRendering();
+            }
+        }
+    }
+}
+
+struct MaskLuminanceToAlpha
+{
+    guint32 operator()(guint32 in)
+    {
+        guint r = 0, g = 0, b = 0;
+        Display::ExtractRGB32(in, r, g, b);
+        // the operation of unpremul -> luminance-to-alpha -> multiply by alpha
+        // is equivalent to luminance-to-alpha on premultiplied color values
+        // original computation in double: r*0.2125 + g*0.7154 + b*0.0721
+        guint32 ao = r*109 + g*366 + b*37; // coeffs add up to 512
+        return ((ao + 256) << 15) & 0xff000000; // equivalent to ((ao + 256) / 512) << 24
+    }
+};
+
+/**
+ * Rasterize items.
+ * This method submits the drawing operations required to draw this item
+ * to the supplied DrawingContext, restricting drawing the specified area.
+ *
+ * This method does some common tasks and calls the item-specific rendering
+ * function, _renderItem(), to render e.g. paths or bitmaps.
+ *
+ * @param flags Rendering options. This deals mainly with cache control.
+ */
+unsigned DrawingItem::render(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags, DrawingItem const *stop_at) const
+{
+    bool const outline = flags & RENDER_OUTLINE;
+    bool const render_filters = !(flags & RENDER_NO_FILTERS);
+    bool const forcecache = _filter && render_filters;
+
+    // stop_at is handled in DrawingGroup, but this check is required to handle the case
+    // where a filtered item with background-accessing filter has enable-background: new
+    if (this == stop_at) {
+        return RENDER_STOP;
+    }
+
+    // If we are invisible, return immediately
+    if (!_visible) {
+        return RENDER_OK;
+    }
+
+    if (_ctm.isSingular(1e-18)) {
+        return RENDER_OK;
+    }
+
+    // TODO convert outline rendering to a separate virtual function
+    if (outline) {
+        _renderOutline(dc, rc, area, flags);
+        return RENDER_OK;
+    }
+
+    Geom::OptIntRect carea = area & _drawbox;
+    if (!carea) {
+        return RENDER_OK;
+    }
+
+    Geom::OptIntRect iarea = carea;
+    // expand carea to contain the dependent area of filters.
+    if (forcecache) {
+        iarea = _cacheRect();
+        if (!iarea) {
+            iarea = carea;
+            _filter->area_enlarge(*iarea, this);
+            iarea.intersectWith(_drawbox);
+        }
+    }
+    // carea is the area to paint
+    carea = iarea & _drawbox;
+    if (!carea) {
+        return RENDER_OK;
+    }
+
+    // Device scale for HiDPI screens (typically 1 or 2)
+    int const device_scale = dc.surface()->device_scale();
+
+    std::unique_lock<std::mutex> lock;
+
+    // Render from cache if possible, unless requested not to (hatches).
+    if (_cache && !(flags & RENDER_BYPASS_CACHE)) {
+        lock = std::unique_lock(_cache->mutables);
+
+        if (_cache->surface) {
+            if (_cache->surface->device_scale() != device_scale) {
+                _cache->surface->markDirty();
+            }
+            _cache->surface->prepare();
+            dc.setOperator(ink_css_blend_to_cairo_operator(_blend_mode));
+            _cache->surface->paintFromCache(dc, carea, forcecache);
+            if (!carea) {
+                dc.setSource(0, 0, 0, 0);
+                return RENDER_OK;
+            }
+        } else {
+            // There is no cache. This could be because caching of this item
+            // was just turned on after the last update phase, or because
+            // we were previously outside of the canvas.
+            Geom::OptIntRect cl = _cacheRect();
+            if (!cl)
+                cl = carea;
+            _cache->surface.emplace(*cl, device_scale);
+        }
+
+        if (!forcecache) {
+            lock.unlock(); // Only hold the lock for the full duration of rendering for filters.
+        }
+    } else {
+        // if our caching was turned off after the last update, it was already deleted in setCached()
+    }
+
+    // determine whether this shape needs intermediate rendering.
+    bool const greyscale = _drawing.colorMode() == ColorMode::GRAYSCALE && !(flags & RENDER_OUTLINE);
+    bool const isolate_root = _contains_unisolated_blend || greyscale;
+    bool const needs_intermediate_rendering =
+           _clip                                  // 1. it has a clipping path
+        || _mask                                  // 2. it has a mask
+        || (_filter && render_filters)            // 3. it has a filter
+        || _opacity < 0.995                       // 4. it is non-opaque
+        || _blend_mode != SP_CSS_BLEND_NORMAL     // 5. it has blend mode
+        || _isolation == SP_CSS_ISOLATION_ISOLATE // 6. it is isolated
+        || (_child_type == ChildType::ROOT && isolate_root) // 7. it is the root and needs isolation
+        || (bool)_cache;                          // 8. it is to be cached
+
+    /* How the rendering is done.
+     *
+     * Clipping, masking and opacity are done by rendering them to a surface
+     * and then compositing the object's rendering onto it with the IN operator.
+     * The object itself is rendered to a group.
+     *
+     * Opacity is done by rendering the clipping path with an alpha
+     * value corresponding to the opacity. If there is no clipping path,
+     * the entire intermediate surface is painted with alpha corresponding
+     * to the opacity value.
+     * 
+     */
+    // Short-circuit the simple case.
+    // We also use this path for filter background rendering, because masking, clipping,
+    // filters and opacity do not apply when rendering the ancestors of the filtered
+    // element
+
+    if ((flags & RENDER_FILTER_BACKGROUND) || !needs_intermediate_rendering) {
+        dc.setOperator(ink_css_blend_to_cairo_operator(SP_CSS_BLEND_NORMAL));
+        return _renderItem(dc, rc, *carea, flags & ~RENDER_FILTER_BACKGROUND, stop_at);
+    }
+
+    DrawingSurface intermediate(*carea, device_scale);
+    DrawingContext ict(intermediate);
+    cairo_set_antialias(ict.raw(), cairo_get_antialias(dc.raw())); // propagate antialias setting
+
+    // This path fails for patterns/hatches when stepping the pattern to handle overflows.
+    // The offsets are applied to drawing context (dc) but they are not copied to the
+    // intermediate context. Something like this is needed:
+    // Copy cairo matrix from dc to intermediate, needed for patterns/hatches
+    // cairo_matrix_t cairo_matrix;
+    // cairo_get_matrix(dc.raw(), &cairo_matrix);
+    // cairo_set_matrix(ict.raw(), &cairo_matrix);
+    // For the moment we disable caching for patterns,
+    //   see https://gitlab.com/inkscape/inkscape/-/issues/309
+
+    unsigned render_result = RENDER_OK;
+
+    // 1. Render clipping path with alpha = opacity.
+    ict.setSource(0,0,0,_opacity);
+    // Since clip can be combined with opacity, the result could be incorrect
+    // for overlapping clip children. To fix this we use the SOURCE operator
+    // instead of the default OVER.
+    ict.setOperator(CAIRO_OPERATOR_SOURCE);
+    ict.paint();
+    if (_clip) {
+        ict.pushGroup();
+        _clip->clip(ict, rc, *carea);
+        ict.popGroupToSource();
+        ict.setOperator(CAIRO_OPERATOR_IN);
+        ict.paint();
+    }
+    ict.setOperator(CAIRO_OPERATOR_OVER); // reset back to default
+
+    // 2. Render the mask if present and compose it with the clipping path + opacity.
+    if (_mask) {
+        ict.pushGroup();
+        _mask->render(ict, rc, *carea, flags);
+
+        cairo_surface_t *mask_s = ict.rawTarget();
+        // Convert mask's luminance to alpha
+        ink_cairo_surface_filter(mask_s, mask_s, MaskLuminanceToAlpha());
+        ict.popGroupToSource();
+        ict.setOperator(CAIRO_OPERATOR_IN);
+        ict.paint();
+        ict.setOperator(CAIRO_OPERATOR_OVER);
+    }
+
+    // 3. Render object itself
+    ict.pushGroup();
+    render_result = _renderItem(ict, rc, *carea, flags, stop_at);
+
+    // 4. Apply filter.
+    if (_filter && render_filters) {
+        bool rendered = false;
+        if (_filter->uses_background() && _background_accumulate) {
+            auto bg_root = this;
+            for (; bg_root; bg_root = bg_root->_parent) {
+                if (bg_root->_background_new || bg_root->_filter) break;
+            }
+            if (bg_root) {
+                DrawingSurface bg(*carea, device_scale);
+                DrawingContext bgdc(bg);
+                bg_root->render(bgdc, rc, *carea, flags | RENDER_FILTER_BACKGROUND, this);
+                _filter->render(this, ict, &bgdc, rc);
+                rendered = true;
+            }
+        }
+        if (!rendered) {
+            _filter->render(this, ict, nullptr, rc);
+        }
+        // Note that because the object was rendered to a group,
+        // the internals of the filter need to use cairo_get_group_target()
+        // instead of cairo_get_target().
+    }
+
+    // 4b. Apply greyscale rendering mode, if root node.
+    if (greyscale && _child_type == ChildType::ROOT) {
+        ink_cairo_surface_filter(ict.rawTarget(), ict.rawTarget(), _drawing.grayscaleMatrix());
+    }
+
+    // 5. Render object inside the composited mask + clip
+    ict.popGroupToSource();
+    ict.setOperator(CAIRO_OPERATOR_IN);
+    ict.paint();
+
+    // 6. Paint the completed rendering onto the base context (or into cache)
+    if (_cache && !(flags & RENDER_BYPASS_CACHE)) {
+        if (!forcecache) {
+            lock.lock(); // Only hold the lock for the full duration of rendering for filters.
+        }
+        assert(lock);
+        assert(_cache->surface);
+
+        auto cachect = DrawingContext(*_cache->surface);
+        cachect.rectangle(*carea);
+        cachect.setOperator(CAIRO_OPERATOR_SOURCE);
+        cachect.setSource(&intermediate);
+        cachect.fill();
+        _cache->surface->markClean(*carea);
+    }
+
+    dc.rectangle(*carea);
+    dc.setSource(&intermediate);
+
+    // 7. Render blend mode
+    dc.setOperator(ink_css_blend_to_cairo_operator(_blend_mode));
+    dc.fill();
+    dc.setSource(0,0,0,0);
+    // Web isolation only works if parent doesn't have transform
+
+    // the call above is to clear a ref on the intermediate surface held by dc
+
+    return render_result;
+}
+
+/**
+ * A stand alone render, ignoring all other objects in the document.
+ */
+unsigned DrawingItem::render(DrawingContext &dc, Geom::IntRect const &area, unsigned flags) const
+{
+    auto rc = RenderContext{ 0xff }; // black outlines
+    return render(dc, rc, area, flags);
+}
+
+void DrawingItem::_renderOutline(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags) const
+{
+    // intersect with bbox rather than drawbox, as we want to render things outside
+    // of the clipping path as well
+    auto carea = Geom::intersect(area, _bbox);
+    if (!carea) return;
+
+    // just render everything: item, clip, mask
+    // First, render the object itself
+    _renderItem(dc, rc, *carea, flags, nullptr);
+
+    // render clip and mask, if any
+    auto saved_rgba = rc.outline_color; // save current outline color
+    // render clippath as an object, using a different color
+    if (_clip) {
+        rc.outline_color = _drawing.clipOutlineColor();
+        _clip->render(dc, rc, *carea, flags);
+    }
+    // render mask as an object, using a different color
+    if (_mask) {
+        rc.outline_color = _drawing.maskOutlineColor();
+        _mask->render(dc, rc, *carea, flags);
+    }
+    rc.outline_color = saved_rgba; // restore outline color
+}
+
+/**
+ * Rasterize the clipping path.
+ * This method submits drawing operations required to draw a basic filled shape
+ * of the item to the supplied drawing context. Rendering is limited to the
+ * given area. The rendering of the clipped object is composited into
+ * the result of this call using the IN operator. See the implementation
+ * of render() for details.
+ */
+void DrawingItem::clip(DrawingContext &dc, Inkscape::RenderContext &rc, Geom::IntRect const &area) const
+{
+    // don't bother if the object does not implement clipping (e.g. DrawingImage)
+    if (!_canClip()) return;
+    if (!_visible) return;
+    if (!area.intersects(_bbox)) return;
+
+    dc.setSource(0,0,0,1);
+    dc.pushGroup();
+    // rasterize the clipping path
+    _clipItem(dc, rc, area);
+    if (_clip) {
+        // The item used as the clipping path itself has a clipping path.
+        // Render this item's clipping path onto a temporary surface, then composite it
+        // with the item using the IN operator
+        dc.pushGroup();
+        _clip->clip(dc, rc, area);
+        dc.popGroupToSource();
+        dc.setOperator(CAIRO_OPERATOR_IN);
+        dc.paint();
+    }
+    dc.popGroupToSource();
+    dc.setOperator(CAIRO_OPERATOR_OVER);
+    dc.paint();
+    dc.setSource(0,0,0,0);
+}
+
+/**
+ * Get the item under the specified point.
+ * Searches the tree for the first item in the Z-order which is closer than
+ * @a delta to the given point. The pick should be visual - for example
+ * an object with a thick stroke should pick on the entire area of the stroke.
+ * @param p Search point
+ * @param delta Maximum allowed distance from the point
+ * @param sticky Whether the pick should ignore visibility and sensitivity.
+ *               When false, only visible and sensitive objects are considered.
+ *               When true, invisible and insensitive objects can also be picked.
+ */
+DrawingItem *DrawingItem::pick(Geom::Point const &p, double delta, unsigned flags)
+{
+    // Sometimes there's no BBOX in state, reason unknown (bug 992817)
+    // I made this not an assert to remove the warning
+    if (!(_state & STATE_BBOX) || !(_state & STATE_PICK)) {
+        g_warning("Invalid state when picking: STATE_BBOX = %d, STATE_PICK = %d", _state & STATE_BBOX, _state & STATE_PICK);
+        return nullptr;
+    }
+    // ignore invisible and insensitive items unless sticky
+    if (!(flags & PICK_STICKY) && !(_visible && _sensitive)) {
+        return nullptr;
+    }
+
+    bool outline = flags & PICK_OUTLINE;
+
+    if (!outline) {
+        // pick inside clipping path; if NULL, it means the object is clipped away there
+        if (_clip) {
+            DrawingItem *cpick = _clip->pick(p, delta, flags | PICK_AS_CLIP);
+            if (!cpick) {
+                return nullptr;
+            }
+        }
+        // same for mask
+        if (_mask) {
+            DrawingItem *mpick = _mask->pick(p, delta, flags);
+            if (!mpick) {
+                return nullptr;
+            }
+        }
+    }
+
+    Geom::OptIntRect box = outline || (flags & PICK_AS_CLIP) ? _bbox : _drawbox;
+    if (!box) {
+        return nullptr;
+    }
+
+    Geom::Rect expanded = *box;
+    expanded.expandBy(delta);
+    auto dglyps = cast<DrawingGlyphs>(this);
+    if (dglyps && !(flags & PICK_AS_CLIP)) {
+        expanded = dglyps->getPickBox();
+    }
+
+    if (expanded.contains(p)) {
+        return _pickItem(p, delta, flags);
+    }
+    return nullptr;
+}
+
+// For debugging
+Glib::ustring DrawingItem::name() const
+{
+    if (_item) {
+        if (_item->getId())
+            return _item->getId();
+        else
+            return "No object id";
+    } else {
+        return "No associated object";
+    }
+}
+
+// For debugging: Print drawing tree structure.
+void DrawingItem::recursivePrintTree(unsigned level) const
+{
+    if (level == 0) {
+        std::cout << "Display Item Tree" << std::endl;
+    }
+    std::cout << "DI: ";
+    for (int i = 0; i < level; i++) {
+        std::cout << "  ";
+    }
+    std::cout << name() << std::endl;
+    for (auto &i : _children) {
+        i.recursivePrintTree(level + 1);
+    }
+}
+
+/**
+ * Marks the current visual bounding box of the item for redrawing.
+ * This is called whenever the object changes its visible appearance.
+ * For some cases (such as setting opacity) this is enough, but for others
+ * _markForUpdate() also needs to be called.
+ */
+void DrawingItem::_markForRendering()
+{
+    bool outline = _drawing.renderMode() == RenderMode::OUTLINE || _drawing.outlineOverlay();
+    Geom::OptIntRect dirty = outline ? _bbox : _drawbox;
+    if (!dirty) return;
+
+    // dirty the caches of all parents
+    DrawingItem *bkg_root = nullptr;
+
+    for (auto i = this; i; i = i->_parent) {
+        if (i != this && i->_filter) {
+            i->_filter->area_enlarge(*dirty, i);
+        }
+        if (i->_cache && i->_cache->surface) {
+            i->_cache->surface->markDirty(*dirty);
+        }
+        i->_dropPatternCache();
+        if (i->_background_accumulate) {
+            bkg_root = i;
+        }
+    }
+
+    if (bkg_root && bkg_root->_parent && bkg_root->_parent->_parent) {
+        bkg_root->_invalidateFilterBackground(*dirty);
+    }
+
+    if (auto canvasitem = drawing().getCanvasItemDrawing()) {
+        canvasitem->get_canvas()->redraw_area(*dirty);
+    }
+}
+
+void DrawingItem::_invalidateFilterBackground(Geom::IntRect const &area)
+{
+    if (!_drawbox.intersects(area)) return;
+
+    if (_cache && _cache->surface && _filter && _filter->uses_background()) {
+        _cache->surface->markDirty(area);
+    }
+
+    for (auto & i : _children) {
+        i._invalidateFilterBackground(area);
+    }
+}
+
+/**
+ * Marks the item as needing a recomputation of internal data.
+ *
+ * This mechanism avoids traversing the entire rendering tree (which could be vast)
+ * on every trivial state changed in any item. Only items marked as needing
+ * an update (having some bits in their _state unset) will be traversed
+ * during the update call.
+ *
+ * The _propagate variable is another optimization. We use it to specify that
+ * all children should also have the corresponding flags unset before checking
+ * whether they need to be traversed. This way there is one less traversal
+ * of the tree. Without this we would need to unset state bits in all children.
+ * With _propagate we do this during the update call, when we have to recurse
+ * into children anyway.
+ */
+void DrawingItem::_markForUpdate(unsigned flags, bool propagate)
+{
+    if (propagate) {
+        _propagate_state |= flags;
+    }
+
+    if (_state & flags) {
+        unsigned oldstate = _state;
+        _state &= ~flags;
+        if (oldstate != _state && _parent) {
+            // If we actually reset anything in state, recurse on the parent.
+            _parent->_markForUpdate(flags, false);
+        } else {
+            // If nothing changed, it means our ancestors are already invalidated
+            // up to the root. Do not bother recursing, because it won't change anything.
+            // Also do this if we are the root item, because we have no more ancestors
+            // to invalidate.
+            if (drawing().getCanvasItemDrawing()) {
+                drawing().getCanvasItemDrawing()->request_update();
+            } else {
+                // Typically happens, e.g. for any non-Canvas Drawing.
+            }
+        }
+    }
+}
+
+/**
+ * Compute the caching score.
+ *
+ * Higher scores mean the item is more aggressively prioritized for automatic
+ * caching by Inkscape::Drawing.
+ */
+double DrawingItem::_cacheScore()
+{
+    Geom::OptIntRect cache_rect = _cacheRect();
+    if (!cache_rect) return -1.0;
+    // a crude first approximation:
+    // the basic score is the number of pixels in the drawbox
+    double score = cache_rect->area();
+    // this is multiplied by the filter complexity and its expansion
+    if (_filter && _drawing.renderMode() != RenderMode::NO_FILTERS) {
+        score *= _filter->complexity(_ctm);
+        Geom::IntRect ref_area = Geom::IntRect::from_xywh(0, 0, 16, 16);
+        Geom::IntRect test_area = ref_area;
+        Geom::IntRect limit_area(0, INT_MIN, 16, INT_MAX);
+        _filter->area_enlarge(test_area, this);
+        // area_enlarge never shrinks the rect, so the result of intersection below must be non-empty
+        score *= (double)(test_area & limit_area)->area() / ref_area.area();
+    }
+    // if the object is clipped, add 1/2 of its bbox pixels
+    if (_clip && _clip->_bbox) {
+        score += _clip->_bbox->area() * 0.5;
+    }
+    // if masked, add mask score
+    if (_mask) {
+        score += _mask->_cacheScore();
+    }
+    //g_message("caching score: %f", score);
+    return score;
+}
+
+inline void expandByScale(Geom::IntRect &rect, double scale)
+{
+    double fraction = (scale - 1) / 2;
+    rect.expandBy(rect.width() * fraction, rect.height() * fraction);
+}
+
+Geom::OptIntRect DrawingItem::_cacheRect() const
+{
+    Geom::OptIntRect r = _drawbox & _drawing.cacheLimit();
+    if (_filter && _drawing.cacheLimit() && _drawing.renderMode() != RenderMode::NO_FILTERS && r && r != _drawbox) {
+        // we check unfiltered item is enough inside the cache area to render properly
+        Geom::OptIntRect canvas = r;
+        expandByScale(*canvas, 0.5);
+        Geom::OptIntRect valid = Geom::intersect(canvas, _bbox);
+        if (!valid && _bbox) {
+            valid = _bbox;
+            // contract the item _bbox to get reduced size to render. $ seems good enough
+            expandByScale(*valid, 0.5);
+            // now we get the nearest point to cache area
+            Geom::IntPoint center = _drawing.cacheLimit()->midpoint();
+            Geom::IntPoint nearest = valid->nearestEdgePoint(center);
+            r.expandTo(nearest);
+        }
+        return _drawbox & r;
+    }
+    return r;
+}
+
+void apply_antialias(DrawingContext &dc, int antialias)
+{
+    switch (antialias) {
+        case 0:
+            cairo_set_antialias(dc.raw(), CAIRO_ANTIALIAS_NONE);
+            break;
+        case 1:
+            cairo_set_antialias(dc.raw(), CAIRO_ANTIALIAS_FAST);
+            break;
+        case 2:
+            cairo_set_antialias(dc.raw(), CAIRO_ANTIALIAS_GOOD);
+            break;
+        case 3:
+            cairo_set_antialias(dc.raw(), CAIRO_ANTIALIAS_BEST);
+            break;
+        default:
+            g_assert_not_reached();
+    }
+}
+
+// Remove this node from its parent, then delete it.
+void DrawingItem::unlink()
+{
+    defer([=] {
+        // This only happens for the top-level deleted item.
+        if (_parent) {
+            _markForRendering();
+        }
+
+        switch (_child_type) {
+            case ChildType::NORMAL: {
+                auto it = _parent->_children.iterator_to(*this);
+                _parent->_children.erase(it);
+                break;
+            }
+            case ChildType::CLIP:
+                _parent->_clip = nullptr;
+                break;
+            case ChildType::MASK:
+                _parent->_mask = nullptr;
+                break;
+            case ChildType::FILL:
+                _parent->_fill_pattern = nullptr;
+                break;
+            case ChildType::STROKE:
+                _parent->_stroke_pattern = nullptr;
+                break;
+            case ChildType::ROOT:
+                _drawing._root = nullptr;
+                break;
+            default:
+                break;
+        }
+
+        if (_parent) {
+            bool propagate = _child_type == ChildType::CLIP || _child_type == ChildType::MASK;
+            _parent->_markForUpdate(STATE_ALL, propagate);
+        }
+
+        delete this;
+    });
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-item.h b/src/display/drawing-item.h
new file mode 100644
index 0000000..a003444
--- /dev/null
+++ b/src/display/drawing-item.h
@@ -0,0 +1,276 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Canvas item belonging to an SVG drawing element.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef INKSCAPE_DISPLAY_DRAWING_ITEM_H
+#define INKSCAPE_DISPLAY_DRAWING_ITEM_H
+
+#include <memory>
+#include <list>
+#include <exception>
+
+#include <boost/operators.hpp>
+#include <boost/utility.hpp>
+#include <boost/intrusive/list.hpp>
+
+#include <2geom/rect.h>
+#include <2geom/affine.h>
+
+#include "style-enums.h"
+#include "tags.h"
+
+namespace Glib { class ustring; }
+class SPStyle;
+class SPItem;
+
+namespace Inkscape {
+
+class Drawing;
+class DrawingCache;
+class DrawingItem;
+class DrawingPattern;
+class DrawingContext;
+namespace Filters { class Filter; }
+
+struct RenderContext
+{
+    uint32_t outline_color;
+};
+
+struct UpdateContext
+{
+    Geom::Affine ctm;
+};
+
+struct CacheData;
+
+struct CacheRecord : boost::totally_ordered<CacheRecord>
+{
+    bool operator<(CacheRecord const &other) const { return score < other.score; }
+    bool operator==(CacheRecord const &other) const { return score == other.score; }
+    operator DrawingItem*() const { return item; }
+    double score;
+    size_t cache_size;
+    DrawingItem *item;
+};
+using CacheList = std::list<CacheRecord>;
+
+struct InvalidItemException : std::exception
+{
+    char const *what() const noexcept override { return "Invalid item in drawing"; }
+};
+
+class DrawingItem
+{
+public:
+    enum RenderFlags
+    {
+        RENDER_DEFAULT           = 0,
+        RENDER_CACHE_ONLY        = 1 << 0,
+        RENDER_BYPASS_CACHE      = 1 << 1,
+        RENDER_FILTER_BACKGROUND = 1 << 2,
+        RENDER_OUTLINE           = 1 << 3,
+        RENDER_NO_FILTERS        = 1 << 4,
+        RENDER_VISIBLE_HAIRLINES = 1 << 5
+    };
+    enum StateFlags
+    {
+        STATE_NONE       = 0,
+        STATE_BBOX       = 1 << 0, // bounding boxes are up-to-date
+        STATE_CACHE      = 1 << 1, // cache extents and clean area are up-to-date
+        STATE_PICK       = 1 << 2, // can process pick requests
+        STATE_RENDER     = 1 << 3, // can be rendered
+        STATE_BACKGROUND = 1 << 4, // filter background data is up to date
+        STATE_ALL        = (1 << 5) - 1,
+        STATE_TOTAL_INV  = 1 << 5, // used as a reset flag only
+    };
+    enum PickFlags
+    {
+        PICK_NORMAL  = 0,      // normal pick
+        PICK_STICKY  = 1 << 0, // sticky pick - ignore visibility and sensitivity
+        PICK_AS_CLIP = 1 << 1, // pick with no stroke and opaque fill regardless of item style
+        PICK_OUTLINE = 1 << 2  // pick in outline mode
+    };
+
+    DrawingItem(Drawing &drawing);
+    DrawingItem(DrawingItem const &) = delete;
+    DrawingItem &operator=(DrawingItem const &) = delete;
+    void unlink(); /// Unlink this node and its subtree from the rendering tree and destroy.
+    virtual int tag() const { return tag_of<decltype(*this)>; }
+
+    Geom::OptIntRect const &bbox() const { return _bbox; }
+    Geom::OptIntRect const &drawbox() const { return _drawbox; }
+    Geom::OptRect const &itemBounds() const { return _item_bbox; }
+    Geom::Affine const &ctm() const { return _ctm; }
+    Geom::Affine transform() const { return _transform ? *_transform : Geom::identity(); }
+    Drawing &drawing() const { return _drawing; }
+    DrawingItem *parent() const { return _parent; }
+    bool isAncestorOf(DrawingItem const *item) const;
+    int getUpdateComplexity() const { return _update_complexity; }
+    bool unisolatedBlend() const;
+
+    void appendChild(DrawingItem *item);
+    void prependChild(DrawingItem *item);
+    void clearChildren();
+
+    bool visible() const { return _visible; }
+    void setVisible(bool visible);
+    bool sensitive() const { return _sensitive; }
+    void setSensitive(bool sensitive);
+
+    virtual void setStyle(SPStyle const *style, SPStyle const *context_style = nullptr);
+    virtual void setChildrenStyle(SPStyle const *context_style);
+    void setOpacity(float opacity);
+    void setAntialiasing(unsigned antialias);
+    unsigned antialiasing() const { return _antialias; }
+    void setIsolation(bool isolation); // CSS Compositing and Blending
+    void setBlendMode(SPBlendMode blend_mode);
+    void setTransform(Geom::Affine const &trans);
+    void setClip(DrawingItem *item);
+    void setMask(DrawingItem *item);
+    void setFillPattern(DrawingPattern *pattern);
+    void setStrokePattern(DrawingPattern *pattern);
+    void setZOrder(unsigned zorder);
+    void setItemBounds(Geom::OptRect const &bounds);
+    void setFilterRenderer(std::unique_ptr<Filters::Filter> renderer);
+
+    void setKey(unsigned key) { _key = key; }
+    unsigned key() const { return _key; }
+    void setItem(SPItem *item) { _item = item; }
+    SPItem *getItem() const { return _item; } // SPItem
+
+    void update(Geom::IntRect const &area = Geom::IntRect::infinite(), UpdateContext const &ctx = UpdateContext(), unsigned flags = STATE_ALL, unsigned reset = 0);
+    unsigned render(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags = 0, DrawingItem const *stop_at = nullptr) const;
+    unsigned render(DrawingContext &dc, Geom::IntRect const &area, unsigned flags = 0) const;
+    void clip(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area) const;
+    DrawingItem *pick(Geom::Point const &p, double delta, unsigned flags = 0);
+
+    Glib::ustring name() const; // For debugging
+    void recursivePrintTree(unsigned level = 0) const;  // For debugging
+
+protected:
+    enum class ChildType : unsigned char
+    {
+        ORPHAN = 0, // No parent - implies !parent.
+        NORMAL = 1, // Contained in children of parent.
+        CLIP   = 2, // Referenced by clip of parent.
+        MASK   = 3, // Referenced by mask of parent.
+        FILL   = 4, // Referenced by fill pattern of parent.
+        STROKE = 5, // Referenced by stroke pattern of parent.
+        ROOT   = 6  // Referenced by root of drawing.
+    };
+    enum RenderResult
+    {
+        RENDER_OK   = 0,
+        RENDER_STOP = 1
+    };
+    virtual ~DrawingItem(); // Private to prevent deletion of items that are still in use by a snapshot.
+    void _renderOutline(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags) const;
+    void _markForUpdate(unsigned state, bool propagate);
+    void _markForRendering();
+    void _invalidateFilterBackground(Geom::IntRect const &area);
+    double _cacheScore();
+    Geom::OptIntRect _cacheRect() const;
+    void _setCached(bool cached, bool persistent = false);
+    virtual unsigned _updateItem(Geom::IntRect const &area, UpdateContext const &ctx, unsigned flags, unsigned reset) { return 0; }
+    virtual unsigned _renderItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags, DrawingItem const *stop_at) const { return RENDER_OK; }
+    virtual void _clipItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area) const {}
+    virtual DrawingItem *_pickItem(Geom::Point const &p, double delta, unsigned flags) { return nullptr; }
+    virtual bool _canClip() const { return false; }
+    virtual void _dropPatternCache() {}
+
+    Drawing &_drawing;
+    DrawingItem *_parent;
+
+    using ListHook = boost::intrusive::list_member_hook<>;
+    ListHook _child_hook;
+
+    using ChildrenList = boost::intrusive::list<
+        DrawingItem,
+        boost::intrusive::member_hook<DrawingItem, ListHook, &DrawingItem::_child_hook>
+        >;
+    ChildrenList _children;
+
+    // Todo: Try to get rid of all of these variables, moving them into the object tree.
+    unsigned _key; ///< Auxiliary key used by the object tree for showing clips/masks/patterns.
+    SPItem *_item; ///< Used to associate DrawingItems with SPItems that created them
+    SPStyle const *_style; // Not used by DrawingGlyphs
+    SPStyle const *_context_style; // Used for 'context-fill', 'context-stroke'
+
+    float _opacity;
+    std::unique_ptr<Geom::Affine> _transform; ///< Incremental transform from parent to this item's coords
+    Geom::Affine _ctm; ///< Total transform from item coords to display coords
+    Geom::OptIntRect _bbox; ///< Bounding box in display (pixel) coords including stroke
+    Geom::OptIntRect _drawbox; ///< Full visual bounding box - enlarged by filters, shrunk by clips and masks
+    Geom::OptRect _item_bbox; ///< Geometric bounding box in item's user space.
+                              ///  This is used to compute the filter effect region and render in
+                              ///  objectBoundingBox units.
+
+    DrawingItem *_clip;
+    DrawingItem *_mask;
+    DrawingPattern *_fill_pattern;
+    DrawingPattern *_stroke_pattern;
+    std::unique_ptr<Inkscape::Filters::Filter> _filter;
+    std::unique_ptr<CacheData> _cache;
+    int _update_complexity = 0;
+    bool _contains_unisolated_blend : 1;
+
+    CacheList::iterator _cache_iterator;
+
+    bool style_vector_effect_size   : 1;
+    bool style_vector_effect_rotate : 1;
+    bool style_vector_effect_fixed  : 1;
+
+    unsigned _state : 8;
+    unsigned _propagate_state : 8;
+    ChildType _child_type : 3;
+    unsigned _background_new : 1; ///< Whether enable-background: new is set for this element
+    unsigned _background_accumulate : 1; ///< Whether this element accumulates background 
+                                         ///  (has any ancestor with enable-background: new)
+    unsigned _visible : 1;
+    unsigned _sensitive : 1; ///< Whether this item responds to events
+    unsigned _cached_persistent : 1; ///< If set, will always be cached regardless of score
+    unsigned _has_cache_iterator : 1; ///< If set, _cache_iterator is valid
+    unsigned _pick_children : 1; ///< For groups: if true, children are returned from pick(),
+                                 ///  otherwise the group is returned
+    unsigned _antialias : 2; ///< antialiasing level (NONE/FAST/GOOD(DEFAULT)/BEST)
+
+    bool _isolation : 1;
+    SPBlendMode _blend_mode;
+
+    template<typename F>
+    void defer(F &&f)
+    {
+        // Introduce artificial dependence on a template parameter to allow definition with Drawing forward-declared.
+        auto &drawing = static_cast<std::enable_if_t<(sizeof(F) > 0), Drawing&>>(_drawing);
+        drawing.defer(std::forward<F>(f));
+    }
+
+    friend class Drawing;
+};
+
+/// Apply antialias setting to Cairo.
+void apply_antialias(DrawingContext &dc, int antialias);
+
+} // namespace Inkscape
+
+#endif // INKSCAPE_DISPLAY_DRAWING_ITEM_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-paintserver.cpp b/src/display/drawing-paintserver.cpp
new file mode 100644
index 0000000..e018d8b
--- /dev/null
+++ b/src/display/drawing-paintserver.cpp
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include "drawing-paintserver.h"
+#include "cairo-utils.h"
+
+namespace Inkscape {
+
+DrawingPaintServer::~DrawingPaintServer() = default;
+
+cairo_pattern_t *DrawingSolidColor::create_pattern(cairo_t *, Geom::OptRect const &, double opacity) const
+{
+    return cairo_pattern_create_rgba(c[0], c[1], c[2], alpha * opacity);
+}
+
+void DrawingGradient::common_setup(cairo_pattern_t *pat, Geom::OptRect const &bbox, double opacity) const
+{
+    // set spread type
+    switch (spread) {
+        case SP_GRADIENT_SPREAD_REFLECT:
+            cairo_pattern_set_extend(pat, CAIRO_EXTEND_REFLECT);
+            break;
+        case SP_GRADIENT_SPREAD_REPEAT:
+            cairo_pattern_set_extend(pat, CAIRO_EXTEND_REPEAT);
+            break;
+        case SP_GRADIENT_SPREAD_PAD:
+        default:
+            cairo_pattern_set_extend(pat, CAIRO_EXTEND_PAD);
+            break;
+    }
+
+    // set pattern transform matrix
+    auto gs2user = transform;
+    if (units == SP_GRADIENT_UNITS_OBJECTBOUNDINGBOX && bbox) {
+        auto bbox2user = Geom::Affine(bbox->width(), 0, 0, bbox->height(), bbox->left(), bbox->top());
+        gs2user *= bbox2user;
+    }
+    ink_cairo_pattern_set_matrix(pat, gs2user.inverse());
+}
+
+cairo_pattern_t *DrawingLinearGradient::create_pattern(cairo_t *, Geom::OptRect const &bbox, double opacity) const
+{
+    auto pat = cairo_pattern_create_linear(x1, y1, x2, y2);
+
+    common_setup(pat, bbox, opacity);
+
+    // add stops
+    for (auto &stop : stops) {
+        // multiply stop opacity by paint opacity
+        cairo_pattern_add_color_stop_rgba(pat, stop.offset, stop.color.v.c[0], stop.color.v.c[1], stop.color.v.c[2], stop.opacity * opacity);
+    }
+
+    return pat;
+}
+
+cairo_pattern_t *DrawingRadialGradient::create_pattern(cairo_t *ct, Geom::OptRect const &bbox, double opacity) const
+{
+    Geom::Point focus(fx, fy);
+    Geom::Point center(cx, cy);
+
+    double radius = r;
+    double focusr = fr;
+    double scale = 1.0;
+    double tolerance = cairo_get_tolerance(ct);
+
+    Geom::Affine gs2user = transform;
+
+    if (units == SP_GRADIENT_UNITS_OBJECTBOUNDINGBOX && bbox) {
+        Geom::Affine bbox2user(bbox->width(), 0, 0, bbox->height(), bbox->left(), bbox->top());
+        gs2user *= bbox2user;
+    }
+
+    // we need to use vectors with the same direction to represent the transformed
+    // radius and the focus-center delta, because gs2user might contain non-uniform scaling
+    Geom::Point d(focus - center);
+    Geom::Point d_user(d.length(), 0);
+    Geom::Point r_user(radius, 0);
+    Geom::Point fr_user(focusr, 0);
+    d_user *= gs2user.withoutTranslation();
+    r_user *= gs2user.withoutTranslation();
+    fr_user *= gs2user.withoutTranslation();
+
+    double dx = d_user.x(), dy = d_user.y();
+    cairo_user_to_device_distance(ct, &dx, &dy);
+
+    // compute the tolerance distance in user space
+    // create a vector with the same direction as the transformed d,
+    // with the length equal to tolerance
+    double dl = hypot(dx, dy);
+    double tx = tolerance * dx / dl, ty = tolerance * dy / dl;
+    cairo_device_to_user_distance(ct, &tx, &ty);
+    double tolerance_user = hypot(tx, ty);
+
+    if (d_user.length() + tolerance_user > r_user.length()) {
+        scale = r_user.length() / d_user.length();
+
+        // nudge the focus slightly inside
+        scale *= 1.0 - 2.0 * tolerance / dl;
+    }
+
+    auto pat = cairo_pattern_create_radial(scale * d.x() + center.x(), scale * d.y() + center.y(), focusr, center.x(), center.y(), radius);
+
+    common_setup(pat, bbox, opacity);
+
+    // add stops
+    for (auto &stop : stops) {
+        // multiply stop opacity by paint opacity
+        cairo_pattern_add_color_stop_rgba(pat, stop.offset, stop.color.v.c[0], stop.color.v.c[1], stop.color.v.c[2], stop.opacity * opacity);
+    }
+
+    return pat;
+}
+
+cairo_pattern_t *DrawingMeshGradient::create_pattern(cairo_t *, Geom::OptRect const &bbox, double opacity) const
+{
+#ifdef MESH_DEBUG
+    std::cout << "sp_meshgradient_create_pattern: " << bbox << " " << opacity << std::endl;
+#endif
+
+    auto pat = cairo_pattern_create_mesh();
+
+    for (int i = 0; i < rows; i++) {
+        for (int j = 0; j < cols; j++) {
+            auto &data = patchdata[i][j];
+
+            cairo_mesh_pattern_begin_patch(pat);
+            cairo_mesh_pattern_move_to(pat, data.points[0][0].x(), data.points[0][0].y());
+
+            for (int k = 0; k < 4; k++) {
+                switch (data.pathtype[k]) {
+                case 'l':
+                case 'L':
+                case 'z':
+                case 'Z':
+                    cairo_mesh_pattern_line_to(pat, data.points[k][3].x(), data.points[k][3].y());
+                    break;
+                case 'c':
+                case 'C':
+                    cairo_mesh_pattern_curve_to(pat, data.points[k][1].x(), data.points[k][1].y(),
+                            data.points[k][2].x(), data.points[k][2].y(),
+                            data.points[k][3].x(), data.points[k][3].y());
+                    break;
+                default:
+                    // Shouldn't happen
+                    std::cerr << "sp_mesh_create_pattern: path error" << std::endl;
+                }
+
+                if (data.tensorIsSet[k]) {
+                    Geom::Point t = data.tensorpoints[k];
+                    cairo_mesh_pattern_set_control_point(pat, k, t.x(), t.y());
+                }
+
+                cairo_mesh_pattern_set_corner_color_rgba(pat, k,
+                                                         data.color[k][0],
+                        data.color[k][1],
+                        data.color[k][2],
+                        data.opacity[k] * opacity);
+            }
+
+            cairo_mesh_pattern_end_patch(pat);
+        }
+    }
+
+    // set pattern transform matrix
+    Geom::Affine gs2user = transform;
+    if (units == SP_GRADIENT_UNITS_OBJECTBOUNDINGBOX && bbox) {
+        Geom::Affine bbox2user(bbox->width(), 0, 0, bbox->height(), bbox->left(), bbox->top());
+        gs2user *= bbox2user;
+    }
+    ink_cairo_pattern_set_matrix(pat, gs2user.inverse());
+
+    return pat;
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-paintserver.h b/src/display/drawing-paintserver.h
new file mode 100644
index 0000000..eb68f6b
--- /dev/null
+++ b/src/display/drawing-paintserver.h
@@ -0,0 +1,186 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef INKSCAPE_DISPLAY_DRAWING_PAINT_SERVER_H
+#define INKSCAPE_DISPLAY_DRAWING_PAINT_SERVER_H
+/**
+ * @file
+ * Representation of paint servers used when rendering.
+ */
+/*
+ * Author: PBS <pbs3141@gmail.com>
+ * Copyright (C) 2022 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <array>
+#include <vector>
+#include <cairo.h>
+#include <2geom/rect.h>
+#include <2geom/affine.h>
+#include "object/sp-gradient-spread.h"
+#include "object/sp-gradient-units.h"
+#include "object/sp-gradient-vector.h"
+
+class SPGradient;
+
+namespace Inkscape {
+
+/**
+ * A DrawingPaintServer is a lightweight copy of the resources needed to paint using a paint server.
+ *
+ * It is built by an SPPaintServer, stored in the DrawingItem tree, and used when rendering.
+ *
+ * The pattern information is stored in a rendering-backend agnostic way, and the object remains
+ * valid even after the original SPPaintServer is modified or destroyed.
+ */
+class DrawingPaintServer
+{
+public:
+    virtual ~DrawingPaintServer() = 0;
+
+    /// Produce a pattern that can be used for painting with Cairo.
+    virtual cairo_pattern_t *create_pattern(cairo_t *ct, Geom::OptRect const &bbox, double opacity) const = 0;
+
+    /// Return whether this paint server could benefit from dithering.
+    virtual bool ditherable() const { return false; }
+
+    /// Return whether create_pattern() uses its cairo_t argument. Such pattern cannot be cached, but recreated each time.
+    /// Fixme: The only reson this exists is to work around https://gitlab.freedesktop.org/cairo/cairo/-/issues/146.
+    virtual bool uses_cairo_ctx() const { return false; }
+};
+
+// Todo: Remove, merging with existing implementation for solid colours.
+/**
+ * A simple solid color, storing an RGB color and an opacity.
+ */
+class DrawingSolidColor final
+    : public DrawingPaintServer
+{
+public:
+    DrawingSolidColor(float *c, double alpha)
+        : c({c[0], c[1], c[2]})
+        , alpha(alpha) {}
+
+    cairo_pattern_t *create_pattern(cairo_t *, Geom::OptRect const &, double opacity) const override;
+
+private:
+    std::array<float, 3> c; ///< RGB color components.
+    double alpha;
+};
+
+/**
+ * The base class for all gradients.
+ */
+class DrawingGradient
+    : public DrawingPaintServer
+{
+protected:
+    DrawingGradient(SPGradientSpread spread, SPGradientUnits units, Geom::Affine const &transform)
+        : spread(spread)
+        , units(units)
+        , transform(transform) {}
+
+    bool ditherable() const override { return true; }
+
+    /// Perform some common initialization steps on the given Cairo pattern.
+    void common_setup(cairo_pattern_t *pat, Geom::OptRect const &bbox, double opacity) const;
+
+    SPGradientSpread spread;
+    SPGradientUnits units;
+    Geom::Affine transform;
+};
+
+/**
+ * A linear gradient.
+ */
+class DrawingLinearGradient final
+    : public DrawingGradient
+{
+public:
+    DrawingLinearGradient(SPGradientSpread spread, SPGradientUnits units, Geom::Affine const &transform,
+                          float x1, float y1, float x2, float y2, std::vector<SPGradientStop> stops)
+        : DrawingGradient(spread, units, transform)
+        , x1(x1)
+        , y1(y1)
+        , x2(x2)
+        , y2(y2)
+        , stops(std::move(stops)) {}
+
+    cairo_pattern_t *create_pattern(cairo_t*, Geom::OptRect const &bbox, double opacity) const override;
+
+private:
+    float x1, y1, x2, y2;
+    std::vector<SPGradientStop> stops;
+};
+
+/**
+ * A radial gradient.
+ */
+class DrawingRadialGradient final
+    : public DrawingGradient
+{
+public:
+    DrawingRadialGradient(SPGradientSpread spread, SPGradientUnits units, Geom::Affine const &transform,
+                          float fx, float fy, float cx, float cy, float r, float fr, std::vector<SPGradientStop> stops)
+        : DrawingGradient(spread, units, transform)
+        , fx(fx)
+        , fy(fy)
+        , cx(cx)
+        , cy(cy)
+        , r(r)
+        , fr(fr)
+        , stops(std::move(stops)) {}
+
+    cairo_pattern_t *create_pattern(cairo_t *ct, Geom::OptRect const &bbox, double opacity) const override;
+
+    bool uses_cairo_ctx() const override { return true; }
+
+private:
+    float fx, fy, cx, cy, r, fr;
+    std::vector<SPGradientStop> stops;
+};
+
+/**
+ * A mesh gradient.
+ */
+class DrawingMeshGradient final
+    : public DrawingGradient
+{
+public:
+    struct PatchData
+    {
+        Geom::Point points[4][4];
+        char pathtype[4];
+        bool tensorIsSet[4];
+        Geom::Point tensorpoints[4];
+        std::array<float, 3> color[4];
+        double opacity[4];
+    };
+
+    DrawingMeshGradient(SPGradientSpread spread, SPGradientUnits units, Geom::Affine const &transform,
+                        int rows, int cols, std::vector<std::vector<PatchData>> patchdata)
+        : DrawingGradient(spread, units, transform)
+        , rows(rows)
+        , cols(cols)
+        , patchdata(std::move(patchdata)) {}
+
+    cairo_pattern_t *create_pattern(cairo_t*, Geom::OptRect const &bbox, double opacity) const override;
+
+private:
+    int rows;
+    int cols;
+    std::vector<std::vector<PatchData>> patchdata;
+};
+
+} // namespace Inkscape
+
+#endif // INKSCAPE_DISPLAY_DRAWING_PAINT_SERVER_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-pattern.cpp b/src/display/drawing-pattern.cpp
new file mode 100644
index 0000000..fb21cbc
--- /dev/null
+++ b/src/display/drawing-pattern.cpp
@@ -0,0 +1,304 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Canvas belonging to SVG pattern.
+ *//*
+ * Authors:
+ *   Tomasz Boczkowski <penginsbacon@gmail.com>
+ *
+ * Copyright (C) 2014 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cairomm/region.h>
+#include "cairo-utils.h"
+#include "drawing-context.h"
+#include "drawing-pattern.h"
+#include "drawing-surface.h"
+#include "drawing.h"
+#include "helper/geom.h"
+#include "ui/util.h"
+
+namespace Inkscape {
+
+DrawingPattern::Surface::Surface(Geom::IntRect const &rect, int device_scale)
+    : rect(rect)
+    , surface(Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32, rect.width() * device_scale, rect.height() * device_scale))
+{
+    cairo_surface_set_device_scale(surface->cobj(), device_scale, device_scale);
+}
+
+DrawingPattern::DrawingPattern(Drawing &drawing)
+    : DrawingGroup(drawing)
+    , _overflow_steps(1)
+{
+}
+
+void DrawingPattern::setPatternToUserTransform(Geom::Affine const &transform)
+{
+    defer([=] {
+        auto constexpr EPS = 1e-18;
+        auto current = _pattern_to_user ? *_pattern_to_user : Geom::identity();
+        if (Geom::are_near(transform, current, EPS)) return;
+        _markForRendering();
+        _pattern_to_user = transform.isIdentity(EPS) ? nullptr : std::make_unique<Geom::Affine>(transform);
+        _markForUpdate(STATE_ALL, true);
+    });
+}
+
+void DrawingPattern::setTileRect(Geom::Rect const &tile_rect)
+{
+    defer([=] {
+        _tile_rect = tile_rect;
+        _markForUpdate(STATE_ALL, true);
+    });
+}
+
+void DrawingPattern::setOverflow(Geom::Affine const &initial_transform, int steps, Geom::Affine const &step_transform)
+{
+    defer([=] {
+        _overflow_initial_transform = initial_transform;
+        _overflow_steps = steps;
+        _overflow_step_transform = step_transform;
+    });
+}
+
+cairo_pattern_t *DrawingPattern::renderPattern(RenderContext &rc, Geom::IntRect const &area, float opacity, int device_scale) const
+{
+    if (opacity < 1e-3) {
+        // Invisible.
+        return nullptr;
+    }
+
+    if (!_tile_rect || _tile_rect->hasZeroArea()) {
+        // Empty.
+        return nullptr;
+    }
+
+    // Calculate various transforms.
+    auto const dt = Geom::Translate(-_tile_rect->min()) * Geom::Scale(_pattern_resolution / _tile_rect->dimensions()); // AKA user_to_tile.
+    auto const idt = dt.inverse();
+    auto const pattern_to_tile = _pattern_to_user ? _pattern_to_user->inverse() * dt : dt;
+    auto const screen_to_tile = _ctm.inverse() * pattern_to_tile;
+
+    // Return a canonical choice of rectangle with the same periodic tiling as rect.
+    auto canonicalised = [&, this] (Geom::IntRect rect) {
+        for (int i = 0; i < 2; i++) {
+            if (rect.dimensions()[i] >= _pattern_resolution[i]) {
+                rect[i] = {0, _pattern_resolution[i]};
+            } else {
+                rect[i] -= Util::rounddown(rect[i].min(), _pattern_resolution[i]);
+            }
+        }
+        return rect;
+    };
+
+    // Return whether the periodic tiling of a contains the periodic tiling of b.
+    auto wrapped_contains = [&] (Geom::IntRect const &a, Geom::IntRect const &b) {
+        auto check = [&] (int i) {
+            int const period = _pattern_resolution[i];
+            if (a[i].extent() >= period) return true;
+            if (b[i].extent() > a[i].extent()) return false;
+            return Util::rounddown(b[i].min() - a[i].min(), period) >= b[i].max() - a[i].max();
+        };
+        return check(0) && check(1);
+    };
+
+    // Return whether the periodic tiling of a intersects with or touches the periodic tiling of b.
+    auto wrapped_touches = [&] (Geom::IntRect const &a, Geom::IntRect const &b) {
+        auto check = [&] (int i) {
+            int const period = _pattern_resolution[i];
+            if (a[i].extent() >= period) return true;
+            if (b[i].extent() >= period) return true;
+            return Util::rounddown(b[i].max() - a[i].min(), period) >= b[i].min() - a[i].max();
+        };
+        return check(0) && check(1);
+    };
+
+    // Calculate the minimum and maximum translates of a that overlap with b.
+    auto overlapping_translates = [&, this] (Geom::IntRect const &a, Geom::IntRect const &b) {
+        Geom::IntPoint min, max;
+        for (int i = 0; i < 2; i++) {
+            min[i] = Util::roundup  (b[i].min() - a[i].max() + 1, _pattern_resolution[i]);
+            max[i] = Util::rounddown(b[i].max() - a[i].min() - 1, _pattern_resolution[i]);
+        }
+        return std::make_pair(min, max);
+    };
+
+    // Paint the periodic tiling of a into b, and remove the painted region from dirty.
+    auto wrapped_paint = [&, this] (Surface const &a, Geom::IntRect &b, Cairo::RefPtr<Cairo::Context> const &cr, Cairo::RefPtr<Cairo::Region> const &dirty) {
+        auto const [min, max] = overlapping_translates(a.rect, b);
+        for (int x = min.x(); x <= max.x(); x += _pattern_resolution.x()) {
+            for (int y = min.y(); y <= max.y(); y += _pattern_resolution.y()) {
+                auto const rect = a.rect + Geom::IntPoint(x, y);
+                dirty->subtract(geom_to_cairo(rect));
+                cr->set_source(a.surface, rect.left(), rect.top());
+                cr->paint();
+            }
+        }
+    };
+
+    // Calculate the requested area to draw within tile rasterisation space.
+    auto const area_orig = (Geom::Rect(area) * screen_to_tile).roundOutwards();
+    auto const area_tile = canonicalised(area_orig);
+
+    // Simplest solution for now to protecting pattern cache is a mutex. This makes all
+    // pattern rendering single-threaded, however patterns are typically not the bottleneck.
+    auto lock = std::lock_guard(mutables);
+
+    auto get_surface = [&, this] () -> std::pair<Surface*, Cairo::RefPtr<Cairo::Region>> {
+        // If there is a rectangle containing the requested area, just use that.
+        for (auto &s : surfaces) {
+            if (wrapped_contains(s.rect, area_tile)) {
+                return { &s, {} };
+            }
+        }
+
+        // Otherwise, recursively merge the requested area with all overlapping or touching rectangles, and paint the missing part.
+        std::vector<Surface> merged;
+        auto expanded = area_tile;
+
+        while (true) {
+            bool modified = false;
+
+            for (auto it = surfaces.begin(); it != surfaces.end(); ) {
+                if (wrapped_touches(expanded, it->rect)) {
+                    expanded.unionWith(it->rect + rounddown(expanded.max() - it->rect.min(), _pattern_resolution));
+                    merged.emplace_back(std::move(*it));
+                    *it = std::move(surfaces.back());
+                    surfaces.pop_back();
+                    modified = true;
+                } else {
+                    ++it;
+                }
+            }
+
+            if (!modified) break;
+        }
+
+        // Canonicalise the expanded rectangle. (Stops Cairo's coordinates overflowing and the pattern disappearing.)
+        expanded = canonicalised(expanded);
+
+        // Create a new surface covering the expanded rectangle.
+        auto surface = Surface(expanded, device_scale);
+        auto cr = Cairo::Context::create(surface.surface);
+        cr->translate(-surface.rect.left(), -surface.rect.top());
+
+        // Paste all the old surfaces into the new surface, tracking the remaining dirty region.
+        auto dirty = Cairo::Region::create(geom_to_cairo(expanded));
+
+        for (auto &m : merged) {
+            wrapped_paint(m, expanded, cr, dirty);
+        }
+
+        // Emplace the surface, and return it along with the remaining dirty region.
+        surfaces.emplace_back(std::move(surface));
+        return std::make_pair(&surfaces.back(), std::move(dirty));
+    };
+
+    // Find an already-drawn surface containing the requested area, or create if it none exists.
+    auto [surface, dirty] = get_surface();
+
+    // Draw the pattern contents to the dirty areas of the surface, taking care of possible wrapping.
+    Inkscape::DrawingContext dc(surface->surface->cobj(), surface->rect.min());
+
+    auto paint = [&, this] (Geom::IntRect const &rect) {
+        if (_overflow_steps == 1) {
+            render(dc, rc, rect);
+        } else {
+            // Overflow transforms need to be transformed to the old coordinate system
+            // before stretching to the pattern resolution.
+            auto const initial_transform = idt * _overflow_initial_transform * dt;
+            auto const step_transform    = idt * _overflow_step_transform    * dt;
+            dc.transform(initial_transform);
+            for (int i = 0; i < _overflow_steps; i++) {
+                // render() fails to handle transforms applied here when using cache.
+                render(dc, rc, rect, RENDER_BYPASS_CACHE);
+                dc.transform(step_transform);
+                // auto raw = pattern_surface.raw();
+                // auto filename = "drawing-pattern" + std::to_string(i) + ".png";
+                // cairo_surface_write_to_png(pattern_surface.raw(), filename.c_str());
+            }
+        }
+    };
+
+    if (dirty) {
+        for (int i = 0; i < dirty->get_num_rectangles(); i++) {
+            auto const rect = cairo_to_geom(dirty->get_rectangle(i));
+            for (int x = 0; x <= 1; x++) {
+                for (int y = 0; y <= 1; y++) {
+                    auto const wrap = _pattern_resolution * Geom::IntPoint(x, y);
+                    auto const rect2 = rect & Geom::IntRect(wrap, wrap + _pattern_resolution);
+                    if (!rect2) continue;
+                    auto save = DrawingContext::Save(dc);
+                    // Clip to rectangle to be drawn.
+                    dc.rectangle(*rect2);
+                    dc.clip();
+                    // Draw the pattern.
+                    dc.translate(wrap);
+                    paint(*rect2 - wrap);
+                    // Apply opacity, if necessary.
+                    if (opacity < 1.0 - 1e-3) {
+                        dc.setOperator(CAIRO_OPERATOR_DEST_IN);
+                        dc.setSource(0.0, 0.0, 0.0, opacity);
+                        dc.paint();
+                    }
+                }
+            }
+        }
+        dirty.clear();
+    }
+
+    // Debug: Show pattern tile.
+    // surface->surface->write_to_png("/tmp/patternsurface.png");
+
+    // Create and return pattern.
+    auto cp = cairo_pattern_create_for_surface(surface->surface->cobj());
+    auto const shift = surface->rect.min() + rounddown(area_orig.min() - surface->rect.min(), _pattern_resolution);
+    ink_cairo_pattern_set_matrix(cp, pattern_to_tile * Geom::Translate(-shift));
+    cairo_pattern_set_extend(cp, CAIRO_EXTEND_REPEAT);
+    return cp;
+}
+
+unsigned DrawingPattern::_updateItem(Geom::IntRect const &area, UpdateContext const &ctx, unsigned flags, unsigned reset)
+{
+    _dropPatternCache();
+
+    if (!_tile_rect || _tile_rect->hasZeroArea()) {
+        return STATE_NONE;
+    }
+
+    // Calculate the desired resolution of a pattern tile.
+    double const det_ctm = ctx.ctm.det();
+    double const det_ps2user = _pattern_to_user ? _pattern_to_user->det() : 1.0;
+    double scale = std::sqrt(std::abs(det_ctm * det_ps2user));
+    // Fixme: When scale is too big (zooming in a pattern), Cairo doesn't render the pattern.
+    // More precisely it fails when setting pattern matrix in DrawingPattern::renderPattern.
+    // Correct solution should make use of visible area and change pattern tile rect accordingly.
+    auto const c = _tile_rect->dimensions() * scale;
+    _pattern_resolution = c.ceil();
+
+    // Map tile rect to the origin and stretch it to the desired resolution.
+    auto const dt = Geom::Translate(-_tile_rect->min()) * Geom::Scale(_pattern_resolution / _tile_rect->dimensions());
+
+    // Apply this transform to the actual pattern tree.
+    return DrawingGroup::_updateItem(Geom::IntRect::infinite(), { dt }, flags, reset);
+}
+
+void DrawingPattern::_dropPatternCache()
+{
+    surfaces.clear();
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-pattern.h b/src/display/drawing-pattern.h
new file mode 100644
index 0000000..8cd0f39
--- /dev/null
+++ b/src/display/drawing-pattern.h
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Canvas belonging to SVG pattern.
+ *//*
+ * Authors:
+ *   Tomasz Boczkowski <penginsbacon@gmail.com>
+ *
+ * Copyright (C) 2014 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef INKSCAPE_DISPLAY_DRAWING_PATTERN_H
+#define INKSCAPE_DISPLAY_DRAWING_PATTERN_H
+
+#include <mutex>
+#include <cairomm/surface.h>
+#include "drawing-group.h"
+
+using cairo_pattern_t = struct _cairo_pattern;
+
+namespace Inkscape {
+
+/**
+ * @brief Drawing tree node used for rendering paints.
+ *
+ * DrawingPattern is used for rendering patterns and hatches.
+ *
+ * It renders its children to a cairo_pattern_t structure that can be
+ * applied as source for fill or stroke operations.
+ */
+class DrawingPattern
+    : public DrawingGroup
+{
+public:
+    DrawingPattern(Drawing &drawing);
+    int tag() const override { return tag_of<decltype(*this)>; }
+
+    /**
+     * Set the transformation from pattern to user coordinate systems.
+     * @see SPPattern description for explanation of coordinate systems.
+     */
+    void setPatternToUserTransform(Geom::Affine const &);
+
+    /**
+     * Set the tile rect position and dimensions in content coordinate system
+     */
+    void setTileRect(Geom::Rect const &);
+
+    /**
+     * Turn on overflow rendering.
+     *
+     * Overflow is implemented as repeated rendering of pattern contents. In every step
+     * a translation transform is applied.
+     */
+    void setOverflow(Geom::Affine const &initial_transform, int steps, Geom::Affine const &step_transform);
+
+    /**
+     * Render the pattern.
+     *
+     * Returns cairo_pattern_t structure that can be set as source surface.
+     */
+    cairo_pattern_t *renderPattern(RenderContext &rc, Geom::IntRect const &area, float opacity, int device_scale) const;
+
+protected:
+    ~DrawingPattern() override = default;
+
+    unsigned _updateItem(Geom::IntRect const &area, UpdateContext const &ctx, unsigned flags, unsigned reset) override;
+
+    void _dropPatternCache() override;
+
+    std::unique_ptr<Geom::Affine> _pattern_to_user;
+
+    // Set by overflow.
+    Geom::Affine _overflow_initial_transform;
+    Geom::Affine _overflow_step_transform;
+    int _overflow_steps;
+
+    Geom::OptRect _tile_rect;
+
+    // Set on update.
+    Geom::IntPoint _pattern_resolution;
+
+    struct Surface
+    {
+        Surface(Geom::IntRect const &rect, int device_scale);
+        Geom::IntRect rect;
+        Cairo::RefPtr<Cairo::ImageSurface> surface;
+    };
+
+    mutable std::mutex mutables;
+
+    // Parts of the pattern tile that have been rendered. Read/written on render, cleared on update.
+    mutable std::vector<Surface> surfaces;
+};
+
+} // namespace Inkscape
+
+#endif // INKSCAPE_DISPLAY_DRAWING_PATTERN_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-shape.cpp b/src/display/drawing-shape.cpp
new file mode 100644
index 0000000..d99e99f
--- /dev/null
+++ b/src/display/drawing-shape.cpp
@@ -0,0 +1,444 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Shape (styled path) belonging to an SVG drawing.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <glibmm.h>
+#include <2geom/curves.h>
+#include <2geom/pathvector.h>
+#include <2geom/path-sink.h>
+#include <2geom/svg-path-parser.h>
+
+#include "dither-lock.h"
+#include "style.h"
+
+#include "curve.h"
+#include "drawing.h"
+#include "drawing-context.h"
+#include "drawing-shape.h"
+#include "control/canvas-item-drawing.h"
+
+#include "helper/geom.h"
+
+#include "ui/widget/canvas.h" // Canvas area
+
+namespace Inkscape {
+
+DrawingShape::DrawingShape(Drawing &drawing)
+    : DrawingItem(drawing)
+    , style_vector_effect_stroke(false)
+    , style_stroke_extensions_hairline(false)
+    , style_clip_rule(SP_WIND_RULE_EVENODD)
+    , style_fill_rule(SP_WIND_RULE_EVENODD)
+    , style_opacity(SP_SCALE24_MAX)
+    , _last_pick(nullptr)
+    , _repick_after(0)
+{
+}
+
+void DrawingShape::setPath(std::shared_ptr<SPCurve const> curve)
+{
+    defer([this, curve = std::move(curve)] () mutable {
+        _markForRendering();
+        _curve = std::move(curve);
+        _markForUpdate(STATE_ALL, false);
+    });
+}
+
+void DrawingShape::setStyle(SPStyle const *style, SPStyle const *context_style)
+{
+    DrawingItem::setStyle(style, context_style);
+
+    auto vector_effect_stroke = false;
+    auto stroke_extensions_hairline = false;
+    auto clip_rule = SP_WIND_RULE_EVENODD;
+    auto fill_rule = SP_WIND_RULE_EVENODD;
+    auto opacity = SP_SCALE24_MAX;
+    if (style) {
+        vector_effect_stroke = style->vector_effect.stroke;
+        stroke_extensions_hairline = style->stroke_extensions.hairline;
+        clip_rule = style->clip_rule.value;
+        fill_rule = style->fill_rule.value;
+        opacity = style->opacity.value;
+    }
+
+    defer([=, nrstyle = NRStyleData(_style)] () mutable {
+        _nrstyle.set(std::move(nrstyle));
+        style_vector_effect_stroke = vector_effect_stroke;
+        style_stroke_extensions_hairline = stroke_extensions_hairline;
+        style_clip_rule = clip_rule;
+        style_fill_rule = fill_rule;
+        style_opacity = opacity;
+    });
+}
+
+void DrawingShape::setChildrenStyle(SPStyle const *context_style)
+{
+    DrawingItem::setChildrenStyle(context_style);
+
+    defer([this, nrstyle = NRStyleData(_style, _context_style)] () mutable {
+        _nrstyle.set(std::move(nrstyle));
+    });
+}
+
+unsigned DrawingShape::_updateItem(Geom::IntRect const &area, UpdateContext const &ctx, unsigned flags, unsigned reset)
+{
+    // update markers
+    for (auto &c : _children) {
+        c.update(area, ctx, flags, reset);
+    }
+
+    // clear Cairo data to force update
+    if (flags & STATE_RENDER) {
+        _nrstyle.invalidate();
+    }
+
+    auto calc_curve_bbox = [&, this] () -> Geom::OptIntRect {
+        if (!_curve) {
+            return {};
+        }
+
+        auto rect = bounds_exact_transformed(_curve->get_pathvector(), ctx.ctm);
+        if (!rect) {
+            return {};
+        }
+
+        float stroke_max = 0.0f;
+
+        // Get the normal stroke.
+        if (_drawing.renderMode() != RenderMode::OUTLINE && _nrstyle.data.stroke.type != NRStyleData::PaintType::NONE) {
+            // Expand by stroke width.
+            stroke_max = _nrstyle.data.stroke_width * 0.5f;
+
+            // Scale by view transformation, unless vector effect stroke.
+            if (!style_vector_effect_stroke) {
+                stroke_max *= max_expansion(ctx.ctm);
+            }
+
+            // Cap minimum line width if asked.
+            if (_drawing.renderMode() == RenderMode::VISIBLE_HAIRLINES || style_stroke_extensions_hairline) {
+                stroke_max = std::max(stroke_max, 0.5f);
+            }
+        }
+
+        // Get the outline stroke.
+        if (_drawing.renderMode() == RenderMode::OUTLINE || _drawing.outlineOverlay()) {
+            stroke_max = std::max(stroke_max, 0.5f);
+        }
+
+        if (stroke_max > 0.0f) {
+            // Expand by mitres, if present.
+            if (_nrstyle.data.line_join == CAIRO_LINE_JOIN_MITER && _nrstyle.data.miter_limit >= 1.0f) {
+                stroke_max *= _nrstyle.data.miter_limit;
+            }
+
+            // Apply expansion if non-zero.
+            if (stroke_max > 0.01) {
+                rect->expandBy(stroke_max);
+            }
+        }
+
+        return rect->roundOutwards();
+    };
+
+    if (flags & STATE_BBOX) {
+        _bbox = calc_curve_bbox();
+
+        for (auto &c : _children) {
+            _bbox.unionWith(c.bbox());
+        }
+    }
+
+    return _state | flags;
+}
+
+void DrawingShape::_renderFill(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area) const
+{
+    Inkscape::DrawingContext::Save save(dc);
+    dc.transform(_ctm);
+
+    auto has_fill = _nrstyle.prepareFill(dc, rc, area, _item_bbox, _fill_pattern);
+
+    if (has_fill) {
+        dc.path(_curve->get_pathvector());
+        auto dl = DitherLock(dc, _nrstyle.data.fill.ditherable() && _drawing.useDithering());
+        _nrstyle.applyFill(dc, has_fill);
+        dc.fillPreserve();
+        dc.newPath(); // clear path
+    }
+}
+
+void DrawingShape::_renderStroke(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags) const
+{
+    Inkscape::DrawingContext::Save save(dc);
+    dc.transform(_ctm);
+
+    auto has_stroke = _nrstyle.prepareStroke(dc, rc, area, _item_bbox, _stroke_pattern);
+    if (!style_stroke_extensions_hairline && _nrstyle.data.stroke_width == 0) {
+        has_stroke.reset();
+    }
+
+    if (has_stroke) {
+        // TODO: remove segments outside of bbox when no dashes present
+        dc.path(_curve->get_pathvector());
+        if (style_vector_effect_stroke) {
+            dc.restore();
+            dc.save();
+        }
+        auto dl = DitherLock(dc, _nrstyle.data.stroke.ditherable() && _drawing.useDithering());
+        _nrstyle.applyStroke(dc, has_stroke);
+
+        // If the stroke is a hairline, set it to exactly 1px on screen.
+        // If visible hairline mode is on, make sure the line is at least 1px.
+        if (flags & RENDER_VISIBLE_HAIRLINES || style_stroke_extensions_hairline) {
+            double dx = 1.0, dy = 0.0;
+            dc.device_to_user_distance(dx, dy);
+            auto pixel_size = std::hypot(dx, dy);
+            if (style_stroke_extensions_hairline || _nrstyle.data.stroke_width < pixel_size) {
+                dc.setHairline();
+            }
+        }
+
+        dc.strokePreserve();
+        dc.newPath(); // clear path
+    }
+}
+
+void DrawingShape::_renderMarkers(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags, DrawingItem const *stop_at) const
+{
+    // marker rendering
+    for (auto &i : _children) {
+        i.render(dc, rc, area, flags, stop_at);
+    }
+}
+
+unsigned DrawingShape::_renderItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags, DrawingItem const *stop_at) const
+{
+    if (!_curve) return RENDER_OK;
+
+    auto visible = area & _bbox;
+    if (!visible) return RENDER_OK; // skip if not within bounding box
+
+    bool outline = flags & RENDER_OUTLINE;
+
+    if (outline) {
+        auto rgba = rc.outline_color;
+
+        // paint-order doesn't matter
+        {
+            Inkscape::DrawingContext::Save save(dc);
+            dc.transform(_ctm);
+            dc.path(_curve->get_pathvector());
+        }
+        {
+            Inkscape::DrawingContext::Save save(dc);
+            dc.setSource(rgba);
+            dc.setLineWidth(0.5);
+            dc.setTolerance(0.5);
+            dc.stroke();
+        }
+
+        _renderMarkers(dc, rc, area, flags, stop_at);
+        return RENDER_OK;
+    }
+
+    if (_nrstyle.data.paint_order_layer[0] == NRStyleData::PAINT_ORDER_NORMAL) {
+        // This is the most common case, special case so we don't call get_pathvector(), etc. twice
+
+        {
+            // we assume the context has no path
+            Inkscape::DrawingContext::Save save(dc);
+            dc.transform(_ctm);
+
+            // update fill and stroke paints.
+            // this cannot be done during nr_arena_shape_update, because we need a Cairo context
+            // to render svg:pattern
+            auto has_fill   = _nrstyle.prepareFill(dc, rc, *visible, _item_bbox, _fill_pattern);
+            auto has_stroke = _nrstyle.prepareStroke(dc, rc, *visible, _item_bbox, _stroke_pattern);
+            if (!_nrstyle.data.hairline && _nrstyle.data.stroke_width == 0) {
+                has_stroke.reset();
+            }
+            if (has_fill || has_stroke) {
+                dc.path(_curve->get_pathvector());
+                // TODO: remove segments outside of bbox when no dashes present
+                if (has_fill) {
+                    auto dl = DitherLock(dc, _nrstyle.data.fill.ditherable() && _drawing.useDithering());
+                    _nrstyle.applyFill(dc, has_fill);
+                    dc.fillPreserve();
+                }
+                if (style_vector_effect_stroke) {
+                    dc.restore();
+                    dc.save();
+                }
+                if (has_stroke) {
+                    auto dl = DitherLock(dc, _nrstyle.data.stroke.ditherable() && _drawing.useDithering());
+                    _nrstyle.applyStroke(dc, has_stroke);
+
+                    // If the draw mode is set to visible hairlines, don't let anything get smaller
+                    // than half a pixel.
+                    if (flags & RENDER_VISIBLE_HAIRLINES) {
+                        double dx = 1.0, dy = 0.0;
+                        dc.device_to_user_distance(dx, dy);
+                        auto half_pixel_size = std::hypot(dx, dy) * 0.5;
+                        if (_nrstyle.data.stroke_width < half_pixel_size) {
+                            dc.setLineWidth(half_pixel_size);
+                        }
+                    }
+
+                    dc.strokePreserve();
+                }
+                dc.newPath(); // clear path
+            } // has fill or stroke pattern
+        }
+        _renderMarkers(dc, rc, area, flags, stop_at);
+        return RENDER_OK;
+
+    }
+
+    // Handle different paint orders
+    for (auto &i : _nrstyle.data.paint_order_layer) {
+        switch (i) {
+            case NRStyleData::PAINT_ORDER_FILL:
+                _renderFill(dc, rc, *visible);
+                break;
+            case NRStyleData::PAINT_ORDER_STROKE:
+                _renderStroke(dc, rc, *visible, flags);
+                break;
+            case NRStyleData::PAINT_ORDER_MARKER:
+                _renderMarkers(dc, rc, area, flags, stop_at);
+                break;
+            default:
+                // PAINT_ORDER_AUTO Should not happen
+                break;
+        }
+    }
+
+    return RENDER_OK;
+}
+
+void DrawingShape::_clipItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &/*area*/) const
+{
+    if (!_curve) return;
+
+    Inkscape::DrawingContext::Save save(dc);
+    if (style_clip_rule == SP_WIND_RULE_EVENODD) {
+        dc.setFillRule(CAIRO_FILL_RULE_EVEN_ODD);
+    } else {
+        dc.setFillRule(CAIRO_FILL_RULE_WINDING);
+    }
+    dc.transform(_ctm);
+    dc.path(_curve->get_pathvector());
+    dc.fill();
+}
+
+DrawingItem *DrawingShape::_pickItem(Geom::Point const &p, double delta, unsigned flags)
+{
+    if (_repick_after > 0)
+        --_repick_after;
+
+    if (_repick_after > 0) { // we are a slow, huge path
+        return _last_pick;   // skip this pick, returning what was returned last time
+    }
+
+    if (!_curve) return nullptr;
+    bool outline = flags & PICK_OUTLINE;
+    bool pick_as_clip = flags & PICK_AS_CLIP;
+
+    if (SP_SCALE24_TO_FLOAT(style_opacity) == 0 && !outline && !pick_as_clip && !_drawing.selectZeroOpacity()) {
+        // fully transparent, no pick unless outline mode
+        return nullptr;
+    }
+
+    gint64 tstart = g_get_monotonic_time();
+
+    double width;
+    if (pick_as_clip) {
+        width = 0; // no width should be applied to clip picking
+                   // this overrides display mode and stroke style considerations
+    } else if (outline) {
+        width = 0.5; // in outline mode, everything is stroked with the same 0.5px line width
+    } else if (_nrstyle.data.stroke.type != NRStyleData::PaintType::NONE && (_nrstyle.data.stroke.opacity > 1e-3 || _drawing.selectZeroOpacity())) {
+        // for normal picking calculate the distance corresponding top the stroke width
+        float scale = max_expansion(_ctm);
+        width = std::max(0.125f, _nrstyle.data.stroke_width * scale) / 2;
+    } else {
+        width = 0;
+    }
+
+    double dist = Geom::infinity();
+    int wind = 0;
+    bool needfill = pick_as_clip || (_nrstyle.data.fill.type != NRStyleData::PaintType::NONE && (_nrstyle.data.fill.opacity > 1e-3  || _drawing.selectZeroOpacity()) && !outline);
+    bool wind_evenodd = (pick_as_clip ? style_clip_rule : style_fill_rule) == SP_WIND_RULE_EVENODD;
+
+    // actual shape picking
+    if (_drawing.getCanvasItemDrawing()) {
+        Geom::Rect viewbox = _drawing.getCanvasItemDrawing()->get_canvas()->get_area_world();
+        viewbox.expandBy (width);
+        pathv_matrix_point_bbox_wind_distance(_curve->get_pathvector(), _ctm, p, nullptr, needfill? &wind : nullptr, &dist, 0.5, &viewbox);
+    } else {
+        pathv_matrix_point_bbox_wind_distance(_curve->get_pathvector(), _ctm, p, nullptr, needfill? &wind : nullptr, &dist, 0.5, nullptr);
+    }
+
+    gint64 tfinish = g_get_monotonic_time();
+    gint64 this_pick = tfinish - tstart;
+    //g_print ("pick time %lu\n", this_pick);
+    if (this_pick > 10000) { // slow picking, remember to skip several new picks
+        _repick_after = this_pick / 5000;
+    }
+
+    // covered by fill?
+    if (needfill) {
+        if (wind_evenodd) {
+            if (wind & 0x1) {
+                _last_pick = this;
+                return this;
+            }
+        } else {
+            if (wind != 0) {
+                _last_pick = this;
+                return this;
+            }
+        }
+    }
+
+    // close to the edge, as defined by strokewidth and delta?
+    // this ignores dashing (as if the stroke is solid) and always works as if caps are round
+    if (needfill || width > 0) { // if either fill or stroke visible,
+        if ((dist - width) < delta) {
+            _last_pick = this;
+            return this;
+        }
+    }
+
+    // if not picked on the shape itself, try its markers
+    for (auto &i : _children) {
+        DrawingItem *ret = i.pick(p, delta, flags & ~PICK_STICKY);
+        if (ret) {
+            _last_pick = this;
+            return this;
+        }
+    }
+
+    _last_pick = nullptr;
+    return nullptr;
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-shape.h b/src/display/drawing-shape.h
new file mode 100644
index 0000000..0edd7ea
--- /dev/null
+++ b/src/display/drawing-shape.h
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Group belonging to an SVG drawing element.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef INKSCAPE_DISPLAY_DRAWING_SHAPE_H
+#define INKSCAPE_DISPLAY_DRAWING_SHAPE_H
+
+#include "display/drawing-item.h"
+#include "display/nr-style.h"
+
+class SPStyle;
+class SPCurve;
+
+namespace Inkscape {
+
+class DrawingShape
+    : public DrawingItem
+{
+public:
+    DrawingShape(Drawing &drawing);
+    int tag() const override { return tag_of<decltype(*this)>; }
+
+    void setPath(std::shared_ptr<SPCurve const> curve);
+    void setStyle(SPStyle const *style, SPStyle const *context_style = nullptr) override;
+    void setChildrenStyle(SPStyle const *context_style) override;
+
+protected:
+    ~DrawingShape() override = default;
+
+    unsigned _updateItem(Geom::IntRect const &area, UpdateContext const &ctx, unsigned flags, unsigned reset) override;
+    unsigned _renderItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags, DrawingItem const *stop_at) const override;
+    void _clipItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area) const override;
+    DrawingItem *_pickItem(Geom::Point const &p, double delta, unsigned flags) override;
+    bool _canClip() const override { return true; }
+
+    void _renderFill(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area) const;
+    void _renderStroke(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags) const;
+    void _renderMarkers(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags, DrawingItem const *stop_at) const;
+
+    bool style_vector_effect_stroke : 1;
+    bool style_stroke_extensions_hairline : 1;
+    SPWindRule style_clip_rule;
+    SPWindRule style_fill_rule;
+    unsigned style_opacity : 24;
+
+    std::shared_ptr<SPCurve const> _curve;
+    NRStyle _nrstyle;
+
+    DrawingItem *_last_pick;
+    unsigned _repick_after;
+};
+
+} // namespace Inkscape
+
+#endif // INKSCAPE_DISPLAY_DRAWING_SHAPE_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-surface.cpp b/src/display/drawing-surface.cpp
new file mode 100644
index 0000000..9926134
--- /dev/null
+++ b/src/display/drawing-surface.cpp
@@ -0,0 +1,315 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Cairo surface that remembers its origin.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/drawing-surface.h"
+#include "display/drawing-context.h"
+#include "display/cairo-utils.h"
+#include "ui/util.h"
+
+namespace Inkscape {
+
+/**
+ * @class DrawingSurface
+ * Drawing surface that remembers its origin.
+ *
+ * This is a very minimalistic wrapper over cairo_surface_t. The main
+ * extra functionality provided by this class is that it automates
+ * the mapping from "logical space" (coordinates in the rendering)
+ * and the "physical space" (surface pixels). For example, patterns
+ * have to be rendered on tiles which have possibly non-integer
+ * widths and heights.
+ *
+ * This class has delayed allocation functionality - it creates
+ * the Cairo surface it wraps on the first call to createRawContext()
+ * of when a DrawingContext is constructed.
+ */
+
+/**
+ * Creates a surface with the given physical extents.
+ * When a drawing context is created for this surface, its pixels
+ * will cover the area under the given rectangle.
+ */
+DrawingSurface::DrawingSurface(Geom::IntRect const &area, int device_scale)
+    : _surface(nullptr)
+    , _origin(area.min())
+    , _scale(1, 1)
+    , _pixels(area.dimensions())
+    , _device_scale(device_scale)
+{
+    assert(_device_scale > 0);
+}
+
+/**
+ * Creates a surface with the given logical and physical extents.
+ * When a drawing context is created for this surface, its pixels
+ * will cover the area under the given rectangle. IT will contain
+ * the number of pixels specified by the second argument.
+ * @param logbox Logical extents of the surface
+ * @param pixdims Pixel dimensions of the surface.
+ */
+DrawingSurface::DrawingSurface(Geom::Rect const &logbox, Geom::IntPoint const &pixdims, int device_scale)
+    : _surface(nullptr)
+    , _origin(logbox.min())
+    , _scale(pixdims / logbox.dimensions())
+    , _pixels(pixdims)
+    , _device_scale(device_scale)
+{
+    assert(_device_scale > 0);
+}
+
+/** 
+ * Wrap a cairo_surface_t.
+ * This constructor will take an extra reference on @a surface, which will
+ * be released on destruction.
+ */
+DrawingSurface::DrawingSurface(cairo_surface_t *surface, Geom::Point const &origin)
+    : _surface(surface)
+    , _origin(origin)
+    , _scale(1, 1)
+{
+    cairo_surface_reference(surface);
+
+    double x_scale = 0;
+    double y_scale = 0;
+    cairo_surface_get_device_scale( surface, &x_scale, &y_scale);
+    if (x_scale != y_scale) {
+        std::cerr << "DrawingSurface::DrawingSurface: non-uniform device scale!" << std::endl;
+    }
+    _device_scale = x_scale;
+    assert(_device_scale > 0);
+
+    _pixels = Geom::IntPoint(cairo_image_surface_get_width(surface) / _device_scale, cairo_image_surface_get_height(surface) / _device_scale);
+}
+
+DrawingSurface::~DrawingSurface()
+{
+    if (_surface) {
+        cairo_surface_destroy(_surface);
+    }
+}
+
+/// Drop contents of the surface and release the underlying Cairo object.
+void DrawingSurface::dropContents()
+{
+    if (_surface) {
+        cairo_surface_destroy(_surface);
+        _surface = nullptr;
+    }
+}
+
+/**
+ * Create a drawing context for this surface.
+ * It's better to use the surface constructor of DrawingContext.
+ */
+cairo_t *DrawingSurface::createRawContext()
+{
+    // deferred allocation
+    if (!_surface) {
+        _surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32,
+                                              _pixels.x() * _device_scale,
+                                              _pixels.y() * _device_scale);
+        cairo_surface_set_device_scale(_surface, _device_scale, _device_scale);
+    }
+    cairo_t *ct = cairo_create(_surface);
+    if (_scale != Geom::Scale::identity()) {
+        cairo_scale(ct, _scale.vector().x(), _scale.vector().y());
+    }
+    cairo_translate(ct, -_origin.x(), -_origin.y());
+    return ct;
+}
+
+Geom::IntRect DrawingSurface::pixelArea() const
+{
+    return Geom::IntRect::from_xywh(_origin.round(), _pixels);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+DrawingCache::DrawingCache(Geom::IntRect const &area, int device_scale)
+    : DrawingSurface(area, device_scale)
+    , _clean_region(cairo_region_create())
+    , _pending_area(area)
+{
+}
+
+DrawingCache::~DrawingCache()
+{
+    cairo_region_destroy(_clean_region);
+}
+
+void DrawingCache::markDirty(Geom::IntRect const &area)
+{
+    auto const dirty = geom_to_cairo(area);
+    cairo_region_subtract_rectangle(_clean_region, &dirty);
+}
+
+void DrawingCache::markClean(Geom::IntRect const &area)
+{
+    auto const r = area & pixelArea();
+    if (!r) return;
+    auto const clean = geom_to_cairo(*r);
+    cairo_region_union_rectangle(_clean_region, &clean);
+}
+
+/// Call this during the update phase to schedule a transformation of the cache.
+void DrawingCache::scheduleTransform(Geom::IntRect const &new_area, Geom::Affine const &trans)
+{
+    _pending_area = new_area;
+    _pending_transform *= trans;
+}
+
+/// Transforms the cache according to the transform specified during the update phase.
+/// Call this during render phase, before painting.
+void DrawingCache::prepare()
+{
+    Geom::IntRect old_area = pixelArea();
+    bool is_identity = _pending_transform.isIdentity();
+    if (is_identity && _pending_area == old_area) return; // no change
+
+    bool is_integer_translation = is_identity;
+    if (!is_identity && _pending_transform.isTranslation()) {
+        Geom::IntPoint t = _pending_transform.translation().round();
+        if (Geom::are_near(Geom::Point(t), _pending_transform.translation())) {
+            is_integer_translation = true;
+            cairo_region_translate(_clean_region, t.x(), t.y());
+            if (old_area + t == _pending_area) {
+                // if the areas match, the only thing to do
+                // is to ensure that the clean area is not too large
+                // we can exit early
+                auto const limit = geom_to_cairo(_pending_area);
+                cairo_region_intersect_rectangle(_clean_region, &limit);
+                _origin += t;
+                _pending_transform.setIdentity();
+                return;
+            }
+        }
+    }
+
+    // the area has changed, so the cache content needs to be copied
+    Geom::IntPoint old_origin = old_area.min();
+    cairo_surface_t *old_surface = _surface;
+    _surface = nullptr;
+    _pixels = _pending_area.dimensions();
+    _origin = _pending_area.min();
+
+    if (is_integer_translation) {
+        // transform the cache only for integer translations and identities
+        cairo_t *ct = createRawContext();
+        if (!is_identity) {
+            ink_cairo_transform(ct, _pending_transform);
+        }
+        cairo_set_source_surface(ct, old_surface, old_origin.x(), old_origin.y());
+        cairo_set_operator(ct, CAIRO_OPERATOR_SOURCE);
+        cairo_pattern_set_filter(cairo_get_source(ct), CAIRO_FILTER_NEAREST);
+        cairo_paint(ct);
+        cairo_destroy(ct);
+
+        auto const limit = geom_to_cairo(_pending_area);
+        cairo_region_intersect_rectangle(_clean_region, &limit);
+    } else {
+        // dirty everything
+        cairo_region_destroy(_clean_region);
+        _clean_region = cairo_region_create();
+    }
+
+    //std::cout << _pending_transform << old_area << _pending_area << std::endl;
+    cairo_surface_destroy(old_surface);
+    _pending_transform.setIdentity();
+}
+
+/**
+ * Paints the clean area from cache and modifies the @a area
+ * parameter to the bounds of the region that must be repainted.
+ */
+void DrawingCache::paintFromCache(DrawingContext &dc, Geom::OptIntRect &area, bool is_filter)
+{
+    if (!area) return;
+
+    // We subtract the clean region from the area, then get the bounds
+    // of the resulting region. This is the area that needs to be repainted
+    // by the item.
+    // Then we subtract the area that needs to be repainted from the
+    // original area and paint the resulting region from cache.
+    auto const area_c = geom_to_cairo(*area);
+    cairo_region_t *dirty_region = cairo_region_create_rectangle(&area_c);
+    cairo_region_t *cache_region = cairo_region_copy(dirty_region);
+    cairo_region_subtract(dirty_region, _clean_region);
+
+    if (is_filter && !cairo_region_is_empty(dirty_region)) { // To allow fast panning on high zoom on filters
+        cairo_region_destroy(cache_region);
+        cairo_region_destroy(dirty_region);
+        cairo_region_destroy(_clean_region);
+        _clean_region = cairo_region_create();
+        return;
+    }
+
+    if (cairo_region_is_empty(dirty_region)) {
+        area = Geom::OptIntRect();
+    } else {
+        cairo_rectangle_int_t to_repaint;
+        cairo_region_get_extents(dirty_region, &to_repaint);
+        area = cairo_to_geom(to_repaint);
+        cairo_region_subtract_rectangle(cache_region, &to_repaint);
+    }
+    cairo_region_destroy(dirty_region);
+
+    if (!cairo_region_is_empty(cache_region)) {
+        int nr = cairo_region_num_rectangles(cache_region);
+        for (int i = 0; i < nr; ++i) {
+            cairo_rectangle_int_t tmp;
+            cairo_region_get_rectangle(cache_region, i, &tmp);
+            dc.rectangle(cairo_to_geom(tmp));
+        }
+        dc.setSource(this);
+        dc.fill();
+    }
+    cairo_region_destroy(cache_region);
+}
+
+// debugging utility
+void DrawingCache::_dumpCache(Geom::OptIntRect const &area)
+{
+    static int dumpnr = 0;
+    cairo_surface_t *surface = ink_cairo_surface_copy(_surface);
+    DrawingContext dc(surface, _origin);
+    if (!cairo_region_is_empty(_clean_region)) {
+        Inkscape::DrawingContext::Save save(dc);
+        int nr = cairo_region_num_rectangles(_clean_region);
+        cairo_rectangle_int_t tmp;
+        for (int i = 0; i < nr; ++i) {
+            cairo_region_get_rectangle(_clean_region, i, &tmp);
+            dc.rectangle(cairo_to_geom(tmp));
+        }
+        dc.setSource(0,1,0,0.1);
+        dc.fill();
+    }
+    dc.rectangle(*area);
+    dc.setSource(1,0,0,0.1);
+    dc.fill();
+    char *fn = g_strdup_printf("dump%d.png", dumpnr++);
+    cairo_surface_write_to_png(surface, fn);
+    cairo_surface_destroy(surface);
+    g_free(fn);
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-surface.h b/src/display/drawing-surface.h
new file mode 100644
index 0000000..423285a
--- /dev/null
+++ b/src/display/drawing-surface.h
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Cairo surface that remembers its origin.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef INKSCAPE_DISPLAY_DRAWING_SURFACE_H
+#define INKSCAPE_DISPLAY_DRAWING_SURFACE_H
+
+#include <cairo.h>
+#include <2geom/affine.h>
+#include <2geom/rect.h>
+#include <2geom/transforms.h>
+#include "helper/geom.h"
+
+extern "C" {
+typedef struct _cairo cairo_t;
+typedef struct _cairo_surface cairo_surface_t;
+typedef struct _cairo_region cairo_region_t;
+}
+
+namespace Inkscape {
+class DrawingContext;
+
+class DrawingSurface
+{
+public:
+    explicit DrawingSurface(Geom::IntRect const &area, int device_scale = 1);
+    DrawingSurface(Geom::Rect const &logbox, Geom::IntPoint const &pixdims, int device_scale = 1);
+    DrawingSurface(cairo_surface_t *surface, Geom::Point const &origin);
+    virtual ~DrawingSurface();
+
+    Geom::Rect area() const { return Geom::Rect::from_xywh(_origin, dimensions()); } ///< Get the logical extents of the surface.
+    Geom::IntPoint pixels() const { return _pixels; } ///< Get the pixel dimensions of the surface
+    Geom::Point dimensions() const { return _pixels / _scale.vector(); } ///< Get the logical width and weight of the surface as a point.
+    Geom::Point origin() const { return _origin; }
+    Geom::Scale scale() const { return _scale; }
+    int device_scale() const { return _device_scale; }
+    Geom::Affine drawingTransform() const { return Geom::Translate(-_origin) * _scale; } ///< Get the transformation applied to the drawing context on construction.
+    void dropContents();
+
+    cairo_surface_t *raw() { return _surface; }
+    cairo_t *createRawContext();
+
+protected:
+    Geom::IntRect pixelArea() const;
+
+    cairo_surface_t *_surface;
+    Geom::Point _origin;
+    Geom::Scale _scale;
+    Geom::IntPoint _pixels;
+    int _device_scale;
+    bool _has_context;
+
+    friend class DrawingContext;
+};
+
+class DrawingCache
+    : public DrawingSurface
+{
+public:
+    explicit DrawingCache(Geom::IntRect const &area, int device_scale = 1);
+    ~DrawingCache() override;
+
+    void markDirty(Geom::IntRect const &area = Geom::IntRect::infinite());
+    void markClean(Geom::IntRect const &area = Geom::IntRect::infinite());
+    void scheduleTransform(Geom::IntRect const &new_area, Geom::Affine const &trans);
+    void prepare();
+    void paintFromCache(DrawingContext &dc, Geom::OptIntRect &area, bool is_filter);
+
+protected:
+    cairo_region_t *_clean_region;
+    Geom::IntRect _pending_area;
+    Geom::Affine _pending_transform;
+
+private:
+    void _dumpCache(Geom::OptIntRect const &area);
+};
+
+} // namespace Inkscape
+
+#endif // INKSCAPE_DISPLAY_DRAWING_SURFACE_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-text.cpp b/src/display/drawing-text.cpp
new file mode 100644
index 0000000..934ab2b
--- /dev/null
+++ b/src/display/drawing-text.cpp
@@ -0,0 +1,766 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Group belonging to an SVG drawing element.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "2geom/pathvector.h"
+
+#include "dither-lock.h"
+#include "style.h"
+
+#include "cairo-utils.h"
+#include "drawing-context.h"
+#include "drawing-surface.h"
+#include "drawing-text.h"
+#include "drawing.h"
+
+#include "helper/geom.h"
+
+#include "libnrtype/font-instance.h"
+
+namespace Inkscape {
+
+
+DrawingGlyphs::DrawingGlyphs(Drawing &drawing)
+    : DrawingItem(drawing)
+    , _glyph(0)
+{
+}
+
+void DrawingGlyphs::setGlyph(std::shared_ptr<FontInstance> font, int glyph, Geom::Affine const &trans)
+{
+    defer([=, font = std::move(font)] {
+        _markForRendering();
+
+        assert(!_drawing.snapshotted());
+        setTransform(trans);
+
+        _font_data = font->share_data();
+        _glyph = glyph;
+
+        design_units = 1.0;
+        pathvec = nullptr;
+        pathvec_ref  = nullptr;
+        pixbuf = nullptr;
+
+        // Load pathvectors and pixbufs in advance, as must be done on main thread.
+        if (font) {
+            design_units = font->GetDesignUnits();
+            pathvec      = font->PathVector(_glyph);
+            pathvec_ref  = font->PathVector(42);
+
+            if (font->FontHasSVG()) {
+                pixbuf = font->PixBuf(_glyph);
+            }
+        }
+
+        _markForUpdate(STATE_ALL, false);
+    });
+}
+
+void DrawingGlyphs::setStyle(SPStyle const *, SPStyle const *)
+{
+    std::cerr << "DrawingGlyphs: Use parent style" << std::endl;
+}
+
+unsigned DrawingGlyphs::_updateItem(Geom::IntRect const &/*area*/, UpdateContext const &ctx, unsigned /*flags*/, unsigned /*reset*/)
+{
+    auto ggroup = cast<DrawingText>(&std::as_const(*_parent));
+    if (!ggroup) {
+        throw InvalidItemException();
+    }
+
+    if (!pathvec) {
+        return STATE_ALL;
+    }
+
+    _pick_bbox = Geom::IntRect();
+    _bbox = Geom::IntRect();
+
+    /*
+      Make a bounding box for drawing that is a little taller and lower (currently 10% extra) than
+      the font's drawing box.  Extra space is to hold overline or underline, if present.  All
+      characters in a font use the same ascent and descent, but different widths. This lets leading
+      and trailing spaces have text decorations. If it is not done the bounding box is limited to
+      the box surrounding the drawn parts of visible glyphs only, and draws outside are ignored.
+      The box is also a hair wider than the text, since the glyphs do not always start or end at
+      the left and right edges of the box defined in the font.
+    */
+
+    float scale_bigbox = 1.0;
+    if (_transform) {
+        scale_bigbox /= _transform->descrim();
+    }
+
+    /* Because there can be text decorations the bounding box must correspond in Y to a little above the glyph's ascend
+    and a little below its descend.  This leaves room for overline and underline.  The left and right sides
+    come from the glyph's bounding box.  Note that the initial direction of ascender is positive down in Y, and
+    this flips after the transform is applied.  So change the sign on descender. 1.1 provides a little extra space
+    above and below the max/min y positions of the letters to place the text decorations.*/
+
+    Geom::Rect b;
+    if (pathvec) {
+        Geom::OptRect tiltb = Geom::bounds_exact(*pathvec);
+        if (tiltb) {
+            Geom::Rect bigbox(Geom::Point(tiltb->left(), -_dsc * scale_bigbox * 1.1), Geom::Point(tiltb->right(), _asc * scale_bigbox * 1.1));
+            b = bigbox * ctx.ctm;
+        }
+    }
+    if (b.hasZeroArea()) { // Fallback, spaces mostly
+        Geom::Rect bigbox(Geom::Point(0.0, -_dsc * scale_bigbox * 1.1),  Geom::Point(_width * scale_bigbox, _asc * scale_bigbox * 1.1));
+        b = bigbox * ctx.ctm;
+    }
+
+    /*
+      The pick box matches the characters as best as it can, leaving no extra space above or below
+      for decorations.  The pathvector may include spaces, and spaces have no drawable glyph.
+      Catch those and do not pass them to bounds_exact_transformed(), which crashes Inkscape if it
+      sees a nondrawable glyph. Instead mock up a pickbox for them using font characteristics.
+      There may also be some other similar white space characters in some other unforeseen context
+      which should be handled by this code as well..
+    */
+
+    Geom::OptRect pb;
+    if (pathvec) {
+        if (!pathvec->empty()) {
+            pb = bounds_exact_transformed(*pathvec, ctx.ctm);
+        }
+        if (pathvec_ref && !pathvec_ref->empty()) {
+            pb.unionWith(bounds_exact_transformed(*pathvec_ref, ctx.ctm));
+            pb.expandTo(Geom::Point(pb->right() + (_width * ctx.ctm.descrim()), pb->bottom()));
+        }
+    }
+    if (!pb) { // Fallback
+        Geom::Rect pbigbox(Geom::Point(0.0, _asc * scale_bigbox * 0.66),Geom::Point(_width * scale_bigbox, 0.0));
+        pb = pbigbox * ctx.ctm;
+    }
+ 
+#if 0
+    /* FIXME  if this is commented out then not even an approximation of pick on decorations */
+    /* adjust the pick box up or down to include the decorations.
+       This is only approximate since at this point we don't know how wide that line is, if it has
+       an unusual offset, and so forth.  The selection point is set at what is roughly the center of
+       the decoration (vertically) for the wide ones, like wavy and double line.
+       The text decorations are not actually selectable.
+    */
+    if (_decorations.overline || _decorations.underline) {
+        double top = _asc*scale_bigbox*0.66;
+        double bot = 0;
+        if (_decorations.overline) {  top =   _asc * scale_bigbox * 1.025; }
+        if (_decorations.underline) { bot =  -_dsc * scale_bigbox * 0.2;   }
+        Geom::Rect padjbox(Geom::Point(0.0, top),Geom::Point(_width*scale_bigbox, bot));
+        pb.unionWith(padjbox * ctx.ctm);
+    }
+#endif
+
+    if (ggroup->_nrstyle.data.stroke.type != NRStyleData::PaintType::NONE) {
+        // this expands the selection box for cases where the stroke is "thick"
+        float scale = ctx.ctm.descrim();
+        if (_transform) {
+            scale /= _transform->descrim(); // FIXME temporary hack
+        }
+        float width = std::max<double>(0.125, ggroup->_nrstyle.data.stroke_width * scale);
+        if (std::fabs(ggroup->_nrstyle.data.stroke_width * scale) > 0.01) { // FIXME: this is always true
+            b.expandBy(0.5 * width);
+            pb->expandBy(0.5 * width);
+        }
+
+        // save bbox without miters for picking
+        _pick_bbox = pb->roundOutwards();
+
+        float miterMax = width * ggroup->_nrstyle.data.miter_limit;
+        if (miterMax > 0.01) {
+            // grunt mode. we should compute the various miters instead
+            // (one for each point on the curve)
+            b.expandBy(miterMax);
+        }
+        _bbox = b.roundOutwards();
+    } else {
+        _bbox = b.roundOutwards();
+        _pick_bbox = pb->roundOutwards();
+    }
+
+    return STATE_ALL;
+}
+
+DrawingItem *DrawingGlyphs::_pickItem(Geom::Point const &p, double /*delta*/, unsigned flags)
+{
+    auto ggroup = cast<DrawingText>(_parent);
+    if (!ggroup) {
+        throw InvalidItemException();
+    }
+    DrawingItem *result = nullptr;
+    bool invisible = ggroup->_nrstyle.data.fill.type == NRStyleData::PaintType::NONE &&
+                     ggroup->_nrstyle.data.stroke.type == NRStyleData::PaintType::NONE;
+    bool outline = flags & PICK_OUTLINE;
+
+    if (pathvec && _bbox && (outline || !invisible)) {
+        // With text we take a simple approach: pick if the point is in a character bbox
+        Geom::Rect expanded(_pick_bbox);
+        // FIXME, why expand by delta?  When is the next line needed?
+        // expanded.expandBy(delta);
+        if (expanded.contains(p)) {
+            result = this;
+        }
+    }
+    return result;
+}
+
+DrawingText::DrawingText(Drawing &drawing)
+    : DrawingGroup(drawing)
+    , style_vector_effect_stroke(false)
+    , style_stroke_extensions_hairline(false)
+    , style_clip_rule(SP_WIND_RULE_EVENODD)
+{
+}
+
+bool DrawingText::addComponent(std::shared_ptr<FontInstance> const &font, int glyph, Geom::Affine const &trans, float width, float ascent, float descent, float phase_length)
+{
+    // original, did not save a glyph for white space characters, causes problems for text-decoration
+    /*if (!font || !font->PathVector(glyph)) {
+        return false;
+    }*/
+    if (!font) return false;
+
+    defer([=, font = std::move(font)] () mutable {
+        _markForRendering();
+        auto ng = new DrawingGlyphs(_drawing);
+        assert(!_drawing.snapshotted());
+        ng->setGlyph(font, glyph, trans);
+        ng->_width  = width;   // used especially when _drawable = false, otherwise, it is the advance of the font
+        ng->_asc    = ascent;  // of font, not of this one character
+        ng->_dsc    = descent; // of font, not of this one character
+        ng->_pl     = phase_length; // used for phase of dots, dashes, and wavy
+        appendChild(ng);
+    });
+
+    return true;
+}
+
+void DrawingText::setStyle(SPStyle const *style, SPStyle const *context_style)
+{
+    DrawingGroup::setStyle(style, context_style);
+
+    auto vector_effect_stroke = false;
+    auto stroke_extensions_hairline = false;
+    auto clip_rule = SP_WIND_RULE_EVENODD;
+    if (_style) {
+        vector_effect_stroke = _style->vector_effect.stroke;
+        stroke_extensions_hairline = _style->stroke_extensions.hairline;
+        clip_rule = _style->clip_rule.computed;
+    }
+
+    defer([=, nrstyle = NRStyleData(_style, _context_style)] () mutable {
+        _nrstyle.set(std::move(nrstyle));
+        style_vector_effect_stroke = vector_effect_stroke;
+        style_stroke_extensions_hairline = stroke_extensions_hairline;
+        style_clip_rule = clip_rule;
+    });
+}
+
+void DrawingText::setChildrenStyle(SPStyle const *context_style)
+{
+    DrawingGroup::setChildrenStyle(context_style);
+
+    defer([this, nrstyle = NRStyleData(_style, _context_style)] () mutable {
+        _nrstyle.set(std::move(nrstyle));
+    });
+}
+
+unsigned DrawingText::_updateItem(Geom::IntRect const &area, UpdateContext const &ctx, unsigned flags, unsigned reset)
+{
+    _nrstyle.invalidate();
+    return DrawingGroup::_updateItem(area, ctx, flags, reset);
+}
+
+void DrawingText::decorateStyle(DrawingContext &dc, double vextent, double xphase, Geom::Point const &p1, Geom::Point const &p2, double thickness) const
+{
+    double wave[16]={
+        // clang-format off
+        0.000000,  0.382499,  0.706825,  0.923651,   1.000000,  0.923651,  0.706825,  0.382499,
+        0.000000, -0.382499, -0.706825, -0.923651,  -1.000000, -0.923651, -0.706825, -0.382499,
+        // clang-format on
+    };
+    int dashes[16]={
+        // clang-format off
+        8,   7,   6,   5,
+        4,   3,   2,   1,
+        -8, -7,  -6,  -5,
+        -4, -3,  -2,  -1
+        // clang-format on
+    };
+    int dots[16]={
+        // clang-format off
+        4,     3,   2,   1,
+        -4,   -3,  -2,  -1,
+        4,     3,   2,   1,
+        -4,   -3,  -2,  -1
+        // clang-format on
+    };
+    double   step = vextent/32.0;
+    unsigned i  = 15 & (unsigned) round(xphase/step);  // xphase is >= 0.0
+
+    /* For most spans draw the last little bit right to p2 or even a little beyond.
+       This allows decoration continuity within the line, and does not step outside the clip box off the end
+       For the first/last section on the line though, stay well clear of the edge, or when the
+       text is dragged it may "spray" pixels.
+    */
+    /* snap to nearest step in X */
+    Geom::Point ps = Geom::Point(step * round(p1[Geom::X]/step),p1[Geom::Y]);
+    Geom::Point pf = Geom::Point(step * round(p2[Geom::X]/step),p2[Geom::Y]);
+    Geom::Point poff = Geom::Point(0,thickness/2.0);
+
+    if (_nrstyle.data.text_decoration_style & NRStyleData::TEXT_DECORATION_STYLE_ISDOUBLE) {
+        ps -= Geom::Point(0, vextent/12.0);
+        pf -= Geom::Point(0, vextent/12.0);
+        dc.rectangle( Geom::Rect(ps + poff, pf - poff));
+        ps += Geom::Point(0, vextent/6.0);
+        pf += Geom::Point(0, vextent/6.0);
+        dc.rectangle( Geom::Rect(ps + poff, pf - poff));
+    }
+    /* The next three have a problem in that they are phase dependent.  The bits of a line are not
+    necessarily passing through this routine in order, so we have to use the xphase information
+    to figure where in each of their cycles to start.  Only accurate to 1 part in 16.
+    Huge positive offset should keep the phase calculation from ever being negative.
+    */
+    else if(_nrstyle.data.text_decoration_style & NRStyleData::TEXT_DECORATION_STYLE_DOTTED){
+        // FIXME: Per spec, this should produce round dots.
+        Geom::Point pv = ps;
+        while(true){
+            Geom::Point pvlast = pv;
+            if(dots[i]>0){
+                if(pv[Geom::X] > pf[Geom::X]) break;
+
+                pv += Geom::Point(step * (double)dots[i], 0.0);
+
+                if(pv[Geom::X]>= pf[Geom::X]){
+                    // Last dot
+                    dc.rectangle( Geom::Rect(pvlast + poff, pf - poff));
+                    break;
+                } else {
+                    dc.rectangle( Geom::Rect(pvlast + poff, pv - poff));
+                }
+
+                pv += Geom::Point(step * 4.0, 0.0);
+
+            } else {
+                pv += Geom::Point(step * -(double)dots[i], 0.0);
+            }
+            i = 0;  // once in phase, it stays in phase
+        }
+    }
+    else if (_nrstyle.data.text_decoration_style & NRStyleData::TEXT_DECORATION_STYLE_DASHED) {
+        Geom::Point pv = ps;
+        while(true){
+            Geom::Point pvlast = pv;
+            if(dashes[i]>0){
+                if(pv[Geom::X]> pf[Geom::X]) break;
+
+                pv += Geom::Point(step * (double)dashes[i], 0.0);
+
+                if(pv[Geom::X]>= pf[Geom::X]){
+                    // Last dash
+                    dc.rectangle( Geom::Rect(pvlast + poff, pf - poff));
+                    break;
+                } else {
+                    dc.rectangle( Geom::Rect(pvlast + poff, pv - poff));
+                }
+
+                pv += Geom::Point(step * 8.0, 0.0);
+
+            } else {
+                pv += Geom::Point(step * -(double)dashes[i], 0.0);
+            }
+            i = 0;  // once in phase, it stays in phase
+        }
+    }
+    else if (_nrstyle.data.text_decoration_style & NRStyleData::TEXT_DECORATION_STYLE_WAVY) {
+        double   amp  = vextent/10.0;
+        double   x    = ps[Geom::X];
+        double   y    = ps[Geom::Y] + poff[Geom::Y];
+        dc.moveTo(Geom::Point(x, y + amp * wave[i]));
+        while(true){
+           i = ((i + 1) & 15);
+           x += step;
+           dc.lineTo(Geom::Point(x, y + amp * wave[i]));
+           if(x >= pf[Geom::X])break;
+        }
+        y = ps[Geom::Y] - poff[Geom::Y];
+        dc.lineTo(Geom::Point(x, y + amp * wave[i]));
+        while(true){
+           i = ((i - 1) & 15);
+           x -= step;
+           dc.lineTo(Geom::Point(x, y + amp * wave[i]));
+           if(x <= ps[Geom::X])break;
+        }
+        dc.closePath();
+    }
+    else { // TEXT_DECORATION_STYLE_SOLID, also default in case it was not set for some reason
+        dc.rectangle( Geom::Rect(ps + poff, pf - poff));
+    }
+}
+
+/* returns scaled line thickness */
+void DrawingText::decorateItem(DrawingContext &dc, double phase_length, bool under) const
+{
+    if ( _nrstyle.data.font_size <= 1.0e-32 )return;  // might cause a divide by zero or overflow and nothing would be visible anyway
+    double tsp_width_adj                = _nrstyle.data.tspan_width                     / _nrstyle.data.font_size;
+    double tsp_asc_adj                  = _nrstyle.data.ascender                        / _nrstyle.data.font_size;
+    double tsp_size_adj                 = (_nrstyle.data.ascender + _nrstyle.data.descender) / _nrstyle.data.font_size;
+
+    double final_underline_thickness    = CLAMP(_nrstyle.data.underline_thickness,    tsp_size_adj/30.0, tsp_size_adj/10.0);
+    double final_line_through_thickness = CLAMP(_nrstyle.data.line_through_thickness, tsp_size_adj/30.0, tsp_size_adj/10.0);
+
+    double xphase = phase_length/ _nrstyle.data.font_size; // used to figure out phase of patterns
+
+    Geom::Point p1;
+    Geom::Point p2;
+    // All lines must be the same thickness, in combinations, line_through trumps underline
+    double thickness = final_underline_thickness;
+    if ( thickness <= 1.0e-32 )return;  // might cause a divide by zero or overflow and nothing would be visible anyway
+    dc.setTolerance(0.5); // Is this really necessary... could effect dots.
+
+    if( under ) {
+
+        if(_nrstyle.data.text_decoration_line & NRStyleData::TEXT_DECORATION_LINE_UNDERLINE){
+            p1 = Geom::Point(0.0,          -_nrstyle.data.underline_position);
+            p2 = Geom::Point(tsp_width_adj,-_nrstyle.data.underline_position);
+            decorateStyle(dc, tsp_size_adj, xphase, p1, p2, thickness);
+        }
+
+        if(_nrstyle.data.text_decoration_line & NRStyleData::TEXT_DECORATION_LINE_OVERLINE){
+            p1 = Geom::Point(0.0,          tsp_asc_adj -_nrstyle.data.underline_position + 1 * final_underline_thickness);
+            p2 = Geom::Point(tsp_width_adj,tsp_asc_adj -_nrstyle.data.underline_position + 1 * final_underline_thickness);
+            decorateStyle(dc, tsp_size_adj, xphase,  p1, p2, thickness);
+        }
+
+    } else {
+        // Over
+
+        if(_nrstyle.data.text_decoration_line & NRStyleData::TEXT_DECORATION_LINE_LINETHROUGH){
+            thickness = final_line_through_thickness;
+            p1 = Geom::Point(0.0,          _nrstyle.data.line_through_position);
+            p2 = Geom::Point(tsp_width_adj,_nrstyle.data.line_through_position);
+            decorateStyle(dc, tsp_size_adj, xphase,  p1, p2, thickness);
+        }
+
+        // Obviously this does not blink, but it does indicate which text has been set with that attribute
+        if(_nrstyle.data.text_decoration_line & NRStyleData::TEXT_DECORATION_LINE_BLINK){
+            thickness = final_line_through_thickness;
+            p1 = Geom::Point(0.0,          _nrstyle.data.line_through_position - 2*final_line_through_thickness);
+            p2 = Geom::Point(tsp_width_adj,_nrstyle.data.line_through_position - 2*final_line_through_thickness);
+            decorateStyle(dc, tsp_size_adj, xphase,  p1, p2, thickness);
+            p1 = Geom::Point(0.0,          _nrstyle.data.line_through_position + 2*final_line_through_thickness);
+            p2 = Geom::Point(tsp_width_adj,_nrstyle.data.line_through_position + 2*final_line_through_thickness);
+            decorateStyle(dc, tsp_size_adj, xphase,  p1, p2, thickness);
+        }
+    }
+}
+
+unsigned DrawingText::_renderItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags, DrawingItem const *stop_at) const
+{
+    auto visible = area & _bbox;
+    if (!visible) return RENDER_OK;
+
+    bool outline = flags & RENDER_OUTLINE;
+
+    if (outline) {
+        auto rgba = rc.outline_color;
+        Inkscape::DrawingContext::Save save(dc);
+        dc.setSource(rgba);
+        dc.setTolerance(0.5); // low quality, but good enough for outline mode
+
+        for (auto & i : _children) {
+            auto g = cast<DrawingGlyphs>(&i);
+            if (!g) throw InvalidItemException();
+
+            Inkscape::DrawingContext::Save save(dc);
+            // skip glyphs with singular transforms
+            if (g->_ctm.isSingular()) continue;
+            dc.transform(g->_ctm);
+            if (g->pathvec){
+                dc.path(*g->pathvec);
+                dc.fill();
+            }
+        }
+        return RENDER_OK;
+    }
+
+    // NOTE: This is very similar to drawing-shape.cpp; the only differences are in path feeding
+    // and in applying text decorations.
+
+    // Do we have text decorations?
+    bool decorate = (_nrstyle.data.text_decoration_line != NRStyleData::TEXT_DECORATION_LINE_CLEAR );
+
+    // prepareFill / prepareStroke need to be called with _ctm in effect.
+    // However, we might need to apply a different ctm for glyphs.
+    // Therefore, only apply this ctm temporarily.
+    CairoPatternUniqPtr has_stroke;
+    CairoPatternUniqPtr has_fill;
+    CairoPatternUniqPtr has_td_fill;
+    CairoPatternUniqPtr has_td_stroke;
+
+    {
+        Inkscape::DrawingContext::Save save(dc);
+        dc.transform(_ctm);
+
+        has_fill   = _nrstyle.prepareFill  (dc, rc, *visible, _item_bbox, _fill_pattern);
+        has_stroke = _nrstyle.prepareStroke(dc, rc, *visible, _item_bbox, _stroke_pattern);
+
+        // Avoid creating patterns if not needed
+        if (decorate) {
+            has_td_fill   = _nrstyle.prepareTextDecorationFill  (dc, rc, *visible, _item_bbox, _fill_pattern);
+            has_td_stroke = _nrstyle.prepareTextDecorationStroke(dc, rc, *visible, _item_bbox, _stroke_pattern);
+        }
+    }
+
+    if (has_fill || has_stroke || has_td_fill || has_td_stroke) {
+
+        // Determine order for fill and stroke.
+        // Text doesn't have markers, we can do paint-order quick and dirty.
+        bool fill_first = false;
+        if( _nrstyle.data.paint_order_layer[0] == NRStyleData::PAINT_ORDER_NORMAL ||
+            _nrstyle.data.paint_order_layer[0] == NRStyleData::PAINT_ORDER_FILL   ||
+            _nrstyle.data.paint_order_layer[2] == NRStyleData::PAINT_ORDER_STROKE ) {
+            fill_first = true;
+        } // Won't get "stroke fill stroke" but that isn't 'valid'
+
+
+        // Determine geometry of text decoration
+        double phase_length = 0.0;
+        Geom::Affine aff;
+        if (decorate) {
+
+            Geom::Affine rotinv;
+            bool   invset    = false;
+            double leftmost  = DBL_MAX;
+            bool   first_y   = true;
+            double start_y   = 0.0;
+            for (auto & i : _children) {
+
+                auto g = cast<DrawingGlyphs>(&i);
+                if (!g) throw InvalidItemException();
+
+                if (!invset) {
+                    rotinv = g->_ctm.withoutTranslation().inverse();
+                    invset = true;
+                }
+
+                Geom::Point pt = g->_ctm.translation() * rotinv;
+                if (pt[Geom::X] < leftmost) {
+                    leftmost     = pt[Geom::X];
+                    aff          = g->_ctm;
+                    phase_length = g->_pl;
+                }
+
+                // Check for text on a path. FIXME: This needs better test (and probably not here).
+                if (first_y) {
+                    first_y = false;
+                    start_y = pt[Geom::Y];
+                }
+                else if (std::fabs(pt[Geom::Y] - start_y) > 1.0e-6) {
+                    //  If the text has been mapped onto a path, which causes y to vary, drop the
+                    //  text decorations.  To handle that properly would need a conformal map.
+                    decorate = false;
+                }
+            }
+        }
+
+        // Draw text decorations that go UNDER the text (underline, over-line)
+        if (decorate) {
+
+            {
+                Inkscape::DrawingContext::Save save(dc);
+                dc.transform(aff);  // must be leftmost affine in span
+                decorateItem(dc, phase_length, true);
+            }
+
+            {
+                Inkscape::DrawingContext::Save save(dc);
+                dc.transform(_ctm);  // Needed so that fill pattern rotates with text
+
+                if (has_td_fill && fill_first) {
+                    _nrstyle.applyTextDecorationFill(dc, has_td_fill);
+                    dc.fillPreserve();
+                }
+
+                if (has_td_stroke) {
+                    _nrstyle.applyTextDecorationStroke(dc, has_td_stroke);
+                    dc.strokePreserve();
+                }
+
+                if (has_td_fill && !fill_first) {
+                    _nrstyle.applyTextDecorationFill(dc, has_td_fill);
+                    dc.fillPreserve();
+                }
+
+            }
+
+            dc.newPath(); // Clear text-decoration path
+        }
+
+        // Accumulate the path that represents the glyphs and/or draw SVG glyphs.
+        for (auto &i : _children) {
+            auto g = cast<DrawingGlyphs>(&i);
+            if (!g) throw InvalidItemException();
+
+            Inkscape::DrawingContext::Save save(dc);
+            if (g->_ctm.isSingular()) continue;
+            dc.transform(g->_ctm);
+            if (g->pathvec) {
+                if (g->pixbuf) {
+                    // Geom::OptRect box = bounds_exact(*g->pathvec);
+                    // if (box) {
+                    //     Inkscape::DrawingContext::Save save(dc);
+                    //     dc.newPath();
+                    //     dc.rectangle(*box);
+                    //     dc.setLineWidth(0.01);
+                    //     dc.setSource(0x8080ffff);
+                    //     dc.stroke();
+                    // }
+                    {
+                        // pixbuf is in font design units, scale to embox.
+                        double scale = g->design_units;
+                        if (scale <= 0) scale = 1000;
+                        Inkscape::DrawingContext::Save save(dc);
+                        dc.translate(0, 1);
+                        dc.scale(1.0 / scale, -1.0 / scale);
+                        dc.setSource(g->pixbuf->getSurfaceRaw(), 0, 0);
+                        dc.paint(1);
+                    }
+                } else {
+                    dc.path(*g->pathvec);
+                }
+            }
+        }
+
+        // Draw the glyphs (non-SVG glyphs).
+        {
+            Inkscape::DrawingContext::Save save(dc);
+            dc.transform(_ctm);
+            if (has_fill && fill_first) {
+                auto dl = DitherLock(dc, _nrstyle.data.fill.ditherable() && _drawing.useDithering());
+                _nrstyle.applyFill(dc, has_fill);
+                dc.fillPreserve();
+            }
+        }
+        {
+            Inkscape::DrawingContext::Save save(dc);
+            if (!style_vector_effect_stroke) {
+                dc.transform(_ctm);
+            }
+            if (has_stroke) {
+                auto dl = DitherLock(dc, _nrstyle.data.stroke.ditherable() && _drawing.useDithering());
+                _nrstyle.applyStroke(dc, has_stroke);
+
+                // If the stroke is a hairline, set it to exactly 1px on screen.
+                // If visible hairline mode is on, make sure the line is at least 1px.
+                if (flags & RENDER_VISIBLE_HAIRLINES || style_stroke_extensions_hairline) {
+                    double dx = 1.0, dy = 0.0;
+                    dc.device_to_user_distance(dx, dy);
+                    auto pixel_size = std::hypot(dx, dy);
+                    if (style_stroke_extensions_hairline || _nrstyle.data.stroke_width < pixel_size) {
+                       dc.setHairline();
+                    }
+                }
+
+                dc.strokePreserve();
+            }
+        }
+        {
+            Inkscape::DrawingContext::Save save(dc);
+            dc.transform(_ctm);
+            if (has_fill && !fill_first) {
+                auto dl = DitherLock(dc, _nrstyle.data.fill.ditherable() && _drawing.useDithering());
+                _nrstyle.applyFill(dc, has_fill);
+                dc.fillPreserve();
+            }
+        }
+        dc.newPath(); // Clear glyphs path
+
+        // Draw text decorations that go OVER the text (line through, blink)
+        if (decorate) {
+
+            {
+                Inkscape::DrawingContext::Save save(dc);
+                dc.transform(aff);  // must be leftmost affine in span
+                decorateItem(dc, phase_length, false);
+            }
+
+            {
+                Inkscape::DrawingContext::Save save(dc);
+                dc.transform(_ctm);  // Needed so that fill pattern rotates with text
+
+                if (has_td_fill && fill_first) {
+                    _nrstyle.applyTextDecorationFill(dc, has_td_fill);
+                    dc.fillPreserve();
+                }
+
+                if (has_td_stroke) {
+                    _nrstyle.applyTextDecorationStroke(dc, has_td_stroke);
+                    dc.strokePreserve();
+                }
+
+                if (has_td_fill && !fill_first) {
+                    _nrstyle.applyTextDecorationFill(dc, has_td_fill);
+                    dc.fillPreserve();
+                }
+
+            }
+
+            dc.newPath(); // Clear text-decoration path
+        }
+
+    }
+    return RENDER_OK;
+}
+
+void DrawingText::_clipItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &/*area*/) const
+{
+    Inkscape::DrawingContext::Save save(dc);
+
+    if (style_clip_rule == SP_WIND_RULE_EVENODD) {
+        dc.setFillRule(CAIRO_FILL_RULE_EVEN_ODD);
+    } else {
+        dc.setFillRule(CAIRO_FILL_RULE_WINDING);
+    }
+
+    for (auto & i : _children) {
+        auto g = cast<DrawingGlyphs>(&i);
+        if (!g) {
+            throw InvalidItemException();
+        }
+
+        Inkscape::DrawingContext::Save save(dc);
+        dc.transform(g->_ctm);
+        if (g->pathvec){
+            dc.path(*g->pathvec);
+        }
+    }
+    dc.fill();
+}
+
+DrawingItem *DrawingText::_pickItem(Geom::Point const &p, double delta, unsigned flags)
+{
+    return DrawingGroup::_pickItem(p, delta, flags) ? this : nullptr;
+}
+
+} // end namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing-text.h b/src/display/drawing-text.h
new file mode 100644
index 0000000..84b43a9
--- /dev/null
+++ b/src/display/drawing-text.h
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Group belonging to an SVG drawing element.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef INKSCAPE_DISPLAY_DRAWING_TEXT_H
+#define INKSCAPE_DISPLAY_DRAWING_TEXT_H
+
+#include <memory>
+#include "display/drawing-group.h"
+#include "display/nr-style.h"
+
+class SPStyle;
+class FontInstance;
+
+namespace Inkscape {
+
+class Pixbuf;
+
+class DrawingGlyphs
+    : public DrawingItem
+{
+public:
+    DrawingGlyphs(Drawing &drawing);
+    int tag() const override { return tag_of<decltype(*this)>; }
+
+    void setGlyph(std::shared_ptr<FontInstance> font, int glyph, Geom::Affine const &trans);
+    void setStyle(SPStyle const *style, SPStyle const *context_style = nullptr) override; // Not to be used
+    Geom::IntRect getPickBox() const { return _pick_bbox; };
+
+protected:
+    ~DrawingGlyphs() override = default;
+
+    unsigned _updateItem(Geom::IntRect const &area, UpdateContext const &ctx, unsigned flags, unsigned reset) override;
+    DrawingItem *_pickItem(Geom::Point const &p, double delta, unsigned flags) override;
+
+    std::shared_ptr<void const> _font_data; // keeps alive pathvec, pathvec_ref, and pixbuf
+    int            _glyph;
+    float          _width;          // These three are used to set up bounding box
+    float          _asc;            //
+    float          _dsc;            //
+    float          _pl;             // phase length
+    Geom::IntRect  _pick_bbox;
+
+    double design_units;
+    Geom::PathVector const *pathvec; // pathvector of actual glyph
+    Geom::PathVector const *pathvec_ref; // pathvector of reference glyph 42
+    Inkscape::Pixbuf const *pixbuf; // pixbuf, if SVG font
+
+    friend class DrawingText;
+};
+
+class DrawingText
+    : public DrawingGroup
+{
+public:
+    DrawingText(Drawing &drawing);
+    int tag() const override { return tag_of<decltype(*this)>; }
+
+    bool addComponent(std::shared_ptr<FontInstance> const &font, int glyph, Geom::Affine const &trans, float width, float ascent, float descent, float phase_length);
+    void setStyle(SPStyle const *style, SPStyle const *context_style = nullptr) override;
+    void setChildrenStyle(SPStyle const *context_style) override;
+
+protected:
+    ~DrawingText() override = default;
+
+    unsigned _updateItem(Geom::IntRect const &area, UpdateContext const &ctx, unsigned flags, unsigned reset) override;
+    unsigned _renderItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, unsigned flags, DrawingItem const *stop_at) const override;
+    void _clipItem(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area) const override;
+    DrawingItem *_pickItem(Geom::Point const &p, double delta, unsigned flags) override;
+    bool _canClip() const override { return true; }
+
+    void decorateItem(DrawingContext &dc, double phase_length, bool under) const;
+    void decorateStyle(DrawingContext &dc, double vextent, double xphase, Geom::Point const &p1, Geom::Point const &p2, double thickness) const;
+    NRStyle _nrstyle;
+
+    bool style_vector_effect_stroke : 1;
+    bool style_stroke_extensions_hairline : 1;
+    SPWindRule style_clip_rule;
+
+    friend class DrawingGlyphs;
+};
+
+} // namespace Inkscape
+
+#endif // INKSCAPE_DISPLAY_DRAWING_TEXT_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing.cpp b/src/display/drawing.cpp
new file mode 100644
index 0000000..6e4966b
--- /dev/null
+++ b/src/display/drawing.cpp
@@ -0,0 +1,390 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * SVG drawing for display.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *   Johan Engelen <j.b.c.engelen@alumnus.utwente.nl>
+ *
+ * Copyright (C) 2011-2012 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <array>
+#include <thread>
+#include "display/drawing.h"
+#include "display/control/canvas-item-drawing.h"
+#include "nr-filter-gaussian.h"
+#include "nr-filter-types.h"
+
+// Grayscale colormode
+#include "cairo-templates.h"
+#include "drawing-context.h"
+
+namespace Inkscape {
+
+// Hardcoded grayscale color matrix values as default.
+static auto constexpr grayscale_matrix = std::array{
+    0.21, 0.72, 0.072, 0.0, 0.0,
+    0.21, 0.72, 0.072, 0.0, 0.0,
+    0.21, 0.72, 0.072, 0.0, 0.0,
+    0.0 , 0.0 , 0.0  , 1.0, 0.0
+};
+
+static auto rendermode_to_renderflags(RenderMode mode)
+{
+    switch (mode) {
+        case RenderMode::OUTLINE:           return DrawingItem::RENDER_OUTLINE;
+        case RenderMode::NO_FILTERS:        return DrawingItem::RENDER_NO_FILTERS;
+        case RenderMode::VISIBLE_HAIRLINES: return DrawingItem::RENDER_VISIBLE_HAIRLINES;
+        default:                            return DrawingItem::RenderFlags::RENDER_DEFAULT;
+    }
+}
+
+static auto default_numthreads()
+{
+    auto ret = std::thread::hardware_concurrency();
+    return ret == 0 ? 4 : ret; // Sensible fallback if not reported.
+}
+
+Drawing::Drawing(Inkscape::CanvasItemDrawing *canvas_item_drawing)
+    : _canvas_item_drawing(canvas_item_drawing)
+    , _grayscale_matrix(std::vector<double>(grayscale_matrix.begin(), grayscale_matrix.end()))
+{
+    _loadPrefs();
+}
+
+Drawing::~Drawing()
+{
+    delete _root;
+}
+
+void Drawing::setRoot(DrawingItem *root)
+{
+    delete _root;
+    _root = root;
+    if (_root) {
+        assert(_root->_child_type == DrawingItem::ChildType::ORPHAN);
+        _root->_child_type = DrawingItem::ChildType::ROOT;
+    }
+}
+
+void Drawing::setRenderMode(RenderMode mode)
+{
+    assert(mode != RenderMode::OUTLINE_OVERLAY && "Drawing::setRenderMode: OUTLINE_OVERLAY is not a true render mode");
+
+    defer([=] {
+        if (mode == _rendermode) return;
+        _root->_markForRendering();
+        _rendermode = mode;
+        _root->_markForUpdate(DrawingItem::STATE_ALL, true);
+        _clearCache();
+    });
+}
+
+void Drawing::setColorMode(ColorMode mode)
+{
+    defer([=] {
+        if (mode == _colormode) return;
+        _colormode = mode;
+        if (_rendermode != RenderMode::OUTLINE || _image_outline_mode) {
+            _root->_markForRendering();
+        }
+    });
+}
+
+void Drawing::setOutlineOverlay(bool outlineoverlay)
+{
+    defer([=] {
+        if (outlineoverlay == _outlineoverlay) return;
+        _outlineoverlay = outlineoverlay;
+        _root->_markForUpdate(DrawingItem::STATE_ALL, true);
+    });
+}
+
+void Drawing::setGrayscaleMatrix(double value_matrix[20])
+{
+    defer([=] {
+        _grayscale_matrix = Filters::FilterColorMatrix::ColorMatrixMatrix(std::vector<double>(value_matrix, value_matrix + 20));
+        if (_rendermode != RenderMode::OUTLINE) {
+            _root->_markForRendering();
+        }
+    });
+}
+
+void Drawing::setClipOutlineColor(uint32_t col)
+{
+    defer([=] {
+        _clip_outline_color = col;
+        if (_rendermode == RenderMode::OUTLINE || _outlineoverlay) {
+            _root->_markForRendering();
+        }
+    });
+}
+
+void Drawing::setMaskOutlineColor(uint32_t col)
+{
+    defer([=] {
+        _mask_outline_color = col;
+        if (_rendermode == RenderMode::OUTLINE || _outlineoverlay) {
+            _root->_markForRendering();
+        }
+    });
+}
+
+void Drawing::setImageOutlineColor(uint32_t col)
+{
+    defer([=] {
+        _image_outline_color = col;
+        if ((_rendermode == RenderMode::OUTLINE || _outlineoverlay) && !_image_outline_mode) {
+            _root->_markForRendering();
+        }
+    });
+}
+
+void Drawing::setImageOutlineMode(bool enabled)
+{
+    defer([=] {
+        _image_outline_mode = enabled;
+        if (_rendermode == RenderMode::OUTLINE || _outlineoverlay) {
+            _root->_markForRendering();
+        }
+    });
+}
+
+void Drawing::setFilterQuality(int quality)
+{
+    defer([=] {
+        _filter_quality = quality;
+        if (!(_rendermode == RenderMode::OUTLINE || _rendermode == RenderMode::NO_FILTERS)) {
+            _root->_markForUpdate(DrawingItem::STATE_ALL, true);
+            _clearCache();
+        }
+    });
+}
+
+void Drawing::setBlurQuality(int quality)
+{
+    defer([=] {
+        _blur_quality = quality;
+        if (!(_rendermode == RenderMode::OUTLINE || _rendermode == RenderMode::NO_FILTERS)) {
+            _root->_markForUpdate(DrawingItem::STATE_ALL, true);
+            _clearCache();
+        }
+    });
+}
+
+void Drawing::setDithering(bool use_dithering)
+{
+    defer([=] {
+        _use_dithering = use_dithering;
+        #ifdef CAIRO_HAS_DITHER
+        if (_rendermode != RenderMode::OUTLINE) {
+            _root->_markForUpdate(DrawingItem::STATE_ALL, true);
+            _clearCache();
+        }
+        #endif
+    });
+}
+
+void Drawing::setCacheBudget(size_t bytes)
+{
+    defer([=] {
+        _cache_budget = bytes;
+        _pickItemsForCaching();
+    });
+}
+
+void Drawing::setCacheLimit(Geom::OptIntRect const &rect)
+{
+    defer([=] {
+        _cache_limit = rect;
+        for (auto item : _cached_items) {
+            item->_markForUpdate(DrawingItem::STATE_CACHE, false);
+        }
+    });
+}
+
+void Drawing::setClip(std::optional<Geom::PathVector> &&clip)
+{
+    defer([=] {
+        if (clip == _clip) return;
+        _clip = std::move(clip);
+        _root->_markForRendering();
+    });
+}
+
+void Drawing::update(Geom::IntRect const &area, Geom::Affine const &affine, unsigned flags, unsigned reset)
+{
+    if (_root) {
+        _root->update(area, { affine }, flags, reset);
+    }
+    if (flags & DrawingItem::STATE_CACHE) {
+        // Process the updated cache scores.
+        _pickItemsForCaching();
+    }
+}
+
+void Drawing::render(DrawingContext &dc, Geom::IntRect const &area, unsigned flags, int antialiasing_override) const
+{
+    int antialias = _root->antialiasing();
+    if (antialiasing_override >= 0) {
+        antialias = antialiasing_override;
+    }
+    apply_antialias(dc, antialias);
+
+    auto rc = RenderContext{ 0xff }; // black outlines
+    flags |= rendermode_to_renderflags(_rendermode);
+
+    if (_clip) {
+        dc.save();
+        dc.path(*_clip * _root->_ctm);
+        dc.clip();
+    }
+    _root->render(dc, rc, area, flags);
+    if (_clip) {
+        dc.restore();
+    }
+}
+
+DrawingItem *Drawing::pick(Geom::Point const &p, double delta, unsigned flags)
+{
+    return _root->pick(p, delta, flags);
+}
+
+void Drawing::snapshot()
+{
+    assert(!_snapshotted);
+    _snapshotted = true;
+}
+
+void Drawing::unsnapshot()
+{
+    assert(_snapshotted);
+    _snapshotted = false; // Unsnapshot before replaying log so further work is not deferred.
+    _funclog();
+}
+
+void Drawing::_pickItemsForCaching()
+{
+    // Build sorted list of items that should be cached.
+    std::vector<DrawingItem*> to_cache;
+    size_t used = 0;
+    for (auto &rec : _candidate_items) {
+        if (used + rec.cache_size > _cache_budget) break;
+        to_cache.emplace_back(rec.item);
+        used += rec.cache_size;
+    }
+    std::sort(to_cache.begin(), to_cache.end());
+
+    // Uncache the items that are cached but should not be cached.
+    // Note: setCached() modifies _cached_items, so the temporary container is necessary.
+    std::vector<DrawingItem*> to_uncache;
+    std::set_difference(_cached_items.begin(), _cached_items.end(),
+                        to_cache.begin(), to_cache.end(),
+                        std::back_inserter(to_uncache));
+    for (auto item : to_uncache) {
+        item->_setCached(false);
+    }
+
+    // Cache all items that should be cached (no-op if already cached).
+    for (auto item : to_cache) {
+        item->_setCached(true);
+    }
+}
+
+void Drawing::_clearCache()
+{
+    // Note: setCached() modifies _cached_items, so the temporary container is necessary.
+    std::vector<DrawingItem*> to_uncache;
+    std::copy(_cached_items.begin(), _cached_items.end(), std::back_inserter(to_uncache));
+    for (auto item : to_uncache) {
+        item->_setCached(false, true);
+    }
+}
+
+void Drawing::_loadPrefs()
+{
+    auto prefs = Inkscape::Preferences::get();
+
+    // Set the initial values of preferences.
+    _clip_outline_color  = prefs->getIntLimited("/options/wireframecolors/clips",        0x00ff00ff, 0, 0xffffffff); // Green clip outlines by default.
+    _mask_outline_color  = prefs->getIntLimited("/options/wireframecolors/masks",        0x0000ffff, 0, 0xffffffff); // Blue mask outlines by default.
+    _image_outline_color = prefs->getIntLimited("/options/wireframecolors/images",       0xff0000ff, 0, 0xffffffff); // Red image outlines by default.
+    _image_outline_mode  = prefs->getBool      ("/options/rendering/imageinoutlinemode", false);
+    _filter_quality      = prefs->getIntLimited("/options/filterquality/value",          0, Filters::FILTER_QUALITY_WORST, Filters::FILTER_QUALITY_BEST);
+    _blur_quality        = prefs->getInt       ("/options/blurquality/value",            0);
+    _use_dithering       = prefs->getBool      ("/options/dithering/value",              true);
+    _cursor_tolerance    = prefs->getDouble    ("/options/cursortolerance/value",        1.0);
+    _select_zero_opacity = prefs->getBool      ("/options/selection/zeroopacity",        false);
+
+    // Enable caching only for the Canvas's drawing, since only it is persistent.
+    if (_canvas_item_drawing) {
+        // Preference is stored in MiB; convert to bytes, taking care not to overflow.
+        _cache_budget = (size_t{1} << 20) * prefs->getIntLimited("/options/renderingcache/size", 64, 0, 4096);
+    } else {
+        _cache_budget = 0;
+    }
+
+    // Set the global variable governing the number of filter threads, and track it too. (This is ugly, but hopefully transitional.)
+    set_num_filter_threads(prefs->getIntLimited("/options/threading/numthreads", default_numthreads(), 1, 256));
+
+    // Similarly, enable preference tracking only for the Canvas's drawing.
+    if (_canvas_item_drawing) {
+        std::unordered_map<std::string, std::function<void (Preferences::Entry const &)>> actions;
+
+        // Todo: (C++20) Eliminate this repetition by baking the preference metadata into the variables themselves using structural templates.
+        actions.emplace("/options/wireframecolors/clips",        [this] (auto &entry) { setClipOutlineColor (entry.getIntLimited(0x00ff00ff, 0, 0xffffffff)); });
+        actions.emplace("/options/wireframecolors/masks",        [this] (auto &entry) { setMaskOutlineColor (entry.getIntLimited(0x0000ffff, 0, 0xffffffff)); });
+        actions.emplace("/options/wireframecolors/images",       [this] (auto &entry) { setImageOutlineColor(entry.getIntLimited(0xff0000ff, 0, 0xffffffff)); });
+        actions.emplace("/options/rendering/imageinoutlinemode", [this] (auto &entry) { setImageOutlineMode(entry.getBool(false)); });
+        actions.emplace("/options/filterquality/value",          [this] (auto &entry) { setFilterQuality(entry.getIntLimited(0, Filters::FILTER_QUALITY_WORST, Filters::FILTER_QUALITY_BEST)); });
+        actions.emplace("/options/blurquality/value",            [this] (auto &entry) { setBlurQuality(entry.getInt(0)); });
+        actions.emplace("/options/dithering/value",              [this] (auto &entry) { setDithering(entry.getBool(true)); });
+        actions.emplace("/options/cursortolerance/value",        [this] (auto &entry) { setCursorTolerance(entry.getDouble(1.0)); });
+        actions.emplace("/options/selection/zeroopacity",        [this] (auto &entry) { setSelectZeroOpacity(entry.getBool(false)); });
+        actions.emplace("/options/renderingcache/size",          [this] (auto &entry) { setCacheBudget((1 << 20) * entry.getIntLimited(64, 0, 4096)); });
+        actions.emplace("/options/threading/numthreads",         [this] (auto &entry) { set_num_filter_threads(entry.getIntLimited(default_numthreads(), 1, 256)); });
+
+        _pref_tracker = Inkscape::Preferences::PreferencesObserver::create("/options", [actions = std::move(actions)] (auto &entry) {
+            auto it = actions.find(entry.getPath());
+            if (it == actions.end()) return;
+            it->second(entry);
+        });
+    }
+}
+
+/*
+ * Return average color over area. Used by Calligraphic, Dropper, and Spray tools.
+ */
+void Drawing::averageColor(Geom::IntRect const &area, double &R, double &G, double &B, double &A) const
+{
+    auto surface = Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32, area.width(), area.height());
+    auto dc = Inkscape::DrawingContext(surface->cobj(), area.min());
+    render(dc, area);
+
+    ink_cairo_surface_average_color_premul(surface->cobj(), R, G, B, A);
+}
+
+/*
+ * Convenience function to set high quality options for export.
+ */
+void Drawing::setExact()
+{
+    setFilterQuality(Filters::FILTER_QUALITY_BEST);
+    setBlurQuality(BLUR_QUALITY_BEST);
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/drawing.h b/src/display/drawing.h
new file mode 100644
index 0000000..0fc676b
--- /dev/null
+++ b/src/display/drawing.h
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * SVG drawing for display.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef INKSCAPE_DISPLAY_DRAWING_H
+#define INKSCAPE_DISPLAY_DRAWING_H
+
+#include <set>
+#include <cstdint>
+#include <vector>
+#include <boost/operators.hpp>
+#include <2geom/rect.h>
+#include <2geom/pathvector.h>
+#include <sigc++/sigc++.h>
+
+#include "display/drawing-item.h"
+#include "display/rendermode.h"
+#include "nr-filter-colormatrix.h"
+#include "preferences.h"
+#include "util/funclog.h"
+
+namespace Inkscape {
+
+class DrawingItem;
+class CanvasItemDrawing;
+class DrawingContext;
+
+class Drawing
+{
+public:
+    Drawing(CanvasItemDrawing *drawing = nullptr);
+    Drawing(Drawing const &) = delete;
+    Drawing &operator=(Drawing const &) = delete;
+    ~Drawing();
+
+    void setRoot(DrawingItem *root);
+    DrawingItem *root() { return _root; }
+    CanvasItemDrawing *getCanvasItemDrawing() { return _canvas_item_drawing; }
+
+    void setRenderMode(RenderMode);
+    void setColorMode(ColorMode);
+    void setOutlineOverlay(bool);
+    void setGrayscaleMatrix(double[20]);
+    void setClipOutlineColor(uint32_t);
+    void setMaskOutlineColor(uint32_t);
+    void setImageOutlineColor(uint32_t);
+    void setImageOutlineMode(bool);
+    void setFilterQuality(int);
+    void setBlurQuality(int);
+    void setDithering(bool);
+    void setCursorTolerance(double tol) { _cursor_tolerance = tol; }
+    void setSelectZeroOpacity(bool select_zero_opacity) { _select_zero_opacity = select_zero_opacity; }
+    void setCacheBudget(size_t bytes);
+    void setCacheLimit(Geom::OptIntRect const &rect);
+    void setClip(std::optional<Geom::PathVector> &&clip);
+
+    RenderMode renderMode() const { return _rendermode; }
+    ColorMode colorMode() const { return _colormode; }
+    bool outlineOverlay() const { return _outlineoverlay; }
+    auto &grayscaleMatrix() const { return _grayscale_matrix; }
+    uint32_t clipOutlineColor() const { return _clip_outline_color; }
+    uint32_t maskOutlineColor() const { return _mask_outline_color; }
+    uint32_t imageOutlineColor() const { return _image_outline_color; }
+    bool imageOutlineMode() const { return _image_outline_mode; }
+    int filterQuality() const { return _filter_quality; }
+    int blurQuality() const { return _blur_quality; }
+    bool useDithering() const { return _use_dithering; }
+    double cursorTolerance() const { return _cursor_tolerance; }
+    bool selectZeroOpacity() const { return _select_zero_opacity; }
+    Geom::OptIntRect const &cacheLimit() const { return _cache_limit; }
+
+    void update(Geom::IntRect const &area = Geom::IntRect::infinite(), Geom::Affine const &affine = Geom::identity(),
+                unsigned flags = DrawingItem::STATE_ALL, unsigned reset = 0);
+    void render(DrawingContext &dc, Geom::IntRect const &area, unsigned flags = 0, int antialiasing_override = -1) const;
+    DrawingItem *pick(Geom::Point const &p, double delta, unsigned flags);
+
+    void snapshot();
+    void unsnapshot();
+    bool snapshotted() const { return _snapshotted; }
+
+    // Convenience
+    void averageColor(Geom::IntRect const &area, double &R, double &G, double &B, double &A) const;
+    void setExact();
+
+private:
+    void _pickItemsForCaching();
+    void _clearCache();
+    void _loadPrefs();
+
+    DrawingItem *_root = nullptr;
+    CanvasItemDrawing *_canvas_item_drawing = nullptr;
+    std::unique_ptr<Preferences::PreferencesObserver> _pref_tracker;
+
+    RenderMode _rendermode = RenderMode::NORMAL;
+    ColorMode _colormode = ColorMode::NORMAL;
+    bool _outlineoverlay = false;
+    Filters::FilterColorMatrix::ColorMatrixMatrix _grayscale_matrix;
+    uint32_t _clip_outline_color;
+    uint32_t _mask_outline_color;
+    uint32_t _image_outline_color;
+    bool _image_outline_mode; ///< Always draw images as images, even in outline mode.
+    int _filter_quality;
+    int _blur_quality;
+    bool _use_dithering;
+    double _cursor_tolerance;
+    size_t _cache_budget; ///< Maximum allowed size of cache.
+    Geom::OptIntRect _cache_limit;
+    std::optional<Geom::PathVector> _clip;
+    bool _select_zero_opacity;
+
+    std::set<DrawingItem*> _cached_items; // modified by DrawingItem::_setCached()
+    CacheList _candidate_items;           // keep this list always sorted with std::greater
+
+    /*
+     * Simple cacheline separator compatible with x86 (64 bytes) and M* (128 bytes).
+     * Ideally alignas(std::hardware_destructive_interference_size) could be used instead,
+     * but this is extremely painful to make work across all supported platforms/compilers.
+     */
+    char cacheline_separator[127];
+
+    bool _snapshotted = false;
+    Util::FuncLog _funclog;
+
+    template<typename F>
+    void defer(F &&f) { _snapshotted ? _funclog.emplace(std::forward<F>(f)) : f(); }
+
+    friend class DrawingItem;
+};
+
+} // namespace Inkscape
+
+#endif // INKSCAPE_DISPLAY_DRAWING_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/initlock.h b/src/display/initlock.h
new file mode 100644
index 0000000..1a94069
--- /dev/null
+++ b/src/display/initlock.h
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef INITLOCK_H
+#define INITLOCK_H
+
+#include <atomic>
+#include <mutex>
+
+/**
+ * Almost entirely analogous to std::once_flag, but with the ability to be reset if the caller knows it is safe to do so.
+ */
+class InitLock
+{
+public:
+    template <typename F>
+    void init(F &&f) const
+    {
+        // Make sure the fast path is a single load-acquire - not guaranteed with std::once_flag.
+        [[likely]] if (inited.load(std::memory_order_acquire)) {
+            return;
+        }
+
+        std::call_once(once, [&] {
+            f();
+            inited.store(true, std::memory_order_release);
+        });
+    }
+
+    void reset()
+    {
+        inited.store(false, std::memory_order_relaxed);
+
+        // Abomination, but tenuously allowed by Standard.
+        // (The alternative, std::mutex, is too large - we want to create a lot of these objects.)
+        once.~once_flag();
+        new (&once) std::once_flag();
+    }
+
+private:
+    mutable std::once_flag once;
+    mutable std::atomic<bool> inited = false;
+};
+
+#endif // INITLOCK_H
diff --git a/src/display/nr-3dutils.cpp b/src/display/nr-3dutils.cpp
new file mode 100644
index 0000000..3c0eb5e
--- /dev/null
+++ b/src/display/nr-3dutils.cpp
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * 3D utils.
+ *
+ * Authors:
+ *   Jean-Rene Reinhard <jr@komite.net>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <glib.h>
+
+#include "display/nr-3dutils.h"
+#include <cmath>
+#include <2geom/point.h>
+#include <2geom/affine.h>
+
+namespace NR {
+
+void convert_coord(gdouble &x, gdouble &y, gdouble &z, Geom::Affine const &trans) {
+    Geom::Point p = Geom::Point(x, y);
+    p *= trans;
+    x = p[Geom::X];
+    y = p[Geom::Y];
+    z *= trans[0];
+}
+
+gdouble norm(const Fvector &v) {
+    return sqrt(v[X_3D]*v[X_3D] + v[Y_3D]*v[Y_3D] + v[Z_3D]*v[Z_3D]);
+}
+
+void normalize_vector(Fvector &v) {
+    gdouble nv = norm(v);
+    //TODO test nv == 0
+    for (int j = 0; j < 3; j++) {
+        v[j] /= nv;
+    }
+}
+
+gdouble scalar_product(const Fvector &a, const Fvector &b) {
+    return  a[X_3D] * b[X_3D] +
+            a[Y_3D] * b[Y_3D] +
+            a[Z_3D] * b[Z_3D];
+}
+
+void normalized_sum(Fvector &r, const Fvector &a, const Fvector &b) {
+    r[X_3D] = a[X_3D] + b[X_3D];
+    r[Y_3D] = a[Y_3D] + b[Y_3D];
+    r[Z_3D] = a[Z_3D] + b[Z_3D];
+    normalize_vector(r);
+}
+
+}/* namespace NR */
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-3dutils.h b/src/display/nr-3dutils.h
new file mode 100644
index 0000000..52b595c
--- /dev/null
+++ b/src/display/nr-3dutils.h
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_3DUTILS_H
+#define SEEN_NR_3DUTILS_H
+
+/*
+ * 3D utils. Definition of gdouble vectors of dimension 3 and of some basic
+ * functions.
+ *   This looks redundant, why not just use Geom::Point for this?
+ *
+ * Authors:
+ *   Jean-Rene Reinhard <jr@komite.net>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <2geom/forward.h>
+
+namespace NR {
+
+#define X_3D 0
+#define Y_3D 1
+#define Z_3D 2
+
+/**
+ * a type of 3 gdouble components vectors
+ */
+struct Fvector {
+    Fvector() {
+        v[0] = v[1] = v[2] = 0.0;
+    }
+    Fvector(double x, double y, double z) {
+        v[0] = x;
+        v[1] = y;
+        v[2] = z;
+    }
+    double v[3];
+    double &operator[](unsigned i) { return v[i]; }
+    double operator[](unsigned i) const { return v[i]; }
+};
+
+/**
+ * The eye vector
+ */
+const static Fvector EYE_VECTOR(0, 0, 1);
+
+/**
+ * returns the euclidean norm of the vector v
+ *
+ * \param v a reference to a vector with double components
+ * \return the euclidean norm of v
+ */
+double norm(const Fvector &v);
+
+/**
+ * Normalizes a vector
+ *
+ * \param v a reference to a vector to normalize
+ */
+void normalize_vector(Fvector &v);
+
+/**
+ * Computes the scalar product between two Fvectors
+ *
+ * \param a a Fvector reference
+ * \param b a Fvector reference
+ * \return the scalar product of a and b
+ */
+double scalar_product(const Fvector &a, const Fvector &b);
+
+/**
+ * Computes the normalized sum of two Fvectors
+ *
+ * \param r a Fvector reference where we store the result
+ * \param a a Fvector reference
+ * \param b a Fvector reference
+ */
+void normalized_sum(Fvector &r, const Fvector &a, const Fvector &b);
+
+/**
+ * Applies the transformation matrix to (x, y, z). This function assumes that
+ * trans[0] = trans[3]. x and y are transformed according to trans, z is
+ * multiplied by trans[0].
+ *
+ * \param x a reference to a x coordinate
+ * \param y a reference to a y coordinate
+ * \param z a reference to a z coordinate
+ * \param z a reference to a transformation matrix
+ */
+void convert_coord(double &x, double &y, double &z, Geom::Affine const &trans);
+
+} /* namespace NR */
+
+#endif /* __NR_3DUTILS_H__ */
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-blend.cpp b/src/display/nr-filter-blend.cpp
new file mode 100644
index 0000000..249a5df
--- /dev/null
+++ b/src/display/nr-filter-blend.cpp
@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * SVG feBlend renderer
+ *//*
+ * "This filter composites two objects together using commonly used
+ * imaging software blending modes. It performs a pixel-wise combination
+ * of two input images."
+ * http://www.w3.org/TR/SVG11/filters.html#feBlend
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *   Jasper van de Gronde <th.v.d.gronde@hccnet.nl>
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2007-2008 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <glibmm.h>
+#include "display/cairo-templates.h"
+#include "display/cairo-utils.h"
+#include "display/nr-filter-blend.h"
+#include "display/nr-filter-primitive.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-types.h"
+
+namespace Inkscape {
+namespace Filters {
+
+std::set<SPBlendMode> const FilterBlend::_valid_modes {
+    // clang-format off
+    SP_CSS_BLEND_NORMAL,      SP_CSS_BLEND_MULTIPLY,
+    SP_CSS_BLEND_SCREEN,      SP_CSS_BLEND_DARKEN,
+    SP_CSS_BLEND_LIGHTEN,     SP_CSS_BLEND_OVERLAY,
+    SP_CSS_BLEND_COLORDODGE,  SP_CSS_BLEND_COLORBURN,
+    SP_CSS_BLEND_HARDLIGHT,   SP_CSS_BLEND_SOFTLIGHT,
+    SP_CSS_BLEND_DIFFERENCE,  SP_CSS_BLEND_EXCLUSION,
+    SP_CSS_BLEND_HUE,         SP_CSS_BLEND_SATURATION,
+    SP_CSS_BLEND_COLOR,       SP_CSS_BLEND_LUMINOSITY
+    // clang-format on
+        };
+
+FilterBlend::FilterBlend()
+    : _blend_mode(SP_CSS_BLEND_NORMAL)
+    , _input2(NR_FILTER_SLOT_NOT_SET)
+{
+}
+
+FilterBlend::~FilterBlend() = default;
+
+static inline cairo_operator_t get_cairo_op(SPBlendMode _blend_mode)
+{
+    switch (_blend_mode) {
+    case SP_CSS_BLEND_MULTIPLY:
+        return CAIRO_OPERATOR_MULTIPLY;
+    case SP_CSS_BLEND_SCREEN:
+        return CAIRO_OPERATOR_SCREEN;
+    case SP_CSS_BLEND_DARKEN:
+        return CAIRO_OPERATOR_DARKEN;
+    case SP_CSS_BLEND_LIGHTEN:
+        return CAIRO_OPERATOR_LIGHTEN;
+    // New in CSS Compositing and Blending Level 1
+    case SP_CSS_BLEND_OVERLAY:
+        return CAIRO_OPERATOR_OVERLAY;
+    case SP_CSS_BLEND_COLORDODGE:
+        return CAIRO_OPERATOR_COLOR_DODGE;
+    case SP_CSS_BLEND_COLORBURN:
+        return CAIRO_OPERATOR_COLOR_BURN;
+    case SP_CSS_BLEND_HARDLIGHT:
+        return CAIRO_OPERATOR_HARD_LIGHT;
+    case SP_CSS_BLEND_SOFTLIGHT:
+        return CAIRO_OPERATOR_SOFT_LIGHT;
+    case SP_CSS_BLEND_DIFFERENCE:
+        return CAIRO_OPERATOR_DIFFERENCE;
+    case SP_CSS_BLEND_EXCLUSION:
+        return CAIRO_OPERATOR_EXCLUSION;
+    case SP_CSS_BLEND_HUE:
+        return CAIRO_OPERATOR_HSL_HUE;
+    case SP_CSS_BLEND_SATURATION:
+        return CAIRO_OPERATOR_HSL_SATURATION;
+    case SP_CSS_BLEND_COLOR:
+        return CAIRO_OPERATOR_HSL_COLOR;
+    case SP_CSS_BLEND_LUMINOSITY:
+        return CAIRO_OPERATOR_HSL_LUMINOSITY;
+
+    case SP_CSS_BLEND_NORMAL:
+    default:
+        return CAIRO_OPERATOR_OVER;
+    }
+}
+
+void FilterBlend::render_cairo(FilterSlot &slot) const
+{
+    cairo_surface_t *input1 = slot.getcairo(_input);
+    cairo_surface_t *input2 = slot.getcairo(_input2);
+
+    // We may need to transform input surface to correct color interpolation space. The input surface
+    // might be used as input to another primitive but it is likely that all the primitives in a given
+    // filter use the same color interpolation space so we don't copy the input before converting.
+    set_cairo_surface_ci(input1, color_interpolation);
+    set_cairo_surface_ci(input2, color_interpolation);
+
+    // input2 is the "background" image
+    // out should be ARGB32 if any of the inputs is ARGB32
+    cairo_surface_t *out = ink_cairo_surface_create_output(input1, input2);
+    set_cairo_surface_ci(out, color_interpolation);
+
+    ink_cairo_surface_blit(input2, out);
+    cairo_t *out_ct = cairo_create(out);
+    cairo_set_source_surface(out_ct, input1, 0, 0);
+
+    // All of the blend modes are implemented in Cairo as of 1.10.
+    // For a detailed description, see:
+    // http://cairographics.org/operators/
+    cairo_set_operator(out_ct, get_cairo_op(_blend_mode));
+
+    cairo_paint(out_ct);
+    cairo_destroy(out_ct);
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+bool FilterBlend::can_handle_affine(Geom::Affine const &) const
+{
+    // blend is a per-pixel primitive and is immutable under transformations
+    return true;
+}
+
+double FilterBlend::complexity(Geom::Affine const &) const
+{
+    return 1.1;
+}
+
+bool FilterBlend::uses_background() const
+{
+    return _input == NR_FILTER_BACKGROUNDIMAGE || _input == NR_FILTER_BACKGROUNDALPHA ||
+           _input2 == NR_FILTER_BACKGROUNDIMAGE || _input2 == NR_FILTER_BACKGROUNDALPHA;
+}
+
+void FilterBlend::set_input(int slot)
+{
+    _input = slot;
+}
+
+void FilterBlend::set_input(int input, int slot)
+{
+    if (input == 0) _input = slot;
+    if (input == 1) _input2 = slot;
+}
+
+void FilterBlend::set_mode(SPBlendMode mode)
+{
+    if (_valid_modes.count(mode)) {
+        _blend_mode = mode;
+    }
+}
+
+} /* namespace Filters */
+} /* namespace Inkscape */
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-blend.h b/src/display/nr-filter-blend.h
new file mode 100644
index 0000000..d05cd65
--- /dev/null
+++ b/src/display/nr-filter-blend.h
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_BLEND_H
+#define SEEN_NR_FILTER_BLEND_H
+
+/*
+ * SVG feBlend renderer
+ *
+ * "This filter composites two objects together using commonly used
+ * imaging software blending modes. It performs a pixel-wise combination
+ * of two input images."
+ * http://www.w3.org/TR/SVG11/filters.html#feBlend
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+#include <set>
+#include "style-enums.h"
+#include "display/nr-filter-primitive.h"
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterBlend : public FilterPrimitive
+{
+public:
+    FilterBlend();
+    ~FilterBlend() override;
+
+    void render_cairo(FilterSlot &slot) const override;
+    bool can_handle_affine(Geom::Affine const &) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+    bool uses_background() const override;
+
+    void set_input(int slot) override;
+    void set_input(int input, int slot) override;
+    void set_mode(SPBlendMode mode);
+
+    Glib::ustring name() const override { return Glib::ustring("Blend"); }
+
+private:
+    static const std::set<SPBlendMode> _valid_modes;
+    SPBlendMode _blend_mode;
+    int _input2;
+};
+
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_BLEND_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-colormatrix.cpp b/src/display/nr-filter-colormatrix.cpp
new file mode 100644
index 0000000..ae16932
--- /dev/null
+++ b/src/display/nr-filter-colormatrix.cpp
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * feColorMatrix filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *   Jasper van de Gronde <th.v.d.gronde@hccnet.nl>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cmath>
+#include <algorithm>
+#include "display/cairo-templates.h"
+#include "display/cairo-utils.h"
+#include "display/nr-filter-colormatrix.h"
+#include "display/nr-filter-slot.h"
+#include <2geom/math-utils.h>
+
+namespace Inkscape {
+namespace Filters {
+
+FilterColorMatrix::FilterColorMatrix() = default;
+
+FilterColorMatrix::~FilterColorMatrix() = default;
+
+FilterColorMatrix::ColorMatrixMatrix::ColorMatrixMatrix(std::vector<double> const &values)
+{
+    unsigned limit = std::min(static_cast<size_t>(20), values.size());
+    for (unsigned i = 0; i < limit; ++i) {
+        if (i % 5 == 4) {
+            _v[i] = round(values[i]*255*255);
+        } else {
+            _v[i] = round(values[i]*255);
+        }
+    }
+    for (unsigned i = limit; i < 20; ++i) {
+        _v[i] = (i % 6 == 0) ? 255 : 0;
+    }
+}
+
+guint32 FilterColorMatrix::ColorMatrixMatrix::operator()(guint32 in)
+{
+    EXTRACT_ARGB32(in, a, r, g, b)
+    // we need to un-premultiply alpha values for this type of matrix
+    // TODO: unpremul can be ignored if there is an identity mapping on the alpha channel
+    if (a != 0) {
+        r = unpremul_alpha(r, a);
+        g = unpremul_alpha(g, a);
+        b = unpremul_alpha(b, a);
+    }
+
+    gint32 ro = r*_v[0]  + g*_v[1]  + b*_v[2]  + a*_v[3]  + _v[4];
+    gint32 go = r*_v[5]  + g*_v[6]  + b*_v[7]  + a*_v[8]  + _v[9];
+    gint32 bo = r*_v[10] + g*_v[11] + b*_v[12] + a*_v[13] + _v[14];
+    gint32 ao = r*_v[15] + g*_v[16] + b*_v[17] + a*_v[18] + _v[19];
+    ro = (pxclamp(ro, 0, 255*255) + 127) / 255;
+    go = (pxclamp(go, 0, 255*255) + 127) / 255;
+    bo = (pxclamp(bo, 0, 255*255) + 127) / 255;
+    ao = (pxclamp(ao, 0, 255*255) + 127) / 255;
+
+    ro = premul_alpha(ro, ao);
+    go = premul_alpha(go, ao);
+    bo = premul_alpha(bo, ao);
+
+    ASSEMBLE_ARGB32(pxout, ao, ro, go, bo)
+    return pxout;
+}
+
+struct ColorMatrixSaturate
+{
+    ColorMatrixSaturate(double v_in)
+    {
+        // clamp parameter instead of clamping color values
+        double v = std::clamp(v_in, 0.0, 1.0);
+        _v[0] = 0.213+0.787*v; _v[1] = 0.715-0.715*v; _v[2] = 0.072-0.072*v;
+        _v[3] = 0.213-0.213*v; _v[4] = 0.715+0.285*v; _v[5] = 0.072-0.072*v;
+        _v[6] = 0.213-0.213*v; _v[7] = 0.715-0.715*v; _v[8] = 0.072+0.928*v;
+    }
+
+    guint32 operator()(guint32 in)
+    {
+        EXTRACT_ARGB32(in, a, r, g, b)
+
+        // Note: this cannot be done in fixed point, because the loss of precision
+        //       causes overflow for some values of v
+        guint32 ro = r*_v[0] + g*_v[1] + b*_v[2] + 0.5;
+        guint32 go = r*_v[3] + g*_v[4] + b*_v[5] + 0.5;
+        guint32 bo = r*_v[6] + g*_v[7] + b*_v[8] + 0.5;
+
+        ASSEMBLE_ARGB32(pxout, a, ro, go, bo)
+        return pxout;
+    }
+
+private:
+    double _v[9];
+};
+
+struct ColorMatrixHueRotate
+{
+    ColorMatrixHueRotate(double v)
+    {
+        double sinhue, coshue;
+        Geom::sincos(v * M_PI/180.0, sinhue, coshue);
+
+        _v[0] = std::round((0.213 +0.787*coshue -0.213*sinhue)*255);
+        _v[1] = std::round((0.715 -0.715*coshue -0.715*sinhue)*255);
+        _v[2] = std::round((0.072 -0.072*coshue +0.928*sinhue)*255);
+
+        _v[3] = std::round((0.213 -0.213*coshue +0.143*sinhue)*255);
+        _v[4] = std::round((0.715 +0.285*coshue +0.140*sinhue)*255);
+        _v[5] = std::round((0.072 -0.072*coshue -0.283*sinhue)*255);
+
+        _v[6] = std::round((0.213 -0.213*coshue -0.787*sinhue)*255);
+        _v[7] = std::round((0.715 -0.715*coshue +0.715*sinhue)*255);
+        _v[8] = std::round((0.072 +0.928*coshue +0.072*sinhue)*255);
+    }
+
+    guint32 operator()(guint32 in)
+    {
+        EXTRACT_ARGB32(in, a, r, g, b)
+        gint32 maxpx = a*255;
+        gint32 ro = r*_v[0] + g*_v[1] + b*_v[2];
+        gint32 go = r*_v[3] + g*_v[4] + b*_v[5];
+        gint32 bo = r*_v[6] + g*_v[7] + b*_v[8];
+        ro = (pxclamp(ro, 0, maxpx) + 127) / 255;
+        go = (pxclamp(go, 0, maxpx) + 127) / 255;
+        bo = (pxclamp(bo, 0, maxpx) + 127) / 255;
+
+        ASSEMBLE_ARGB32(pxout, a, ro, go, bo)
+        return pxout;
+    }
+
+private:
+    gint32 _v[9];
+};
+
+struct ColorMatrixLuminanceToAlpha
+{
+    guint32 operator()(guint32 in)
+    {
+        // original computation in double: r*0.2125 + g*0.7154 + b*0.0721
+        EXTRACT_ARGB32(in, a, r, g, b)
+        // unpremultiply color values
+        if (a != 0) {
+            r = unpremul_alpha(r, a);
+            g = unpremul_alpha(g, a);
+            b = unpremul_alpha(b, a);
+        }
+        guint32 ao = r*54 + g*182 + b*18;
+        return ((ao + 127) / 255) << 24;
+    }
+};
+
+void FilterColorMatrix::render_cairo(FilterSlot &slot) const
+{
+    cairo_surface_t *input = slot.getcairo(_input);
+    cairo_surface_t *out = nullptr;
+
+    // We may need to transform input surface to correct color interpolation space. The input surface
+    // might be used as input to another primitive but it is likely that all the primitives in a given
+    // filter use the same color interpolation space so we don't copy the input before converting.
+    set_cairo_surface_ci(input, color_interpolation);
+
+    if (type == COLORMATRIX_LUMINANCETOALPHA) {
+        out = ink_cairo_surface_create_same_size(input, CAIRO_CONTENT_ALPHA);
+    } else {
+        out = ink_cairo_surface_create_same_size(input, CAIRO_CONTENT_COLOR_ALPHA);
+        // Set ci to that used for computation
+        set_cairo_surface_ci(out, color_interpolation);
+    }
+
+    switch (type) {
+    case COLORMATRIX_MATRIX:
+        ink_cairo_surface_filter(input, out, FilterColorMatrix::ColorMatrixMatrix(values));
+        break;
+    case COLORMATRIX_SATURATE:
+        ink_cairo_surface_filter(input, out, ColorMatrixSaturate(value));
+        break;
+    case COLORMATRIX_HUEROTATE:
+        ink_cairo_surface_filter(input, out, ColorMatrixHueRotate(value));
+        break;
+    case COLORMATRIX_LUMINANCETOALPHA:
+        ink_cairo_surface_filter(input, out, ColorMatrixLuminanceToAlpha());
+        break;
+    case COLORMATRIX_ENDTYPE:
+    default:
+        break;
+    }
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+bool FilterColorMatrix::can_handle_affine(Geom::Affine const &) const
+{
+    return true;
+}
+
+double FilterColorMatrix::complexity(Geom::Affine const &) const
+{
+    return 2.0;
+}
+
+void FilterColorMatrix::set_type(FilterColorMatrixType t)
+{
+    type = t;
+}
+
+void FilterColorMatrix::set_value(double v)
+{
+    value = v;
+}
+
+void FilterColorMatrix::set_values(std::vector<double> const &v)
+{
+    values = v;
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-colormatrix.h b/src/display/nr-filter-colormatrix.h
new file mode 100644
index 0000000..20d2f72
--- /dev/null
+++ b/src/display/nr-filter-colormatrix.h
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_COLOR_MATRIX_H
+#define SEEN_NR_FILTER_COLOR_MATRIX_H
+
+/*
+ * feColorMatrix filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <vector>
+#include <2geom/forward.h>
+#include "display/nr-filter-primitive.h"
+
+typedef unsigned int guint32;
+typedef signed int gint32;
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterSlot;
+
+enum FilterColorMatrixType
+{
+    COLORMATRIX_MATRIX,
+    COLORMATRIX_SATURATE,
+    COLORMATRIX_HUEROTATE,
+    COLORMATRIX_LUMINANCETOALPHA,
+    COLORMATRIX_ENDTYPE
+};
+
+class FilterColorMatrix : public FilterPrimitive
+{
+public:
+    FilterColorMatrix();
+    ~FilterColorMatrix() override;
+
+    void render_cairo(FilterSlot &slot) const override;
+    bool can_handle_affine(Geom::Affine const &) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+
+    virtual void set_type(FilterColorMatrixType type);
+    virtual void set_value(double value);
+    virtual void set_values(std::vector<double> const &values);
+
+    Glib::ustring name() const override { return Glib::ustring("Color Matrix"); }
+
+public:
+    struct ColorMatrixMatrix
+    {
+        ColorMatrixMatrix(std::vector<double> const &values);
+        guint32 operator()(guint32 in);
+    private:
+        gint32 _v[20];
+    };
+
+private:
+    std::vector<double> values;
+    double value;
+    FilterColorMatrixType type;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_COLOR_MATRIX_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-component-transfer.cpp b/src/display/nr-filter-component-transfer.cpp
new file mode 100644
index 0000000..31ba077
--- /dev/null
+++ b/src/display/nr-filter-component-transfer.cpp
@@ -0,0 +1,245 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * feComponentTransfer filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *   Jasper van de Gronde <th.v.d.gronde@hccnet.nl>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cmath>
+#include "display/cairo-templates.h"
+#include "display/cairo-utils.h"
+#include "display/nr-filter-component-transfer.h"
+#include "display/nr-filter-slot.h"
+
+namespace Inkscape {
+namespace Filters {
+
+FilterComponentTransfer::FilterComponentTransfer() = default;
+
+FilterComponentTransfer::~FilterComponentTransfer() = default;
+
+struct UnmultiplyAlpha
+{
+    guint32 operator()(guint32 in)
+    {
+        EXTRACT_ARGB32(in, a, r, g, b);
+        if (a == 0 )
+            return in;
+        r = unpremul_alpha(r, a);
+        g = unpremul_alpha(g, a);
+        b = unpremul_alpha(b, a);
+        ASSEMBLE_ARGB32(out, a, r, g, b);
+        return out;
+    }
+};
+
+struct MultiplyAlpha
+{
+    guint32 operator()(guint32 in)
+    {
+        EXTRACT_ARGB32(in, a, r, g, b);
+        r = premul_alpha(r, a);
+        g = premul_alpha(g, a);
+        b = premul_alpha(b, a);
+        ASSEMBLE_ARGB32(out, a, r, g, b);
+        return out;
+    }
+};
+
+struct ComponentTransfer
+{
+    ComponentTransfer(guint32 color)
+        : _shift(color * 8)
+        , _mask(0xff << _shift) {}
+
+protected:
+    guint32 _shift;
+    guint32 _mask;
+};
+
+struct ComponentTransferTable : public ComponentTransfer
+{
+    ComponentTransferTable(guint32 color, std::vector<double> const &values)
+        : ComponentTransfer(color)
+        , _v(values.size())
+    {
+        for (unsigned i = 0; i < values.size(); ++i) {
+            _v[i] = std::round(std::clamp(values[i], 0.0, 1.0) * 255);
+        }
+    }
+    
+    guint32 operator()(guint32 in)
+    {
+        if (_v.empty()) {
+            return in;
+        }
+
+        guint32 component = (in & _mask) >> _shift;
+        if (_v.size() == 1 || component == 255) {
+            component = _v.back();
+        } else {
+            guint32 k = (_v.size() - 1) * component;
+            guint32 dx = k % 255;
+            k /= 255;
+            component = _v[k] * 255 + (_v[k + 1] - _v[k]) * dx;
+            component = (component + 127) / 255;
+        }
+        return (in & ~_mask) | (component << _shift);
+    }
+    
+private:
+    std::vector<guint32> _v;
+};
+
+struct ComponentTransferDiscrete : public ComponentTransfer
+{
+    ComponentTransferDiscrete(guint32 color, std::vector<double> const &values)
+        : ComponentTransfer(color)
+        , _v(values.size())
+    {
+        for (unsigned i = 0; i< values.size(); ++i) {
+            _v[i] = std::round(std::clamp(values[i], 0.0, 1.0) * 255);
+        }
+    }
+    
+    guint32 operator()(guint32 in)
+    {
+        guint32 component = (in & _mask) >> _shift;
+        guint32 k = _v.size() * component / 255;
+        if (k == _v.size()) --k;
+        component = _v[k];
+        return (in & ~_mask) | ((guint32)component << _shift);
+    }
+    
+private:
+    std::vector<guint32> _v;
+};
+
+struct ComponentTransferLinear : public ComponentTransfer
+{
+    ComponentTransferLinear(guint32 color, double intercept, double slope)
+        : ComponentTransfer(color)
+        , _intercept(round(intercept * 255 * 255))
+        , _slope(round(slope * 255)) {}
+    
+    guint32 operator()(guint32 in)
+    {
+        gint32 component = (in & _mask) >> _shift;
+
+        // TODO: this can probably be reduced to something simpler
+        component = pxclamp(_slope * component + _intercept, 0, 255 * 255);
+        component = (component + 127) / 255;
+        return (in & ~_mask) | (component << _shift);
+    }
+    
+private:
+    gint32 _intercept;
+    gint32 _slope;
+};
+
+struct ComponentTransferGamma : public ComponentTransfer
+{
+    ComponentTransferGamma(guint32 color, double amplitude, double exponent, double offset)
+        : ComponentTransfer(color)
+        , _amplitude(amplitude)
+        , _exponent(exponent)
+        , _offset(offset) {}
+    
+    guint32 operator()(guint32 in)
+    {
+        double component = (in & _mask) >> _shift;
+        component /= 255.0;
+        component = _amplitude * std::pow(component, _exponent) + _offset;
+        guint32 cpx = pxclamp(component * 255.0, 0, 255);
+        return (in & ~_mask) | (cpx << _shift);
+    }
+
+private:
+    double _amplitude;
+    double _exponent;
+    double _offset;
+};
+
+void FilterComponentTransfer::render_cairo(FilterSlot &slot) const
+{
+    cairo_surface_t *input = slot.getcairo(_input);
+    cairo_surface_t *out = ink_cairo_surface_create_same_size(input, CAIRO_CONTENT_COLOR_ALPHA);
+
+    // We may need to transform input surface to correct color interpolation space. The input surface
+    // might be used as input to another primitive but it is likely that all the primitives in a given
+    // filter use the same color interpolation space so we don't copy the input before converting.
+    set_cairo_surface_ci(out, color_interpolation);
+    set_cairo_surface_ci(input, color_interpolation);
+
+    ink_cairo_surface_blit(input, out);
+
+    // We need to operate on unmultipled by alpha color values otherwise a change in alpha screws
+    // up the premultiplied by alpha r, g, b values.
+    ink_cairo_surface_filter(out, out, UnmultiplyAlpha());
+
+    // parameters: R = 0, G = 1, B = 2, A = 3
+    // Cairo:      R = 2, G = 1, B = 0, A = 3
+    // If tableValues is empty, use identity.
+    for (unsigned i = 0; i < 4; ++i) {
+        guint32 color = 2 - i;
+        if (i == 3) color = 3; // alpha
+
+        switch (type[i]) {
+        case COMPONENTTRANSFER_TYPE_TABLE:
+            if (!tableValues[i].empty()) {
+              ink_cairo_surface_filter(out, out, ComponentTransferTable(color, tableValues[i]));
+            }
+            break;
+        case COMPONENTTRANSFER_TYPE_DISCRETE:
+            if (!tableValues[i].empty()) {
+                ink_cairo_surface_filter(out, out, ComponentTransferDiscrete(color, tableValues[i]));
+            }
+            break;
+        case COMPONENTTRANSFER_TYPE_LINEAR:
+            ink_cairo_surface_filter(out, out, ComponentTransferLinear(color, intercept[i], slope[i]));
+            break;
+        case COMPONENTTRANSFER_TYPE_GAMMA:
+            ink_cairo_surface_filter(out, out, ComponentTransferGamma(color, amplitude[i], exponent[i], offset[i]));
+            break;
+        case COMPONENTTRANSFER_TYPE_ERROR:
+        case COMPONENTTRANSFER_TYPE_IDENTITY:
+        default:
+            break;
+        }
+    }
+
+    ink_cairo_surface_filter(out, out, MultiplyAlpha());
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+bool FilterComponentTransfer::can_handle_affine(Geom::Affine const &) const
+{
+    return true;
+}
+
+double FilterComponentTransfer::complexity(Geom::Affine const &) const
+{
+    return 2.0;
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-component-transfer.h b/src/display/nr-filter-component-transfer.h
new file mode 100644
index 0000000..4e2b0d2
--- /dev/null
+++ b/src/display/nr-filter-component-transfer.h
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_COMPONENT_TRANSFER_H
+#define SEEN_NR_FILTER_COMPONENT_TRANSFER_H
+
+/*
+ * feComponentTransfer filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <vector>
+#include "display/nr-filter-primitive.h"
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterSlot;
+
+enum FilterComponentTransferType
+{
+    COMPONENTTRANSFER_TYPE_IDENTITY,
+    COMPONENTTRANSFER_TYPE_TABLE,
+    COMPONENTTRANSFER_TYPE_DISCRETE,
+    COMPONENTTRANSFER_TYPE_LINEAR,
+    COMPONENTTRANSFER_TYPE_GAMMA,
+    COMPONENTTRANSFER_TYPE_ERROR
+};
+
+class FilterComponentTransfer : public FilterPrimitive
+{
+public:
+    FilterComponentTransfer();
+    ~FilterComponentTransfer() override;
+
+    void render_cairo(FilterSlot &slot) const override;
+    bool can_handle_affine(Geom::Affine const &) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+
+    FilterComponentTransferType type[4];
+    std::vector<double> tableValues[4];
+    double slope[4];
+    double intercept[4];
+    double amplitude[4];
+    double exponent[4];
+    double offset[4];
+
+    Glib::ustring name() const override { return Glib::ustring("Component Transfer"); }
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_COMPONENT_TRANSFER_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-composite.cpp b/src/display/nr-filter-composite.cpp
new file mode 100644
index 0000000..7817573
--- /dev/null
+++ b/src/display/nr-filter-composite.cpp
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * feComposite filter effect renderer
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cmath>
+
+#include "display/cairo-templates.h"
+#include "display/cairo-utils.h"
+#include "display/nr-filter-composite.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+
+namespace Inkscape {
+namespace Filters {
+
+FilterComposite::FilterComposite()
+    : op(COMPOSITE_DEFAULT)
+    , k1(0)
+    , k2(0)
+    , k3(0)
+    , k4(0)
+    , _input2(Inkscape::Filters::NR_FILTER_SLOT_NOT_SET) {}
+
+FilterComposite::~FilterComposite() = default;
+
+struct ComposeArithmetic
+{
+    ComposeArithmetic(double k1, double k2, double k3, double k4)
+        : _k1(round(k1 * 255))
+        , _k2(round(k2 * 255*255))
+        , _k3(round(k3 * 255*255))
+        , _k4(round(k4 * 255*255*255)) {}
+
+    guint32 operator()(guint32 in1, guint32 in2)
+    {
+        EXTRACT_ARGB32(in1, aa, ra, ga, ba)
+        EXTRACT_ARGB32(in2, ab, rb, gb, bb)
+
+        gint32 ao = _k1*aa*ab + _k2*aa + _k3*ab + _k4;
+        gint32 ro = _k1*ra*rb + _k2*ra + _k3*rb + _k4;
+        gint32 go = _k1*ga*gb + _k2*ga + _k3*gb + _k4;
+        gint32 bo = _k1*ba*bb + _k2*ba + _k3*bb + _k4;
+
+        ao = pxclamp(ao, 0, 255*255*255); // r, g and b are premultiplied, so should be clamped to the alpha channel
+        ro = (pxclamp(ro, 0, ao) + (255*255/2)) / (255*255);
+        go = (pxclamp(go, 0, ao) + (255*255/2)) / (255*255);
+        bo = (pxclamp(bo, 0, ao) + (255*255/2)) / (255*255);
+        ao = (ao + (255*255/2)) / (255*255);
+
+        ASSEMBLE_ARGB32(pxout, ao, ro, go, bo)
+        return pxout;
+    }
+
+private:
+    gint32 _k1, _k2, _k3, _k4;
+};
+
+void FilterComposite::render_cairo(FilterSlot &slot) const
+{
+    cairo_surface_t *input1 = slot.getcairo(_input);
+    cairo_surface_t *input2 = slot.getcairo(_input2);
+
+    // We may need to transform input surface to correct color interpolation space. The input surface
+    // might be used as input to another primitive but it is likely that all the primitives in a given
+    // filter use the same color interpolation space so we don't copy the input before converting.
+    set_cairo_surface_ci(input1, color_interpolation);
+    set_cairo_surface_ci(input2, color_interpolation);
+
+    cairo_surface_t *out = ink_cairo_surface_create_output(input1, input2);
+    set_cairo_surface_ci(out, color_interpolation);
+
+    Geom::Rect vp = filter_primitive_area( slot.get_units() );
+    slot.set_primitive_area(_output, vp); // Needed for tiling
+
+    if (op == COMPOSITE_ARITHMETIC) {
+        ink_cairo_surface_blend(input1, input2, out, ComposeArithmetic(k1, k2, k3, k4));
+    } else {
+        ink_cairo_surface_blit(input2, out);
+        cairo_t *ct = cairo_create(out);
+        cairo_set_source_surface(ct, input1, 0, 0);
+        switch(op) {
+        case COMPOSITE_IN:
+            cairo_set_operator(ct, CAIRO_OPERATOR_IN);
+            break;
+        case COMPOSITE_OUT:
+            cairo_set_operator(ct, CAIRO_OPERATOR_OUT);
+            break;
+        case COMPOSITE_ATOP:
+            cairo_set_operator(ct, CAIRO_OPERATOR_ATOP);
+            break;
+        case COMPOSITE_XOR:
+            cairo_set_operator(ct, CAIRO_OPERATOR_XOR);
+            break;
+        case COMPOSITE_LIGHTER:
+            cairo_set_operator(ct, CAIRO_OPERATOR_ADD);
+            break;
+        case COMPOSITE_OVER:
+        case COMPOSITE_DEFAULT:
+        default:
+            // OVER is the default operator
+            break;
+        }
+        cairo_paint(ct);
+        cairo_destroy(ct);
+    }
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+bool FilterComposite::can_handle_affine(Geom::Affine const &) const
+{
+    return true;
+}
+
+void FilterComposite::set_input(int input)
+{
+    _input = input;
+}
+
+void FilterComposite::set_input(int input, int slot)
+{
+    if (input == 0) _input = slot;
+    if (input == 1) _input2 = slot;
+}
+
+void FilterComposite::set_operator(FeCompositeOperator op_)
+{
+    if (op_ == COMPOSITE_DEFAULT) {
+        op = COMPOSITE_OVER;
+    } else if (op_ != COMPOSITE_ENDOPERATOR) {
+        op = op_;
+    }
+}
+
+void FilterComposite::set_arithmetic(double k1_, double k2_, double k3_, double k4_)
+{
+    if (!std::isfinite(k1) || !std::isfinite(k2) || !std::isfinite(k3) || !std::isfinite(k4)) {
+        g_warning("Non-finite parameter for feComposite arithmetic operator");
+        return;
+    }
+    k1 = k1_;
+    k2 = k2_;
+    k3 = k3_;
+    k4 = k4_;
+}
+
+double FilterComposite::complexity(Geom::Affine const &) const
+{
+    return 1.1;
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-composite.h b/src/display/nr-filter-composite.h
new file mode 100644
index 0000000..6196303
--- /dev/null
+++ b/src/display/nr-filter-composite.h
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_COMPOSITE_H
+#define SEEN_NR_FILTER_COMPOSITE_H
+
+/*
+ * feComposite filter effect renderer
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "object/filters/composite.h"
+#include "display/nr-filter-primitive.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterComposite : public FilterPrimitive
+{
+public:
+    FilterComposite();
+    ~FilterComposite() override;
+
+    void render_cairo(FilterSlot &) const override;
+    bool can_handle_affine(Geom::Affine const &) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+
+    void set_input(int input) override;
+    void set_input(int input, int slot) override;
+
+    void set_operator(FeCompositeOperator op);
+    void set_arithmetic(double k1, double k2, double k3, double k4);
+
+    Glib::ustring name() const override { return Glib::ustring("Composite"); }
+
+private:
+    FeCompositeOperator op;
+    double k1, k2, k3, k4;
+    int _input2;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_COMPOSITE_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-convolve-matrix.cpp b/src/display/nr-filter-convolve-matrix.cpp
new file mode 100644
index 0000000..059ae40
--- /dev/null
+++ b/src/display/nr-filter-convolve-matrix.cpp
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * feConvolveMatrix filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *   Jasper van de Gronde <th.v.d.gronde@hccnet.nl>
+ *
+ * Copyright (C) 2007,2009 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <vector>
+#include "display/cairo-templates.h"
+#include "display/cairo-utils.h"
+#include "display/nr-filter-convolve-matrix.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+#include "display/nr-filter-utils.h"
+
+namespace Inkscape {
+namespace Filters {
+
+FilterConvolveMatrix::FilterConvolveMatrix() = default;
+
+FilterConvolveMatrix::~FilterConvolveMatrix() = default;
+
+enum PreserveAlphaMode
+{
+    PRESERVE_ALPHA,
+    NO_PRESERVE_ALPHA
+};
+
+template <PreserveAlphaMode preserve_alpha>
+struct ConvolveMatrix : public SurfaceSynth
+{
+    ConvolveMatrix(cairo_surface_t *s, int targetX, int targetY, int orderX, int orderY,
+                   double divisor, double bias, std::vector<double> const &kernel)
+        : SurfaceSynth(s)
+        , _kernel(kernel.size())
+        , _targetX(targetX)
+        , _targetY(targetY)
+        , _orderX(orderX)
+        , _orderY(orderY)
+        , _bias(bias)
+    {
+        for (unsigned i = 0; i < _kernel.size(); ++i) {
+            _kernel[i] = kernel[i] / divisor;
+        }
+        // the matrix is given rotated 180 degrees
+        // which corresponds to reverse element order
+        std::reverse(_kernel.begin(), _kernel.end());
+    }
+
+    guint32 operator()(int x, int y) const
+    {
+        int startx = std::max(0, x - _targetX);
+        int starty = std::max(0, y - _targetY);
+        int endx = std::min(_w, startx + _orderX);
+        int endy = std::min(_h, starty + _orderY);
+        int limitx = endx - startx;
+        int limity = endy - starty;
+        double suma = 0.0, sumr = 0.0, sumg = 0.0, sumb = 0.0;
+
+        for (int i = 0; i < limity; ++i) {
+            for (int j = 0; j < limitx; ++j) {
+                guint32 px = pixelAt(startx + j, starty + i);
+                double coeff = _kernel[i * _orderX + j];
+                EXTRACT_ARGB32(px, a,r,g,b)
+
+                sumr += r * coeff;
+                sumg += g * coeff;
+                sumb += b * coeff;
+                if (preserve_alpha == NO_PRESERVE_ALPHA) {
+                    suma += a * coeff;
+                }
+            }
+        }
+        if (preserve_alpha == PRESERVE_ALPHA) {
+            suma = alphaAt(x, y);
+        } else {
+            suma += _bias * 255;
+        }
+
+        guint32 ao = pxclamp(round(suma), 0, 255);
+        guint32 ro = pxclamp(round(sumr + ao * _bias), 0, ao);
+        guint32 go = pxclamp(round(sumg + ao * _bias), 0, ao);
+        guint32 bo = pxclamp(round(sumb + ao * _bias), 0, ao);
+        ASSEMBLE_ARGB32(pxout, ao,ro,go,bo);
+        return pxout;
+    }
+
+private:
+    std::vector<double> _kernel;
+    int _targetX, _targetY, _orderX, _orderY;
+    double _bias;
+};
+
+void FilterConvolveMatrix::render_cairo(FilterSlot &slot) const
+{
+    static bool bias_warning = false;
+    static bool edge_warning = false;
+
+    if (orderX<=0 || orderY<=0) {
+        g_warning("Empty kernel!");
+        return;
+    }
+    if (targetX<0 || targetX>=orderX || targetY<0 || targetY>=orderY) {
+        g_warning("Invalid target!");
+        return;
+    }
+    if (kernelMatrix.size()!=(unsigned int)(orderX*orderY)) {
+        //g_warning("kernelMatrix does not have orderX*orderY elements!");
+        return;
+    }
+
+    cairo_surface_t *input = slot.getcairo(_input);
+    cairo_surface_t *out = ink_cairo_surface_create_identical(input);
+
+    // We may need to transform input surface to correct color interpolation space. The input surface
+    // might be used as input to another primitive but it is likely that all the primitives in a given
+    // filter use the same color interpolation space so we don't copy the input before converting.
+    set_cairo_surface_ci(out, color_interpolation);
+    set_cairo_surface_ci(input, color_interpolation);
+
+    if (bias != 0 && !bias_warning) {
+        g_warning("It is unknown whether Inkscape's implementation of bias in feConvolveMatrix is correct!");
+        bias_warning = true;
+        // The SVG specification implies that feConvolveMatrix is defined for premultiplied
+        // colors (which makes sense). It also says that bias should simply be added to the result
+        // for each color (without taking the alpha into account). However, it also says that one
+        // purpose of bias is "to have .5 gray value be the zero response of the filter".
+        // It seems sensible to indeed support the latter behaviour instead of the former,
+        // but this does appear to go against the standard.
+        // Note that Batik simply does not support bias!=0
+    }
+    if (edgeMode != CONVOLVEMATRIX_EDGEMODE_NONE && !edge_warning) {
+        g_warning("Inkscape only supports edgeMode=\"none\" (and a filter uses a different one)!");
+        edge_warning = true;
+    }
+
+    //guint32 *in_data = reinterpret_cast<guint32*>(cairo_image_surface_get_data(input));
+    //guint32 *out_data = reinterpret_cast<guint32*>(cairo_image_surface_get_data(out));
+
+    //int width = cairo_image_surface_get_width(input);
+    //int height = cairo_image_surface_get_height(input);
+
+    // Set up predivided kernel matrix
+    /*std::vector<double> kernel(kernelMatrix);
+    for(size_t i=0; i<kernel.size(); i++) {
+        kernel[i] /= divisor; // The code that creates this object makes sure that divisor != 0
+    }*/
+
+    if (preserveAlpha) {
+        //convolve2D<true>(out_data, in_data, width, height, &kernel.front(), orderX, orderY,
+        //    targetX, targetY, bias);
+        ink_cairo_surface_synthesize(out, ConvolveMatrix<PRESERVE_ALPHA>(input,
+            targetX, targetY, orderX, orderY, divisor, bias, kernelMatrix));
+    } else {
+        //convolve2D<false>(out_data, in_data, width, height, &kernel.front(), orderX, orderY,
+        //    targetX, targetY, bias);
+        ink_cairo_surface_synthesize(out, ConvolveMatrix<NO_PRESERVE_ALPHA>(input,
+            targetX, targetY, orderX, orderY, divisor, bias, kernelMatrix));
+    }
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+void FilterConvolveMatrix::set_targetX(int coord)
+{
+    targetX = coord;
+}
+
+void FilterConvolveMatrix::set_targetY(int coord)
+{
+    targetY = coord;
+}
+
+void FilterConvolveMatrix::set_orderX(int coord)
+{
+    orderX = coord;
+}
+
+void FilterConvolveMatrix::set_orderY(int coord)
+{
+    orderY = coord;
+}
+
+void FilterConvolveMatrix::set_divisor(double d)
+{
+    divisor = d;
+}
+
+void FilterConvolveMatrix::set_bias(double b)
+{
+    bias = b;
+}
+
+void FilterConvolveMatrix::set_kernelMatrix(std::vector<gdouble> km)
+{
+    kernelMatrix = std::move(km);
+}
+
+void FilterConvolveMatrix::set_edgeMode(FilterConvolveMatrixEdgeMode mode)
+{
+    edgeMode = mode;
+}
+
+void FilterConvolveMatrix::set_preserveAlpha(bool pa)
+{
+    preserveAlpha = pa;
+}
+
+void FilterConvolveMatrix::area_enlarge(Geom::IntRect &area, Geom::Affine const &/*trans*/) const
+{
+    //Seems to me that since this filter's operation is resolution dependent,
+    // some spurious pixels may still appear at the borders when low zooming or rotating. Needs a better fix.
+    area.setMin(area.min() - Geom::IntPoint(targetX, targetY));
+    // This makes sure the last row/column in the original image corresponds
+    // to the last row/column in the new image that can be convolved without
+    // adjusting the boundary conditions).
+    area.setMax(area.max() + Geom::IntPoint(orderX - targetX - 1, orderY - targetY - 1));
+}
+
+double FilterConvolveMatrix::complexity(Geom::Affine const &) const
+{
+    return kernelMatrix.size();
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-convolve-matrix.h b/src/display/nr-filter-convolve-matrix.h
new file mode 100644
index 0000000..44cb3e4
--- /dev/null
+++ b/src/display/nr-filter-convolve-matrix.h
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_CONVOLVE_MATRIX_H
+#define SEEN_NR_FILTER_CONVOLVE_MATRIX_H
+
+/*
+ * feConvolveMatrix filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/nr-filter-primitive.h"
+#include <vector>
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterSlot;
+
+enum FilterConvolveMatrixEdgeMode
+{
+    CONVOLVEMATRIX_EDGEMODE_DUPLICATE,
+    CONVOLVEMATRIX_EDGEMODE_WRAP,
+    CONVOLVEMATRIX_EDGEMODE_NONE,
+    CONVOLVEMATRIX_EDGEMODE_ENDTYPE
+};
+
+class FilterConvolveMatrix : public FilterPrimitive
+{
+public:
+    FilterConvolveMatrix();
+    ~FilterConvolveMatrix() override;
+
+    void render_cairo(FilterSlot &slot) const override;
+    void area_enlarge(Geom::IntRect &area, Geom::Affine const &trans) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+
+    void set_targetY(int coord);
+    void set_targetX(int coord);
+    void set_orderY(int coord);
+    void set_orderX(int coord);
+    void set_kernelMatrix(std::vector<gdouble> km);
+    void set_bias(double b);
+    void set_divisor(double d);
+    void set_edgeMode(FilterConvolveMatrixEdgeMode mode);
+    void set_preserveAlpha(bool pa);
+
+    Glib::ustring name() const override { return Glib::ustring("Convolve Matrix"); }
+
+private:
+    std::vector<double> kernelMatrix;
+    int targetX, targetY;
+    int orderX, orderY;
+    double divisor, bias;
+    FilterConvolveMatrixEdgeMode edgeMode;
+    bool preserveAlpha;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_CONVOLVE_MATRIX_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-diffuselighting.cpp b/src/display/nr-filter-diffuselighting.cpp
new file mode 100644
index 0000000..8f80998
--- /dev/null
+++ b/src/display/nr-filter-diffuselighting.cpp
@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * feDiffuseLighting renderer
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *   Jean-Rene Reinhard <jr@komite.net>
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2007-2010 Authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"  // only include where actually required!
+#endif
+
+#include <glib.h>
+
+#include "display/cairo-templates.h"
+#include "display/cairo-utils.h"
+#include "display/nr-3dutils.h"
+#include "display/nr-filter-diffuselighting.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+#include "display/nr-filter-utils.h"
+#include "display/nr-light.h"
+#include "svg/svg-color.h"
+
+namespace Inkscape {
+namespace Filters {
+
+FilterDiffuseLighting::FilterDiffuseLighting()
+    : light_type(NO_LIGHT)
+    , diffuseConstant(1)
+    , surfaceScale(1)
+    , lighting_color(0xffffffff) {}
+
+FilterDiffuseLighting::~FilterDiffuseLighting() = default;
+
+struct DiffuseLight : public SurfaceSynth
+{
+    DiffuseLight(cairo_surface_t *bumpmap, double scale, double kd)
+        : SurfaceSynth(bumpmap)
+        , _scale(scale)
+        , _kd(kd) {}
+
+protected:
+    guint32 diffuseLighting(int x, int y, NR::Fvector const &light, NR::Fvector const &light_components)
+    {
+        NR::Fvector normal = surfaceNormalAt(x, y, _scale);
+        double k = _kd * NR::scalar_product(normal, light);
+
+        guint32 r = CLAMP_D_TO_U8(k * light_components[LIGHT_RED]);
+        guint32 g = CLAMP_D_TO_U8(k * light_components[LIGHT_GREEN]);
+        guint32 b = CLAMP_D_TO_U8(k * light_components[LIGHT_BLUE]);
+
+        ASSEMBLE_ARGB32(pxout, 255, r, g, b)
+        return pxout;
+    }
+
+    double _scale, _kd;
+};
+
+struct DiffuseDistantLight : public DiffuseLight
+{
+    DiffuseDistantLight(cairo_surface_t *bumpmap, DistantLightData const &light, guint32 color,
+                        double scale, double diffuse_constant)
+        : DiffuseLight(bumpmap, scale, diffuse_constant)
+    {
+        DistantLight dl(light, color);
+        dl.light_vector(_lightv);
+        dl.light_components(_light_components);
+    }
+
+    guint32 operator()(int x, int y)
+    {
+        return diffuseLighting(x, y, _lightv, _light_components);
+    }
+
+private:
+    NR::Fvector _lightv, _light_components;
+};
+
+struct DiffusePointLight : public DiffuseLight
+{
+    DiffusePointLight(cairo_surface_t *bumpmap, PointLightData const &light, guint32 color,
+                      Geom::Affine const &trans, double scale, double diffuse_constant,
+                      double x0, double y0, int device_scale)
+        : DiffuseLight(bumpmap, scale, diffuse_constant)
+        , _light(light, color, trans, device_scale)
+        , _x0(x0)
+        , _y0(y0)
+    {
+        _light.light_components(_light_components);
+    }
+
+    guint32 operator()(int x, int y)
+    {
+        NR::Fvector light;
+        _light.light_vector(light, _x0 + x, _y0 + y, _scale * alphaAt(x, y) / 255.0);
+        return diffuseLighting(x, y, light, _light_components);
+    }
+
+private:
+    PointLight _light;
+    NR::Fvector _light_components;
+    double _x0, _y0;
+};
+
+struct DiffuseSpotLight : public DiffuseLight
+{
+    DiffuseSpotLight(cairo_surface_t *bumpmap, SpotLightData const &light, guint32 color,
+                     Geom::Affine const &trans, double scale, double diffuse_constant,
+                     double x0, double y0, int device_scale)
+        : DiffuseLight(bumpmap, scale, diffuse_constant)
+        , _light(light, color, trans, device_scale)
+        , _x0(x0)
+        , _y0(y0) {}
+
+    guint32 operator()(int x, int y)
+    {
+        NR::Fvector light, light_components;
+        _light.light_vector(light, _x0 + x, _y0 + y, _scale * alphaAt(x, y)/255.0);
+        _light.light_components(light_components, light);
+        return diffuseLighting(x, y, light, light_components);
+    }
+
+private:
+    SpotLight _light;
+    double _x0, _y0;
+};
+
+void FilterDiffuseLighting::render_cairo(FilterSlot &slot) const
+{
+    cairo_surface_t *input = slot.getcairo(_input);
+    cairo_surface_t *out = ink_cairo_surface_create_same_size(input, CAIRO_CONTENT_COLOR_ALPHA);
+
+    double r = SP_RGBA32_R_F(lighting_color);
+    double g = SP_RGBA32_G_F(lighting_color);
+    double b = SP_RGBA32_B_F(lighting_color);
+
+    if (icc) {
+        unsigned char ru, gu, bu;
+        icc_color_to_sRGB(&*icc, &ru, &gu, &bu);
+        r = SP_COLOR_U_TO_F(ru);
+        g = SP_COLOR_U_TO_F(gu);
+        b = SP_COLOR_U_TO_F(bu);
+    }
+
+    // Only alpha channel of input is used, no need to check input color_interpolation_filter value.
+    // Lighting color is always defined in terms of sRGB, preconvert to linearRGB
+    // if color_interpolation_filters set to linearRGB (for efficiency assuming
+    // next filter primitive has same value of cif).
+    if (color_interpolation == SP_CSS_COLOR_INTERPOLATION_LINEARRGB) {
+        r = srgb_to_linear(r);
+        g = srgb_to_linear(g);
+        b = srgb_to_linear(b);
+    }
+    set_cairo_surface_ci(out, color_interpolation);
+    guint32 color = SP_RGBA32_F_COMPOSE(r, g, b, 1.0);
+
+    int device_scale = slot.get_device_scale();
+
+    Geom::Rect slot_area = slot.get_slot_area();
+    Geom::Point p = slot_area.min();
+
+    // trans has inverse y... so we can't just scale by device_scale! We must instead explicitly
+    // scale the point and spot light coordinates (as well as "scale").
+
+    Geom::Affine trans = slot.get_units().get_matrix_primitiveunits2pb();
+
+    double x0 = p.x(), y0 = p.y();
+    double scale = surfaceScale * trans.descrim() * device_scale;
+
+    switch (light_type) {
+    case DISTANT_LIGHT:
+        ink_cairo_surface_synthesize(out, DiffuseDistantLight(input, light.distant, color, scale, diffuseConstant));
+        break;
+    case POINT_LIGHT:
+        ink_cairo_surface_synthesize(out, DiffusePointLight(input, light.point, color, trans, scale, diffuseConstant, x0, y0, device_scale));
+        break;
+    case SPOT_LIGHT:
+        ink_cairo_surface_synthesize(out, DiffuseSpotLight(input, light.spot, color, trans, scale, diffuseConstant, x0, y0, device_scale));
+        break;
+    default: {
+        cairo_t *ct = cairo_create(out);
+        cairo_set_source_rgba(ct, 0, 0, 0, 1);
+        cairo_set_operator(ct, CAIRO_OPERATOR_SOURCE);
+        cairo_paint(ct);
+        cairo_destroy(ct);
+        break;
+        }
+    }
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+void FilterDiffuseLighting::area_enlarge(Geom::IntRect &area, Geom::Affine const & /*trans*/) const
+{
+    // TODO: support kernelUnitLength
+
+    // We expand the area by 1 in every direction to avoid artifacts on tile edges.
+    // However, it means that edge pixels will be incorrect.
+    area.expandBy(1);
+}
+
+double FilterDiffuseLighting::complexity(Geom::Affine const &) const
+{
+    return 9.0;
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-diffuselighting.h b/src/display/nr-filter-diffuselighting.h
new file mode 100644
index 0000000..69577b5
--- /dev/null
+++ b/src/display/nr-filter-diffuselighting.h
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_DIFFUSELIGHTING_H
+#define SEEN_NR_FILTER_DIFFUSELIGHTING_H
+
+/*
+ * feDiffuseLighting renderer
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *   Jean-Rene Reinhard <jr@komite.net>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <optional>
+#include "display/nr-light-types.h"
+#include "display/nr-filter-primitive.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+#include "svg/svg-icc-color.h"
+
+class SPFeDistantLight;
+class SPFePointLight;
+class SPFeSpotLight;
+struct SVGICCColor;
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterDiffuseLighting : public FilterPrimitive
+{
+public:
+    FilterDiffuseLighting();
+    ~FilterDiffuseLighting() override;
+
+    void render_cairo(FilterSlot &slot) const override;
+    void set_icc(SVGICCColor const &icc_) { icc = icc_; }
+    void area_enlarge(Geom::IntRect &area, Geom::Affine const &trans) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+
+    union {
+        DistantLightData distant;
+        PointLightData point;
+        SpotLightData spot;
+    } light;
+    LightType light_type;
+    double diffuseConstant;
+    double surfaceScale;
+    guint32 lighting_color;
+
+    Glib::ustring name() const override { return "Diffuse Lighting"; }
+
+private:
+    std::optional<SVGICCColor> icc;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_DIFFUSELIGHTING_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-displacement-map.cpp b/src/display/nr-filter-displacement-map.cpp
new file mode 100644
index 0000000..869bccb
--- /dev/null
+++ b/src/display/nr-filter-displacement-map.cpp
@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * feDisplacementMap filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/cairo-templates.h"
+#include "display/cairo-utils.h"
+#include "display/nr-filter-displacement-map.h"
+#include "display/nr-filter-types.h"
+#include "display/nr-filter-units.h"
+
+namespace Inkscape {
+namespace Filters {
+
+struct Displace
+{
+    Displace(cairo_surface_t *texture, cairo_surface_t *map,
+            unsigned xch, unsigned ych, double scalex, double scaley)
+        : _texture(texture)
+        , _map(map)
+        , _xch(xch)
+        , _ych(ych)
+        , _scalex(scalex / 255.0)
+        , _scaley(scaley / 255.0)
+    {
+    }
+
+    guint32 operator()(int x, int y)
+    {
+        guint32 mappx = _map.pixelAt(x, y);
+        guint32 a = (mappx & 0xff000000) >> 24;
+        guint32 xpx = 0, ypx = 0;
+        double xtex = x, ytex = y;
+        
+        guint32 xshift = _xch * 8, yshift = _ych * 8;
+        xpx = (mappx & (0xff << xshift)) >> xshift;
+        ypx = (mappx & (0xff << yshift)) >> yshift;
+        if (a) {
+            if (_xch != 3) xpx = unpremul_alpha(xpx, a);
+            if (_ych != 3) ypx = unpremul_alpha(ypx, a);
+        }
+        xtex += _scalex * (xpx - 127.5);
+        ytex += _scaley * (ypx - 127.5);
+
+        if (xtex >= 0 && xtex < _texture._w - 1 &&
+            ytex >= 0 && ytex < _texture._h - 1)
+        {
+            return _texture.pixelAt(xtex, ytex);
+        } else {
+            return 0;
+        }
+    }
+
+private:
+    SurfaceSynth _texture;
+    SurfaceSynth _map;
+    unsigned _xch, _ych;
+    double _scalex, _scaley;
+};
+
+void FilterDisplacementMap::render_cairo(FilterSlot &slot) const
+{
+    cairo_surface_t *texture = slot.getcairo(_input);
+    cairo_surface_t *map = slot.getcairo(_input2);
+    cairo_surface_t *out = ink_cairo_surface_create_identical(texture);
+    // color_interpolation_filters for out same as texture. See spec.
+    copy_cairo_surface_ci(texture, out);
+
+    // We may need to transform map surface to correct color interpolation space. The map surface
+    // might be used as input to another primitive but it is likely that all the primitives in a given
+    // filter use the same color interpolation space so we don't copy the map before converting.
+    set_cairo_surface_ci(map, color_interpolation);
+
+    Geom::Affine trans = slot.get_units().get_matrix_primitiveunits2pb();
+
+    int device_scale = slot.get_device_scale();
+    double scalex = scale * trans.expansionX() * device_scale;
+    double scaley = scale * trans.expansionY() * device_scale;
+
+    ink_cairo_surface_synthesize(out, Displace(texture, map, Xchannel, Ychannel, scalex, scaley));
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+void FilterDisplacementMap::set_input(int slot)
+{
+    _input = slot;
+}
+
+void FilterDisplacementMap::set_scale(double s)
+{
+    scale = s;
+}
+
+void FilterDisplacementMap::set_input(int input, int slot)
+{
+    if (input == 0) _input = slot;
+    if (input == 1) _input2 = slot;
+}
+
+void FilterDisplacementMap::set_channel_selector(int s, FilterDisplacementMapChannelSelector channel)
+{
+    if (channel > DISPLACEMENTMAP_CHANNEL_ALPHA || channel < DISPLACEMENTMAP_CHANNEL_RED) {
+        g_warning("Selected an invalid channel value. (%d)", channel);
+        return;
+    }
+
+    // channel numbering:
+    // a = 3, r = 2, g = 1, b = 0
+    // this way we can get the component value using:
+    // component = (color & (ch*8)) >> (ch*8)
+    unsigned ch;
+    switch (channel) {
+    case DISPLACEMENTMAP_CHANNEL_ALPHA:
+        ch = 3;
+        break;
+    case DISPLACEMENTMAP_CHANNEL_RED:
+        ch = 2;
+        break;
+    case DISPLACEMENTMAP_CHANNEL_GREEN:
+        ch = 1;
+        break;
+    case DISPLACEMENTMAP_CHANNEL_BLUE:
+        ch = 0;
+        break;
+    default:
+        return;
+    }
+
+    if (s == 0) Xchannel = ch;
+    if (s == 1) Ychannel = ch;
+}
+
+void FilterDisplacementMap::area_enlarge(Geom::IntRect &area, Geom::Affine const &trans) const
+{
+    //I assume scale is in user coordinates (?!?)
+    //FIXME: trans should be multiplied by some primitiveunits2user, shouldn't it?
+    
+    double scalex = scale / 2. * (std::fabs(trans[0]) + std::fabs(trans[1]));
+    double scaley = scale / 2. * (std::fabs(trans[2]) + std::fabs(trans[3]));
+
+    //FIXME: no +2 should be there!... (noticeable only for big scales at big zoom factor)
+    area.expandBy(scalex + 2, scaley + 2);
+}
+
+double FilterDisplacementMap::complexity(Geom::Affine const &) const
+{
+    return 3.0;
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-displacement-map.h b/src/display/nr-filter-displacement-map.h
new file mode 100644
index 0000000..e6813d6
--- /dev/null
+++ b/src/display/nr-filter-displacement-map.h
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_DISPLACEMENT_MAP_H
+#define SEEN_NR_FILTER_DISPLACEMENT_MAP_H
+
+/*
+ * feDisplacementMap filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "object/filters/displacementmap.h"
+#include "display/nr-filter-primitive.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterDisplacementMap : public FilterPrimitive
+{
+public:
+    void render_cairo(FilterSlot &slot) const override;
+    void area_enlarge(Geom::IntRect &area, Geom::Affine const &trans) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+
+    void set_input(int slot) override;
+    void set_input(int input, int slot) override;
+    void set_scale(double s);
+    void set_channel_selector(int s, FilterDisplacementMapChannelSelector channel);
+
+    Glib::ustring name() const override { return Glib::ustring("Displacement Map"); }
+
+private:
+    double scale;
+    int _input2;
+    unsigned Xchannel, Ychannel;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_DISPLACEMENT_MAP_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-flood.cpp b/src/display/nr-filter-flood.cpp
new file mode 100644
index 0000000..cc7fcb2
--- /dev/null
+++ b/src/display/nr-filter-flood.cpp
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * feFlood filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *   Tavmjong Bah <tavmjong@free.fr> (use primitive filter region)
+ *
+ * Copyright (C) 2007, 2011 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"  // only include where actually required!
+#endif
+
+#include "display/cairo-utils.h"
+#include "display/nr-filter-flood.h"
+#include "display/nr-filter-slot.h"
+#include "svg/svg-icc-color.h"
+#include "svg/svg-color.h"
+#include "color.h"
+
+namespace Inkscape {
+namespace Filters {
+
+FilterFlood::FilterFlood() = default;
+
+FilterFlood::~FilterFlood() = default;
+
+void FilterFlood::render_cairo(FilterSlot &slot) const
+{
+    cairo_surface_t *input = slot.getcairo(_input);
+
+    double r = SP_RGBA32_R_F(color);
+    double g = SP_RGBA32_G_F(color);
+    double b = SP_RGBA32_B_F(color);
+    double a = opacity;
+
+    if (icc) {
+        unsigned char ru, gu, bu;
+        icc_color_to_sRGB(&*icc, &ru, &gu, &bu);
+        r = SP_COLOR_U_TO_F(ru);
+        g = SP_COLOR_U_TO_F(gu);
+        b = SP_COLOR_U_TO_F(bu);
+    }
+
+    cairo_surface_t *out = ink_cairo_surface_create_same_size(input, CAIRO_CONTENT_COLOR_ALPHA);
+
+    // Flood color is always defined in terms of sRGB, preconvert to linearRGB
+    // if color_interpolation_filters set to linearRGB (for efficiency assuming
+    // next filter primitive has same value of cif).
+    if (color_interpolation == SP_CSS_COLOR_INTERPOLATION_LINEARRGB) {
+        r = srgb_to_linear(r);
+        g = srgb_to_linear(g);
+        b = srgb_to_linear(b);
+    }
+    set_cairo_surface_ci(out, color_interpolation);
+
+    // Get filter primitive area in user units
+    Geom::Rect fp = filter_primitive_area(slot.get_units());
+
+    // Convert to Cairo units
+    Geom::Rect fp_cairo = fp * slot.get_units().get_matrix_user2pb();
+
+    // Get area in slot (tile to fill)
+    Geom::Rect sa = slot.get_slot_area();
+
+    // Get overlap
+    Geom::OptRect optoverlap = intersect(fp_cairo, sa);
+    if (optoverlap) {
+        Geom::Rect overlap = *optoverlap;
+
+        auto d = fp_cairo.min() - sa.min();
+        if (d.x() < 0.0) d.x() = 0.0;
+        if (d.y() < 0.0) d.y() = 0.0;
+
+        cairo_t *ct = cairo_create(out);
+        cairo_set_source_rgba(ct, r, g, b, a);
+        cairo_set_operator(ct, CAIRO_OPERATOR_SOURCE);
+        cairo_rectangle(ct, d.x(), d.y(), overlap.width(), overlap.height());
+        cairo_fill(ct);
+        cairo_destroy(ct);
+    }
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+bool FilterFlood::can_handle_affine(Geom::Affine const &) const
+{
+    // flood is a per-pixel primitive and is immutable under transformations
+    return true;
+}
+
+void FilterFlood::set_color(guint32 c)
+{
+    color = c;
+}
+
+void FilterFlood::set_opacity(double o)
+{
+    opacity = o;
+}
+
+double FilterFlood::complexity(Geom::Affine const &) const
+{
+    // flood is actually less expensive than normal rendering,
+    // but when flood is processed, the object has already been rendered
+    return 1.0;
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-flood.h b/src/display/nr-filter-flood.h
new file mode 100644
index 0000000..2228e00
--- /dev/null
+++ b/src/display/nr-filter-flood.h
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_FLOOD_H
+#define SEEN_NR_FILTER_FLOOD_H
+
+/*
+ * feFlood filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <optional>
+#include "display/nr-filter-primitive.h"
+
+struct SVGICCColor;
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterFlood : public FilterPrimitive
+{
+public:
+    FilterFlood();
+    ~FilterFlood() override;
+
+    void render_cairo(FilterSlot &slot) const override;
+    bool can_handle_affine(Geom::Affine const &) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+    bool uses_background()  const override { return false; }
+    
+    void set_opacity(double o);
+    void set_color(guint32 c);
+    void set_icc(SVGICCColor const &icc_) { icc = icc_; }
+
+    Glib::ustring name() const override { return Glib::ustring("Flood"); }
+
+private:
+    double opacity;
+    guint32 color;
+    std::optional<SVGICCColor> icc;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_FLOOD_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-gaussian.cpp b/src/display/nr-filter-gaussian.cpp
new file mode 100644
index 0000000..4e04bfd
--- /dev/null
+++ b/src/display/nr-filter-gaussian.cpp
@@ -0,0 +1,747 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Gaussian blur renderer
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *   bulia byak
+ *   Jasper van de Gronde <th.v.d.gronde@hccnet.nl>
+ *
+ * Copyright (C) 2006-2008 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"  // only include where actually required!
+#endif
+
+#include <algorithm>
+#include <cmath>
+#include <complex>
+#include <cstdlib>
+#include <glib.h>
+#include <limits>
+#if HAVE_OPENMP
+#include <omp.h>
+#endif //HAVE_OPENMP
+
+#include "display/cairo-utils.h"
+#include "display/nr-filter-primitive.h"
+#include "display/nr-filter-gaussian.h"
+#include "display/nr-filter-types.h"
+#include "display/nr-filter-units.h"
+#include "display/nr-filter-slot.h"
+#include <2geom/affine.h>
+#include "util/fixed_point.h"
+
+#ifndef INK_UNUSED
+#define INK_UNUSED(x) ((void)(x))
+#endif
+
+// IIR filtering method based on:
+// L.J. van Vliet, I.T. Young, and P.W. Verbeek, Recursive Gaussian Derivative Filters,
+// in: A.K. Jain, S. Venkatesh, B.C. Lovell (eds.),
+// ICPR'98, Proc. 14th Int. Conference on Pattern Recognition (Brisbane, Aug. 16-20),
+// IEEE Computer Society Press, Los Alamitos, 1998, 509-514.
+//
+// Using the backwards-pass initialization procedure from:
+// Boundary Conditions for Young - van Vliet Recursive Filtering
+// Bill Triggs, Michael Sdika
+// IEEE Transactions on Signal Processing, Volume 54, Number 5 - may 2006
+
+// Number of IIR filter coefficients used. Currently only 3 is supported.
+// "Recursive Gaussian Derivative Filters" says this is enough though (and
+// some testing indeed shows that the quality doesn't improve much if larger
+// filters are used).
+static size_t const N = 3;
+
+template<typename InIt, typename OutIt, typename Size>
+inline void copy_n(InIt beg_in, Size N, OutIt beg_out) {
+    std::copy(beg_in, beg_in+N, beg_out);
+}
+
+// Type used for IIR filter coefficients (can be 10.21 signed fixed point, see Anisotropic Gaussian Filtering Using Fixed Point Arithmetic, Christoph H. Lampert & Oliver Wirjadi, 2006)
+typedef double IIRValue;
+
+// Type used for FIR filter coefficients (can be 16.16 unsigned fixed point, should have 8 or more bits in the fractional part, the integer part should be capable of storing approximately 20*255)
+typedef Inkscape::Util::FixedPoint<unsigned int,16> FIRValue;
+
+template<typename T> static inline T sqr(T const& v) { return v*v; }
+
+template<typename T> static inline T clip(T const& v, T const& a, T const& b) {
+    if ( v < a ) return a;
+    if ( v > b ) return b;
+    return v;
+}
+
+template<typename Tt, typename Ts>
+static inline Tt round_cast(Ts v) {
+    static Ts const rndoffset(.5);
+    return static_cast<Tt>(v+rndoffset);
+}
+/*
+template<>
+inline unsigned char round_cast(double v) {
+    // This (fast) rounding method is based on:
+    // http://stereopsis.com/sree/fpu2006.html
+#if G_BYTE_ORDER==G_LITTLE_ENDIAN
+    double const dmr = 6755399441055744.0;
+    v = v + dmr;
+    return ((unsigned char*)&v)[0];
+#elif G_BYTE_ORDER==G_BIG_ENDIAN
+    double const dmr = 6755399441055744.0;
+    v = v + dmr;
+    return ((unsigned char*)&v)[7];
+#else
+    static double const rndoffset(.5);
+    return static_cast<unsigned char>(v+rndoffset);
+#endif
+}*/
+
+template<typename Tt, typename Ts>
+static inline Tt clip_round_cast(Ts const v) {
+    Ts const minval = std::numeric_limits<Tt>::min();
+    Ts const maxval = std::numeric_limits<Tt>::max();
+    Tt const minval_rounded = std::numeric_limits<Tt>::min();
+    Tt const maxval_rounded = std::numeric_limits<Tt>::max();
+    if ( v < minval ) return minval_rounded;
+    if ( v > maxval ) return maxval_rounded;
+    return round_cast<Tt>(v);
+}
+
+template<typename Tt, typename Ts>
+static inline Tt clip_round_cast_varmax(Ts const v, Tt const maxval_rounded) {
+    Ts const minval = std::numeric_limits<Tt>::min();
+    Tt const maxval = maxval_rounded;
+    Tt const minval_rounded = std::numeric_limits<Tt>::min();
+    if ( v < minval ) return minval_rounded;
+    if ( v > maxval ) return maxval_rounded;
+    return round_cast<Tt>(v);
+}
+
+namespace Inkscape {
+namespace Filters {
+
+FilterGaussian::FilterGaussian()
+{
+    _deviation_x = _deviation_y = 0.0;
+}
+
+FilterGaussian::~FilterGaussian()
+{
+}
+
+static int
+_effect_area_scr(double const deviation)
+{
+    return (int)std::ceil(std::fabs(deviation) * 3.0);
+}
+
+static void
+_make_kernel(FIRValue *const kernel, double const deviation)
+{
+    int const scr_len = _effect_area_scr(deviation);
+    g_assert(scr_len >= 0);
+    double const d_sq = sqr(deviation) * 2;
+    double k[scr_len+1]; // This is only called for small kernel sizes (above approximately 10 coefficients the IIR filter is used)
+
+    // Compute kernel and sum of coefficients
+    // Note that actually only half the kernel is computed, as it is symmetric
+    double sum = 0;
+    for ( int i = scr_len; i >= 0 ; i-- ) {
+        k[i] = std::exp(-sqr(i) / d_sq);
+        if ( i > 0 ) sum += k[i];
+    }
+    // the sum of the complete kernel is twice as large (plus the center element which we skipped above to prevent counting it twice)
+    sum = 2*sum + k[0];
+
+    // Normalize kernel (making sure the sum is exactly 1)
+    double ksum = 0;
+    FIRValue kernelsum = 0;
+    for ( int i = scr_len; i >= 1 ; i-- ) {
+        ksum += k[i]/sum;
+        kernel[i] = ksum-static_cast<double>(kernelsum);
+        kernelsum += kernel[i];
+    }
+    kernel[0] = FIRValue(1)-2*kernelsum;
+}
+
+// Return value (v) should satisfy:
+//  2^(2*v)*255<2^32
+//  255<2^(32-2*v)
+//  2^8<=2^(32-2*v)
+//  8<=32-2*v
+//  2*v<=24
+//  v<=12
+static int
+_effect_subsample_step_log2(double const deviation, int const quality)
+{
+    // To make sure FIR will always be used (unless the kernel is VERY big):
+    //  deviation/step <= 3
+    //  deviation/3 <= step
+    //  log(deviation/3) <= log(step)
+    // So when x below is >= 1/3 FIR will almost always be used.
+    // This means IIR is almost only used with the modes BETTER or BEST.
+    int stepsize_l2;
+    switch (quality) {
+        case BLUR_QUALITY_WORST:
+            // 2 == log(x*8/3))
+            // 2^2 == x*2^3/3
+            // x == 3/2
+            stepsize_l2 = clip(static_cast<int>(log(deviation*(3./2.))/log(2.)), 0, 12);
+            break;
+        case BLUR_QUALITY_WORSE:
+            // 2 == log(x*16/3))
+            // 2^2 == x*2^4/3
+            // x == 3/2^2
+            stepsize_l2 = clip(static_cast<int>(log(deviation*(3./4.))/log(2.)), 0, 12);
+            break;
+        case BLUR_QUALITY_BETTER:
+            // 2 == log(x*32/3))
+            // 2 == x*2^5/3
+            // x == 3/2^4
+            stepsize_l2 = clip(static_cast<int>(log(deviation*(3./16.))/log(2.)), 0, 12);
+            break;
+        case BLUR_QUALITY_BEST:
+            stepsize_l2 = 0; // no subsampling at all
+            break;
+        case BLUR_QUALITY_NORMAL:
+        default:
+            // 2 == log(x*16/3))
+            // 2 == x*2^4/3
+            // x == 3/2^3
+            stepsize_l2 = clip(static_cast<int>(log(deviation*(3./8.))/log(2.)), 0, 12);
+            break;
+    }
+    return stepsize_l2;
+}
+
+static void calcFilter(double const sigma, double b[N]) {
+    assert(N==3);
+    std::complex<double> const d1_org(1.40098,  1.00236);
+    double const d3_org = 1.85132;
+    double qbeg = 1; // Don't go lower than sigma==2 (we'd probably want a normal convolution in that case anyway)
+    double qend = 2*sigma;
+    double const sigmasqr = sqr(sigma);
+    do { // Binary search for right q (a linear interpolation scheme is suggested, but this should work fine as well)
+        double const q = (qbeg+qend)/2;
+        // Compute scaled filter coefficients
+        std::complex<double> const d1 = pow(d1_org, 1.0/q);
+        double const d3 = pow(d3_org, 1.0/q);
+        // Compute actual sigma^2
+        double const ssqr = 2*(2*(d1/sqr(d1-1.)).real()+d3/sqr(d3-1.));
+        if ( ssqr < sigmasqr ) {
+            qbeg = q;
+        } else {
+            qend = q;
+        }
+    } while(qend-qbeg>(sigma/(1<<30)));
+    // Compute filter coefficients
+    double const q = (qbeg+qend)/2;
+    std::complex<double> const d1 = pow(d1_org, 1.0/q);
+    double const d3 = pow(d3_org, 1.0/q);
+    double const absd1sqr = std::norm(d1); // d1*d2 = d1*conj(d1) = |d1|^2 = std::norm(d1)
+    double const re2d1 = 2*d1.real(); // d1+d2 = d1+conj(d1) = 2*real(d1)
+    double const bscale = 1.0/(absd1sqr*d3);
+    b[2] = -bscale;
+    b[1] =  bscale*(d3+re2d1);
+    b[0] = -bscale*(absd1sqr+d3*re2d1);
+}
+
+static void calcTriggsSdikaM(double const b[N], double M[N*N]) {
+    assert(N==3);
+    double a1=b[0], a2=b[1], a3=b[2];
+    double const Mscale = 1.0/((1+a1-a2+a3)*(1-a1-a2-a3)*(1+a2+(a1-a3)*a3));
+    M[0] = 1-a2-a1*a3-sqr(a3);
+    M[1] = (a1+a3)*(a2+a1*a3);
+    M[2] = a3*(a1+a2*a3);
+    M[3] = a1+a2*a3;
+    M[4] = (1-a2)*(a2+a1*a3);
+    M[5] = a3*(1-a2-a1*a3-sqr(a3));
+    M[6] = a1*(a1+a3)+a2*(1-a2);
+    M[7] = a1*(a2-sqr(a3))+a3*(1+a2*(a2-1)-sqr(a3));
+    M[8] = a3*(a1+a2*a3);
+    for(unsigned int i=0; i<9; i++) M[i] *= Mscale;
+}
+
+template<unsigned int SIZE>
+static void calcTriggsSdikaInitialization(double const M[N*N], IIRValue const uold[N][SIZE], IIRValue const uplus[SIZE], IIRValue const vplus[SIZE], IIRValue const alpha, IIRValue vold[N][SIZE]) {
+    for(unsigned int c=0; c<SIZE; c++) {
+        double uminp[N];
+        for(unsigned int i=0; i<N; i++) uminp[i] = uold[i][c] - uplus[c];
+        for(unsigned int i=0; i<N; i++) {
+            double voldf = 0;
+            for(unsigned int j=0; j<N; j++) {
+                voldf += uminp[j]*M[i*N+j];
+            }
+            // Properly takes care of the scaling coefficient alpha and vplus (which is already appropriately scaled)
+            // This was arrived at by starting from a version of the blur filter that ignored the scaling coefficient
+            // (and scaled the final output by alpha^2) and then gradually reintroducing the scaling coefficient.
+            vold[i][c] = voldf*alpha;
+            vold[i][c] += vplus[c];
+        }
+    }
+}
+
+// Filters over 1st dimension
+template<typename PT, unsigned int PC, bool PREMULTIPLIED_ALPHA>
+static void
+filter2D_IIR(PT *const dest, int const dstr1, int const dstr2,
+             PT const *const src, int const sstr1, int const sstr2,
+             int const n1, int const n2, IIRValue const b[N+1], double const M[N*N],
+             IIRValue *const tmpdata[], int const num_threads)
+{
+    assert(src && dest);
+
+#if G_BYTE_ORDER == G_LITTLE_ENDIAN
+    static unsigned int const alpha_PC = PC-1;
+    #define PREMUL_ALPHA_LOOP for(unsigned int c=0; c<PC-1; ++c)
+#else
+    static unsigned int const alpha_PC = 0;
+    #define PREMUL_ALPHA_LOOP for(unsigned int c=1; c<PC; ++c)
+#endif
+
+INK_UNUSED(num_threads); // to suppress unused argument compiler warning
+#if HAVE_OPENMP
+#pragma omp parallel for num_threads(num_threads)
+#endif // HAVE_OPENMP
+    for ( int c2 = 0 ; c2 < n2 ; c2++ ) {
+#if HAVE_OPENMP
+        unsigned int tid = omp_get_thread_num();
+#else
+        unsigned int tid = 0;
+#endif // HAVE_OPENMP
+        // corresponding line in the source and output buffer
+        PT const * srcimg = src  + c2*sstr2;
+        PT       * dstimg = dest + c2*dstr2 + n1*dstr1;
+        // Border constants
+        IIRValue imin[PC];  copy_n(srcimg + (0)*sstr1, PC, imin);
+        IIRValue iplus[PC]; copy_n(srcimg + (n1-1)*sstr1, PC, iplus);
+        // Forward pass
+        IIRValue u[N+1][PC];
+        for(unsigned int i=0; i<N; i++) copy_n(imin, PC, u[i]);
+        for ( int c1 = 0 ; c1 < n1 ; c1++ ) {
+            for(unsigned int i=N; i>0; i--) copy_n(u[i-1], PC, u[i]);
+            copy_n(srcimg, PC, u[0]);
+            srcimg += sstr1;
+            for(unsigned int c=0; c<PC; c++) u[0][c] *= b[0];
+            for(unsigned int i=1; i<N+1; i++) {
+                for(unsigned int c=0; c<PC; c++) u[0][c] += u[i][c]*b[i];
+            }
+            copy_n(u[0], PC, tmpdata[tid]+c1*PC);
+        }
+        // Backward pass
+        IIRValue v[N+1][PC];
+        calcTriggsSdikaInitialization<PC>(M, u, iplus, iplus, b[0], v);
+        dstimg -= dstr1;
+        if ( PREMULTIPLIED_ALPHA ) {
+            dstimg[alpha_PC] = clip_round_cast<PT>(v[0][alpha_PC]);
+            PREMUL_ALPHA_LOOP dstimg[c] = clip_round_cast_varmax<PT>(v[0][c], dstimg[alpha_PC]);
+        } else {
+            for(unsigned int c=0; c<PC; c++) dstimg[c] = clip_round_cast<PT>(v[0][c]);
+        }
+        int c1=n1-1;
+        while(c1-->0) {
+            for(unsigned int i=N; i>0; i--) copy_n(v[i-1], PC, v[i]);
+            copy_n(tmpdata[tid]+c1*PC, PC, v[0]);
+            for(unsigned int c=0; c<PC; c++) v[0][c] *= b[0];
+            for(unsigned int i=1; i<N+1; i++) {
+                for(unsigned int c=0; c<PC; c++) v[0][c] += v[i][c]*b[i];
+            }
+            dstimg -= dstr1;
+            if ( PREMULTIPLIED_ALPHA ) {
+                dstimg[alpha_PC] = clip_round_cast<PT>(v[0][alpha_PC]);
+                PREMUL_ALPHA_LOOP dstimg[c] = clip_round_cast_varmax<PT>(v[0][c], dstimg[alpha_PC]);
+            } else {
+                for(unsigned int c=0; c<PC; c++) dstimg[c] = clip_round_cast<PT>(v[0][c]);
+            }
+        }
+    }
+}
+
+// Filters over 1st dimension
+// Assumes kernel is symmetric
+// Kernel should have scr_len+1 elements
+template<typename PT, unsigned int PC>
+static void
+filter2D_FIR(PT *const dst, int const dstr1, int const dstr2,
+             PT const *const src, int const sstr1, int const sstr2,
+             int const n1, int const n2, FIRValue const *const kernel, int const scr_len, int const num_threads)
+{
+    assert(src && dst);
+
+    // Past pixels seen (to enable in-place operation)
+    PT history[scr_len+1][PC];
+
+INK_UNUSED(num_threads); // suppresses unused argument compiler warning
+#if HAVE_OPENMP
+#pragma omp parallel for num_threads(num_threads) private(history)
+#endif // HAVE_OPENMP
+    for ( int c2 = 0 ; c2 < n2 ; c2++ ) {
+
+        // corresponding line in the source buffer
+        int const src_line = c2 * sstr2;
+
+        // current line in the output buffer
+        int const dst_line = c2 * dstr2;
+
+        int skipbuf[4] = {INT_MIN, INT_MIN, INT_MIN, INT_MIN};
+
+        // history initialization
+        PT imin[PC]; copy_n(src + src_line, PC, imin);
+        for(int i=0; i<scr_len; i++) copy_n(imin, PC, history[i]);
+
+        for ( int c1 = 0 ; c1 < n1 ; c1++ ) {
+
+            int const src_disp = src_line + c1 * sstr1;
+            int const dst_disp = dst_line + c1 * dstr1;
+
+            // update history
+            for(int i=scr_len; i>0; i--) copy_n(history[i-1], PC, history[i]);
+            copy_n(src + src_disp, PC, history[0]);
+
+            // for all bytes of the pixel
+            for ( unsigned int byte = 0 ; byte < PC ; byte++) {
+
+                if(skipbuf[byte] > c1) continue;
+
+                FIRValue sum = 0;
+                int last_in = -1;
+                int different_count = 0;
+
+                // go over our point's neighbours in the history
+                for ( int i = 0 ; i <= scr_len ; i++ ) {
+                    // value at the pixel
+                    PT in_byte = history[i][byte];
+
+                    // is it the same as last one we saw?
+                    if(in_byte != last_in) different_count++;
+                    last_in = in_byte;
+
+                    // sum pixels weighted by the kernel
+                    sum += in_byte * kernel[i];
+                }
+
+                // go over our point's neighborhood on x axis in the in buffer
+                int nb_src_disp = src_disp + byte;
+                for ( int i = 1 ; i <= scr_len ; i++ ) {
+                    // the pixel we're looking at
+                    int c1_in = c1 + i;
+                    if (c1_in >= n1) {
+                        c1_in = n1 - 1;
+                    } else {
+                        nb_src_disp += sstr1;
+                    }
+
+                    // value at the pixel
+                    PT in_byte = src[nb_src_disp];
+
+                    // is it the same as last one we saw?
+                    if(in_byte != last_in) different_count++;
+                    last_in = in_byte;
+
+                    // sum pixels weighted by the kernel
+                    sum += in_byte * kernel[i];
+                }
+
+                // store the result in bufx
+                dst[dst_disp + byte] = round_cast<PT>(sum);
+
+                // optimization: if there was no variation within this point's neighborhood,
+                // skip ahead while we keep seeing the same last_in byte:
+                // blurring flat color would not change it anyway
+                if (different_count <= 1) { // note that different_count is at least 1, because last_in is initialized to -1
+                    int pos = c1 + 1;
+                    int nb_src_disp = src_disp + (1+scr_len)*sstr1 + byte; // src_line + (pos+scr_len) * sstr1 + byte
+                    int nb_dst_disp = dst_disp + (1)        *dstr1 + byte; // dst_line + (pos) * sstr1 + byte
+                    while(pos + scr_len < n1 && src[nb_src_disp] == last_in) {
+                        dst[nb_dst_disp] = last_in;
+                        pos++;
+                        nb_src_disp += sstr1;
+                        nb_dst_disp += dstr1;
+                    }
+                    skipbuf[byte] = pos;
+                }
+            }
+        }
+    }
+}
+
+static void
+gaussian_pass_IIR(Geom::Dim2 d, double deviation, cairo_surface_t *src, cairo_surface_t *dest,
+    IIRValue **tmpdata, int num_threads)
+{
+    // Filter variables
+    IIRValue b[N+1];  // scaling coefficient + filter coefficients (can be 10.21 fixed point)
+    double bf[N];  // computed filter coefficients
+    double M[N*N]; // matrix used for initialization procedure (has to be double)
+
+    // Compute filter
+    calcFilter(deviation, bf);
+    for(double & i : bf) i = -i;
+    b[0] = 1; // b[0] == alpha (scaling coefficient)
+    for(size_t i=0; i<N; i++) {
+        b[i+1] = bf[i];
+        b[0] -= b[i+1];
+    }
+
+    // Compute initialization matrix
+    calcTriggsSdikaM(bf, M);
+
+    int stride = cairo_image_surface_get_stride(src);
+    int w = cairo_image_surface_get_width(src);
+    int h = cairo_image_surface_get_height(src);
+    if (d != Geom::X) std::swap(w, h);
+
+    // Filter
+    switch (cairo_image_surface_get_format(src)) {
+    case CAIRO_FORMAT_A8:        ///< Grayscale
+        filter2D_IIR<unsigned char,1,false>(
+            cairo_image_surface_get_data(dest), d == Geom::X ? 1 : stride, d == Geom::X ? stride : 1,
+            cairo_image_surface_get_data(src),  d == Geom::X ? 1 : stride, d == Geom::X ? stride : 1,
+            w, h, b, M, tmpdata, num_threads);
+        break;
+    case CAIRO_FORMAT_ARGB32: ///< Premultiplied 8 bit RGBA
+        filter2D_IIR<unsigned char,4,true>(
+            cairo_image_surface_get_data(dest), d == Geom::X ? 4 : stride, d == Geom::X ? stride : 4,
+            cairo_image_surface_get_data(src),  d == Geom::X ? 4 : stride, d == Geom::X ? stride : 4,
+            w, h, b, M, tmpdata, num_threads);
+        break;
+    default:
+        g_warning("gaussian_pass_IIR: unsupported image format");
+    };
+}
+
+static void
+gaussian_pass_FIR(Geom::Dim2 d, double deviation, cairo_surface_t *src, cairo_surface_t *dest,
+    int num_threads)
+{
+    int scr_len = _effect_area_scr(deviation);
+    // Filter kernel for x direction
+    std::vector<FIRValue> kernel(scr_len + 1);
+    _make_kernel(&kernel[0], deviation);
+
+    int stride = cairo_image_surface_get_stride(src);
+    int w = cairo_image_surface_get_width(src);
+    int h = cairo_image_surface_get_height(src);
+    if (d != Geom::X) std::swap(w, h);
+
+    // Filter (x)
+    switch (cairo_image_surface_get_format(src)) {
+    case CAIRO_FORMAT_A8:        ///< Grayscale
+        filter2D_FIR<unsigned char,1>(
+            cairo_image_surface_get_data(dest), d == Geom::X ? 1 : stride, d == Geom::X ? stride : 1,
+            cairo_image_surface_get_data(src),  d == Geom::X ? 1 : stride, d == Geom::X ? stride : 1,
+            w, h, &kernel[0], scr_len, num_threads);
+        break;
+    case CAIRO_FORMAT_ARGB32: ///< Premultiplied 8 bit RGBA
+        filter2D_FIR<unsigned char,4>(
+            cairo_image_surface_get_data(dest), d == Geom::X ? 4 : stride, d == Geom::X ? stride : 4,
+            cairo_image_surface_get_data(src),  d == Geom::X ? 4 : stride, d == Geom::X ? stride : 4,
+            w, h, &kernel[0], scr_len, num_threads);
+        break;
+    default:
+        g_warning("gaussian_pass_FIR: unsupported image format");
+    };
+}
+
+void FilterGaussian::render_cairo(FilterSlot &slot) const
+{
+    cairo_surface_t *in = slot.getcairo(_input);
+    if (!(in && ink_cairo_surface_get_width(in) && ink_cairo_surface_get_height(in))) {
+        return;
+    }
+
+    // We may need to transform input surface to correct color interpolation space. The input surface
+    // might be used as input to another primitive but it is likely that all the primitives in a given
+    // filter use the same color interpolation space so we don't copy the input before converting.
+    set_cairo_surface_ci(in, color_interpolation);
+
+    // zero deviation = no change in output
+    if (_deviation_x <= 0 && _deviation_y <= 0) {
+        cairo_surface_t *cp = ink_cairo_surface_copy(in);
+        slot.set(_output, cp);
+        cairo_surface_destroy(cp);
+        return;
+    }
+
+    // Handle bounding box case.
+    double dx = _deviation_x;
+    double dy = _deviation_y;
+    if( slot.get_units().get_primitive_units() == SP_FILTER_UNITS_OBJECTBOUNDINGBOX ) {
+        Geom::OptRect const bbox = slot.get_units().get_item_bbox();
+        if( bbox ) {
+            dx *= (*bbox).width();
+            dy *= (*bbox).height();
+        }
+    }
+
+    Geom::Affine trans = slot.get_units().get_matrix_user2pb();
+
+    double deviation_x_orig = dx * trans.expansionX();
+    double deviation_y_orig = dy * trans.expansionY();
+
+    int device_scale = slot.get_device_scale();
+
+    deviation_x_orig *= device_scale;
+    deviation_y_orig *= device_scale;
+
+    cairo_format_t fmt = cairo_image_surface_get_format(in);
+    int bytes_per_pixel = 0;
+    switch (fmt) {
+        case CAIRO_FORMAT_A8:
+            bytes_per_pixel = 1; break;
+        case CAIRO_FORMAT_ARGB32:
+        default:
+            bytes_per_pixel = 4; break;
+    }
+
+    int quality = slot.get_blurquality();
+    int threads = get_num_filter_threads();
+    int x_step = 1 << _effect_subsample_step_log2(deviation_x_orig, quality);
+    int y_step = 1 << _effect_subsample_step_log2(deviation_y_orig, quality);
+    bool resampling = x_step > 1 || y_step > 1;
+    int w_orig = ink_cairo_surface_get_width(in);  // Pixels
+    int h_orig = ink_cairo_surface_get_height(in);
+    int w_downsampled = resampling ? static_cast<int>(ceil(static_cast<double>(w_orig)/x_step))+1 : w_orig;
+    int h_downsampled = resampling ? static_cast<int>(ceil(static_cast<double>(h_orig)/y_step))+1 : h_orig;
+    double deviation_x = deviation_x_orig / x_step;
+    double deviation_y = deviation_y_orig / y_step;
+    int scr_len_x = _effect_area_scr(deviation_x);
+    int scr_len_y = _effect_area_scr(deviation_y);
+
+    // Decide which filter to use for X and Y
+    // This threshold was determined by trial-and-error for one specific machine,
+    // so there's a good chance that it's not optimal.
+    // Whatever you do, don't go below 1 (and preferably not even below 2), as
+    // the IIR filter gets unstable there.
+    bool use_IIR_x = deviation_x > 3;
+    bool use_IIR_y = deviation_y > 3;
+
+    // Temporary storage for IIR filter
+    // NOTE: This can be eliminated, but it reduces the precision a bit
+    IIRValue * tmpdata[threads];
+    std::fill_n(tmpdata, threads, (IIRValue*)0);
+    if ( use_IIR_x || use_IIR_y ) {
+        for(int i = 0; i < threads; ++i) {
+            tmpdata[i] = new IIRValue[std::max(w_downsampled,h_downsampled)*bytes_per_pixel];
+        }
+    }
+
+    cairo_surface_t *downsampled = nullptr;
+    if (resampling) {
+        // Divide by device scale as w_downsampled is in pixels while
+        // cairo_surface_create_similar() uses device units.
+        downsampled = cairo_surface_create_similar(in, cairo_surface_get_content(in),
+            w_downsampled/device_scale, h_downsampled/device_scale);
+        cairo_t *ct = cairo_create(downsampled);
+        cairo_scale(ct, static_cast<double>(w_downsampled)/w_orig, static_cast<double>(h_downsampled)/h_orig);
+        cairo_set_source_surface(ct, in, 0, 0);
+        cairo_paint(ct);
+        cairo_destroy(ct);
+    } else {
+        downsampled = ink_cairo_surface_copy(in);
+    }
+    cairo_surface_flush(downsampled);
+
+    if (scr_len_x > 0) {
+        if (use_IIR_x) {
+            gaussian_pass_IIR(Geom::X, deviation_x, downsampled, downsampled, tmpdata, threads);
+        } else {
+            gaussian_pass_FIR(Geom::X, deviation_x, downsampled, downsampled, threads);
+        }
+    }
+
+    if (scr_len_y > 0) {
+        if (use_IIR_y) {
+            gaussian_pass_IIR(Geom::Y, deviation_y, downsampled, downsampled, tmpdata, threads);
+        } else {
+            gaussian_pass_FIR(Geom::Y, deviation_y, downsampled, downsampled, threads);
+        }
+    }
+
+    // free the temporary data
+    if ( use_IIR_x || use_IIR_y ) {
+        for(int i = 0; i < threads; ++i) {
+            delete[] tmpdata[i];
+        }
+    }
+
+    cairo_surface_mark_dirty(downsampled);
+    if (resampling) {
+        cairo_surface_t *upsampled = cairo_surface_create_similar(downsampled, cairo_surface_get_content(downsampled),
+                                                                  w_orig / device_scale, h_orig / device_scale);
+        cairo_t *ct = cairo_create(upsampled);
+        cairo_scale(ct, static_cast<double>(w_orig) / w_downsampled, static_cast<double>(h_orig) / h_downsampled);
+        cairo_set_source_surface(ct, downsampled, 0, 0);
+        cairo_paint(ct);
+        cairo_destroy(ct);
+
+        set_cairo_surface_ci(upsampled, color_interpolation);
+
+        slot.set(_output, upsampled);
+        cairo_surface_destroy(upsampled);
+        cairo_surface_destroy(downsampled);
+    } else {
+        set_cairo_surface_ci(downsampled, color_interpolation);
+
+        slot.set(_output, downsampled);
+        cairo_surface_destroy(downsampled);
+    }
+}
+
+void FilterGaussian::area_enlarge(Geom::IntRect &area, Geom::Affine const &trans) const
+{
+    int area_x = _effect_area_scr(_deviation_x * trans.expansionX());
+    int area_y = _effect_area_scr(_deviation_y * trans.expansionY());
+    // maximum is used because rotations can mix up these directions
+    // TODO: calculate a more tight-fitting rendering area
+    int area_max = std::max(area_x, area_y);
+    area.expandBy(area_max);
+}
+
+bool FilterGaussian::can_handle_affine(Geom::Affine const &) const
+{
+    // Previously we tried to be smart and return true for rotations.
+    // However, the transform passed here is NOT the total transform
+    // from filter user space to screen.
+    // TODO: fix this, or replace can_handle_affine() with isotropic().
+    return false;
+}
+
+double FilterGaussian::complexity(Geom::Affine const &trans) const
+{
+    int area_x = _effect_area_scr(_deviation_x * trans.expansionX());
+    int area_y = _effect_area_scr(_deviation_y * trans.expansionY());
+    return 2.0 * area_x * area_y;
+}
+
+void FilterGaussian::set_deviation(double deviation)
+{
+    if (std::isfinite(deviation) && deviation >= 0) {
+        _deviation_x = _deviation_y = deviation;
+    }
+}
+
+void FilterGaussian::set_deviation(double x, double y)
+{
+    if (std::isfinite(x) && x >= 0 && std::isfinite(y) && y >= 0) {
+        _deviation_x = x;
+        _deviation_y = y;
+    }
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-gaussian.h b/src/display/nr-filter-gaussian.h
new file mode 100644
index 0000000..837ca87
--- /dev/null
+++ b/src/display/nr-filter-gaussian.h
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_GAUSSIAN_H
+#define SEEN_NR_FILTER_GAUSSIAN_H
+
+/*
+ * Gaussian blur renderer
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *   bulia byak
+ *   Jasper van de Gronde <th.v.d.gronde@hccnet.nl>
+ *
+ * Copyright (C) 2006 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <2geom/forward.h>
+#include "display/nr-filter-primitive.h"
+
+enum
+{
+    BLUR_QUALITY_BEST = 2,
+    BLUR_QUALITY_BETTER = 1,
+    BLUR_QUALITY_NORMAL = 0,
+    BLUR_QUALITY_WORSE = -1,
+    BLUR_QUALITY_WORST = -2
+};
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterGaussian : public FilterPrimitive
+{
+public:
+    FilterGaussian();
+    ~FilterGaussian() override;
+
+    void render_cairo(FilterSlot &slot) const override;
+    void area_enlarge(Geom::IntRect &area, Geom::Affine const &m) const override;
+    bool can_handle_affine(Geom::Affine const &m) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+
+    /**
+     * Set the standard deviation value for gaussian blur. Deviation along
+     * both axis is set to the provided value.
+     * Negative value, NaN and infinity are considered an error and no
+     * changes to filter state are made. If not set, default value of zero
+     * is used, which means the filter results in transparent black image.
+     */
+    void set_deviation(double deviation);
+
+    /**
+     * Set the standard deviation value for gaussian blur. First parameter
+     * sets the deviation alogn x-axis, second along y-axis.
+     * Negative value, NaN and infinity are considered an error and no
+     * changes to filter state are made. If not set, default value of zero
+     * is used, which means the filter results in transparent black image.
+     */
+    void set_deviation(double x, double y);
+
+    Glib::ustring name() const override { return Glib::ustring("Gaussian Blur"); }
+
+private:
+    double _deviation_x;
+    double _deviation_y;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_GAUSSIAN_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-image.cpp b/src/display/nr-filter-image.cpp
new file mode 100644
index 0000000..efc25b6
--- /dev/null
+++ b/src/display/nr-filter-image.cpp
@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * feImage filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *   Tavmjong Bah <tavmjong@free.fr>
+ *   Abhishek Sharma
+ *
+ * Copyright (C) 2007-2011 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+#include "display/nr-filter-image.h"
+#include "document.h"
+#include "object/sp-item.h"
+#include "display/cairo-utils.h"
+#include "display/drawing-context.h"
+#include "display/drawing.h"
+#include "display/drawing-item.h"
+#include "display/nr-filter.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+#include "enums.h"
+#include <glibmm/fileutils.h>
+
+namespace Inkscape {
+namespace Filters {
+
+void FilterImage::update()
+{
+    if (!item) {
+        return;
+    }
+
+    item->update();
+}
+
+void FilterImage::render_cairo(FilterSlot &slot) const
+{
+    if (!item) {
+        return;
+    }
+
+    Geom::OptRect area = item->drawbox();
+    if (!area) {
+        return;
+    }
+
+    // Viewport is filter primitive area (in user coordinates).
+    // Note: viewport calculation in non-trivial. Do not rely
+    // on get_matrix_primitiveunits2pb().
+    Geom::Rect vp = filter_primitive_area(slot.get_units());
+    slot.set_primitive_area(_output, vp); // Needed for tiling
+
+    double feImageX      = vp.left();
+    double feImageY      = vp.top();
+    double feImageWidth  = vp.width();
+    double feImageHeight = vp.height();
+
+    // feImage is suppose to use the same parameters as a normal SVG image.
+    // If a width or height is set to zero, the image is not suppose to be displayed.
+    // This does not seem to be what Firefox or Opera does, nor does the W3C displacement
+    // filter test expect this behavior. If the width and/or height are zero, we use
+    // the width and height of the object bounding box.
+    Geom::Affine m = slot.get_units().get_matrix_user2filterunits().inverse();
+    Geom::Point bbox_00 = Geom::Point(0,0) * m;
+    Geom::Point bbox_w0 = Geom::Point(1,0) * m;
+    Geom::Point bbox_0h = Geom::Point(0,1) * m;
+    double bbox_width = Geom::distance(bbox_00, bbox_w0);
+    double bbox_height = Geom::distance(bbox_00, bbox_0h);
+
+    if (feImageWidth  == 0) feImageWidth  = bbox_width;
+    if (feImageHeight == 0) feImageHeight = bbox_height;
+
+    int device_scale = slot.get_device_scale();
+
+    Geom::Rect sa = slot.get_slot_area();
+    cairo_surface_t *out = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, sa.width() * device_scale, sa.height() * device_scale);
+    cairo_surface_set_device_scale(out, device_scale, device_scale);
+
+    Inkscape::DrawingContext dc(out, sa.min());
+    Geom::Affine user2pb = slot.get_units().get_matrix_user2pb();
+    dc.transform(user2pb); // we are now in primitive units
+
+    Geom::IntRect render_rect = area->roundOutwards();
+
+    // Internal image, like <use>
+    if (from_element) {
+        dc.translate(feImageX, feImageY);
+        item->render(dc, slot.get_rendercontext(), render_rect);
+
+        // For the moment, we'll assume that any image is in sRGB color space
+        set_cairo_surface_ci(out, SP_CSS_COLOR_INTERPOLATION_SRGB);
+    } else {
+        // For the moment, we'll assume that any image is in sRGB color space
+        // set_cairo_surface_ci(out, SP_CSS_COLOR_INTERPOLATION_SRGB);
+        // This seemed like a sensible thing to do but it breaks filters-displace-01-f.svg
+
+        // Now that we have the viewport, we must map image inside.
+        // Partially copied from sp-image.cpp.
+
+        auto image_width  = area->width();
+        auto image_height = area->height();
+
+        // Do nothing if preserveAspectRatio is "none".
+        if (aspect_align != SP_ASPECT_NONE) {
+
+            // Check aspect ratio of image vs. viewport
+            double feAspect = feImageHeight / feImageWidth;
+            double aspect = (double)image_height / image_width;
+            bool ratio = feAspect < aspect;
+
+            double ax, ay; // Align side
+            switch (aspect_align) {
+                case SP_ASPECT_XMIN_YMIN:
+                    ax = 0.0;
+                    ay = 0.0;
+                    break;
+                case SP_ASPECT_XMID_YMIN:
+                    ax = 0.5;
+                    ay = 0.0;
+                    break;
+                case SP_ASPECT_XMAX_YMIN:
+                    ax = 1.0;
+                    ay = 0.0;
+                    break;
+                case SP_ASPECT_XMIN_YMID:
+                    ax = 0.0;
+                    ay = 0.5;
+                    break;
+                case SP_ASPECT_XMID_YMID:
+                    ax = 0.5;
+                    ay = 0.5;
+                    break;
+                case SP_ASPECT_XMAX_YMID:
+                    ax = 1.0;
+                    ay = 0.5;
+                    break;
+                case SP_ASPECT_XMIN_YMAX:
+                    ax = 0.0;
+                    ay = 1.0;
+                    break;
+                case SP_ASPECT_XMID_YMAX:
+                    ax = 0.5;
+                    ay = 1.0;
+                    break;
+                case SP_ASPECT_XMAX_YMAX:
+                    ax = 1.0;
+                    ay = 1.0;
+                    break;
+                default:
+                    ax = 0.0;
+                    ay = 0.0;
+                    break;
+            }
+
+            if (aspect_clip == SP_ASPECT_SLICE) {
+                // image clipped by viewbox
+
+                if (ratio) {
+                    // clip top/bottom
+                    feImageY -= ay * (feImageWidth * aspect - feImageHeight);
+                    feImageHeight = feImageWidth * aspect;
+                } else {
+                    // clip sides
+                    feImageX -= ax * (feImageHeight / aspect - feImageWidth);
+                    feImageWidth = feImageHeight / aspect;
+                }
+
+            } else {
+                // image fits into viewbox
+
+                if (ratio) {
+                    // fit to height
+                    feImageX += ax * (feImageWidth - feImageHeight / aspect );
+                    feImageWidth = feImageHeight / aspect;
+                } else {
+                    // fit to width
+                    feImageY += ay * (feImageHeight - feImageWidth * aspect);
+                    feImageHeight = feImageWidth * aspect;
+                }
+            }
+        }
+
+        double scaleX = feImageWidth / image_width;
+        double scaleY = feImageHeight / image_height;
+
+        dc.translate(feImageX, feImageY);
+        dc.scale(scaleX, scaleY);
+        item->render(dc, slot.get_rendercontext(), render_rect);
+    }
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+bool FilterImage::can_handle_affine(Geom::Affine const &) const
+{
+    return true;
+}
+
+double FilterImage::complexity(Geom::Affine const &) const
+{
+    // TODO: right now we cannot actually measure this in any meaningful way.
+    return 1.1;
+}
+
+void FilterImage::set_align(unsigned align)
+{
+    aspect_align = align;
+}
+
+void FilterImage::set_clip(unsigned clip)
+{
+    aspect_clip = clip;
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-image.h b/src/display/nr-filter-image.h
new file mode 100644
index 0000000..0cfca31
--- /dev/null
+++ b/src/display/nr-filter-image.h
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_IMAGE_H
+#define SEEN_NR_FILTER_IMAGE_H
+
+/*
+ * feImage filter primitive renderer
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <memory>
+#include <string>
+#include "display/nr-filter-primitive.h"
+
+class SPDocument;
+class SPItem;
+
+namespace Inkscape {
+class Pixbuf;
+class DrawingItem;
+
+namespace Filters {
+class FilterSlot;
+
+class FilterImage : public FilterPrimitive
+{
+public:
+    void update() override;
+    void render_cairo(FilterSlot &slot) const override;
+    bool can_handle_affine(Geom::Affine const &) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+
+    void set_document(SPDocument *document);
+    void set_href(char const *href);
+    void set_align(unsigned align);
+    void set_clip(unsigned clip);
+
+    Glib::ustring name() const override { return Glib::ustring("Image"); }
+
+    Inkscape::DrawingItem *item;
+    bool from_element = false;
+
+    unsigned aspect_align, aspect_clip;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_IMAGE_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-merge.cpp b/src/display/nr-filter-merge.cpp
new file mode 100644
index 0000000..050a879
--- /dev/null
+++ b/src/display/nr-filter-merge.cpp
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * feMerge filter effect renderer
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <vector>
+#include "display/cairo-utils.h"
+#include "display/nr-filter-merge.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-utils.h"
+
+namespace Inkscape {
+namespace Filters {
+
+FilterMerge::FilterMerge()
+    : _input_image({NR_FILTER_SLOT_NOT_SET}) {}
+
+void FilterMerge::render_cairo(FilterSlot &slot) const
+{
+    if (_input_image.empty()) return;
+
+    Geom::Rect vp = filter_primitive_area(slot.get_units());
+    slot.set_primitive_area(_output, vp); // Needed for tiling
+
+    // output is RGBA if at least one input is RGBA
+    bool rgba32 = false;
+    cairo_surface_t *out = nullptr;
+    for (auto &i : _input_image) {
+        cairo_surface_t *in = slot.getcairo(i);
+        if (cairo_surface_get_content(in) == CAIRO_CONTENT_COLOR_ALPHA) {
+            out = ink_cairo_surface_create_identical(in);
+            set_cairo_surface_ci(out, color_interpolation);
+            rgba32 = true;
+            break;
+        }
+    }
+
+    if (!rgba32) {
+        out = ink_cairo_surface_create_identical(slot.getcairo(_input_image[0]));
+    }
+    cairo_t *out_ct = cairo_create(out);
+
+    for (auto &i : _input_image) {
+        cairo_surface_t *in = slot.getcairo(i);
+
+        set_cairo_surface_ci(in, color_interpolation);
+        cairo_set_source_surface(out_ct, in, 0, 0);
+        cairo_paint(out_ct);
+    }
+
+    cairo_destroy(out_ct);
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+bool FilterMerge::can_handle_affine(Geom::Affine const &) const
+{
+    // Merge is a per-pixel primitive and is immutable under transformations
+    return true;
+}
+
+double FilterMerge::complexity(Geom::Affine const &) const
+{
+    return 1.02;
+}
+
+bool FilterMerge::uses_background() const
+{
+    for (int input : _input_image) {
+        if (input == NR_FILTER_BACKGROUNDIMAGE || input == NR_FILTER_BACKGROUNDALPHA) {
+            return true;
+        }
+    }
+    return false;
+}
+
+void FilterMerge::set_input(int slot)
+{
+    _input_image[0] = slot;
+}
+
+void FilterMerge::set_input(int input, int slot)
+{
+    if (input < 0) return;
+
+    if (_input_image.size() > input) {
+        _input_image[input] = slot;
+    } else {
+        for (int i = _input_image.size(); i < input ; i++) {
+            _input_image.emplace_back(NR_FILTER_SLOT_NOT_SET);
+        }
+        _input_image.push_back(slot);
+    }
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-merge.h b/src/display/nr-filter-merge.h
new file mode 100644
index 0000000..c55f0df
--- /dev/null
+++ b/src/display/nr-filter-merge.h
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_MERGE_H
+#define SEEN_NR_FILTER_MERGE_H
+
+/*
+ * feMerge filter effect renderer
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <vector>
+#include "display/nr-filter-primitive.h"
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterMerge : public FilterPrimitive
+{
+public:
+    FilterMerge();
+
+    void render_cairo(FilterSlot &) const override;
+    bool can_handle_affine(Geom::Affine const &) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+    bool uses_background() const override;
+
+    void set_input(int input) override;
+    void set_input(int input, int slot) override;
+
+    Glib::ustring name() const override { return Glib::ustring("Merge"); }
+
+private:
+    std::vector<int> _input_image;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_MERGE_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-morphology.cpp b/src/display/nr-filter-morphology.cpp
new file mode 100644
index 0000000..1cc2aad
--- /dev/null
+++ b/src/display/nr-filter-morphology.cpp
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * feMorphology filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"  // only include where actually required!
+#endif
+
+#include <cmath>
+#include <algorithm>
+#include <deque>
+#include <functional>
+#include "display/cairo-templates.h"
+#include "display/cairo-utils.h"
+#include "display/nr-filter-morphology.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+
+namespace Inkscape {
+namespace Filters {
+
+FilterMorphology::FilterMorphology() = default;
+
+FilterMorphology::~FilterMorphology() = default;
+
+enum MorphologyOp
+{
+    ERODE,
+    DILATE
+};
+
+namespace {
+
+/* This performs one "half" of the morphology operation by calculating 
+ * the componentwise extreme in the specified axis with the given radius.
+ * Extreme of row extremes is equal to the extreme of components, so this
+ * doesn't change the result.
+ * The algorithm is due to: Petr Dokládal, Eva Dokládalová (2011), "Computationally efficient, one-pass algorithm for morphological filters"
+ * TODO: Currently only the 1D algorithm is implemented, but it should not be too difficult (and at the very least more memory efficient) to implement the full 2D algorithm.
+ *       One problem with the 2D algorithm is that it is harder to parallelize.
+ */
+template <typename Comparison, Geom::Dim2 axis, int BPP>
+void morphologicalFilter1D(cairo_surface_t * const input, cairo_surface_t * const out, double radius)
+{
+    Comparison comp;
+
+    int w = cairo_image_surface_get_width(out);
+    int h = cairo_image_surface_get_height(out);
+    if (axis == Geom::Y) std::swap(w,h);
+
+    int stridein = cairo_image_surface_get_stride(input);
+    int strideout = cairo_image_surface_get_stride(out);
+
+    unsigned char *in_data = cairo_image_surface_get_data(input);
+    unsigned char *out_data = cairo_image_surface_get_data(out);
+
+    int ri = round(radius); // TODO: Support fractional radii?
+    int wi = 2*ri+1;
+
+    #if HAVE_OPENMP
+    int limit = w * h;
+    #pragma omp parallel for if(limit > OPENMP_THRESHOLD) num_threads(get_num_filter_threads())
+    #endif // HAVE_OPENMP
+    for (int i = 0; i < h; ++i) {
+        // TODO: Store position and value in one 32 bit integer? 24 bits should be enough for a position, it would be quite strange to have an image with a width/height of more than 16 million(!).
+        std::deque<std::pair<int, unsigned char>> vals[BPP]; // In my tests it was actually slightly faster to allocate it here than allocate it once for all threads and retrieving the correct set based on the thread id.
+
+        // Initialize with transparent black
+        for (int p = 0; p < BPP; ++p) {
+            vals[p].emplace_back(-1, 0); // TODO: Only do this when performing an erosion?
+        }
+
+        // Process "row"
+        unsigned char *in_p = in_data + i * (axis == Geom::X ? stridein : BPP);
+        unsigned char *out_p = out_data + i * (axis == Geom::X ? strideout : BPP);
+        /* This is the "short but slow" version, which might be easier to follow, the longer but faster version follows.
+        for (int j = 0; j < w+ri; ++j) {
+            for(int p = 0; p < BPP; ++p) { // Iterate over channels
+                // Push new value onto FIFO, erasing any previous values that are "useless" (see paper) or out-of-range
+                if (!vals[p].empty() && vals[p].front().first+wi <= j) vals[p].pop_front(); // out-of-range
+                if (j < w) {
+                    while(!vals[p].empty() && !comp(vals[p].back().second, *in_p)) vals[p].pop_back(); // useless
+                    vals[p].emplace_back(j, *in_p);
+                    ++in_p;
+                } else if (j == w) { // Transparent black beyond the image. TODO: Only do this when performing an erosion?
+                    while(!vals[p].empty() && !comp(vals[p].back().second, 0)) vals[p].pop_back();
+                    vals[p].emplace_back(j, 0);
+                }
+                // Set output
+                if (j >= ri) {
+                    *out_p = vals[p].front().second;
+                    ++out_p;
+                }
+            }
+            if (axis == Geom::Y && j < w  ) in_p += stridein - BPP;
+            if (axis == Geom::Y && j >= ri) out_p += strideout - BPP;
+        }*/
+        for (int j = 0; j < std::min(ri,w); ++j) {
+            for(int p = 0; p < BPP; ++p) { // Iterate over channels
+                // Push new value onto FIFO, erasing any previous values that are "useless" (see paper) or out-of-range
+                if (!vals[p].empty() && vals[p].front().first <= j) vals[p].pop_front(); // out-of-range
+                while(!vals[p].empty() && !comp(vals[p].back().second, *in_p)) vals[p].pop_back(); // useless
+                vals[p].emplace_back(j + wi, *in_p);
+                ++in_p;
+            }
+            if (axis == Geom::Y) in_p += stridein - BPP;
+        }
+        // We have now done all preparatory work.
+        // If w<=ri, then the following loop does nothing (which is as it should).
+        for (int j = ri; j < w; ++j) {
+            for(int p = 0; p < BPP; ++p) { // Iterate over channels
+                // Push new value onto FIFO, erasing any previous values that are "useless" (see paper) or out-of-range
+                if (!vals[p].empty() && vals[p].front().first <= j) vals[p].pop_front(); // out-of-range
+                while(!vals[p].empty() && !comp(vals[p].back().second, *in_p)) vals[p].pop_back(); // useless
+                vals[p].emplace_back(j + wi, *in_p);
+                ++in_p;
+                // Set output
+                *out_p = vals[p].front().second;
+                ++out_p;
+            }
+            if (axis == Geom::Y) {
+                in_p += stridein - BPP;
+                out_p += strideout - BPP;
+            }
+        }
+        // We have now done all work which involves both input and output.
+        // The following loop makes sure that the border is handled correctly.
+        for(int p = 0; p < BPP; ++p) { // Iterate over channels
+            while(!vals[p].empty() && !comp(vals[p].back().second, 0)) vals[p].pop_back();
+            vals[p].emplace_back(w + wi, 0);
+        }
+        // Now we just have to finish the output.
+        for (int j = std::max(w,ri); j < w+ri; ++j) {
+            for(int p = 0; p < BPP; ++p) { // Iterate over channels
+                // Remove out-of-range values
+                if (!vals[p].empty() && vals[p].front().first <= j) vals[p].pop_front(); // out-of-range
+                // Set output
+                *out_p = vals[p].front().second;
+                ++out_p;
+            }
+            if (axis == Geom::Y) out_p += strideout - BPP;
+        }
+    }
+
+    cairo_surface_mark_dirty(out);
+}
+
+} // namespace
+
+void FilterMorphology::render_cairo(FilterSlot &slot) const
+{
+    cairo_surface_t *input = slot.getcairo(_input);
+
+    if (xradius == 0.0 || yradius == 0.0) {
+        // output is transparent black
+        cairo_surface_t *out = ink_cairo_surface_create_identical(input);
+        copy_cairo_surface_ci(input, out);
+        slot.set(_output, out);
+        cairo_surface_destroy(out);
+        return;
+    }
+
+    int device_scale = slot.get_device_scale();
+    Geom::Affine p2pb = slot.get_units().get_matrix_primitiveunits2pb();
+    double xr = fabs(xradius * p2pb.expansionX()) * device_scale;
+    double yr = fabs(yradius * p2pb.expansionY()) * device_scale;
+    int bpp = cairo_image_surface_get_format(input) == CAIRO_FORMAT_A8 ? 1 : 4;
+
+    cairo_surface_t *interm = ink_cairo_surface_create_identical(input);
+
+    if (Operator == MORPHOLOGY_OPERATOR_DILATE) {
+        if (bpp == 1) {
+            morphologicalFilter1D< std::greater<unsigned char>, Geom::X, 1 >(input, interm, xr);
+        } else {
+            morphologicalFilter1D< std::greater<unsigned char>, Geom::X, 4 >(input, interm, xr);
+        }
+    } else {
+        if (bpp == 1) {
+            morphologicalFilter1D< std::less<unsigned char>, Geom::X, 1 >(input, interm, xr);
+        } else {
+            morphologicalFilter1D< std::less<unsigned char>, Geom::X, 4 >(input, interm, xr);
+        }
+    }
+
+    cairo_surface_t *out = ink_cairo_surface_create_identical(interm);
+
+    // color_interpolation_filters for out same as input. See spec (DisplacementMap).
+    copy_cairo_surface_ci(input, out);
+
+    if (Operator == MORPHOLOGY_OPERATOR_DILATE) {
+        if (bpp == 1) {
+            morphologicalFilter1D< std::greater<unsigned char>, Geom::Y, 1 >(interm, out, yr);
+        } else {
+            morphologicalFilter1D< std::greater<unsigned char>, Geom::Y, 4 >(interm, out, yr);
+        }
+    } else {
+        if (bpp == 1) {
+            morphologicalFilter1D< std::less<unsigned char>, Geom::Y, 1 >(interm, out, yr);
+        } else {
+            morphologicalFilter1D< std::less<unsigned char>, Geom::Y, 4 >(interm, out, yr);
+        }
+    }
+
+    cairo_surface_destroy(interm);
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+void FilterMorphology::area_enlarge(Geom::IntRect &area, Geom::Affine const &trans) const
+{
+    int enlarge_x = std::ceil(xradius * trans.expansionX());
+    int enlarge_y = std::ceil(yradius * trans.expansionY());
+
+    area.expandBy(enlarge_x, enlarge_y);
+}
+
+double FilterMorphology::complexity(Geom::Affine const &trans) const
+{
+    int enlarge_x = std::ceil(xradius * trans.expansionX());
+    int enlarge_y = std::ceil(yradius * trans.expansionY());
+    return enlarge_x * enlarge_y;
+}
+
+void FilterMorphology::set_operator(FilterMorphologyOperator o)
+{
+    Operator = o;
+}
+
+void FilterMorphology::set_xradius(double x)
+{
+    xradius = x;
+}
+
+void FilterMorphology::set_yradius(double y)
+{
+    yradius = y;
+}
+
+} /* namespace Filters */
+} /* namespace Inkscape */
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-morphology.h b/src/display/nr-filter-morphology.h
new file mode 100644
index 0000000..e1944e0
--- /dev/null
+++ b/src/display/nr-filter-morphology.h
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_MORPHOLOGY_H
+#define SEEN_NR_FILTER_MORPHOLOGY_H
+
+/*
+ * feMorphology filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/nr-filter-primitive.h"
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterSlot;
+
+enum FilterMorphologyOperator
+{
+    MORPHOLOGY_OPERATOR_ERODE,
+    MORPHOLOGY_OPERATOR_DILATE,
+    MORPHOLOGY_OPERATOR_END
+};
+
+class FilterMorphology : public FilterPrimitive
+{
+public:
+    FilterMorphology();
+    ~FilterMorphology() override;
+
+    void render_cairo(FilterSlot &slot) const override;
+    void area_enlarge(Geom::IntRect &area, Geom::Affine const &trans) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+
+    void set_operator(FilterMorphologyOperator o);
+    void set_xradius(double x);
+    void set_yradius(double y);
+
+    Glib::ustring name() const override { return Glib::ustring("Morphology"); }
+
+private:
+    FilterMorphologyOperator Operator;
+    double xradius;
+    double yradius;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_MORPHOLOGY_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-offset.cpp b/src/display/nr-filter-offset.cpp
new file mode 100644
index 0000000..6a1ccaa
--- /dev/null
+++ b/src/display/nr-filter-offset.cpp
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * feOffset filter primitive renderer
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/cairo-utils.h"
+#include "display/nr-filter-offset.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+
+namespace Inkscape {
+namespace Filters {
+
+using Geom::X;
+using Geom::Y;
+
+FilterOffset::FilterOffset()
+    : dx(0)
+    , dy(0) {}
+
+FilterOffset::~FilterOffset() = default;
+
+void FilterOffset::render_cairo(FilterSlot &slot) const
+{
+    cairo_surface_t *in = slot.getcairo(_input);
+    cairo_surface_t *out = ink_cairo_surface_create_identical(in);
+    // color_interpolation_filters for out same as in. See spec (DisplacementMap).
+    copy_cairo_surface_ci(in, out);
+    cairo_t *ct = cairo_create(out);
+
+    Geom::Rect vp = filter_primitive_area(slot.get_units());
+    slot.set_primitive_area(_output, vp); // Needed for tiling
+
+    Geom::Affine p2pb = slot.get_units().get_matrix_primitiveunits2pb();
+    double x = dx * p2pb.expansionX();
+    double y = dy * p2pb.expansionY();
+
+    cairo_set_source_surface(ct, in, x, y);
+    cairo_paint(ct);
+    cairo_destroy(ct);
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+bool FilterOffset::can_handle_affine(Geom::Affine const &) const
+{
+    return true;
+}
+
+void FilterOffset::set_dx(double amount)
+{
+    dx = amount;
+}
+
+void FilterOffset::set_dy(double amount)
+{
+    dy = amount;
+}
+
+void FilterOffset::area_enlarge(Geom::IntRect &area, Geom::Affine const &trans) const
+{
+    Geom::Point offset(dx, dy);
+    offset *= trans;
+    offset[X] -= trans[4];
+    offset[Y] -= trans[5];
+    double x0, y0, x1, y1;
+    x0 = area.left();
+    y0 = area.top();
+    x1 = area.right();
+    y1 = area.bottom();
+
+    if (offset[X] > 0) {
+        x0 -= std::ceil(offset[X]);
+    } else {
+        x1 -= std::floor(offset[X]);
+    }
+
+    if (offset[Y] > 0) {
+        y0 -= std::ceil(offset[Y]);
+    } else {
+        y1 -= std::floor(offset[Y]);
+    }
+
+    area = Geom::IntRect(x0, y0, x1, y1);
+}
+
+double FilterOffset::complexity(Geom::Affine const &) const
+{
+    return 1.02;
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-offset.h b/src/display/nr-filter-offset.h
new file mode 100644
index 0000000..f27cc5d
--- /dev/null
+++ b/src/display/nr-filter-offset.h
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_OFFSET_H
+#define SEEN_NR_FILTER_OFFSET_H
+
+/*
+ * feOffset filter primitive renderer
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/nr-filter-primitive.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterOffset : public FilterPrimitive
+{
+public:
+    FilterOffset();
+    ~FilterOffset() override;
+
+    void render_cairo(FilterSlot &slot) const override;
+    void area_enlarge(Geom::IntRect &area, Geom::Affine const &trans) const override;
+    bool can_handle_affine(Geom::Affine const &) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+
+    void set_dx(double amount);
+    void set_dy(double amount);
+
+    Glib::ustring name() const override { return Glib::ustring("Offset"); }
+
+private:
+    double dx, dy;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_OFFSET_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-primitive.cpp b/src/display/nr-filter-primitive.cpp
new file mode 100644
index 0000000..ac53238
--- /dev/null
+++ b/src/display/nr-filter-primitive.cpp
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * SVG filters rendering
+ *
+ * Author:
+ *   Niko Kiirala <niko@kiirala.com>
+ *   Tavmjong Bah <tavmjong@free.fr> (primitive subregion)
+ *
+ * Copyright (C) 2006 Niko Kiirala
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/nr-filter-primitive.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-types.h"
+#include "svg/svg-length.h"
+
+#include "inkscape.h"
+#include "desktop.h"
+
+#include "document.h"
+#include "style.h"
+
+namespace Inkscape {
+namespace Filters {
+
+FilterPrimitive::FilterPrimitive()
+{
+    _input = NR_FILTER_SLOT_NOT_SET;
+    _output = NR_FILTER_SLOT_NOT_SET;
+
+    // Primitive subregion, should default to the union of all subregions of referenced nodes
+    // (i.e. other filter primitives except feTile).  If no referenced nodes, defaults to filter
+    // region expressed in percent. At the moment, we do not check referenced nodes.
+
+    // We must keep track if a value is set or not, if not set then the region defaults to 0%, 0%,
+    // 100%, 100% ("x", "y", "width", "height") of the -> filter <- region. If set, then
+    // percentages are in terms of bounding box or viewbox, depending on value of "primitiveUnits".
+
+    // NB: SVGLength.set takes prescaled percent values: 1 means 100%
+    _subregion_x.unset(SVGLength::PERCENT, 0, 0);
+    _subregion_y.unset(SVGLength::PERCENT, 0, 0);
+    _subregion_width.unset(SVGLength::PERCENT, 1, 0);
+    _subregion_height.unset(SVGLength::PERCENT, 1, 0);
+
+    color_interpolation = SP_CSS_COLOR_INTERPOLATION_AUTO;
+}
+
+FilterPrimitive::~FilterPrimitive() = default;
+
+void FilterPrimitive::render_cairo(FilterSlot &slot) const
+{
+    // passthrough
+    cairo_surface_t *in = slot.getcairo(_input);
+    slot.set(_output, in);
+}
+
+void FilterPrimitive::set_input(int slot)
+{
+    set_input(0, slot);
+}
+
+void FilterPrimitive::set_input(int input, int slot)
+{
+    if (input == 0) _input = slot;
+}
+
+void FilterPrimitive::set_output(int slot)
+{
+    if (slot >= 0) _output = slot;
+}
+
+// We need to copy reference even if unset as we need to know if
+// someone has unset a value.
+void FilterPrimitive::set_x(SVGLength const &length)
+{
+    _subregion_x = length;
+}
+
+void FilterPrimitive::set_y(SVGLength const &length)
+{
+    _subregion_y = length;
+}
+
+void FilterPrimitive::set_width(SVGLength const &length)
+{
+    _subregion_width = length;
+}
+
+void FilterPrimitive::set_height(SVGLength const &length)
+{
+    _subregion_height = length;
+}
+
+void FilterPrimitive::set_subregion(SVGLength const &x, SVGLength const &y,
+                                    SVGLength const &width, SVGLength const &height)
+{
+    _subregion_x = x;
+    _subregion_y = y;
+    _subregion_width = width;
+    _subregion_height = height;
+}
+
+Geom::Rect FilterPrimitive::filter_primitive_area(FilterUnits const &units) const
+{
+    Geom::OptRect const fa_opt = units.get_filter_area();
+    if (!fa_opt) {
+        std::cerr << "FilterPrimitive::filter_primitive_area: filter area undefined." << std::endl;
+        return Geom::Rect::from_xywh(0, 0, 0, 0);
+    }
+    Geom::Rect fa = *fa_opt;
+
+    // x, y, width, and height are independently defined (i.e. one can be defined, by default, to
+    // the filter area (via default value ) while another is defined relative to the bounding
+    // box). It is better to keep track of them separately and then compose the Rect at the end.
+    double x = 0;
+    double y = 0;
+    double width = 0;
+    double height = 0;
+
+    // If subregion not set, by special case use filter region.
+    if (!_subregion_x._set)      x = fa.left();
+    if (!_subregion_y._set)      y = fa.top();
+    if (!_subregion_width._set)  width  = fa.width();
+    if (!_subregion_height._set) height = fa.height();
+
+    if (units.get_primitive_units() == SP_FILTER_UNITS_OBJECTBOUNDINGBOX) {
+
+        Geom::OptRect const bb_opt = units.get_item_bbox();
+        if (!bb_opt) {
+            std::cerr << "FilterPrimitive::filter_primitive_area: bounding box undefined and 'primitiveUnits' is 'objectBoundingBox'." << std::endl;
+            return Geom::Rect();
+        }
+        Geom::Rect bb = *bb_opt;
+
+        // Update computed values for ex, em, %.
+        // For %, assumes primitive unit is objectBoundingBox.
+        // TODO: fetch somehow the object ex and em lengths; 12, 6 are just dummy values.
+        auto const len_x = bb.width();
+        auto const len_y = bb.height();
+
+        auto compute = [] (SVGLength length, double scale) {
+            length.update(12, 6, scale);
+            return length.computed;
+        };
+
+        auto const subregion_x_computed = compute(_subregion_x, len_x);
+        auto const subregion_y_computed = compute(_subregion_y, len_y);
+        auto const subregion_w_computed = compute(_subregion_width, len_x);
+        auto const subregion_h_computed = compute(_subregion_height, len_y);
+
+        // Values are in terms of fraction of bounding box.
+        if (_subregion_x._set      && _subregion_x.unit      != SVGLength::PERCENT)      x = bb.left() + bb.width() * _subregion_x.value;
+        if (_subregion_y._set      && _subregion_y.unit      != SVGLength::PERCENT)      y = bb.top() + bb.height() * _subregion_y.value;
+        if (_subregion_width._set  && _subregion_width.unit  != SVGLength::PERCENT)  width = bb.width()  * _subregion_width.value;
+        if (_subregion_height._set && _subregion_height.unit != SVGLength::PERCENT) height = bb.height() * _subregion_height.value;
+        // Values are in terms of percent                                                         
+        if (_subregion_x._set      && _subregion_x.unit      == SVGLength::PERCENT)      x = bb.left() + subregion_x_computed;
+        if (_subregion_y._set      && _subregion_y.unit      == SVGLength::PERCENT)      y = bb.top() + subregion_y_computed;
+        if (_subregion_width._set  && _subregion_width.unit  == SVGLength::PERCENT)  width = subregion_w_computed;
+        if (_subregion_height._set && _subregion_height.unit == SVGLength::PERCENT) height = subregion_h_computed;
+    } else {
+        // Values are in terms of user space coordinates or percent of viewport (already calculated in sp-filter-primitive.cpp).
+        if (_subregion_x._set     )      x = _subregion_x.computed;
+        if (_subregion_y._set     )      y = _subregion_y.computed;
+        if (_subregion_width._set )  width = _subregion_width.computed;
+        if (_subregion_height._set) height = _subregion_height.computed;
+    }
+
+    return Geom::Rect::from_xywh(x, y, width, height);
+}
+
+void FilterPrimitive::setStyle(SPStyle const *style)
+{
+    if (style) {
+        color_interpolation = style->color_interpolation_filters.computed;
+    } else {
+        color_interpolation = SP_CSS_COLOR_INTERPOLATION_AUTO;
+    }
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-primitive.h b/src/display/nr-filter-primitive.h
new file mode 100644
index 0000000..82891a7
--- /dev/null
+++ b/src/display/nr-filter-primitive.h
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * SVG filters rendering
+ *
+ * Author:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2006-2007 Niko Kiirala
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+#ifndef SEEN_NR_FILTER_PRIMITIVE_H
+#define SEEN_NR_FILTER_PRIMITIVE_H
+
+#include <memory>
+#include <2geom/forward.h>
+#include <2geom/rect.h>
+
+#include <glibmm/ustring.h>
+
+#include "display/nr-filter-types.h"
+#include "svg/svg-length.h"
+#include "style-enums.h"
+
+class SPStyle;
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterSlot;
+class FilterUnits;
+
+class FilterPrimitive
+{
+public:
+    FilterPrimitive();
+    virtual ~FilterPrimitive();
+
+    virtual void update() {}
+    virtual void render_cairo(FilterSlot &slot) const;
+    virtual void area_enlarge(Geom::IntRect &area, Geom::Affine const &m) const {}
+
+    /**
+     * Sets the input slot number 'slot' to be used as input in rendering
+     * filter primitive 'primitive'
+     * For filter primitive types accepting more than one input, this sets the
+     * first input.
+     * If any of the required input slots is not set, the output of previous
+     * filter primitive is used, or SourceGraphic if this is the first
+     * primitive for this filter.
+     */
+    virtual void set_input(int slot);
+
+    /**
+     * Sets the input slot number 'slot' to be user as input number 'input' in
+     * rendering filter primitive 'primitive'
+     * First input for a filter primitive is number 0. For primitives with
+     * attributes 'in' and 'in2', these are numbered 0 and 1, respectively.
+     * If any of required input slots for a filter is not set, the output of
+     * previous filter primitive is used, or SourceGraphic if this is the first
+     * filter primitive for this filter.
+     */
+    virtual void set_input(int input, int slot);
+
+    /**
+     * Sets the slot number 'slot' to be used as output from filter primitive
+     * 'primitive'
+     * If output slot for a filter element is not set, one of the unused image
+     * slots is used.
+     * It is an error to specify a pre-defined slot as 'slot'. Such call does
+     * not have any effect to the state of filter or its primitives.
+     */
+    virtual void set_output(int slot);
+
+    // returns cache score factor, reflecting the cost of rendering this filter
+    // this should return how many times slower this primitive is that normal rendering
+    virtual double complexity(Geom::Affine const &/*ctm*/) const { return 1.0; }
+
+    virtual bool uses_background() const
+    {
+        return _input == NR_FILTER_BACKGROUNDIMAGE || _input == NR_FILTER_BACKGROUNDALPHA;
+    }
+
+    /**
+     * Sets the filter primitive subregion. Passing an unset length
+     * (length._set == false) WILL change the parameter as it is
+     * important to know if a parameter is unset.
+     */
+    void set_x(SVGLength const &length);
+    void set_y(SVGLength const &length);
+    void set_width(SVGLength const &length);
+    void set_height(SVGLength const &length);
+    void set_subregion(SVGLength const &x, SVGLength const &y,
+                       SVGLength const &width, SVGLength const &height);
+
+    /**
+     * Returns the filter primitive area in user coordinate system.
+     */
+    Geom::Rect filter_primitive_area(FilterUnits const &units) const;
+
+    /**
+     *Indicate whether the filter primitive can handle the given affine.
+     *
+     * Results of some filter primitives depend on the coordinate system used when rendering.
+     * A gaussian blur with equal x and y deviation will remain unchanged by rotations.
+     * Per-pixel filters like color matrix and blend will not change regardless of
+     * the transformation.
+     *
+     * When any filter returns false, filter rendering is performed on an intermediate surface
+     * with edges parallel to the axes of the user coordinate system. This means
+     * the matrices from FilterUnits will contain at most a (possibly non-uniform) scale
+     * and a translation. When all primitives of the filter return true, the rendering is
+     * performed in display coordinate space and no intermediate surface is used.
+     */
+    virtual bool can_handle_affine(Geom::Affine const &) const { return false; }
+
+    /**
+     * Sets style for access to properties used by filter primitives.
+     */
+    void setStyle(SPStyle const *style);
+
+    // Useful for debugging
+    virtual Glib::ustring name() const { return "No name"; }
+
+protected:
+    int _input;
+    int _output;
+
+    /* Filter primitive subregion */
+    SVGLength _subregion_x;
+    SVGLength _subregion_y;
+    SVGLength _subregion_width;
+    SVGLength _subregion_height;
+
+    SPColorInterpolation color_interpolation;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_PRIMITIVE_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-skeleton.cpp b/src/display/nr-filter-skeleton.cpp
new file mode 100644
index 0000000..3c55005
--- /dev/null
+++ b/src/display/nr-filter-skeleton.cpp
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Filter primitive renderer skeleton class
+ * You can create your new filter primitive renderer by replacing
+ * all occurrences of Skeleton, skeleton and SKELETON with your filter
+ * type, like gaussian or blend in respective case.
+ *
+ * This can be accomplished with the following sed command:
+ * sed -e "s/Skeleton/Name/g" -e "s/skeleton/name/" -e "s/SKELETON/NAME/"
+ * nr-filter-skeleton.cpp >nr-filter-name.cpp
+ *
+ * (on one line, replace occurrences of 'name' with your filter name)
+ *
+ * Remember to convert the .h file too. The sed command is same for both
+ * files.
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/nr-filter-skeleton.h"
+#include "display/cairo-utils.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+
+namespace Inkscape {
+namespace Filters {
+
+FilterSkeleton::FilterSkeleton()
+{
+}
+
+FilterSkeleton::~FilterSkeleton()
+{
+}
+
+void FilterSkeleton::render_cairo(FilterSlot &slot) const
+{
+    cairo_surface_t *in = slot.getcairo(_input);
+    cairo_surface_t *out = ink_cairo_surface_create_identical(in);
+
+//    cairo_t *ct = cairo_create(out);
+
+//    cairo_set_source_surface(ct, in, offset[X], offset[Y]);
+//    cairo_paint(ct);
+//    cairo_destroy(ct);
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-skeleton.h b/src/display/nr-filter-skeleton.h
new file mode 100644
index 0000000..111bcb5
--- /dev/null
+++ b/src/display/nr-filter-skeleton.h
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_SKELETON_H
+#define SEEN_NR_FILTER_SKELETON_H
+
+/*
+ * Filter primitive renderer skeleton class
+ * You can create your new filter primitive renderer by replacing
+ * all occurrences of Skeleton, skeleton and SKELETON with your filter
+ * type, like gaussian or blend in respective case.
+ *
+ * This can be accomplished with the following sed command:
+ * sed -e "s/Skeleton/Name/g" -e "s/skeleton/name/" -e "s/SKELETON/NAME/"
+ * nr-filter-skeleton.h >nr-filter-name.h
+ *
+ * (on one line, replace occurrences of 'name' with your filter name)
+ *
+ * Remember to convert the .cpp file too. The sed command is same for both
+ * files.
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/nr-filter-primitive.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterSkeleton : public FilterPrimitive
+{
+public:
+    FilterSkeleton();
+    ~FilterSkeleton() override;
+
+    void render_cairo(FilterSlot &slot) const override;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_SKELETON_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-slot.cpp b/src/display/nr-filter-slot.cpp
new file mode 100644
index 0000000..b9d3b1a
--- /dev/null
+++ b/src/display/nr-filter-slot.cpp
@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * A container class for filter slots. Allows for simple getting and
+ * setting images in filter slots without having to bother with
+ * table indexes and such.
+ *
+ * Author:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2006,2007 Niko Kiirala
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cassert>
+#include <cstring>
+
+#include <2geom/transforms.h>
+#include "cairo-utils.h"
+#include "drawing-context.h"
+#include "drawing-surface.h"
+#include "nr-filter-types.h"
+#include "nr-filter-gaussian.h"
+#include "nr-filter-slot.h"
+#include "nr-filter-units.h"
+
+namespace Inkscape {
+namespace Filters {
+
+FilterSlot::FilterSlot(DrawingContext *bgdc, DrawingContext &graphic, FilterUnits const &units, RenderContext &rc, int blurquality)
+    : _source_graphic(graphic.rawTarget())
+    , _background_ct(bgdc ? bgdc->raw() : nullptr)
+    , _source_graphic_area(graphic.targetLogicalBounds().roundOutwards()) // fixme
+    , _background_area(bgdc ? bgdc->targetLogicalBounds().roundOutwards() : Geom::IntRect()) // fixme
+    , _units(units)
+    , _last_out(NR_FILTER_SOURCEGRAPHIC)
+    , _blurquality(blurquality)
+    , rc(rc)
+    , device_scale(graphic.surface()->device_scale())
+{
+    using Geom::X;
+    using Geom::Y;
+
+    // compute slot bbox
+    Geom::Affine trans = _units.get_matrix_display2pb();
+    Geom::Rect bbox_trans = graphic.targetLogicalBounds() * trans;
+    Geom::Point min = bbox_trans.min();
+    _slot_x = min[X];
+    _slot_y = min[Y];
+
+    if (trans.isTranslation()) {
+        _slot_w = _source_graphic_area.width();
+        _slot_h = _source_graphic_area.height();
+    } else {
+        _slot_w = std::ceil(bbox_trans.width());
+        _slot_h = std::ceil(bbox_trans.height());
+    }
+}
+
+FilterSlot::~FilterSlot()
+{
+    for (auto &_slot : _slots) {
+        cairo_surface_destroy(_slot.second);
+    }
+}
+
+cairo_surface_t *FilterSlot::getcairo(int slot_nr)
+{
+    if (slot_nr == NR_FILTER_SLOT_NOT_SET)
+        slot_nr = _last_out;
+
+    SlotMap::iterator s = _slots.find(slot_nr);
+
+    /* If we didn't have the specified image, but we could create it
+     * from the other information we have, let's do that */
+    if (s == _slots.end()
+        && (slot_nr == NR_FILTER_SOURCEGRAPHIC
+            || slot_nr == NR_FILTER_SOURCEALPHA
+            || slot_nr == NR_FILTER_BACKGROUNDIMAGE
+            || slot_nr == NR_FILTER_BACKGROUNDALPHA
+            || slot_nr == NR_FILTER_FILLPAINT
+            || slot_nr == NR_FILTER_STROKEPAINT))
+    {
+        switch (slot_nr) {
+            case NR_FILTER_SOURCEGRAPHIC: {
+                cairo_surface_t *tr = _get_transformed_source_graphic();
+                // Assume all source graphics are sRGB
+                set_cairo_surface_ci( tr, SP_CSS_COLOR_INTERPOLATION_SRGB );
+                _set_internal(NR_FILTER_SOURCEGRAPHIC, tr);
+                cairo_surface_destroy(tr);
+            } break;
+            case NR_FILTER_BACKGROUNDIMAGE: {
+                cairo_surface_t *bg = _get_transformed_background();
+                // Assume all backgrounds are sRGB
+                set_cairo_surface_ci( bg, SP_CSS_COLOR_INTERPOLATION_SRGB );
+                _set_internal(NR_FILTER_BACKGROUNDIMAGE, bg);
+                cairo_surface_destroy(bg);
+            } break;
+            case NR_FILTER_SOURCEALPHA: {
+                cairo_surface_t *src = getcairo(NR_FILTER_SOURCEGRAPHIC);
+                cairo_surface_t *alpha = ink_cairo_extract_alpha(src);
+                _set_internal(NR_FILTER_SOURCEALPHA, alpha);
+                cairo_surface_destroy(alpha);
+            } break;
+            case NR_FILTER_BACKGROUNDALPHA: {
+                cairo_surface_t *src = getcairo(NR_FILTER_BACKGROUNDIMAGE);
+                cairo_surface_t *ba = ink_cairo_extract_alpha(src);
+                _set_internal(NR_FILTER_BACKGROUNDALPHA, ba);
+                cairo_surface_destroy(ba);
+            } break;
+            case NR_FILTER_FILLPAINT: //TODO
+            case NR_FILTER_STROKEPAINT: //TODO
+            default:
+                break;
+        }
+        s = _slots.find(slot_nr);
+    }
+
+    if (s == _slots.end()) {
+        // create empty surface
+        cairo_surface_t *empty = cairo_surface_create_similar(
+            _source_graphic, cairo_surface_get_content(_source_graphic),
+            _slot_w, _slot_h);
+        _set_internal(slot_nr, empty);
+        cairo_surface_destroy(empty);
+        s = _slots.find(slot_nr);
+    }
+
+    if (s->second && cairo_surface_status(s->second) == CAIRO_STATUS_NO_MEMORY) {
+        // Simulate Cairomm behaviour by throwing std::bad_alloc.
+        throw std::bad_alloc();
+    }
+
+    return s->second;
+}
+
+cairo_surface_t *FilterSlot::_get_transformed_source_graphic() const
+{
+    Geom::Affine trans = _units.get_matrix_display2pb();
+
+    if (trans.isTranslation()) {
+        cairo_surface_reference(_source_graphic);
+        return _source_graphic;
+    }
+
+    cairo_surface_t *tsg = cairo_surface_create_similar(
+        _source_graphic, cairo_surface_get_content(_source_graphic),
+        _slot_w, _slot_h);
+    cairo_t *tsg_ct = cairo_create(tsg);
+
+    cairo_translate(tsg_ct, -_slot_x, -_slot_y);
+    ink_cairo_transform(tsg_ct, trans);
+    cairo_translate(tsg_ct, _source_graphic_area.left(), _source_graphic_area.top());
+    cairo_set_source_surface(tsg_ct, _source_graphic, 0, 0);
+    cairo_set_operator(tsg_ct, CAIRO_OPERATOR_SOURCE);
+    cairo_paint(tsg_ct);
+    cairo_destroy(tsg_ct);
+
+    return tsg;
+}
+
+cairo_surface_t *FilterSlot::_get_transformed_background() const
+{
+    Geom::Affine trans = _units.get_matrix_display2pb();
+
+    cairo_surface_t *tbg;
+
+    if (_background_ct) {
+        cairo_surface_t *bg = cairo_get_group_target(_background_ct);
+        tbg = cairo_surface_create_similar(
+            bg, cairo_surface_get_content(bg),
+            _slot_w, _slot_h);
+        cairo_t *tbg_ct = cairo_create(tbg);
+
+        cairo_translate(tbg_ct, -_slot_x, -_slot_y);
+        ink_cairo_transform(tbg_ct, trans);
+        cairo_translate(tbg_ct, _background_area.left(), _background_area.top());
+        cairo_set_source_surface(tbg_ct, bg, 0, 0);
+        cairo_set_operator(tbg_ct, CAIRO_OPERATOR_SOURCE);
+        cairo_paint(tbg_ct);
+        cairo_destroy(tbg_ct);
+    } else {
+        tbg = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, _slot_w * device_scale, _slot_h * device_scale);
+    }
+
+    return tbg;
+}
+
+cairo_surface_t *FilterSlot::get_result(int res)
+{
+    cairo_surface_t *result = getcairo(res);
+
+    Geom::Affine trans = _units.get_matrix_pb2display();
+    if (trans.isIdentity()) {
+        cairo_surface_reference(result);
+        return result;
+    }
+
+    cairo_surface_t *r = cairo_surface_create_similar(_source_graphic,
+        cairo_surface_get_content(_source_graphic),
+        _source_graphic_area.width(),
+        _source_graphic_area.height());
+    copy_cairo_surface_ci( result, r );
+    cairo_t *r_ct = cairo_create(r);
+
+    cairo_translate(r_ct, -_source_graphic_area.left(), -_source_graphic_area.top());
+    ink_cairo_transform(r_ct, trans);
+    cairo_translate(r_ct, _slot_x, _slot_y);
+    cairo_set_source_surface(r_ct, result, 0, 0);
+    cairo_set_operator(r_ct, CAIRO_OPERATOR_SOURCE);
+    cairo_paint(r_ct);
+    cairo_destroy(r_ct);
+
+    return r;
+}
+
+void FilterSlot::_set_internal(int slot_nr, cairo_surface_t *surface)
+{
+    // destroy after referencing
+    // this way assigning a surface to a slot it already occupies will not cause errors
+    cairo_surface_reference(surface);
+
+    SlotMap::iterator s = _slots.find(slot_nr);
+    if (s != _slots.end()) {
+        cairo_surface_destroy(s->second);
+    }
+
+    _slots[slot_nr] = surface;
+}
+
+void FilterSlot::set(int slot_nr, cairo_surface_t *surface)
+{
+    g_return_if_fail(surface != nullptr);
+
+    if (slot_nr == NR_FILTER_SLOT_NOT_SET)
+        slot_nr = NR_FILTER_UNNAMED_SLOT;
+
+    _set_internal(slot_nr, surface);
+    _last_out = slot_nr;
+}
+
+void FilterSlot::set_primitive_area(int slot_nr, Geom::Rect &area)
+{
+    if (slot_nr == NR_FILTER_SLOT_NOT_SET)
+        slot_nr = NR_FILTER_UNNAMED_SLOT;
+
+    _primitiveAreas[slot_nr] = area;
+}
+
+Geom::Rect FilterSlot::get_primitive_area(int slot_nr) const
+{
+    if (slot_nr == NR_FILTER_SLOT_NOT_SET)
+        slot_nr = _last_out;
+
+    auto s = _primitiveAreas.find(slot_nr);
+
+    if (s == _primitiveAreas.end()) {
+        return *_units.get_filter_area();
+    }
+    return s->second;
+}
+
+Geom::Rect FilterSlot::get_slot_area() const
+{
+    return Geom::Rect::from_xywh(_slot_x, _slot_y, _slot_w, _slot_h);
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-slot.h b/src/display/nr-filter-slot.h
new file mode 100644
index 0000000..ecd9f00
--- /dev/null
+++ b/src/display/nr-filter-slot.h
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_SLOT_H
+#define SEEN_NR_FILTER_SLOT_H
+
+/*
+ * A container class for filter slots. Allows for simple getting and
+ * setting images in filter slots without having to bother with
+ * table indexes and such.
+ *
+ * Author:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2006,2007 Niko Kiirala
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <map>
+#include "nr-filter-types.h"
+#include "nr-filter-units.h"
+
+extern "C" {
+typedef struct _cairo cairo_t;
+typedef struct _cairo_surface cairo_surface_t;
+}
+
+namespace Inkscape {
+class DrawingContext;
+class DrawingItem;
+class RenderContext;
+
+namespace Filters {
+
+class FilterSlot final
+{
+public:
+    /** Creates a new FilterSlot object. */
+    FilterSlot(DrawingContext *bgdc, DrawingContext &graphic, FilterUnits const &units, RenderContext &rc, int blurquality);
+
+    /** Destroys the FilterSlot object and all its contents */
+    ~FilterSlot();
+
+    /** Returns the pixblock in specified slot.
+     * Parameter 'slot' may be either an positive integer or one of
+     * pre-defined filter slot types: NR_FILTER_SLOT_NOT_SET,
+     * NR_FILTER_SOURCEGRAPHIC, NR_FILTER_SOURCEALPHA,
+     * NR_FILTER_BACKGROUNDIMAGE, NR_FILTER_BACKGROUNDALPHA,
+     * NR_FILTER_FILLPAINT, NR_FILTER_SOURCEPAINT.
+     */
+    cairo_surface_t *getcairo(int slot);
+
+    /** Sets or re-sets the pixblock associated with given slot.
+     * If there was a pixblock already assigned with this slot,
+     * that pixblock is destroyed.
+     */
+    void set(int slot, cairo_surface_t *s);
+
+    cairo_surface_t *get_result(int slot_nr);
+
+    void set_primitive_area(int slot, Geom::Rect &area);
+    Geom::Rect get_primitive_area(int slot) const;
+    
+    /** Returns the number of slots in use. */
+    int get_slot_count() const { return _slots.size(); }
+
+    /** Gets the gaussian filtering quality. Affects used interpolation methods */
+    int get_blurquality() const { return _blurquality; }
+
+    /** Gets the device scale; for high DPI monitors. */
+    int get_device_scale() const { return device_scale; }
+
+    FilterUnits const &get_units() const { return _units; }
+    Geom::Rect get_slot_area() const;
+
+    RenderContext &get_rendercontext() const { return rc; }
+
+private:
+    using SlotMap = std::map<int, cairo_surface_t *>;
+    SlotMap _slots;
+
+    // We need to keep track of the primitive area as this is needed in feTile
+    using PrimitiveAreaMap = std::map<int, Geom::Rect>;
+    PrimitiveAreaMap _primitiveAreas;
+
+    int _slot_w, _slot_h;
+    double _slot_x, _slot_y;
+    cairo_surface_t *_source_graphic;
+    cairo_t *_background_ct;
+    Geom::IntRect _source_graphic_area;
+    Geom::IntRect _background_area; ///< needed to extract background
+    FilterUnits const &_units;
+    int _last_out;
+    int _blurquality;
+    int device_scale;
+    RenderContext &rc;
+
+    cairo_surface_t *_get_transformed_source_graphic() const;
+    cairo_surface_t *_get_transformed_background() const;
+    cairo_surface_t *_get_fill_paint() const;
+    cairo_surface_t *_get_stroke_paint() const;
+
+    void _set_internal(int slot, cairo_surface_t *s);
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_SLOT_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-specularlighting.cpp b/src/display/nr-filter-specularlighting.cpp
new file mode 100644
index 0000000..64402bb
--- /dev/null
+++ b/src/display/nr-filter-specularlighting.cpp
@@ -0,0 +1,241 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * feSpecularLighting renderer
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *   Jean-Rene Reinhard <jr@komite.net>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"  // only include where actually required!
+#endif
+
+#include <glib.h>
+#include <cmath>
+
+#include "display/cairo-templates.h"
+#include "display/cairo-utils.h"
+#include "display/nr-3dutils.h"
+#include "display/nr-filter-specularlighting.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+#include "display/nr-filter-utils.h"
+#include "display/nr-light.h"
+#include "svg/svg-icc-color.h"
+#include "svg/svg-color.h"
+
+namespace Inkscape {
+namespace Filters {
+
+FilterSpecularLighting::FilterSpecularLighting()
+    : light_type(NO_LIGHT)
+    , specularConstant(1)
+    , specularExponent(1)
+    , surfaceScale(1)
+    , lighting_color(0xffffffff) {}
+
+FilterSpecularLighting::~FilterSpecularLighting() = default;
+
+struct SpecularLight : public SurfaceSynth
+{
+    SpecularLight(cairo_surface_t *bumpmap, double scale, double specular_constant, double specular_exponent)
+        : SurfaceSynth(bumpmap)
+        , _scale(scale)
+        , _ks(specular_constant)
+        , _exp(specular_exponent) {}
+
+protected:
+    guint32 specularLighting(int x, int y, NR::Fvector const &halfway, NR::Fvector const &light_components)
+    {
+        NR::Fvector normal = surfaceNormalAt(x, y, _scale);
+        double sp = NR::scalar_product(normal, halfway);
+        double k = sp <= 0.0 ? 0.0 : _ks * std::pow(sp, _exp);
+
+        guint32 r = CLAMP_D_TO_U8(k * light_components[LIGHT_RED]);
+        guint32 g = CLAMP_D_TO_U8(k * light_components[LIGHT_GREEN]);
+        guint32 b = CLAMP_D_TO_U8(k * light_components[LIGHT_BLUE]);
+        guint32 a = std::max(std::max(r, g), b);
+
+        r = premul_alpha(r, a);
+        g = premul_alpha(g, a);
+        b = premul_alpha(b, a);
+
+        ASSEMBLE_ARGB32(pxout, a,r,g,b)
+        return pxout;
+    }
+
+    double _scale, _ks, _exp;
+};
+
+struct SpecularDistantLight : public SpecularLight
+{
+    SpecularDistantLight(cairo_surface_t *bumpmap, DistantLightData const &light, guint32 color,
+                         double scale, double specular_constant, double specular_exponent)
+        : SpecularLight(bumpmap, scale, specular_constant, specular_exponent)
+    {
+        DistantLight dl(light, color);
+        NR::Fvector lv;
+        dl.light_vector(lv);
+        dl.light_components(_light_components);
+        NR::normalized_sum(_halfway, lv, NR::EYE_VECTOR);
+    }
+
+    guint32 operator()(int x, int y)
+    {
+        return specularLighting(x, y, _halfway, _light_components);
+    }
+
+private:
+    NR::Fvector _halfway, _light_components;
+};
+
+struct SpecularPointLight : public SpecularLight
+{
+    SpecularPointLight(cairo_surface_t *bumpmap, PointLightData const &light, guint32 color,
+                       Geom::Affine const &trans, double scale, double specular_constant,
+                       double specular_exponent, double x0, double y0, int device_scale)
+        : SpecularLight(bumpmap, scale, specular_constant, specular_exponent)
+        , _light(light, color, trans, device_scale)
+        , _x0(x0)
+        , _y0(y0)
+    {
+        _light.light_components(_light_components);
+    }
+
+    guint32 operator()(int x, int y)
+    {
+        NR::Fvector light, halfway;
+        _light.light_vector(light, _x0 + x, _y0 + y, _scale * alphaAt(x, y) / 255.0);
+        NR::normalized_sum(halfway, light, NR::EYE_VECTOR);
+        return specularLighting(x, y, halfway, _light_components);
+    }
+
+private:
+    PointLight _light;
+    NR::Fvector _light_components;
+    double _x0, _y0;
+};
+
+struct SpecularSpotLight : public SpecularLight
+{
+    SpecularSpotLight(cairo_surface_t *bumpmap, SpotLightData const &light, guint32 color,
+                      Geom::Affine const &trans, double scale, double specular_constant,
+                      double specular_exponent, double x0, double y0, int device_scale)
+        : SpecularLight(bumpmap, scale, specular_constant, specular_exponent)
+        , _light(light, color, trans, device_scale)
+        , _x0(x0)
+        , _y0(y0) {}
+
+    guint32 operator()(int x, int y)
+    {
+        NR::Fvector light, halfway, light_components;
+        _light.light_vector(light, _x0 + x, _y0 + y, _scale * alphaAt(x, y) / 255.0);
+        _light.light_components(light_components, light);
+        NR::normalized_sum(halfway, light, NR::EYE_VECTOR);
+        return specularLighting(x, y, halfway, light_components);
+    }
+
+private:
+    SpotLight _light;
+    double _x0, _y0;
+};
+
+void FilterSpecularLighting::render_cairo(FilterSlot &slot) const
+{
+    cairo_surface_t *input = slot.getcairo(_input);
+    cairo_surface_t *out = ink_cairo_surface_create_same_size(input, CAIRO_CONTENT_COLOR_ALPHA);
+
+    double r = SP_RGBA32_R_F(lighting_color);
+    double g = SP_RGBA32_G_F(lighting_color);
+    double b = SP_RGBA32_B_F(lighting_color);
+
+    if (icc) {
+        unsigned char ru, gu, bu;
+        icc_color_to_sRGB(&*icc, &ru, &gu, &bu);
+        r = SP_COLOR_U_TO_F(ru);
+        g = SP_COLOR_U_TO_F(gu);
+        b = SP_COLOR_U_TO_F(bu);
+    }
+
+    // Only alpha channel of input is used, no need to check input color_interpolation_filter value.
+    // Lighting color is always defined in terms of sRGB, preconvert to linearRGB
+    // if color_interpolation_filters set to linearRGB (for efficiency assuming
+    // next filter primitive has same value of cif).
+    if (color_interpolation == SP_CSS_COLOR_INTERPOLATION_LINEARRGB) {
+        r = srgb_to_linear(r);
+        g = srgb_to_linear(g);
+        b = srgb_to_linear(b);
+    }
+    set_cairo_surface_ci(out, color_interpolation);
+    guint32 color = SP_RGBA32_F_COMPOSE(r, g, b, 1.0);
+
+    int device_scale = slot.get_device_scale();
+
+    // trans has inverse y... so we can't just scale by device_scale! We must instead explicitly
+    // scale the point and spot light coordinates (as well as "scale").
+
+    Geom::Affine trans = slot.get_units().get_matrix_primitiveunits2pb();
+
+    Geom::Point p = slot.get_slot_area().min();
+    double x0 = p[Geom::X];
+    double y0 = p[Geom::Y];
+    double scale = surfaceScale * trans.descrim() * device_scale;
+    double ks = specularConstant;
+    double se = specularExponent;
+
+    switch (light_type) {
+    case DISTANT_LIGHT:
+        ink_cairo_surface_synthesize(out,
+            SpecularDistantLight(input, light.distant, color, scale, ks, se));
+        break;
+    case POINT_LIGHT:
+        ink_cairo_surface_synthesize(out,
+            SpecularPointLight(input, light.point, color, trans, scale, ks, se, x0, y0, device_scale));
+        break;
+    case SPOT_LIGHT:
+        ink_cairo_surface_synthesize(out,
+            SpecularSpotLight(input, light.spot, color, trans, scale, ks, se, x0, y0, device_scale));
+        break;
+    default: {
+        cairo_t *ct = cairo_create(out);
+        cairo_set_source_rgba(ct, 0,0,0,1);
+        cairo_set_operator(ct, CAIRO_OPERATOR_SOURCE);
+        cairo_paint(ct);
+        cairo_destroy(ct);
+        break;
+        }
+    }
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+void FilterSpecularLighting::area_enlarge(Geom::IntRect &area, Geom::Affine const & /*trans*/) const
+{
+    // TODO: support kernelUnitLength
+    area.expandBy(1);
+}
+
+double FilterSpecularLighting::complexity(Geom::Affine const &) const
+{
+    return 9.0;
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-specularlighting.h b/src/display/nr-filter-specularlighting.h
new file mode 100644
index 0000000..fdc7eb9
--- /dev/null
+++ b/src/display/nr-filter-specularlighting.h
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_SPECULARLIGHTING_H
+#define SEEN_NR_FILTER_SPECULARLIGHTING_H
+
+/*
+ * feSpecularLighting renderer
+ *
+ * Authors:
+ *   Niko Kiirala <niko@kiirala.com>
+ *   Jean-Rene Reinhard <jr@komite.net>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/nr-light-types.h"
+#include "display/nr-filter-primitive.h"
+
+class SPFeDistantLight;
+class SPFePointLight;
+class SPFeSpotLight;
+struct SVGICCColor;
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterSlot;
+
+class FilterSpecularLighting : public FilterPrimitive
+{
+public:
+    FilterSpecularLighting();
+    ~FilterSpecularLighting() override;
+
+    void render_cairo(FilterSlot &slot) const override;
+    void set_icc(SVGICCColor const &icc_) { icc = icc_; }
+    void area_enlarge(Geom::IntRect &area, Geom::Affine const &trans) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+
+    union
+    {
+        DistantLightData distant;
+        PointLightData point;
+        SpotLightData spot;
+    } light;
+    LightType light_type;
+    double surfaceScale;
+    double specularConstant;
+    double specularExponent;
+    guint32 lighting_color;
+
+    Glib::ustring name() const override { return Glib::ustring("Specular Lighting"); }
+
+private:
+    std::optional<SVGICCColor> icc;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_SPECULARLIGHTING_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-tile.cpp b/src/display/nr-filter-tile.cpp
new file mode 100644
index 0000000..81966ba
--- /dev/null
+++ b/src/display/nr-filter-tile.cpp
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * feTile filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <glib.h>
+
+#include "display/cairo-utils.h"
+#include "display/nr-filter-tile.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+
+namespace Inkscape {
+namespace Filters {
+
+FilterTile::FilterTile() = default;
+
+FilterTile::~FilterTile() = default;
+
+void FilterTile::render_cairo(FilterSlot &slot) const
+{
+    // This input source contains only the "rendering" tile.
+    cairo_surface_t *in = slot.getcairo(_input);
+
+    // For debugging
+    // static int i = 0;
+    // ++i;
+    // std::stringstream filename;
+    // filename << "dump." << i << ".png";
+    // cairo_surface_write_to_png( in, filename.str().c_str() );
+
+    // This is the feTile source area as determined by the input primitive area (see SVG spec).
+    Geom::Rect tile_area = slot.get_primitive_area(_input);
+
+    if (tile_area.width() == 0.0 || tile_area.height() == 0.0) {
+
+        slot.set(_output, in);
+        std::cerr << "FileTile::render_cairo: tile has zero width or height" << std::endl;
+
+    } else {
+
+        cairo_surface_t *out = ink_cairo_surface_create_identical(in);
+        // color_interpolation_filters for out same as in.
+        copy_cairo_surface_ci(in, out);
+        cairo_t *ct = cairo_create(out);
+
+        // The rectangle of the "rendering" tile.
+        Geom::Rect sa = slot.get_slot_area();
+
+        Geom::Affine trans = slot.get_units().get_matrix_user2pb();
+
+        // Create feTile tile ----------------
+
+        // Get tile area in pixbuf units (tile transformed).
+        Geom::Rect tt = tile_area * trans;
+        
+        // Shift between "rendering" tile and feTile tile
+        Geom::Point shift = sa.min() - tt.min(); 
+
+        // Create feTile tile surface
+        cairo_surface_t *tile = cairo_surface_create_similar(in, cairo_surface_get_content(in),
+                                                             tt.width(), tt.height());
+        cairo_t *ct_tile = cairo_create(tile);
+        cairo_set_source_surface(ct_tile, in, shift[Geom::X], shift[Geom::Y]);
+        cairo_paint(ct_tile);
+
+        // Paint tiles ------------------
+        
+        // For debugging
+        // std::stringstream filename;
+        // filename << "tile." << i << ".png";
+        // cairo_surface_write_to_png( tile, filename.str().c_str() );
+        
+        // Determine number of feTile rows and columns
+        Geom::Rect pr = filter_primitive_area(slot.get_units());
+        int tile_cols = std::ceil(pr.width()  / tile_area.width());
+        int tile_rows = std::ceil(pr.height() / tile_area.height());
+
+        // Do tiling (TO DO: restrict to slot area.)
+        for (int col = 0; col < tile_cols; ++col) {
+            for (int row = 0; row < tile_rows; ++row) {
+                Geom::Point offset(col * tile_area.width(), row * tile_area.height());
+                offset *= trans;
+                offset[Geom::X] -= trans[4];
+                offset[Geom::Y] -= trans[5];
+        
+                cairo_set_source_surface(ct, tile, offset[Geom::X], offset[Geom::Y]);
+                cairo_paint(ct);
+            }
+        }
+        slot.set(_output, out);
+
+        // Clean up
+        cairo_destroy(ct);
+        cairo_surface_destroy(out);
+        cairo_destroy(ct_tile);
+        cairo_surface_destroy(tile);
+    }
+}
+
+void FilterTile::area_enlarge(Geom::IntRect &area, Geom::Affine const &trans) const
+{
+    // Set to very large rectangle so we get tile source. It will be clipped later.
+
+    // Note, setting to infinite using Geom::IntRect::infinite() causes overflow/underflow problems.
+    Geom::IntCoord max = std::numeric_limits<Geom::IntCoord>::max() / 4;
+    area = Geom::IntRect(-max, -max, max, max);
+}
+
+double FilterTile::complexity(Geom::Affine const &) const
+{
+    return 1.0;
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-tile.h b/src/display/nr-filter-tile.h
new file mode 100644
index 0000000..653eee8
--- /dev/null
+++ b/src/display/nr-filter-tile.h
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_TILE_H
+#define SEEN_NR_FILTER_TILE_H
+
+/*
+ * feTile filter primitive renderer
+ *
+ * Authors:
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/nr-filter-primitive.h"
+
+namespace Inkscape {
+namespace Filters {
+
+class FilterSlot;
+
+class FilterTile : public FilterPrimitive
+{
+public:
+    FilterTile();
+    ~FilterTile() override;
+
+    void render_cairo(FilterSlot &slot) const override;
+    void area_enlarge(Geom::IntRect &area, Geom::Affine const &trans) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+
+    Glib::ustring name() const override { return Glib::ustring("Tile"); }
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_TILE_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-turbulence.cpp b/src/display/nr-filter-turbulence.cpp
new file mode 100644
index 0000000..f13b977
--- /dev/null
+++ b/src/display/nr-filter-turbulence.cpp
@@ -0,0 +1,450 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * feTurbulence filter primitive renderer
+ *
+ * Authors:
+ *   World Wide Web Consortium <http://www.w3.org/>
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *
+ * This file has a considerable amount of code adapted from
+ *  the W3C SVG filter specs, available at:
+ *  http://www.w3.org/TR/SVG11/filters.html#feTurbulence
+ *
+ * W3C original code is licensed under the terms of
+ *  the (GPL compatible) W3C® SOFTWARE NOTICE AND LICENSE:
+ *  http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231
+ *
+ * Copyright (C) 2007 authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/cairo-templates.h"
+#include "display/cairo-utils.h"
+#include "display/nr-filter.h"
+#include "display/nr-filter-turbulence.h"
+#include "display/nr-filter-units.h"
+#include "display/nr-filter-utils.h"
+#include <cmath>
+
+namespace Inkscape {
+namespace Filters{
+
+class TurbulenceGenerator
+{
+public:
+    TurbulenceGenerator()
+        : _tile()
+        , _baseFreq()
+        , _latticeSelector()
+        , _gradient()
+        , _seed(0)
+        , _octaves(0)
+        , _stitchTiles(false)
+        , _wrapx(0)
+        , _wrapy(0)
+        , _wrapw(0)
+        , _wraph(0)
+        , _inited(false)
+        , _fractalnoise(false) {}
+
+    void init(long seed, Geom::Rect const &tile, Geom::Point const &freq, bool stitch, bool fractalnoise, int octaves)
+    {
+        // setup random number generator
+        _setupSeed(seed);
+
+        // set values
+        _tile = tile;
+        _baseFreq = freq;
+        _stitchTiles = stitch;
+        _fractalnoise = fractalnoise;
+        _octaves = octaves;
+
+        int i;
+        for (int k = 0; k < 4; ++k) {
+            for (i = 0; i < BSize; ++i) {
+                _latticeSelector[i] = i;
+
+                do {
+                    _gradient[i][k][0] = static_cast<double>(_random() % (BSize * 2) - BSize) / BSize;
+                    _gradient[i][k][1] = static_cast<double>(_random() % (BSize * 2) - BSize) / BSize;
+                } while (_gradient[i][k][0] == 0 && _gradient[i][k][1] == 0);
+
+                // normalize gradient
+                double s = hypot(_gradient[i][k][0], _gradient[i][k][1]);
+                _gradient[i][k][0] /= s;
+                _gradient[i][k][1] /= s;
+            }
+        }
+        while (--i) {
+            // shuffle lattice selectors
+            int j = _random() % BSize;
+            std::swap(_latticeSelector[i], _latticeSelector[j]);
+        }
+
+        // fill out the remaining part of the gradient
+        for (i = 0; i < BSize + 2; ++i)
+        {
+            _latticeSelector[BSize + i] = _latticeSelector[i];
+
+            for (int k = 0; k < 4; ++k) {
+                _gradient[BSize + i][k][0] = _gradient[i][k][0];
+                _gradient[BSize + i][k][1] = _gradient[i][k][1];
+            }
+        }
+
+        // When stitching tiled turbulence, the frequencies must be adjusted
+        // so that the tile borders will be continuous.
+        if (_stitchTiles) {
+            if (_baseFreq[Geom::X] != 0.0) {
+                double freq = _baseFreq[Geom::X];
+                double lo = std::floor(_tile.width() * freq) / _tile.width();
+                double hi = std::ceil(_tile.width() * freq) / _tile.width();
+                _baseFreq[Geom::X] = freq / lo < hi / freq ? lo : hi;
+            }
+            if (_baseFreq[Geom::Y] != 0.0) {
+                double freq = _baseFreq[Geom::Y];
+                double lo = std::floor(_tile.height() * freq) / _tile.height();
+                double hi = std::ceil(_tile.height() * freq) / _tile.height();
+                _baseFreq[Geom::Y] = freq / lo < hi / freq ? lo : hi;
+            }
+
+            _wrapw = _tile.width() * _baseFreq[Geom::X] + 0.5;
+            _wraph = _tile.height() * _baseFreq[Geom::Y] + 0.5;
+            _wrapx = _tile.left() * _baseFreq[Geom::X] + PerlinOffset + _wrapw;
+            _wrapy = _tile.top() * _baseFreq[Geom::Y] + PerlinOffset + _wraph;
+        }
+        _inited = true;
+    }
+
+    G_GNUC_PURE
+    guint32 turbulencePixel(Geom::Point const &p) const
+    {
+        int wrapx = _wrapx, wrapy = _wrapy, wrapw = _wrapw, wraph = _wraph;
+
+        double pixel[4];
+        double x = p[Geom::X] * _baseFreq[Geom::X];
+        double y = p[Geom::Y] * _baseFreq[Geom::Y];
+        double ratio = 1.0;
+
+        for (double & k : pixel)
+            k = 0.0;
+
+        for (int octave = 0; octave < _octaves; ++octave)
+        {
+            double tx = x + PerlinOffset;
+            double bx = floor(tx);
+            double rx0 = tx - bx, rx1 = rx0 - 1.0;
+            int bx0 = bx, bx1 = bx0 + 1;
+
+            double ty = y + PerlinOffset;
+            double by = floor(ty);
+            double ry0 = ty - by, ry1 = ry0 - 1.0;
+            int by0 = by, by1 = by0 + 1;
+
+            if (_stitchTiles) {
+                if (bx0 >= wrapx) bx0 -= wrapw;
+                if (bx1 >= wrapx) bx1 -= wrapw;
+                if (by0 >= wrapy) by0 -= wraph;
+                if (by1 >= wrapy) by1 -= wraph;
+            }
+            bx0 &= BMask;
+            bx1 &= BMask;
+            by0 &= BMask;
+            by1 &= BMask;
+
+            int i = _latticeSelector[bx0];
+            int j = _latticeSelector[bx1];
+            int b00 = _latticeSelector[i + by0];
+            int b01 = _latticeSelector[i + by1];
+            int b10 = _latticeSelector[j + by0];
+            int b11 = _latticeSelector[j + by1];
+
+            double sx = _scurve(rx0);
+            double sy = _scurve(ry0);
+
+            double result[4];
+            // channel numbering: R=0, G=1, B=2, A=3
+            for (int k = 0; k < 4; ++k) {
+                double const *qxa = _gradient[b00][k];
+                double const *qxb = _gradient[b10][k];
+                double a = _lerp(sx, rx0 * qxa[0] + ry0 * qxa[1],
+                                     rx1 * qxb[0] + ry0 * qxb[1]);
+                double const *qya = _gradient[b01][k];
+                double const *qyb = _gradient[b11][k];
+                double b = _lerp(sx, rx0 * qya[0] + ry1 * qya[1],
+                                     rx1 * qyb[0] + ry1 * qyb[1]);
+                result[k] = _lerp(sy, a, b);
+            }
+
+            if (_fractalnoise) {
+                for (int k = 0; k < 4; ++k)
+                    pixel[k] += result[k] / ratio;
+            } else {
+                for (int k = 0; k < 4; ++k)
+                    pixel[k] += fabs(result[k]) / ratio;
+            }
+
+            x *= 2;
+            y *= 2;
+            ratio *= 2;
+
+            if(_stitchTiles)
+            {
+                // Update stitch values. Subtracting PerlinOffset before the multiplication and
+                // adding it afterward simplifies to subtracting it once.
+                wrapw *= 2;
+                wraph *= 2;
+                wrapx = wrapx*2 - PerlinOffset;
+                wrapy = wrapy*2 - PerlinOffset;
+            }
+        }
+
+        if (_fractalnoise) {
+            guint32 r = CLAMP_D_TO_U8((pixel[0]*255.0 + 255.0) / 2);
+            guint32 g = CLAMP_D_TO_U8((pixel[1]*255.0 + 255.0) / 2);
+            guint32 b = CLAMP_D_TO_U8((pixel[2]*255.0 + 255.0) / 2);
+            guint32 a = CLAMP_D_TO_U8((pixel[3]*255.0 + 255.0) / 2);
+            r = premul_alpha(r, a);
+            g = premul_alpha(g, a);
+            b = premul_alpha(b, a);
+            ASSEMBLE_ARGB32(pxout, a,r,g,b);
+            return pxout;
+        } else {
+            guint32 r = CLAMP_D_TO_U8(pixel[0]*255.0);
+            guint32 g = CLAMP_D_TO_U8(pixel[1]*255.0);
+            guint32 b = CLAMP_D_TO_U8(pixel[2]*255.0);
+            guint32 a = CLAMP_D_TO_U8(pixel[3]*255.0);
+            r = premul_alpha(r, a);
+            g = premul_alpha(g, a);
+            b = premul_alpha(b, a);
+            ASSEMBLE_ARGB32(pxout, a,r,g,b);
+            return pxout;
+        }
+    }
+
+    //G_GNUC_PURE
+    /*guint32 turbulencePixel(Geom::Point const &p) const {
+        if (!_fractalnoise) {
+            guint32 r = CLAMP_D_TO_U8(turbulence(0, p)*255.0);
+            guint32 g = CLAMP_D_TO_U8(turbulence(1, p)*255.0);
+            guint32 b = CLAMP_D_TO_U8(turbulence(2, p)*255.0);
+            guint32 a = CLAMP_D_TO_U8(turbulence(3, p)*255.0);
+            r = premul_alpha(r, a);
+            g = premul_alpha(g, a);
+            b = premul_alpha(b, a);
+            ASSEMBLE_ARGB32(pxout, a,r,g,b);
+            return pxout;
+        } else {
+            guint32 r = CLAMP_D_TO_U8((turbulence(0, p)*255.0 + 255.0) / 2);
+            guint32 g = CLAMP_D_TO_U8((turbulence(1, p)*255.0 + 255.0) / 2);
+            guint32 b = CLAMP_D_TO_U8((turbulence(2, p)*255.0 + 255.0) / 2);
+            guint32 a = CLAMP_D_TO_U8((turbulence(3, p)*255.0 + 255.0) / 2);
+            r = premul_alpha(r, a);
+            g = premul_alpha(g, a);
+            b = premul_alpha(b, a);
+            ASSEMBLE_ARGB32(pxout, a,r,g,b);
+            return pxout;
+        }
+    }*/
+
+    bool ready() const { return _inited; }
+    void dirty() { _inited = false; }
+
+private:
+    void _setupSeed(long seed)
+    {
+        _seed = seed;
+        if (_seed <= 0) _seed = -(_seed % (RAND_m - 1)) + 1;
+        if (_seed > RAND_m - 1) _seed = RAND_m - 1;
+    }
+
+    long _random()
+    {
+        /* Produces results in the range [1, 2**31 - 2].
+         * Algorithm is: r = (a * r) mod m
+         * where a = 16807 and m = 2**31 - 1 = 2147483647
+         * See [Park & Miller], CACM vol. 31 no. 10 p. 1195, Oct. 1988
+         * To test: the algorithm should produce the result 1043618065
+         * as the 10,000th generated number if the original seed is 1. */
+        _seed = RAND_a * (_seed % RAND_q) - RAND_r * (_seed / RAND_q);
+        if (_seed <= 0) _seed += RAND_m;
+        return _seed;
+    }
+
+    static inline double _scurve(double t)
+    {
+        return t * t * (3.0 - 2.0 * t);
+    }
+
+    static inline double _lerp(double t, double a, double b)
+    {
+        return a + t * (b - a);
+    }
+
+    // random number generator constants
+    static long constexpr
+        RAND_m = 2147483647, // 2**31 - 1
+        RAND_a = 16807, // 7**5; primitive root of m
+        RAND_q = 127773, // m / a
+        RAND_r = 2836; // m % a
+
+    // other constants
+    static int constexpr BSize = 0x100;
+    static int constexpr BMask = 0xff;
+
+    static double constexpr PerlinOffset = 4096.0;
+
+    Geom::Rect _tile;
+    Geom::Point _baseFreq;
+    int _latticeSelector[2 * BSize + 2];
+    double _gradient[2 * BSize + 2][4][2];
+    long _seed;
+    int _octaves;
+    bool _stitchTiles;
+    int _wrapx;
+    int _wrapy;
+    int _wrapw;
+    int _wraph;
+    bool _inited;
+    bool _fractalnoise;
+};
+
+FilterTurbulence::FilterTurbulence()
+    : gen(std::make_unique<TurbulenceGenerator>())
+    , XbaseFrequency(0)
+    , YbaseFrequency(0)
+    , numOctaves(1)
+    , seed(0)
+    , updated(false)
+    , fTileWidth(10) //guessed
+    , fTileHeight(10) //guessed
+    , fTileX(1) //guessed
+    , fTileY(1) //guessed
+{
+}
+
+FilterTurbulence::~FilterTurbulence() = default;
+
+void FilterTurbulence::set_baseFrequency(int axis, double freq)
+{
+    if (axis == 0) XbaseFrequency = freq;
+    if (axis == 1) YbaseFrequency = freq;
+    gen->dirty();
+}
+
+void FilterTurbulence::set_numOctaves(int num)
+{
+    numOctaves = num;
+    gen->dirty();
+}
+
+void FilterTurbulence::set_seed(double s)
+{
+    seed = s;
+    gen->dirty();
+}
+
+void FilterTurbulence::set_stitchTiles(bool st)\
+{
+    stitchTiles = st;
+    gen->dirty();
+}
+
+void FilterTurbulence::set_type(FilterTurbulenceType t)
+{
+    type = t;
+    gen->dirty();
+}
+
+void FilterTurbulence::set_updated(bool /*u*/)
+{
+}
+
+struct Turbulence
+{
+    Turbulence(TurbulenceGenerator const &gen, Geom::Affine const &trans, int x0, int y0)
+        : _gen(gen)
+        , _trans(trans)
+        , _x0(x0), _y0(y0) {}
+
+    guint32 operator()(int x, int y)
+    {
+        Geom::Point point(x + _x0, y + _y0);
+        point *= _trans;
+        return _gen.turbulencePixel(point);
+    }
+
+private:
+    TurbulenceGenerator const &_gen;
+    Geom::Affine _trans;
+    int _x0, _y0;
+};
+
+void FilterTurbulence::render_cairo(FilterSlot &slot) const
+{
+    cairo_surface_t *input = slot.getcairo(_input);
+    cairo_surface_t *out = ink_cairo_surface_create_same_size(input, CAIRO_CONTENT_COLOR_ALPHA);
+
+    // It is probably possible to render at a device scale greater than one
+    // but for the moment rendering at a device scale of one is the easiest.
+    // cairo_image_surface_get_width() returns width in pixels but
+    // cairo_surface_create_similar() requires width in device units so divide by device scale.
+    // We are rendering at a device scale of 1... so divide by device scale again!
+    double x_scale = 0;
+    double y_scale = 0;
+    cairo_surface_get_device_scale(input, &x_scale, &y_scale);
+    int width  = ceil(cairo_image_surface_get_width( input)/x_scale/x_scale);
+    int height = ceil(cairo_image_surface_get_height(input)/y_scale/y_scale);
+    cairo_surface_t *temp = cairo_surface_create_similar (input, CAIRO_CONTENT_COLOR_ALPHA, width, height);
+    cairo_surface_set_device_scale( temp, 1, 1 );
+
+    // color_interpolation_filter is determined by CSS value (see spec. Turbulence).
+    set_cairo_surface_ci(out, color_interpolation);
+
+    if (!gen->ready()) {
+        Geom::Point ta(fTileX, fTileY);
+        Geom::Point tb(fTileX + fTileWidth, fTileY + fTileHeight);
+        gen->init(seed, Geom::Rect(ta, tb),
+                  Geom::Point(XbaseFrequency, YbaseFrequency), stitchTiles,
+                  type == TURBULENCE_FRACTALNOISE, numOctaves);
+    }
+
+    Geom::Affine unit_trans = slot.get_units().get_matrix_primitiveunits2pb().inverse();
+    Geom::Rect slot_area = slot.get_slot_area();
+    double x0 = slot_area.min()[Geom::X];
+    double y0 = slot_area.min()[Geom::Y];
+    ink_cairo_surface_synthesize(temp, Turbulence(*gen, unit_trans, x0, y0));
+
+    // cairo_surface_write_to_png( temp, "turbulence0.png" );
+
+    cairo_t *ct = cairo_create(out);
+    cairo_set_source_surface(ct, temp, 0, 0);
+    cairo_paint(ct);
+    cairo_destroy(ct);
+
+    cairo_surface_destroy(temp);
+
+    cairo_surface_mark_dirty(out);
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
+double FilterTurbulence::complexity(Geom::Affine const &) const
+{
+    return 5.0;
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-turbulence.h b/src/display/nr-filter-turbulence.h
new file mode 100644
index 0000000..37decc9
--- /dev/null
+++ b/src/display/nr-filter-turbulence.h
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_TURBULENCE_H
+#define SEEN_NR_FILTER_TURBULENCE_H
+
+/*
+ * feTurbulence filter primitive renderer
+ *
+ * Authors:
+ *   World Wide Web Consortium <http://www.w3.org/>
+ *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * This file has a considerable amount of code adapted from
+ *  the W3C SVG filter specs, available at:
+ *  http://www.w3.org/TR/SVG11/filters.html#feTurbulence
+ *
+ * W3C original code is licensed under the terms of
+ *  the (GPL compatible) W3C® SOFTWARE NOTICE AND LICENSE:
+ *  http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231
+ *
+ * Copyright (C) 2007 authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <memory>
+#include <2geom/point.h>
+
+#include "display/nr-filter-primitive.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-units.h"
+
+namespace Inkscape {
+namespace Filters {
+
+enum FilterTurbulenceType
+{
+    TURBULENCE_FRACTALNOISE,
+    TURBULENCE_TURBULENCE,
+    TURBULENCE_ENDTYPE
+};
+
+class TurbulenceGenerator;
+
+class FilterTurbulence : public FilterPrimitive
+{
+public:
+    FilterTurbulence();
+    ~FilterTurbulence() override;
+
+    void render_cairo(FilterSlot &slot) const override;
+    double complexity(Geom::Affine const &ctm) const override;
+    bool uses_background() const override { return false; }
+
+    void set_baseFrequency(int axis, double freq);
+    void set_numOctaves(int num);
+    void set_seed(double s);
+    void set_stitchTiles(bool st);
+    void set_type(FilterTurbulenceType t);
+    void set_updated(bool u);
+
+    Glib::ustring name() const override { return Glib::ustring("Turbulence"); }
+
+private:
+    std::unique_ptr<TurbulenceGenerator> gen;
+
+    void turbulenceInit(long seed);
+
+    double XbaseFrequency, YbaseFrequency;
+    int numOctaves;
+    double seed;
+    bool stitchTiles;
+    FilterTurbulenceType type;
+    bool updated;
+
+    double fTileWidth;
+    double fTileHeight;
+
+    double fTileX;
+    double fTileY;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_TURBULENCE_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-types.h b/src/display/nr-filter-types.h
new file mode 100644
index 0000000..41112c5
--- /dev/null
+++ b/src/display/nr-filter-types.h
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * TODO: insert short description here
+ *//*
+ * Authors: see git history
+ *
+ * Copyright (C) 2014 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+#ifndef SEEN_NR_FILTER_TYPES_H
+#define SEEN_NR_FILTER_TYPES_H
+
+namespace Inkscape {
+namespace Filters {
+
+enum FilterPrimitiveType
+{
+    NR_FILTER_BLEND,
+    NR_FILTER_COLORMATRIX,
+    NR_FILTER_COMPONENTTRANSFER,
+    NR_FILTER_COMPOSITE,
+    NR_FILTER_CONVOLVEMATRIX,
+    NR_FILTER_DIFFUSELIGHTING,
+    NR_FILTER_DISPLACEMENTMAP,
+    NR_FILTER_FLOOD,
+    NR_FILTER_GAUSSIANBLUR,
+    NR_FILTER_IMAGE,
+    NR_FILTER_MERGE,
+    NR_FILTER_MORPHOLOGY,
+    NR_FILTER_OFFSET,
+    NR_FILTER_SPECULARLIGHTING,
+    NR_FILTER_TILE,
+    NR_FILTER_TURBULENCE,
+    NR_FILTER_ENDPRIMITIVETYPE // This must be last
+};
+
+enum FilterSlotType
+{
+    NR_FILTER_SLOT_NOT_SET = -1,
+    NR_FILTER_SOURCEGRAPHIC = -2,
+    NR_FILTER_SOURCEALPHA = -3,
+    NR_FILTER_BACKGROUNDIMAGE = -4,
+    NR_FILTER_BACKGROUNDALPHA = -5,
+    NR_FILTER_FILLPAINT = -6,
+    NR_FILTER_STROKEPAINT = -7,
+    NR_FILTER_UNNAMED_SLOT = -8
+};
+/* Unnamed slot is for Inkscape::Filters::FilterSlot internal use. Passing it as
+ * parameter to Inkscape::Filters::FilterSlot accessors may have unforeseen consequences. */
+
+enum FilterQuality
+{
+    FILTER_QUALITY_BEST = 2,
+    FILTER_QUALITY_BETTER = 1,
+    FILTER_QUALITY_NORMAL = 0,
+    FILTER_QUALITY_WORSE = -1,
+    FILTER_QUALITY_WORST = -2
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_FILTER_TYPES_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-units.cpp b/src/display/nr-filter-units.cpp
new file mode 100644
index 0000000..7fdf936
--- /dev/null
+++ b/src/display/nr-filter-units.cpp
@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Utilities for handling coordinate system transformations in filters
+ *
+ * Author:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2007 Niko Kiirala
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <glib.h>
+
+#include "display/nr-filter-units.h"
+#include "object/sp-filter-units.h"
+#include <2geom/transforms.h>
+
+using Geom::X;
+using Geom::Y;
+
+namespace Inkscape {
+namespace Filters {
+
+FilterUnits::FilterUnits() :
+    filterUnits(SP_FILTER_UNITS_OBJECTBOUNDINGBOX),
+    primitiveUnits(SP_FILTER_UNITS_USERSPACEONUSE),
+    resolution_x(-1), resolution_y(-1),
+    paraller_axis(false), automatic_resolution(true)
+{}
+
+FilterUnits::FilterUnits(SPFilterUnits const filterUnits, SPFilterUnits const primitiveUnits) :
+    filterUnits(filterUnits), primitiveUnits(primitiveUnits),
+    resolution_x(-1), resolution_y(-1),
+    paraller_axis(false), automatic_resolution(true)
+{}
+
+void FilterUnits::set_ctm(Geom::Affine const &ctm) {
+    this->ctm = ctm;
+}
+
+void FilterUnits::set_resolution(double const x_res, double const y_res) {
+    g_assert(x_res > 0);
+    g_assert(y_res > 0);
+
+    resolution_x = x_res;
+    resolution_y = y_res;
+}
+
+void FilterUnits::set_item_bbox(Geom::OptRect const &bbox) {
+    item_bbox = bbox;
+}
+
+void FilterUnits::set_filter_area(Geom::OptRect const &area) {
+    filter_area = area;
+}
+
+void FilterUnits::set_paraller(bool const paraller) {
+    paraller_axis = paraller;
+}
+
+void FilterUnits::set_automatic_resolution(bool const automatic) {
+    automatic_resolution = automatic;
+}
+
+Geom::Affine FilterUnits::get_matrix_user2pb() const {
+    g_assert(resolution_x > 0);
+    g_assert(resolution_y > 0);
+    g_assert(filter_area);
+
+    Geom::Affine u2pb = ctm;
+
+    if (paraller_axis || !automatic_resolution) {
+        u2pb[0] = resolution_x / filter_area->width();
+        u2pb[1] = 0;
+        u2pb[2] = 0;
+        u2pb[3] = resolution_y / filter_area->height();
+        u2pb[4] = ctm[4];
+        u2pb[5] = ctm[5];
+    }
+
+    return u2pb;
+}
+
+Geom::Affine FilterUnits::get_matrix_units2pb(SPFilterUnits units) const {
+    if ( item_bbox && (units == SP_FILTER_UNITS_OBJECTBOUNDINGBOX) ) {
+
+        Geom::Affine u2pb = get_matrix_user2pb();
+
+        /* TODO: make sure that user coordinate system (0,0) is in correct
+         * place in pixblock coordinates */
+        Geom::Scale scaling(item_bbox->width(), item_bbox->height());
+        u2pb *= scaling;
+        return u2pb;
+
+    } else if (units == SP_FILTER_UNITS_USERSPACEONUSE) {
+        return get_matrix_user2pb();
+    } else {
+        g_warning("Error in Inkscape::Filters::FilterUnits::get_matrix_units2pb: unrecognized unit type (%d)", units);
+        return Geom::Affine();
+    }
+}
+
+Geom::Affine FilterUnits::get_matrix_filterunits2pb() const {
+    return get_matrix_units2pb(filterUnits);
+}
+
+Geom::Affine FilterUnits::get_matrix_primitiveunits2pb() const {
+    return get_matrix_units2pb(primitiveUnits);
+}
+
+Geom::Affine FilterUnits::get_matrix_display2pb() const {
+    Geom::Affine d2pb = ctm.inverse();
+    d2pb *= get_matrix_user2pb();
+    return d2pb;
+}
+
+Geom::Affine FilterUnits::get_matrix_pb2display() const {
+    Geom::Affine pb2d = get_matrix_user2pb().inverse();
+    pb2d *= ctm;
+    return pb2d;
+}
+
+Geom::Affine FilterUnits::get_matrix_user2units(SPFilterUnits units) const {
+    if (item_bbox && units == SP_FILTER_UNITS_OBJECTBOUNDINGBOX) {
+        /* No need to worry about rotations: bounding box coordinates
+         * always have base vectors paraller with userspace coordinates */
+        Geom::Point min(item_bbox->min());
+        Geom::Point max(item_bbox->max());
+        double scale_x = 1.0 / (max[X] - min[X]);
+        double scale_y = 1.0 / (max[Y] - min[Y]);
+        //return Geom::Translate(min) * Geom::Scale(scale_x,scale_y); ?
+        return Geom::Affine(scale_x, 0,
+                            0, scale_y,
+                            min[X] * scale_x, min[Y] * scale_y);
+    } else if (units == SP_FILTER_UNITS_USERSPACEONUSE) {
+        return Geom::identity();
+    } else {
+        g_warning("Error in Inkscape::Filters::FilterUnits::get_matrix_user2units: unrecognized unit type (%d)", units);
+        return Geom::Affine();
+    }
+}
+
+Geom::Affine FilterUnits::get_matrix_user2filterunits() const {
+    return get_matrix_user2units(filterUnits);
+}
+
+Geom::Affine FilterUnits::get_matrix_user2primitiveunits() const {
+    return get_matrix_user2units(primitiveUnits);
+}
+
+Geom::IntRect FilterUnits::get_pixblock_filterarea_paraller() const {
+    g_assert(filter_area);
+
+    Geom::Affine u2pb = get_matrix_user2pb();
+    Geom::Rect r = *filter_area * u2pb;
+    Geom::IntRect ir = r.roundOutwards();
+    return ir;
+}
+
+FilterUnits& FilterUnits::operator=(FilterUnits const &other) = default;
+
+} /* namespace Filters */
+} /* namespace Inkscape */
+
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-units.h b/src/display/nr-filter-units.h
new file mode 100644
index 0000000..3c2cd9c
--- /dev/null
+++ b/src/display/nr-filter-units.h
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_UNITS_H
+#define SEEN_NR_FILTER_UNITS_H
+
+/*
+ * Utilities for handling coordinate system transformations in filters
+ *
+ * Author:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2007 Niko Kiirala
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "object/sp-filter-units.h"
+#include <2geom/affine.h>
+#include <2geom/rect.h>
+
+namespace Inkscape {
+namespace Filters {
+
+/* Notes:
+ * - "filter units" is a coordinate system where the filter region is contained
+ *   between (0,0) and (1,1). Do not confuse this with the filterUnits property
+ * - "primitive units" is the coordinate system in which all lengths and distances
+ *   in the filter definition should be interpreted. They are affected by the value
+ *   of the primitiveUnits attribute
+ * - "pb" is the coordinate system in which filter rendering happens.
+ *   It might be aligned with user or screen coordinates depending on
+ *   the filter primitives used in the filter.
+ * - "display" are world coordinates of the canvas - pixel grid coordinates
+ *   of the drawing area translated so that (0,0) corresponds to the document origin
+ */
+class FilterUnits {
+public:
+    FilterUnits();
+    FilterUnits(SPFilterUnits const filterUnits, SPFilterUnits const primitiveUnits);
+
+    /**
+     * Sets the current transformation matrix, i.e. transformation matrix
+     * from object's user coordinates to screen coordinates
+     */
+    void set_ctm(Geom::Affine const &ctm);
+
+    /**
+     * Sets the resolution, the filter should be rendered with.
+     */
+    void set_resolution(double const x_res, double const y_res);
+
+    /**
+     * Sets the item bounding box in user coordinates
+     */
+    void set_item_bbox(Geom::OptRect const &bbox);
+
+    /**
+     * Sets the filter effects area in user coordinates
+     */
+    void set_filter_area(Geom::OptRect const &area);
+
+    /**
+     * Sets, if x and y axis in pixblock coordinates should be paraller
+     * to x and y of user coordinates.
+     */
+    void set_paraller(bool const paraller);
+
+    /**
+     * Sets, if filter resolution is automatic.
+     * NOTE: even if resolution is automatic, it must be set with
+     * set_resolution. This only tells, if the set value is automatic.
+     */
+    void set_automatic_resolution(bool const automatic);
+
+    /**
+     * Gets the item bounding box in user coordinates
+     */
+    Geom::OptRect get_item_bbox() const { return item_bbox; };
+
+    /**
+     * Gets the filter effects area in user coordinates
+     */
+    Geom::OptRect get_filter_area() const { return filter_area; };
+
+    /**
+     * Gets Filter Units (userSpaceOnUse or objectBoundingBox)
+     */
+    SPFilterUnits get_filter_units() const { return filterUnits; };
+
+    /**
+     * Gets Primitive Units (userSpaceOnUse or objectBoundingBox)
+     */
+    SPFilterUnits get_primitive_units() const { return primitiveUnits; };
+
+    /**
+     * Gets the user coordinates to pixblock coordinates transformation matrix.
+     */
+    Geom::Affine get_matrix_user2pb() const;
+
+    /**
+     * Gets the filterUnits to pixblock coordinates transformation matrix.
+     */
+    Geom::Affine get_matrix_filterunits2pb() const;
+
+    /**
+     * Gets the primitiveUnits to pixblock coordinates transformation matrix.
+     */
+    Geom::Affine get_matrix_primitiveunits2pb() const;
+
+    /**
+     * Gets the display coordinates to pixblock coordinates transformation
+     * matrix.
+     */
+    Geom::Affine get_matrix_display2pb() const;
+
+    /**
+     * Gets the pixblock coordinates to display coordinates transformation
+     * matrix
+     */
+    Geom::Affine get_matrix_pb2display() const;
+
+    /**
+     * Gets the user coordinates to filterUnits transformation matrix.
+     */
+    Geom::Affine get_matrix_user2filterunits() const;
+
+    /**
+     * Gets the user coordinates to primitiveUnits transformation matrix.
+     */
+    Geom::Affine get_matrix_user2primitiveunits() const;
+
+    /**
+     * Returns the filter area in pixblock coordinates.
+     * NOTE: use only in filters, that define TRAIT_PARALLER in
+     * get_input_traits. The filter effects area may not be representable
+     * by simple rectangle otherwise. */
+    Geom::IntRect get_pixblock_filterarea_paraller() const;
+
+    FilterUnits& operator=(FilterUnits const &other);
+
+private:
+    Geom::Affine get_matrix_units2pb(SPFilterUnits units) const;
+    Geom::Affine get_matrix_user2units(SPFilterUnits units) const;
+
+    SPFilterUnits filterUnits, primitiveUnits;
+    double resolution_x, resolution_y;
+    bool paraller_axis;
+    bool automatic_resolution;
+    Geom::Affine ctm;
+    Geom::OptRect item_bbox;
+    Geom::OptRect filter_area;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif /* __NR_FILTER_UNITS_H__ */
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter-utils.h b/src/display/nr-filter-utils.h
new file mode 100644
index 0000000..0e7612d
--- /dev/null
+++ b/src/display/nr-filter-utils.h
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_NR_FILTER_UTILS_H
+#define SEEN_NR_FILTER_UTILS_H
+
+/**
+ * @file
+ * Definition of functions needed by several filters.
+ */
+/*
+ * Authors:
+ *   Jean-Rene Reinhard <jr@komite.net>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+namespace Inkscape {
+namespace Filters {
+
+/**
+ * Clamps an integer value to a value between 0 and 255. Needed by filters where
+ * rendering computations can lead to component values out of bound.
+ *
+ * \return 0 if the value is smaller than 0, 255 if it is greater 255, else v
+ * \param v the value to clamp
+ */
+inline int clamp(int const val) {
+    if (val < 0) return 0;
+    if (val > 255) return 255;
+    return val;
+}
+
+/**
+ * Clamps an integer value to a value between 0 and 255^3.
+ *
+ * \return 0 if the value is smaller than 0, 255^3 (16581375) if it is greater than 255^3, else v
+ * \param v the value to clamp
+ */
+inline int clamp3(int const val) {
+    if (val < 0) return 0;
+    if (val > 16581375) return 16581375;
+    return val;
+}
+
+/**
+ * Macro to use the clamp function with double inputs and unsigned char output
+ */
+#define CLAMP_D_TO_U8(v) (unsigned char) clamp((int)round((v)))
+
+/**
+ * Clamps an integer to a value between 0 and alpha. Useful when handling
+ * images with premultiplied alpha, as setting some of RGB channels
+ * to a value bigger than alpha confuses the alpha blending in Inkscape
+ * \return 0 if val is negative, alpha if val is bigger than alpha, val otherwise
+ * \param val the value to clamp
+ * \param alpha the maximum value to clamp to
+ */
+inline int clamp_alpha(int const val, int const alpha) {
+    if (val < 0) return 0;
+    if (val > alpha) return alpha;
+    return val;
+}
+
+/**
+ * Macro to use the clamp function with double inputs and unsigned char output
+ */
+#define CLAMP_D_TO_U8_ALPHA(v,a) (unsigned char) clamp_alpha((int)round((v)),(a))
+
+} /* namespace Filters */
+} /* namespace Inkscape */
+
+#endif /* __NR_FILTER_UTILS_H__ */
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter.cpp b/src/display/nr-filter.cpp
new file mode 100644
index 0000000..e776cce
--- /dev/null
+++ b/src/display/nr-filter.cpp
@@ -0,0 +1,420 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * SVG filters rendering
+ *
+ * Author:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2006-2008 Niko Kiirala
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <glib.h>
+#include <cmath>
+#include <cstring>
+#include <string>
+#include <cairo.h>
+
+#include "display/nr-filter.h"
+#include "display/nr-filter-primitive.h"
+#include "display/nr-filter-slot.h"
+#include "display/nr-filter-types.h"
+#include "display/nr-filter-units.h"
+
+#include "display/nr-filter-blend.h"
+#include "display/nr-filter-composite.h"
+#include "display/nr-filter-convolve-matrix.h"
+#include "display/nr-filter-colormatrix.h"
+#include "display/nr-filter-component-transfer.h"
+#include "display/nr-filter-diffuselighting.h"
+#include "display/nr-filter-displacement-map.h"
+#include "display/nr-filter-image.h"
+#include "display/nr-filter-flood.h"
+#include "display/nr-filter-gaussian.h"
+#include "display/nr-filter-merge.h"
+#include "display/nr-filter-morphology.h"
+#include "display/nr-filter-offset.h"
+#include "display/nr-filter-specularlighting.h"
+#include "display/nr-filter-tile.h"
+#include "display/nr-filter-turbulence.h"
+
+#include "display/cairo-utils.h"
+#include "display/drawing.h"
+#include "display/drawing-item.h"
+#include "display/drawing-context.h"
+#include "display/drawing-surface.h"
+#include <2geom/affine.h>
+#include <2geom/rect.h>
+#include "svg/svg-length.h"
+//#include "sp-filter-units.h"
+
+namespace Inkscape {
+namespace Filters {
+
+using Geom::X;
+using Geom::Y;
+
+Filter::Filter()
+{
+    _common_init();
+}
+
+Filter::Filter(int n)
+{
+    if (n > 0) primitives.reserve(n);
+    _common_init();
+}
+
+void Filter::_common_init()
+{
+    _slot_count = 1;
+    // Having "not set" here as value means the output of last filter
+    // primitive will be used as output of this filter
+    _output_slot = NR_FILTER_SLOT_NOT_SET;
+
+    // These are the default values for filter region,
+    // as specified in SVG standard
+    // NB: SVGLength.set takes prescaled percent values: -.10 means -10%
+    _region_x.set(SVGLength::PERCENT, -.10, 0);
+    _region_y.set(SVGLength::PERCENT, -.10, 0);
+    _region_width.set(SVGLength::PERCENT, 1.20, 0);
+    _region_height.set(SVGLength::PERCENT, 1.20, 0);
+
+    // Filter resolution, negative value here stands for "automatic"
+    _x_pixels = -1.0;
+    _y_pixels = -1.0;
+
+    _filter_units = SP_FILTER_UNITS_OBJECTBOUNDINGBOX;
+    _primitive_units = SP_FILTER_UNITS_USERSPACEONUSE;
+}
+
+void Filter::update()
+{
+    for (auto &p : primitives) {
+        p->update();
+    }
+}
+
+int Filter::render(Inkscape::DrawingItem const *item, DrawingContext &graphic, DrawingContext *bgdc, RenderContext &rc) const
+{
+    // std::cout << "Filter::render() for: " << const_cast<Inkscape::DrawingItem *>(item)->name() << std::endl;
+    // std::cout << "  graphic drawing_scale: " << graphic.surface()->device_scale() << std::endl;
+
+    if (primitives.empty()) {
+        // when no primitives are defined, clear source graphic
+        graphic.setSource(0,0,0,0);
+        graphic.setOperator(CAIRO_OPERATOR_SOURCE);
+        graphic.paint();
+        graphic.setOperator(CAIRO_OPERATOR_OVER);
+        return 1;
+    }
+    FilterQuality filterquality = (FilterQuality)item->drawing().filterQuality();
+    int blurquality = item->drawing().blurQuality();
+
+    Geom::Affine trans = item->ctm();
+
+    Geom::OptRect filter_area = filter_effect_area(item->itemBounds());
+    if (!filter_area) return 1;
+
+    FilterUnits units(_filter_units, _primitive_units);
+    units.set_ctm(trans);
+    units.set_item_bbox(item->itemBounds());
+    units.set_filter_area(*filter_area);
+
+    auto resolution = _filter_resolution(*filter_area, trans, filterquality);
+    if (!(resolution.first > 0 && resolution.second > 0)) {
+        // zero resolution - clear source graphic and return
+        graphic.setSource(0,0,0,0);
+        graphic.setOperator(CAIRO_OPERATOR_SOURCE);
+        graphic.paint();
+        graphic.setOperator(CAIRO_OPERATOR_OVER);
+        return 1;
+    }
+
+    units.set_resolution(resolution.first, resolution.second);
+    if (_x_pixels > 0) {
+        units.set_automatic_resolution(false);
+    }
+    else {
+        units.set_automatic_resolution(true);
+    }
+
+    units.set_paraller(false);
+    Geom::Affine pbtrans = units.get_matrix_display2pb();
+    for (auto &i : primitives) {
+        if (!i->can_handle_affine(pbtrans)) {
+            units.set_paraller(true);
+            break;
+        }
+    }
+
+    auto slot = FilterSlot(bgdc, graphic, units, rc, blurquality);
+
+    for (auto &i : primitives) {
+        i->render_cairo(slot);
+    }
+
+    Geom::Point origin = graphic.targetLogicalBounds().min();
+    cairo_surface_t *result = slot.get_result(_output_slot);
+
+    // Assume for the moment that we paint the filter in sRGB
+    set_cairo_surface_ci(result, SP_CSS_COLOR_INTERPOLATION_SRGB);
+
+    graphic.setSource(result, origin[Geom::X], origin[Geom::Y]);
+    graphic.setOperator(CAIRO_OPERATOR_SOURCE);
+    graphic.paint();
+    graphic.setOperator(CAIRO_OPERATOR_OVER);
+    cairo_surface_destroy(result);
+
+    return 0;
+}
+
+void Filter::add_primitive(std::unique_ptr<FilterPrimitive> primitive)
+{
+    primitives.emplace_back(std::move(primitive));
+}
+
+void Filter::set_filter_units(SPFilterUnits unit)
+{
+    _filter_units = unit;
+}
+
+void Filter::set_primitive_units(SPFilterUnits unit)
+{
+    _primitive_units = unit;
+}
+
+void Filter::area_enlarge(Geom::IntRect &bbox, Inkscape::DrawingItem const *item) const
+{
+    for (auto const &i : primitives) {
+        if (i) i->area_enlarge(bbox, item->ctm());
+    }
+
+/*
+  TODO: something. See images at the bottom of filters.svg with medium-low
+  filtering quality.
+
+    FilterQuality const filterquality = ...
+
+    if (_x_pixels <= 0 && (filterquality == FILTER_QUALITY_BEST ||
+                           filterquality == FILTER_QUALITY_BETTER)) {
+        return;
+    }
+
+    Geom::Rect item_bbox;
+    Geom::OptRect maybe_bbox = item->itemBounds();
+    if (maybe_bbox.empty()) {
+        // Code below needs a bounding box
+        return;
+    }
+    item_bbox = *maybe_bbox;
+
+    std::pair<double,double> res_low
+        = _filter_resolution(item_bbox, item->ctm(), filterquality);
+    //std::pair<double,double> res_full
+    //    = _filter_resolution(item_bbox, item->ctm(), FILTER_QUALITY_BEST);
+    double pixels_per_block = fmax(item_bbox.width() / res_low.first,
+                                   item_bbox.height() / res_low.second);
+    bbox.x0 -= (int)pixels_per_block;
+    bbox.x1 += (int)pixels_per_block;
+    bbox.y0 -= (int)pixels_per_block;
+    bbox.y1 += (int)pixels_per_block;
+*/
+}
+
+Geom::OptRect Filter::filter_effect_area(Geom::OptRect const &bbox) const
+{
+    Geom::Point minp, maxp;
+
+    if (_filter_units == SP_FILTER_UNITS_OBJECTBOUNDINGBOX) {
+        double len_x = bbox ? bbox->width() : 0;
+        double len_y = bbox ? bbox->height() : 0;
+        /* TODO: fetch somehow the object ex and em lengths */
+
+        // Update for em, ex, and % values
+        auto compute = [] (SVGLength length, double scale) {
+            length.update(12, 6, scale);
+            return length.computed;
+        };
+        auto const region_x_computed = compute(_region_x, len_x);
+        auto const region_y_computed = compute(_region_y, len_y);
+        auto const region_w_computed = compute(_region_width, len_x);
+        auto const region_h_computed = compute(_region_height, len_y);;
+
+        if (!bbox) return Geom::OptRect();
+
+        if (_region_x.unit == SVGLength::PERCENT) {
+            minp[X] = bbox->left() + region_x_computed;
+        } else {
+            minp[X] = bbox->left() + region_x_computed * len_x;
+        }
+        if (_region_width.unit == SVGLength::PERCENT) {
+            maxp[X] = minp[X] + region_w_computed;
+        } else {
+            maxp[X] = minp[X] + region_w_computed * len_x;
+        }
+
+        if (_region_y.unit == SVGLength::PERCENT) {
+            minp[Y] = bbox->top() + region_y_computed;
+        } else {
+            minp[Y] = bbox->top() + region_y_computed * len_y;
+        }
+        if (_region_height.unit == SVGLength::PERCENT) {
+            maxp[Y] = minp[Y] + region_h_computed;
+        } else {
+            maxp[Y] = minp[Y] + region_h_computed * len_y;
+        }
+    } else if (_filter_units == SP_FILTER_UNITS_USERSPACEONUSE) {
+        // Region already set in sp-filter.cpp
+        minp[X] = _region_x.computed;
+        maxp[X] = minp[X] + _region_width.computed;
+        minp[Y] = _region_y.computed;
+        maxp[Y] = minp[Y] + _region_height.computed;
+    } else {
+        g_warning("Error in Inkscape::Filters::Filter::filter_effect_area: unrecognized value of _filter_units");
+    }
+
+    Geom::OptRect area(minp, maxp);
+    // std::cout << "Filter::filter_effect_area: area: " << *area << std::endl;
+    return area;
+}
+
+double Filter::complexity(Geom::Affine const &ctm) const
+{
+    double factor = 1.0;
+    for (auto &i : primitives) {
+        if (i) {
+            double f = i->complexity(ctm);
+            factor += f - 1.0;
+        }
+    }
+    return factor;
+}
+
+bool Filter::uses_background() const
+{
+    for (auto &i : primitives) {
+        if (i && i->uses_background()) {
+            return true;
+        }
+    }
+    return false;
+}
+
+void Filter::clear_primitives()
+{
+    primitives.clear();
+}
+
+void Filter::set_x(SVGLength const &length)
+{
+  if (length._set)
+      _region_x = length;
+}
+
+void Filter::set_y(SVGLength const &length)
+{
+  if (length._set)
+      _region_y = length;
+}
+
+void Filter::set_width(SVGLength const &length)
+{
+  if (length._set)
+      _region_width = length;
+}
+
+void Filter::set_height(SVGLength const &length)
+{
+  if (length._set)
+      _region_height = length;
+}
+
+void Filter::set_resolution(double pixels)
+{
+    if (pixels > 0) {
+        _x_pixels = pixels;
+        _y_pixels = pixels;
+    }
+}
+
+void Filter::set_resolution(double x_pixels, double y_pixels)
+{
+    if (x_pixels >= 0 && y_pixels >= 0) {
+        _x_pixels = x_pixels;
+        _y_pixels = y_pixels;
+    }
+}
+
+void Filter::reset_resolution()
+{
+    _x_pixels = -1;
+    _y_pixels = -1;
+}
+
+int Filter::_resolution_limit(FilterQuality quality)
+{
+    switch (quality) {
+        case FILTER_QUALITY_WORST:
+            return 32;
+        case FILTER_QUALITY_WORSE:
+            return 64;
+        case FILTER_QUALITY_NORMAL:
+            return 256;
+        case FILTER_QUALITY_BETTER:
+        case FILTER_QUALITY_BEST:
+        default:
+            return -1;
+    }
+}
+
+std::pair<double, double> Filter::_filter_resolution(Geom::Rect const &area, Geom::Affine const &trans, FilterQuality filterquality) const
+{
+    std::pair<double, double> resolution;
+    if (_x_pixels > 0) {
+        double y_len;
+        if (_y_pixels > 0) {
+            y_len = _y_pixels;
+        } else {
+            y_len = (_x_pixels * (area.max()[Y] - area.min()[Y])) / (area.max()[X] - area.min()[X]);
+        }
+        resolution.first = _x_pixels;
+        resolution.second = y_len;
+    } else {
+        auto origo = area.min() * trans;
+        auto max_i = Geom::Point(area.max()[X], area.min()[Y]) * trans;
+        auto max_j = Geom::Point(area.min()[X], area.max()[Y]) * trans;
+        double i_len = (origo - max_i).length();
+        double j_len = (origo - max_j).length();
+        int limit = _resolution_limit(filterquality);
+        if (limit > 0 && (i_len > limit || j_len > limit)) {
+            double aspect_ratio = i_len / j_len;
+            if (i_len > j_len) {
+                i_len = limit;
+                j_len = i_len / aspect_ratio;
+            }
+            else {
+                j_len = limit;
+                i_len = j_len * aspect_ratio;
+            }
+        }
+        resolution.first = i_len;
+        resolution.second = j_len;
+    }
+    return resolution;
+}
+
+} // namespace Filters
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-filter.h b/src/display/nr-filter.h
new file mode 100644
index 0000000..a8787b2
--- /dev/null
+++ b/src/display/nr-filter.h
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef INKSCAPE_DISPLAY_NR_FILTER_H
+#define INKSCAPE_DISPLAY_NR_FILTER_H
+
+/*
+ * SVG filters rendering
+ *
+ * Author:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2006 Niko Kiirala
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <memory>
+#include <cairo.h>
+#include "display/nr-filter-primitive.h"
+#include "display/nr-filter-types.h"
+#include "svg/svg-length.h"
+#include "object/sp-filter-units.h"
+
+namespace Inkscape {
+class DrawingContext;
+class DrawingItem;
+class RenderContext;
+
+namespace Filters {
+
+class Filter final
+{
+public:
+    /// Update any embedded DrawingItems prior to rendering.
+    void update();
+
+    /** Given background state from @a bgdc and an intermediate rendering from the surface
+     * backing @a graphic, modify the contents of the surface backing @a graphic to represent
+     * the results of filter rendering. @a bgarea and @a area specify bounding boxes
+     * of both surfaces in world coordinates; Cairo contexts are assumed to be in default state
+     * (0,0 = surface origin, no path, OVER operator) */
+    int render(Inkscape::DrawingItem const *item, DrawingContext &graphic, DrawingContext *bgdc, RenderContext &rc) const;
+
+    /**
+     * Creates a new filter primitive under this filter object.
+     * New primitive is placed so that it will be executed after all filter
+     * primitives defined beforehand for this filter object.
+     * Should this filter not have enough space for a new primitive, the filter
+     * is enlarged to accommodate the new filter element. It may be enlarged by
+     * more that one element.
+     * Returns a handle (non-negative integer) to the filter primitive created.
+     * Returns -1 if type is not a valid filter primitive type or a filter
+     * primitive of such type cannot be created.
+     */
+    void add_primitive(std::unique_ptr<FilterPrimitive> primitive);
+
+    /**
+     * Removes all filter primitives from this filter.
+     * All pointers to filter primitives inside this filter should be
+     * considered invalid after calling this function.
+     */
+    void clear_primitives();
+
+    /**
+     * Sets the slot number 'slot' to be used as result from this filter.
+     * If output is not set, the output from last filter primitive is used as
+     * output from the filter.
+     * It is an error to specify a pre-defined slot as 'slot'. Such call does
+     * not have any effect to the state of filter or its primitives.
+     */
+    void set_output(int slot);
+
+    void set_x(SVGLength const &length);
+    void set_y(SVGLength const &length);
+    void set_width(SVGLength const &length);
+    void set_height(SVGLength const &length);
+
+    /**
+     * Sets the filter effects region.
+     * Passing an unset length (length._set == false) as any of the parameters
+     * results in that parameter not being changed.
+     * Filter will not hold any references to the passed SVGLength object after
+     * function returns.
+     * If any of these parameters does not get set, the default value for that
+     * parameter as defined in the SVG standard is used instead.
+     */
+    void set_region(SVGLength const &x, SVGLength const &y,
+                    SVGLength const &width, SVGLength const &height);
+
+    /**
+     * Resets the filter effects region to its default value as defined
+     * in SVG standard.
+     */
+    void reset_region();
+
+    /**
+     * Sets the width of intermediate images in pixels. If not set, suitable
+     * resolution is determined automatically. If x_pixels is less than zero,
+     * calling this function results in no changes to filter state.
+     */
+    void set_resolution(double x_pixels);
+
+    /**
+     * Sets the width and height of intermediate images in pixels. If not set,
+     * suitable resolution is determined automatically. If either parameter is
+     * less than zero, calling this function results in no changes to filter
+     * state.
+     */
+    void set_resolution(double x_pixels, double y_pixels);
+
+    /**
+     * Resets the filter resolution to its default value, i.e. automatically
+     * determined.
+     */
+    void reset_resolution();
+
+    /**
+     * Set the filterUnits-property. If not set, the default value of 
+     * objectBoundingBox is used. If the parameter value is not a
+     * valid enumeration value from SPFilterUnits, no changes to filter state
+     * are made.
+     */
+    void set_filter_units(SPFilterUnits unit);
+
+    /**
+     * Set the primitiveUnits-property. If not set, the default value of
+     * userSpaceOnUse is used. If the parameter value is not a valid
+     * enumeration value from SPFilterUnits, no changes to filter state
+     * are made.
+     */
+    void set_primitive_units(SPFilterUnits unit);
+
+    /** 
+     * Modifies the given area to accommodate for filters needing pixels
+     * outside the rendered area.
+     * When this function returns, area contains the area that needs
+     * to be rendered so that after filtering, the original area is
+     * drawn correctly.
+     */
+    void area_enlarge(Geom::IntRect &area, Inkscape::DrawingItem const *item) const;
+
+    /**
+     * Returns the filter effects area in user coordinate system.
+     * The given bounding box should be a bounding box as specified in
+     * SVG standard and in user coordinate system.
+     */
+    Geom::OptRect filter_effect_area(Geom::OptRect const &bbox) const;
+
+    // returns cache score factor
+    double complexity(Geom::Affine const &ctm) const;
+
+    // says whether the filter accesses any of the background images
+    bool uses_background() const;
+
+    /** Creates a new filter with space for one filter element */
+    Filter();
+
+    /** 
+     * Creates a new filter with space for n filter elements. If number of
+     * filter elements is known beforehand, it's better to use this
+     * constructor.
+     */
+    Filter(int n);
+
+private:
+    std::vector<std::unique_ptr<FilterPrimitive>> primitives;
+
+    /** Amount of image slots used when this filter was rendered last time */
+    int _slot_count;
+
+    /** Image slot from which filter output should be read.
+     * Negative values mean 'not set' */
+    int _output_slot;
+
+    SVGLength _region_x;
+    SVGLength _region_y;
+    SVGLength _region_width;
+    SVGLength _region_height;
+
+    /* x- and y-resolutions for filter rendering.
+     * Negative values mean 'not set'.
+     * If _y_pixels is set, _x_pixels should be set too. */
+    double _x_pixels;
+    double _y_pixels;
+
+    SPFilterUnits _filter_units;
+    SPFilterUnits _primitive_units;
+
+    void _common_init();
+    static int _resolution_limit(FilterQuality quality);
+    std::pair<double, double> _filter_resolution(Geom::Rect const &area,
+                                                 Geom::Affine const &trans,
+                                                 FilterQuality q) const;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // INKSCAPE_DISPLAY_NR_FILTER_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-light-types.h b/src/display/nr-light-types.h
new file mode 100644
index 0000000..a111f6c
--- /dev/null
+++ b/src/display/nr-light-types.h
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * TODO: insert short description here
+ *//*
+ * Authors: see git history
+ *
+ * Copyright (C) 2014 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+#ifndef SEEN_NR_LIGHT_TYPES_H
+#define SEEN_NR_LIGHT_TYPES_H
+
+namespace Inkscape {
+namespace Filters {
+
+enum LightType
+{
+    NO_LIGHT = 0,
+    DISTANT_LIGHT,
+    POINT_LIGHT,
+    SPOT_LIGHT
+};
+
+struct DistantLightData
+{
+    double azimuth, elevation;
+};
+
+struct PointLightData
+{
+    double x, y, z;
+};
+
+struct SpotLightData
+{
+    double x, y, z;
+    double pointsAtX, pointsAtY, pointsAtZ;
+    double limitingConeAngle;
+    double specularExponent;
+};
+
+} // namespace Filters
+} // namespace Inkscape
+
+#endif // SEEN_NR_LIGHT_TYPES_H
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-light.cpp b/src/display/nr-light.cpp
new file mode 100644
index 0000000..00404fd
--- /dev/null
+++ b/src/display/nr-light.cpp
@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Light rendering helpers
+ *
+ * Author:
+ *   Jean-Rene Reinhard <jr@komite.net>
+ *
+ * Copyright (C) 2006 Jean-Rene Reinhard
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cmath>
+
+#include "display/nr-light.h"
+#include "display/nr-3dutils.h"
+#include "object/filters/distantlight.h"
+#include "object/filters/pointlight.h"
+#include "object/filters/spotlight.h"
+#include "color.h"
+
+namespace Inkscape {
+namespace Filters {
+   
+DistantLight::DistantLight(DistantLightData const &light, guint32 lighting_color)
+{
+    color = lighting_color;
+    azimuth = M_PI / 180 * light.azimuth;
+    elevation = M_PI / 180 * light.elevation;
+}
+
+DistantLight::~DistantLight() = default;
+
+void DistantLight::light_vector(NR::Fvector &v) {
+    v[X_3D] = std::cos(azimuth)*std::cos(elevation);
+    v[Y_3D] = std::sin(azimuth)*std::cos(elevation);
+    v[Z_3D] = std::sin(elevation);
+} 
+
+void DistantLight::light_components(NR::Fvector &lc) {
+    lc[LIGHT_RED] = SP_RGBA32_R_U(color);
+    lc[LIGHT_GREEN] = SP_RGBA32_G_U(color);
+    lc[LIGHT_BLUE] = SP_RGBA32_B_U(color);
+}
+
+PointLight::PointLight(PointLightData const &light, guint32 lighting_color, const Geom::Affine &trans, int device_scale) {
+    color = lighting_color;
+    l_x = light.x * device_scale;
+    l_y = light.y * device_scale;
+    l_z = light.z * device_scale;
+    NR::convert_coord(l_x, l_y, l_z, trans);
+}
+
+PointLight::~PointLight() = default;
+
+void PointLight::light_vector(NR::Fvector &v, double x, double y, double z) {
+    v[X_3D] = l_x - x;
+    v[Y_3D] = l_y - y;
+    v[Z_3D] = l_z - z;
+    NR::normalize_vector(v);
+} 
+
+void PointLight::light_components(NR::Fvector &lc) {
+    lc[LIGHT_RED] = SP_RGBA32_R_U(color);
+    lc[LIGHT_GREEN] = SP_RGBA32_G_U(color);
+    lc[LIGHT_BLUE] = SP_RGBA32_B_U(color);
+}
+
+SpotLight::SpotLight(SpotLightData const &light, guint32 lighting_color, const Geom::Affine &trans, int device_scale)
+{
+    double p_x, p_y, p_z;
+    color = lighting_color;
+    l_x = light.x * device_scale;
+    l_y = light.y * device_scale;
+    l_z = light.z * device_scale;
+    p_x = light.pointsAtX * device_scale;
+    p_y = light.pointsAtY * device_scale;
+    p_z = light.pointsAtZ * device_scale;
+    cos_lca = std::cos(M_PI / 180 * light.limitingConeAngle);
+    speExp = light.specularExponent;
+    NR::convert_coord(l_x, l_y, l_z, trans);
+    NR::convert_coord(p_x, p_y, p_z, trans);
+    S[X_3D] = p_x - l_x;
+    S[Y_3D] = p_y - l_y;
+    S[Z_3D] = p_z - l_z;
+    NR::normalize_vector(S);
+}
+
+SpotLight::~SpotLight() = default;
+
+void SpotLight::light_vector(NR::Fvector &v, double x, double y, double z) {
+    v[X_3D] = l_x - x;
+    v[Y_3D] = l_y - y;
+    v[Z_3D] = l_z - z;
+    NR::normalize_vector(v);
+} 
+
+void SpotLight::light_components(NR::Fvector &lc, const NR::Fvector &L) {
+    double spmod = (-1) * NR::scalar_product(L, S);
+    if (spmod <= cos_lca)
+        spmod = 0;
+    else
+        spmod = std::pow(spmod, speExp);
+    lc[LIGHT_RED] = spmod * SP_RGBA32_R_U(color);
+    lc[LIGHT_GREEN] = spmod * SP_RGBA32_G_U(color);
+    lc[LIGHT_BLUE] = spmod * SP_RGBA32_B_U(color);
+}
+
+} /* namespace Filters */
+} /* namespace Inkscape */
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-light.h b/src/display/nr-light.h
new file mode 100644
index 0000000..7f59c87
--- /dev/null
+++ b/src/display/nr-light.h
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * TODO: insert short description here
+ *//*
+ * Authors: see git history
+ *
+ * Copyright (C) 2017 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+#ifndef SEEN_NR_LIGHT_H
+#define SEEN_NR_LIGHT_H
+
+/** \file
+ * These classes provide tools to compute interesting objects relative to light
+ * sources. Each class provides a constructor converting information contained
+ * in a sp light object into information useful in the current setting, a
+ * method to get the light vector (at a given point) and a method to get the
+ * light color components (at a given point).
+ */
+
+#include <2geom/forward.h>
+
+#include "display/nr-3dutils.h"
+#include "display/nr-light-types.h"
+
+class SPFeDistantLight;
+class SPFePointLight;
+class SPFeSpotLight;
+typedef unsigned int guint32;
+
+namespace Inkscape {
+namespace Filters {
+
+enum LightComponent {
+    LIGHT_RED = 0,
+    LIGHT_GREEN,
+    LIGHT_BLUE
+};
+
+class DistantLight {
+    public:
+        /**
+         * Constructor
+         *
+         * \param light the sp light object
+         * \param lighting_color the lighting_color used
+         */
+        DistantLight(DistantLightData const &light, guint32 lighting_color);
+        virtual ~DistantLight();
+
+        /**
+         * Computes the light vector of the distant light
+         *
+         * \param v a Fvector reference where we store the result
+         */
+        void light_vector(NR::Fvector &v);
+
+        /**
+         * Computes the light components of the distant light
+         *
+         * \param lc a Fvector reference where we store the result, X=R, Y=G, Z=B
+         */
+        void light_components(NR::Fvector &lc);
+
+    private:
+        guint32 color;
+        double azimuth; //azimuth in rad
+        double elevation; //elevation in rad
+};
+
+class PointLight {
+    public:
+        /**
+         * Constructor
+         *
+         * \param light the sp light object
+         * \param lighting_color the lighting_color used
+         * \param trans the transformation between absolute coordinate (those
+         * employed in the sp light object) and current coordinate (those
+         * employed in the rendering)
+         * \param device_scale for high DPI monitors.
+         */
+        PointLight(PointLightData const &light, guint32 lighting_color, const Geom::Affine &trans, int device_scale = 1);
+        virtual ~PointLight();
+        /**
+         * Computes the light vector of the distant light at point (x,y,z).
+         * x, y and z are given in the arena_item coordinate, they are used as
+         * is
+         *
+         * \param v a Fvector reference where we store the result
+         * \param x x coordinate of the current point
+         * \param y y coordinate of the current point
+         * \param z z coordinate of the current point
+         */
+        void light_vector(NR::Fvector &v, double x, double y, double z);
+
+        /**
+         * Computes the light components of the distant light
+         *
+         * \param lc a Fvector reference where we store the result, X=R, Y=G, Z=B
+         */
+        void light_components(NR::Fvector &lc);
+
+    private:
+        guint32 color;
+        //light position coordinates in render setting
+        double l_x;
+        double l_y;
+        double l_z;
+};
+
+class SpotLight {
+    public:
+        /**
+         * Constructor
+         *
+         * \param light the sp light object
+         * \param lighting_color the lighting_color used
+         * \param trans the transformation between absolute coordinate (those
+         * employed in the sp light object) and current coordinate (those
+         * employed in the rendering)
+         * \param device_scale for high DPI monitors.
+         */
+        SpotLight(SpotLightData const &light, guint32 lighting_color, const Geom::Affine &trans, int device_scale = 1);
+        virtual ~SpotLight();
+
+        /**
+         * Computes the light vector of the distant light at point (x,y,z).
+         * x, y and z are given in the arena_item coordinate, they are used as
+         * is
+         *
+         * \param v a Fvector reference where we store the result
+         * \param x x coordinate of the current point
+         * \param y y coordinate of the current point
+         * \param z z coordinate of the current point
+         */
+        void light_vector(NR::Fvector &v, double x, double y, double z);
+
+        /**
+         * Computes the light components of the distant light at the current
+         * point. We only need the light vector to compute these
+         *
+         * \param lc a Fvector reference where we store the result, X=R, Y=G, Z=B
+         * \param L the light vector of the current point
+         */
+        void light_components(NR::Fvector &lc, const NR::Fvector &L);
+
+    private:
+        guint32 color;
+        //light position coordinates in render setting
+        double l_x;
+        double l_y;
+        double l_z;
+        double cos_lca; //cos of the limiting cone angle
+        double speExp; //specular exponent;
+        NR::Fvector S; //unit vector from light position in the direction
+                   //the spot point at
+};
+
+
+} /* namespace Filters */
+} /* namespace Inkscape */
+
+#endif // __NR_LIGHT_H__
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-style.cpp b/src/display/nr-style.cpp
new file mode 100644
index 0000000..a6a0ded
--- /dev/null
+++ b/src/display/nr-style.cpp
@@ -0,0 +1,423 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Style information for rendering.
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2010 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "display/nr-style.h"
+#include "style.h"
+
+#include "display/drawing-context.h"
+#include "display/drawing-pattern.h"
+#include "display/drawing-surface.h"
+
+#include "object/sp-paint-server.h"
+
+namespace Inkscape {
+
+void NRStyleData::Paint::clear()
+{
+    server.reset();
+    type = PaintType::NONE;
+}
+
+void NRStyleData::Paint::set(SPColor const &c)
+{
+    clear();
+    type = PaintType::COLOR;
+    color = c;
+}
+
+void NRStyleData::Paint::set(SPPaintServer *ps)
+{
+    clear();
+    if (ps) {
+        type = PaintType::SERVER;
+        server = ps->create_drawing_paintserver();
+    }
+}
+
+void NRStyleData::Paint::set(SPIPaint const *paint)
+{
+    if (paint->isPaintserver()) {
+        SPPaintServer* server = paint->value.href->getObject();
+        if (server && server->isValid()) {
+            set(server);
+        } else if (paint->colorSet) {
+            set(paint->value.color);
+        } else {
+            clear();
+        }
+    } else if (paint->isColor()) {
+        set(paint->value.color);
+    } else if (paint->isNone()) {
+        clear();
+    } else if (paint->paintOrigin == SP_CSS_PAINT_ORIGIN_CONTEXT_FILL ||
+               paint->paintOrigin == SP_CSS_PAINT_ORIGIN_CONTEXT_STROKE) {
+        // A marker in the defs section will result in ending up here.
+        // std::cerr << "NRStyleData::Paint::set: Double" << std::endl;
+    } else {
+        g_assert_not_reached();
+    }
+}
+
+NRStyleData::NRStyleData()
+    : fill()
+    , stroke()
+    , stroke_width(0.0)
+    , hairline(false)
+    , miter_limit(0.0)
+    , n_dash(0)
+    , dash_offset(0.0)
+    , fill_rule(CAIRO_FILL_RULE_EVEN_ODD)
+    , line_cap(CAIRO_LINE_CAP_BUTT)
+    , line_join(CAIRO_LINE_JOIN_MITER)
+    , text_decoration_line(TEXT_DECORATION_LINE_CLEAR)
+    , text_decoration_style(TEXT_DECORATION_STYLE_CLEAR)
+    , text_decoration_fill()
+    , text_decoration_stroke()
+    , text_decoration_stroke_width(0.0)
+    , phase_length(0.0)
+    , tspan_line_start(false)
+    , tspan_line_end(false)
+    , tspan_width(0)
+    , ascender(0)
+    , descender(0)
+    , underline_thickness(0)
+    , underline_position(0)
+    , line_through_thickness(0)
+    , line_through_position(0)
+    , font_size(0)
+{
+    paint_order_layer[0] = PAINT_ORDER_NORMAL;
+}
+
+bool NRStyleData::Paint::ditherable() const
+{
+    return type == PaintType::SERVER && server && server->ditherable();
+}
+
+NRStyleData::NRStyleData(SPStyle const *style, SPStyle const *context_style)
+{
+    // Handle 'context-fill' and 'context-stroke': Work in progress
+    const SPIPaint *style_fill = &style->fill;
+    if (style_fill->paintOrigin == SP_CSS_PAINT_ORIGIN_CONTEXT_FILL) {
+        if (context_style) {
+            style_fill = &context_style->fill;
+        } else {
+            // A marker in the defs section will result in ending up here.
+            //std::cerr << "NRStyleData::set: 'context-fill': 'context_style' is NULL" << std::endl;
+        }
+    } else if (style_fill->paintOrigin == SP_CSS_PAINT_ORIGIN_CONTEXT_STROKE) {
+        if (context_style) {
+            style_fill = &context_style->stroke;
+        } else {
+            //std::cerr << "NRStyleData::set: 'context-stroke': 'context_style' is NULL" << std::endl;
+        }
+    }
+    
+    fill.set(style_fill);
+    fill.opacity = SP_SCALE24_TO_FLOAT(style->fill_opacity.value);
+
+    switch (style->fill_rule.computed) {
+        case SP_WIND_RULE_EVENODD:
+            fill_rule = CAIRO_FILL_RULE_EVEN_ODD;
+            break;
+        case SP_WIND_RULE_NONZERO:
+            fill_rule = CAIRO_FILL_RULE_WINDING;
+            break;
+        default:
+            g_assert_not_reached();
+    }
+
+    const SPIPaint *style_stroke = &style->stroke;
+    if (style_stroke->paintOrigin == SP_CSS_PAINT_ORIGIN_CONTEXT_FILL) {
+        if (context_style) {
+            style_stroke = &context_style->fill;
+        } else {
+            //std::cerr << "NRStyleData::set: 'context-fill': 'context_style' is NULL" << std::endl;
+        }
+    } else if (style_stroke->paintOrigin == SP_CSS_PAINT_ORIGIN_CONTEXT_STROKE) {
+        if (context_style) {
+            style_stroke = &context_style->stroke;
+        } else {
+            //std::cerr << "NRStyleData::set: 'context-stroke': 'context_style' is NULL" << std::endl;
+        }
+    }
+
+    stroke.set(style_stroke);
+    stroke.opacity = SP_SCALE24_TO_FLOAT(style->stroke_opacity.value);
+    stroke_width = style->stroke_width.computed;
+    hairline = style->stroke_extensions.hairline;
+    switch (style->stroke_linecap.computed) {
+        case SP_STROKE_LINECAP_ROUND:
+            line_cap = CAIRO_LINE_CAP_ROUND;
+            break;
+        case SP_STROKE_LINECAP_SQUARE:
+            line_cap = CAIRO_LINE_CAP_SQUARE;
+            break;
+        case SP_STROKE_LINECAP_BUTT:
+            line_cap = CAIRO_LINE_CAP_BUTT;
+            break;
+        default:
+            g_assert_not_reached();
+    }
+    switch (style->stroke_linejoin.computed) {
+        case SP_STROKE_LINEJOIN_ROUND:
+            line_join = CAIRO_LINE_JOIN_ROUND;
+            break;
+        case SP_STROKE_LINEJOIN_BEVEL:
+            line_join = CAIRO_LINE_JOIN_BEVEL;
+            break;
+        case SP_STROKE_LINEJOIN_MITER:
+            line_join = CAIRO_LINE_JOIN_MITER;
+            break;
+        default:
+            g_assert_not_reached();
+    }
+    miter_limit = style->stroke_miterlimit.value;
+
+    n_dash = style->stroke_dasharray.values.size();
+    if (n_dash > 0 && style->stroke_dasharray.is_valid()) {
+        dash_offset = style->stroke_dashoffset.computed;
+        dash.resize(n_dash);
+        for (int i = 0; i < n_dash; ++i) {
+            dash[i] = style->stroke_dasharray.values[i].computed;
+        }
+    } else {
+        dash_offset = 0.0;
+        dash.clear();
+    }
+
+    for (int i = 0; i < PAINT_ORDER_LAYERS; ++i) {
+        switch (style->paint_order.layer[i]) {
+            case SP_CSS_PAINT_ORDER_NORMAL:
+                paint_order_layer[i]=PAINT_ORDER_NORMAL;
+                break;
+            case SP_CSS_PAINT_ORDER_FILL:
+                paint_order_layer[i]=PAINT_ORDER_FILL;
+                break;
+            case SP_CSS_PAINT_ORDER_STROKE:
+                paint_order_layer[i]=PAINT_ORDER_STROKE;
+                break;
+            case SP_CSS_PAINT_ORDER_MARKER:
+                paint_order_layer[i]=PAINT_ORDER_MARKER;
+                break;
+        }
+    }
+
+    text_decoration_line = TEXT_DECORATION_LINE_CLEAR;
+    if (style->text_decoration_line.inherit     ) { text_decoration_line |= TEXT_DECORATION_LINE_INHERIT;                                }
+    if (style->text_decoration_line.underline   ) { text_decoration_line |= TEXT_DECORATION_LINE_UNDERLINE   + TEXT_DECORATION_LINE_SET; }
+    if (style->text_decoration_line.overline    ) { text_decoration_line |= TEXT_DECORATION_LINE_OVERLINE    + TEXT_DECORATION_LINE_SET; }
+    if (style->text_decoration_line.line_through) { text_decoration_line |= TEXT_DECORATION_LINE_LINETHROUGH + TEXT_DECORATION_LINE_SET; }
+    if (style->text_decoration_line.blink       ) { text_decoration_line |= TEXT_DECORATION_LINE_BLINK       + TEXT_DECORATION_LINE_SET; }
+
+    text_decoration_style = TEXT_DECORATION_STYLE_CLEAR;
+    if (style->text_decoration_style.inherit ) { text_decoration_style |= TEXT_DECORATION_STYLE_INHERIT;                              }
+    if (style->text_decoration_style.solid   ) { text_decoration_style |= TEXT_DECORATION_STYLE_SOLID    + TEXT_DECORATION_STYLE_SET; }
+    if (style->text_decoration_style.isdouble) { text_decoration_style |= TEXT_DECORATION_STYLE_ISDOUBLE + TEXT_DECORATION_STYLE_SET; }
+    if (style->text_decoration_style.dotted  ) { text_decoration_style |= TEXT_DECORATION_STYLE_DOTTED   + TEXT_DECORATION_STYLE_SET; }
+    if (style->text_decoration_style.dashed  ) { text_decoration_style |= TEXT_DECORATION_STYLE_DASHED   + TEXT_DECORATION_STYLE_SET; }
+    if (style->text_decoration_style.wavy    ) { text_decoration_style |= TEXT_DECORATION_STYLE_WAVY     + TEXT_DECORATION_STYLE_SET; }
+ 
+    /* FIXME
+       The meaning of text-decoration-color in CSS3 for SVG is ambiguous (2014-05-06).  Set
+       it for fill, for stroke, for both?  Both would seem like the obvious choice but what happens
+       is that for text which is just fill (very common) it makes the lines fatter because it
+       enables stroke on the decorations when it wasn't present on the text.  That contradicts the
+       usual behavior where the text and decorations by default have the same fill/stroke.
+       
+       The behavior here is that if color is defined it is applied to text_decoration_fill/stroke
+       ONLY if the corresponding fill/stroke is also present.
+       
+       Hopefully the standard will be clarified to resolve this issue.
+    */
+
+    // Unless explicitly set on an element, text decoration is inherited from
+    // closest ancestor where 'text-decoration' was set. That is, setting
+    // 'text-decoration' on an ancestor fixes the fill and stroke of the
+    // decoration to the fill and stroke values of that ancestor.
+    auto style_td = style;
+    if (style->text_decoration.style_td) style_td = style->text_decoration.style_td;
+    text_decoration_stroke.opacity = SP_SCALE24_TO_FLOAT(style_td->stroke_opacity.value);
+    text_decoration_stroke_width = style_td->stroke_width.computed;
+
+    // Priority is given in order:
+    //   * text_decoration_fill
+    //   * text_decoration_color (only if fill set)
+    //   * fill
+    if (style_td->text_decoration_fill.set) {
+        text_decoration_fill.set(&(style_td->text_decoration_fill));
+    } else if (style_td->text_decoration_color.set) {
+        if(style->fill.isPaintserver() || style->fill.isColor()) {
+            // SVG sets color specifically
+            text_decoration_fill.set(style->text_decoration_color.value.color);
+        } else {
+            // No decoration fill because no text fill
+            text_decoration_fill.clear();
+        }
+    } else {
+        // Pick color/pattern from text
+        text_decoration_fill.set(&style_td->fill);
+    }
+
+    if (style_td->text_decoration_stroke.set) {
+        text_decoration_stroke.set(&style_td->text_decoration_stroke);
+    } else if (style_td->text_decoration_color.set) {
+        if(style->stroke.isPaintserver() || style->stroke.isColor()) {
+            // SVG sets color specifically
+            text_decoration_stroke.set(style->text_decoration_color.value.color);
+        } else {
+            // No decoration stroke because no text stroke
+            text_decoration_stroke.clear();
+        }
+    } else {
+        // Pick color/pattern from text
+        text_decoration_stroke.set(&style_td->stroke);
+    }
+
+    if (text_decoration_line != TEXT_DECORATION_LINE_CLEAR) {
+        phase_length           = style->text_decoration_data.phase_length;
+        tspan_line_start       = style->text_decoration_data.tspan_line_start;
+        tspan_line_end         = style->text_decoration_data.tspan_line_end;
+        tspan_width            = style->text_decoration_data.tspan_width;
+        ascender               = style->text_decoration_data.ascender;
+        descender              = style->text_decoration_data.descender;
+        underline_thickness    = style->text_decoration_data.underline_thickness;
+        underline_position     = style->text_decoration_data.underline_position;
+        line_through_thickness = style->text_decoration_data.line_through_thickness;
+        line_through_position  = style->text_decoration_data.line_through_position;
+        font_size              = style->font_size.computed;
+    }
+
+    text_direction = style->direction.computed;
+}
+
+auto NRStyle::preparePaint(Inkscape::DrawingContext &dc, Inkscape::RenderContext &rc, Geom::IntRect const &area, Geom::OptRect const &paintbox, Inkscape::DrawingPattern const *pattern, NRStyleData::Paint const &paint, CachedPattern const &cp) const -> CairoPatternUniqPtr
+{
+    if (paint.type == NRStyleData::PaintType::SERVER && pattern) {
+        // If a DrawingPattern, then always regenerate the pattern, because it may depend on 'area'.
+        // Even if not, regenerating the pattern is a no-op because DrawingPattern has a cache.
+        return CairoPatternUniqPtr(pattern->renderPattern(rc, area, paint.opacity, dc.surface()->device_scale()));
+    }
+
+    // Otherwise, init or re-use cached pattern.
+    cp.inited.init([&, this] {
+        // Handle remaining non-DrawingPattern cases.
+        switch (paint.type) {
+            case NRStyleData::PaintType::SERVER:
+                if (paint.server) {
+                    cp.pattern = CairoPatternUniqPtr(paint.server->create_pattern(dc.raw(), paintbox, paint.opacity));
+                } else {
+                    std::cerr << "Null pattern detected" << std::endl;
+                    cp.pattern = CairoPatternUniqPtr(cairo_pattern_create_rgba(0, 0, 0, 0));
+                }
+                break;
+            case NRStyleData::PaintType::COLOR: {
+                auto const &c = paint.color.v.c;
+                cp.pattern = CairoPatternUniqPtr(cairo_pattern_create_rgba(c[0], c[1], c[2], paint.opacity));
+                break;
+            }
+            default:
+                cp.pattern.reset();
+                break;
+        }
+    });
+
+    return copy(cp.pattern);
+}
+
+void NRStyle::set(NRStyleData &&data_)
+{
+    data = std::move(data_);
+    invalidate();
+}
+
+auto NRStyle::prepareFill(Inkscape::DrawingContext &dc, Inkscape::RenderContext &rc, Geom::IntRect const &area, Geom::OptRect const &paintbox, Inkscape::DrawingPattern const *pattern) const -> CairoPatternUniqPtr
+{
+    return preparePaint(dc, rc, area, paintbox, pattern, data.fill, fill_pattern);
+}
+
+auto NRStyle::prepareStroke(Inkscape::DrawingContext &dc, Inkscape::RenderContext &rc, Geom::IntRect const &area, Geom::OptRect const &paintbox, Inkscape::DrawingPattern const *pattern) const -> CairoPatternUniqPtr
+{
+    return preparePaint(dc, rc, area, paintbox, pattern, data.stroke, stroke_pattern);
+}
+
+auto NRStyle::prepareTextDecorationFill(Inkscape::DrawingContext &dc, Inkscape::RenderContext &rc, Geom::IntRect const &area, Geom::OptRect const &paintbox, Inkscape::DrawingPattern const *pattern) const -> CairoPatternUniqPtr
+{
+    return preparePaint(dc, rc, area, paintbox, pattern, data.text_decoration_fill, text_decoration_fill_pattern);
+}
+
+auto NRStyle::prepareTextDecorationStroke(Inkscape::DrawingContext &dc, Inkscape::RenderContext &rc, Geom::IntRect const &area, Geom::OptRect const &paintbox, Inkscape::DrawingPattern const *pattern) const -> CairoPatternUniqPtr
+{
+    return preparePaint(dc, rc, area, paintbox, pattern, data.text_decoration_stroke, text_decoration_stroke_pattern);
+}
+
+void NRStyle::applyFill(Inkscape::DrawingContext &dc, CairoPatternUniqPtr const &cp) const
+{
+    dc.setSource(cp.get());
+    dc.setFillRule(data.fill_rule);
+}
+
+void NRStyle::applyTextDecorationFill(Inkscape::DrawingContext &dc, CairoPatternUniqPtr const &cp) const
+{
+    dc.setSource(cp.get());
+    // Fill rule does not matter, no intersections.
+}
+
+void NRStyle::applyStroke(Inkscape::DrawingContext &dc, CairoPatternUniqPtr const &cp) const
+{
+    dc.setSource(cp.get());
+    if (data.hairline) {
+        dc.setHairline();
+    } else {
+        dc.setLineWidth(data.stroke_width);
+    }
+    dc.setLineCap(data.line_cap);
+    dc.setLineJoin(data.line_join);
+    dc.setMiterLimit(data.miter_limit);
+    cairo_set_dash(dc.raw(), data.dash.empty() ? nullptr : data.dash.data(), data.dash.empty() ? 0 : data.n_dash, data.dash_offset); // fixme
+}
+
+void NRStyle::applyTextDecorationStroke(Inkscape::DrawingContext &dc, CairoPatternUniqPtr const &cp) const
+{
+    dc.setSource(cp.get());
+    if (data.hairline) {
+        dc.setHairline();
+    } else {
+        dc.setLineWidth(data.text_decoration_stroke_width);
+    }
+    dc.setLineCap(CAIRO_LINE_CAP_BUTT);
+    dc.setLineJoin(CAIRO_LINE_JOIN_MITER);
+    dc.setMiterLimit(data.miter_limit);
+    cairo_set_dash(dc.raw(), nullptr, 0, 0.0); // fixme (no dash)
+}
+
+void NRStyle::invalidate()
+{
+    // force pattern update
+    fill_pattern.reset();
+    stroke_pattern.reset();
+    text_decoration_fill_pattern.reset();
+    text_decoration_stroke_pattern.reset();
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-style.h b/src/display/nr-style.h
new file mode 100644
index 0000000..c3d889e
--- /dev/null
+++ b/src/display/nr-style.h
@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Style information for rendering.
+ * Only used by classes DrawingShape and DrawingText
+ *//*
+ * Authors:
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ *
+ * Copyright (C) 2010 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef INKSCAPE_DISPLAY_NR_STYLE_H
+#define INKSCAPE_DISPLAY_NR_STYLE_H
+
+#include <memory>
+#include <array>
+#include <cairo.h>
+#include <2geom/rect.h>
+#include "color.h"
+#include "drawing-paintserver.h"
+#include "initlock.h"
+
+class SPPaintServer;
+class SPStyle;
+class SPIPaint;
+
+namespace Inkscape {
+class DrawingContext;
+class DrawingPattern;
+class RenderContext;
+
+struct CairoPatternFreer { void operator()(cairo_pattern_t *p) const { cairo_pattern_destroy(p); } };
+using CairoPatternUniqPtr = std::unique_ptr<cairo_pattern_t, CairoPatternFreer>;
+inline CairoPatternUniqPtr copy(CairoPatternUniqPtr const &p)
+{
+    if (!p) return {};
+    cairo_pattern_reference(p.get());
+    return CairoPatternUniqPtr(p.get());
+}
+
+struct NRStyleData
+{
+    NRStyleData();
+    explicit NRStyleData(SPStyle const *style, SPStyle const *context_style = nullptr);
+
+    enum class PaintType
+    {
+        NONE,
+        COLOR,
+        SERVER
+    };
+
+    struct Paint
+    {
+        PaintType type = PaintType::NONE;
+        SPColor color = 0;
+        std::unique_ptr<DrawingPaintServer> server;
+        float opacity = 1.0;
+
+        void clear();
+        void set(SPColor const &c);
+        void set(SPPaintServer *ps);
+        void set(SPIPaint const *paint);
+        bool ditherable() const;
+    };
+
+    Paint fill;
+    Paint stroke;
+    float stroke_width;
+    bool hairline;
+    float miter_limit;
+    int n_dash;
+    std::vector<double> dash;
+    float dash_offset;
+    cairo_fill_rule_t fill_rule;
+    cairo_line_cap_t line_cap;
+    cairo_line_join_t line_join;
+
+    enum PaintOrderType
+    {
+        PAINT_ORDER_NORMAL,
+        PAINT_ORDER_FILL,
+        PAINT_ORDER_STROKE,
+        PAINT_ORDER_MARKER
+    };
+
+    std::array<PaintOrderType, 3> paint_order_layer;
+
+    enum TextDecorationLine
+    {
+        TEXT_DECORATION_LINE_CLEAR       = 0x00,
+        TEXT_DECORATION_LINE_SET         = 0x01,
+        TEXT_DECORATION_LINE_INHERIT     = 0x02,
+        TEXT_DECORATION_LINE_UNDERLINE   = 0x04,
+        TEXT_DECORATION_LINE_OVERLINE    = 0x08,
+        TEXT_DECORATION_LINE_LINETHROUGH = 0x10,
+        TEXT_DECORATION_LINE_BLINK       = 0x20
+    };
+
+    enum TextDecorationStyle
+    {
+        TEXT_DECORATION_STYLE_CLEAR      = 0x00,
+        TEXT_DECORATION_STYLE_SET        = 0x01,
+        TEXT_DECORATION_STYLE_INHERIT    = 0x02,
+        TEXT_DECORATION_STYLE_SOLID      = 0x04,
+        TEXT_DECORATION_STYLE_ISDOUBLE   = 0x08,
+        TEXT_DECORATION_STYLE_DOTTED     = 0x10,
+        TEXT_DECORATION_STYLE_DASHED     = 0x20,
+        TEXT_DECORATION_STYLE_WAVY       = 0x40
+    };
+
+    int   text_decoration_line;
+    int   text_decoration_style;
+    Paint text_decoration_fill;
+    Paint text_decoration_stroke;
+    float text_decoration_stroke_width;
+
+    // These are the same as in style.h
+    float phase_length;
+    bool  tspan_line_start;
+    bool  tspan_line_end;
+    float tspan_width;
+    float ascender;
+    float descender;
+    float underline_thickness;
+    float underline_position; 
+    float line_through_thickness;
+    float line_through_position;
+    float font_size;
+
+    int   text_direction;
+};
+
+class NRStyle
+{
+public:
+    void set(NRStyleData &&data);
+    CairoPatternUniqPtr prepareFill(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, Geom::OptRect const &paintbox, DrawingPattern const *pattern) const;
+    CairoPatternUniqPtr prepareStroke(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, Geom::OptRect const &paintbox, DrawingPattern const *pattern) const;
+    CairoPatternUniqPtr prepareTextDecorationFill(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, Geom::OptRect const &paintbox, DrawingPattern const *pattern) const;
+    CairoPatternUniqPtr prepareTextDecorationStroke(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, Geom::OptRect const &paintbox, DrawingPattern const *pattern) const;
+    void applyFill(DrawingContext &dc, CairoPatternUniqPtr const &cp) const;
+    void applyStroke(DrawingContext &dc, CairoPatternUniqPtr const &cp) const;
+    void applyTextDecorationFill(DrawingContext &dc, CairoPatternUniqPtr const &cp) const;
+    void applyTextDecorationStroke(DrawingContext &dc, CairoPatternUniqPtr const &cp) const;
+    void invalidate();
+
+    NRStyleData data;
+
+private:
+    struct CachedPattern
+    {
+        InitLock inited;
+        mutable CairoPatternUniqPtr pattern;
+        void reset() { inited.reset(); pattern.reset(); }
+    };
+
+    CairoPatternUniqPtr preparePaint(DrawingContext &dc, RenderContext &rc, Geom::IntRect const &area, Geom::OptRect const &paintbox, DrawingPattern const *pattern, NRStyleData::Paint const &paint, CachedPattern const &cp) const;
+
+    CachedPattern fill_pattern;
+    CachedPattern stroke_pattern;
+    CachedPattern text_decoration_fill_pattern;
+    CachedPattern text_decoration_stroke_pattern;
+};
+
+} // namespace Inkscape
+
+#endif // INKSCAPE_DISPLAY_NR_STYLE_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-svgfonts.cpp b/src/display/nr-svgfonts.cpp
new file mode 100644
index 0000000..feea0e7
--- /dev/null
+++ b/src/display/nr-svgfonts.cpp
@@ -0,0 +1,434 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * SVGFonts rendering implementation
+ *
+ * Authors:
+ *    Felipe C. da S. Sanches <juca@members.fsf.org>
+ *    Jon A. Cruz <jon@joncruz.org>
+ *
+ * Copyright (C) 2008 Felipe C. da S. Sanches
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ * Read the file 'COPYING' for more information.
+ */
+
+#include <2geom/pathvector.h>
+#include <2geom/transforms.h>
+#include <cairo.h>
+#include <vector>
+
+#include "svg/svg.h"
+#include "display/cairo-utils.h"
+#include "display/nr-svgfonts.h"
+#include "display/nr-svgfonts.h"
+#include "display/curve.h"
+
+#include "xml/repr.h"
+
+#include "object/sp-path.h"
+#include "object/sp-object-group.h"
+#include "object/sp-use.h"
+#include "object/sp-use-reference.h"
+#include "object/sp-font-face.h"
+#include "object/sp-glyph.h"
+#include "object/sp-missing-glyph.h"
+#include "object/sp-font.h"
+#include "object/sp-glyph-kerning.h"
+
+// ************************//
+// UserFont Implementation //
+// ************************//
+
+// I wrote this binding code because Cairomm does not yet support userfonts. I have moved this code to cairomm and sent them a patch.
+// Once Cairomm incorporate the UserFonts binding, this code should be removed from inkscape and Cairomm API should be used.
+
+static cairo_user_data_key_t key;
+
+static cairo_status_t font_init_cb (cairo_scaled_font_t  *scaled_font,
+                                    cairo_t * /*cairo*/, cairo_font_extents_t *metrics){
+    cairo_font_face_t* face = cairo_scaled_font_get_font_face(scaled_font);
+    SvgFont* instance = static_cast<SvgFont*>(cairo_font_face_get_user_data(face, &key));
+    return instance->scaled_font_init(scaled_font, metrics);
+}
+
+static cairo_status_t font_text_to_glyphs_cb ( cairo_scaled_font_t  *scaled_font,
+                                               const char           *utf8,
+                                               int                  utf8_len,
+                                               cairo_glyph_t        **glyphs,
+                                               int                  *num_glyphs,
+                                               cairo_text_cluster_t **clusters,
+                                               int                  *num_clusters,
+                                               cairo_text_cluster_flags_t *flags){
+    cairo_font_face_t* face = cairo_scaled_font_get_font_face(scaled_font);
+    SvgFont* instance = static_cast<SvgFont*>(cairo_font_face_get_user_data(face, &key));
+    return instance->scaled_font_text_to_glyphs(scaled_font, utf8, utf8_len, glyphs, num_glyphs, clusters, num_clusters, flags);
+}
+
+static cairo_status_t font_render_glyph_cb (cairo_scaled_font_t  *scaled_font,
+                                            unsigned long         glyph,
+                                            cairo_t              *cr,
+                                            cairo_text_extents_t *metrics){
+    cairo_font_face_t* face = cairo_scaled_font_get_font_face(scaled_font);
+    SvgFont* instance = static_cast<SvgFont*>(cairo_font_face_get_user_data(face, &key));
+    return instance->scaled_font_render_glyph(scaled_font, glyph, cr, metrics);
+}
+
+UserFont::UserFont(SvgFont* instance){
+    this->face = cairo_user_font_face_create ();
+    cairo_user_font_face_set_init_func          (this->face, font_init_cb);
+    cairo_user_font_face_set_render_glyph_func  (this->face, font_render_glyph_cb);
+    cairo_user_font_face_set_text_to_glyphs_func(this->face, font_text_to_glyphs_cb);
+
+    cairo_font_face_set_user_data (this->face, &key, (void*)instance, (cairo_destroy_func_t) nullptr);
+}
+
+//******************************//
+// SvgFont class Implementation //
+//******************************//
+SvgFont::SvgFont(SPFont* spfont){
+    this->font = spfont;
+    this->missingglyph = nullptr;
+    this->userfont = nullptr;
+}
+
+cairo_status_t
+SvgFont::scaled_font_init (cairo_scaled_font_t  */*scaled_font*/,
+                           cairo_font_extents_t */*metrics*/)
+{
+//TODO
+//  metrics->ascent  = .75;
+//  metrics->descent = .25;
+  return CAIRO_STATUS_SUCCESS;
+}
+
+unsigned int size_of_substring(const char* substring, gchar* str){
+    const gchar* original_substring = substring;
+
+    while((g_utf8_get_char(substring)==g_utf8_get_char(str)) && g_utf8_get_char(substring) != 0 && g_utf8_get_char(str) != 0){
+        substring = g_utf8_next_char(substring);
+        str = g_utf8_next_char(str);
+    }
+    if (g_utf8_get_char(substring)==0)
+        return substring - original_substring;
+    else
+        return 0;
+}
+
+
+namespace {
+
+//TODO: in these functions, verify what happens when using unicode strings.
+
+bool MatchVKerningRule(SPVkern const *vkern,
+                       SPGlyph *glyph,
+                       char const *previous_unicode,
+                       gchar const *previous_glyph_name)
+{
+    bool value = (vkern->u1->contains(previous_unicode[0])
+                  || vkern->g1->contains(previous_glyph_name))
+        && (vkern->u2->contains(glyph->unicode[0])
+            || vkern->g2->contains(glyph->glyph_name.c_str()));
+
+    return value;
+}
+
+bool MatchHKerningRule(SPHkern const *hkern,
+                       SPGlyph *glyph,
+                       char const *previous_unicode,
+                       gchar const *previous_glyph_name)
+{
+    bool value = (hkern->u1->contains(previous_unicode[0])
+                  || hkern->g1->contains(previous_glyph_name))
+        && (hkern->u2->contains(glyph->unicode[0])
+            || hkern->g2->contains(glyph->glyph_name.c_str()));
+
+    return value;
+}
+
+} // namespace
+
+cairo_status_t
+SvgFont::scaled_font_text_to_glyphs (cairo_scaled_font_t  */*scaled_font*/,
+                                     const char           *utf8,
+                                     int                  /*utf8_len*/,
+                                     cairo_glyph_t        **glyphs,
+                                     int                  *num_glyphs,
+                                     cairo_text_cluster_t **/*clusters*/,
+                                     int                  */*num_clusters*/,
+                                     cairo_text_cluster_flags_t */*flags*/)
+{
+    //This function receives a text string to be rendered. It then defines what is the sequence of glyphs that
+    // is used to properly render this string. It also defines the respective coordinates of each glyph. Thus, it
+    // has to read the attributes of the SVGFont hkern and vkern nodes in order to adjust the glyph kerning.
+    //It also determines the usage of the missing-glyph in portions of the string that does not match any of the declared glyphs.
+
+    unsigned long i;
+    int count = 0;
+    gchar* _utf8 = (gchar*) utf8;
+    unsigned int len;
+
+    bool missing;
+    //First we find out what's the number of glyphs needed.
+    while(g_utf8_get_char(_utf8)){
+        missing = true;
+        for (i=0; i < (unsigned long) this->glyphs.size(); i++){
+            if ( (len = size_of_substring(this->glyphs[i]->unicode.c_str(), _utf8)) ){
+                //TODO: store this cluster
+                _utf8+=len;
+                count++;
+                missing=false;
+                break;
+            }
+        }
+        if (missing){
+            //TODO: store this cluster
+            _utf8++;
+            count++;
+        }
+    }
+
+
+    //We use that info to allocate memory for the glyphs
+    *glyphs = (cairo_glyph_t*) malloc(count*sizeof(cairo_glyph_t));
+
+    char* previous_unicode = nullptr; //This is used for kerning
+    gchar* previous_glyph_name = nullptr; //This is used for kerning
+
+    count=0;
+    double x=0, y=0;//These vars store the position of the glyph within the rendered string
+    bool is_horizontal_text = true; //TODO
+    _utf8 = (char*) utf8;
+
+    double font_height = units_per_em();
+    while(g_utf8_get_char(_utf8)){
+        len = 0;
+        for (i=0; i < (unsigned long) this->glyphs.size(); i++){
+            //check whether is there a glyph declared on the SVG document
+            // that matches with the text string in its current position
+            if ( (len = size_of_substring(this->glyphs[i]->unicode.c_str(), _utf8)) ){
+                for(auto& node: font->children) {
+                    if (!previous_unicode) {
+                        break;
+                    }
+                    //apply glyph kerning if appropriate
+                    auto hkern = cast<SPHkern>(&node);
+                    if (hkern && is_horizontal_text &&
+                        MatchHKerningRule(hkern, this->glyphs[i], previous_unicode, previous_glyph_name) ){
+                        x -= (hkern->k / font_height);
+                    }
+                    auto vkern = cast<SPVkern>(&node);
+                    if (vkern && !is_horizontal_text &&
+                        MatchVKerningRule(vkern, this->glyphs[i], previous_unicode, previous_glyph_name) ){
+                        y -= (vkern->k / font_height);
+                    }
+                }
+                previous_unicode = const_cast<char*>(this->glyphs[i]->unicode.c_str());//used for kerning checking
+                previous_glyph_name = const_cast<char*>(this->glyphs[i]->glyph_name.c_str());//used for kerning checking
+                (*glyphs)[count].index = i;
+                (*glyphs)[count].x = x;
+                (*glyphs)[count++].y = y;
+
+                //advance glyph coordinates:
+                if (is_horizontal_text) {
+                    if (this->glyphs[i]->horiz_adv_x != 0) {
+                        x+=(this->glyphs[i]->horiz_adv_x/font_height);
+                    } else {
+                        x+=(this->font->horiz_adv_x/font_height);
+                    }
+                } else {
+                    y+=(this->font->vert_adv_y/font_height);
+                }
+                _utf8+=len; //advance 'len' bytes in our string pointer
+                //continue;
+                goto raptorz;
+            }
+        }
+    raptorz:
+        if (len==0){
+            (*glyphs)[count].index = i;
+            (*glyphs)[count].x = x;
+            (*glyphs)[count++].y = y;
+
+            //advance glyph coordinates:
+            if (is_horizontal_text) x+=(this->font->horiz_adv_x/font_height);//TODO: use here the height of the font
+            else y+=(this->font->vert_adv_y/font_height);//TODO: use here the "height" of the font
+
+            _utf8 = g_utf8_next_char(_utf8); //advance 1 char in our string pointer
+        }
+    }
+    *num_glyphs = count;
+    return CAIRO_STATUS_SUCCESS;
+}
+
+void
+SvgFont::render_glyph_path(cairo_t* cr, Geom::PathVector* pathv){
+    if (!pathv->empty()){
+        //This glyph has a path description on its d attribute, so we render it:
+        cairo_new_path(cr);
+
+        //adjust scale of the glyph
+        Geom::Scale s(1.0/units_per_em());
+        Geom::Rect area( Geom::Point(0,0), Geom::Point(1,1) ); //I need help here!    (reaction: note that the 'area' parameter is an *optional* rect, so you can pass an empty Geom::OptRect() )
+
+        feed_pathvector_to_cairo (cr, *pathv, s, area, false, 0);
+        cairo_fill(cr);
+    }
+}
+
+void
+SvgFont::glyph_modified(SPObject* /* blah */, unsigned int /* bleh */){
+    this->refresh();
+    //TODO: update rendering on svgfonts preview widget (in the svg fonts dialog)
+}
+
+Geom::PathVector
+SvgFont::flip_coordinate_system(SPFont* spfont, Geom::PathVector pathv){
+    double units_per_em = 1024;
+    for(auto& obj: spfont->children) {
+        if (is<SPFontFace>(&obj)) {
+            //XML Tree being directly used here while it shouldn't be.
+            units_per_em = obj.getRepr()->getAttributeDouble("units_per_em", units_per_em);
+        }
+    }
+
+    double baseline_offset = units_per_em - spfont->horiz_origin_y;
+
+    //This matrix flips y-axis and places the origin at baseline
+    Geom::Affine m(Geom::Coord(1),Geom::Coord(0),Geom::Coord(0),Geom::Coord(-1),Geom::Coord(0),Geom::Coord(baseline_offset));
+    return pathv*m;
+}
+
+cairo_status_t
+SvgFont::scaled_font_render_glyph (cairo_scaled_font_t  */*scaled_font*/,
+                                   unsigned long         glyph,
+                                   cairo_t              *cr,
+                                   cairo_text_extents_t */*metrics*/)
+{
+    // This method does the actual rendering of glyphs.
+
+    // We have glyphs.size() glyphs and possibly one missing-glyph declared on this SVG document
+    // The id of the missing-glyph is always equal to glyphs.size()
+    // All the other glyphs have ids ranging from 0 to glyphs.size()-1
+
+    if (glyph > this->glyphs.size())     return CAIRO_STATUS_SUCCESS;//TODO: this is an error!
+
+    SPObject *node = nullptr;
+    if (glyph == glyphs.size()){
+        if (!missingglyph) {
+            return CAIRO_STATUS_SUCCESS;
+        }
+        node = missingglyph;
+    } else {
+        node = glyphs[glyph];
+    }
+
+    if (!is<SPGlyph>(node) && !is<SPMissingGlyph>(node)) {
+        return CAIRO_STATUS_SUCCESS;  // FIXME: is this the right code to return?
+    }
+
+    auto spfont = cast<SPFont>(node->parent);
+    if (!spfont) {
+        return CAIRO_STATUS_SUCCESS;  // FIXME: is this the right code to return?
+    }
+
+    //glyphs can be described by arbitrary SVG declared in the childnodes of a glyph node
+    // or using the d attribute of a glyph node.
+    // pathv stores the path description from the d attribute:
+    Geom::PathVector pathv;
+    
+    auto glyphNode = cast<SPGlyph>(node);
+    if (glyphNode && glyphNode->d) {
+        pathv = sp_svg_read_pathv(glyphNode->d);
+        pathv = flip_coordinate_system(spfont, pathv);
+        render_glyph_path(cr, &pathv);
+    } else {
+        auto missing = cast<SPMissingGlyph>(node);
+        if (missing && missing->d) {
+            pathv = sp_svg_read_pathv(missing->d);
+            pathv = flip_coordinate_system(spfont, pathv);
+            render_glyph_path(cr, &pathv);
+        }
+    }
+
+    if (node->hasChildren()){
+        //render the SVG described on this glyph's child nodes.
+        for(auto& child: node->children) {
+            {
+                auto path = cast<SPPath>(&child);
+                if (path) {
+                    pathv = path->curve()->get_pathvector();
+                    pathv = flip_coordinate_system(spfont, pathv);
+                    render_glyph_path(cr, &pathv);
+                }
+            }
+            if (is<SPObjectGroup>(&child)) {
+                g_warning("TODO: svgfonts: render OBJECTGROUP");
+            }
+            auto use = cast<SPUse>(&child);
+            if (use) {
+                SPItem* item = use->ref->getObject();
+                auto path = cast<SPPath>(item);
+                if (path) {
+                    auto shape = cast<SPShape>(item);
+                    g_assert(shape != nullptr);
+                    pathv = shape->curve()->get_pathvector();
+                    pathv = flip_coordinate_system(spfont, pathv);
+                    this->render_glyph_path(cr, &pathv);
+                }
+
+                glyph_modified_connection = item->connectModified(sigc::mem_fun(*this, &SvgFont::glyph_modified));
+            }
+        }
+    }
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+cairo_font_face_t*
+SvgFont::get_font_face(){
+    if (!this->userfont) {
+        for(auto& node: font->children) {
+            auto glyph = cast<SPGlyph>(&node);
+            if (glyph) {
+                glyphs.push_back(glyph);
+            }
+            auto missing = cast<SPMissingGlyph>(&node);
+            if (missing) {
+                missingglyph = missing;
+            }
+        }
+        this->userfont = new UserFont(this);
+    }
+    return this->userfont->face;
+}
+
+void SvgFont::refresh(){
+    this->glyphs.clear();
+    delete this->userfont;
+    this->userfont = nullptr;
+}
+
+double SvgFont::units_per_em() {
+    double units_per_em = 1024;
+    for (auto& obj: font->children) {
+        if (is<SPFontFace>(&obj)) {
+            //XML Tree being directly used here while it shouldn't be.
+            units_per_em = obj.getRepr()->getAttributeDouble("units-per-em", units_per_em);
+        }
+    }
+    if (units_per_em <= 0.0) {
+        units_per_em = 1024;
+    }
+    return units_per_em;
+}
+    
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/display/nr-svgfonts.h b/src/display/nr-svgfonts.h
new file mode 100644
index 0000000..ffc54f6
--- /dev/null
+++ b/src/display/nr-svgfonts.h
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef NR_SVGFONTS_H_SEEN
+#define NR_SVGFONTS_H_SEEN
+/*
+ * SVGFonts rendering headear
+ *
+ * Authors:
+ *    Felipe C. da S. Sanches <juca@members.fsf.org>
+ *
+ * Copyright (C) 2008 Felipe C. da S. Sanches
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ * Read the file 'COPYING' for more information.
+ */
+
+#include <cairo.h>
+#include <sigc++/connection.h>
+#include <2geom/pathvector.h>
+
+class SvgFont;
+class SPFont;
+class SPGlyph;
+class SPMissingGlyph;
+class SPObject;
+
+extern "C" { typedef struct _GdkEventExpose GdkEventExpose; }
+
+namespace Gtk {
+class Widget;
+}
+
+class UserFont {
+public:
+    UserFont(SvgFont* instance);
+    cairo_font_face_t* face;
+};
+
+class SvgFont {
+public:
+    SvgFont(SPFont* spfont);
+    void refresh();
+    cairo_font_face_t* get_font_face();
+    cairo_status_t scaled_font_init (cairo_scaled_font_t *scaled_font, cairo_font_extents_t *metrics);
+    cairo_status_t scaled_font_text_to_glyphs (cairo_scaled_font_t *scaled_font, const char *utf8, int utf8_len, cairo_glyph_t **glyphs, int *num_glyphs, cairo_text_cluster_t **clusters, int *num_clusters, cairo_text_cluster_flags_t *flags);
+    cairo_status_t scaled_font_render_glyph (cairo_scaled_font_t *scaled_font, unsigned long glyph, cairo_t *cr, cairo_text_extents_t *metrics);
+
+    Geom::PathVector flip_coordinate_system(SPFont* spfont, Geom::PathVector pathv);
+    void render_glyph_path(cairo_t* cr, Geom::PathVector* pathv);
+    void glyph_modified(SPObject *, unsigned int);
+
+private:
+    SPFont* font;
+    UserFont* userfont;
+    std::vector<SPGlyph*> glyphs;
+    SPMissingGlyph* missingglyph;
+    sigc::connection glyph_modified_connection;
+
+    double units_per_em();
+    //bool drawing_expose_cb (Gtk::Widget *widget, GdkEventExpose *event, void* data);
+};
+
+#endif //#ifndef NR_SVGFONTS_H_SEEN
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8 :
diff --git a/src/display/rendermode.h b/src/display/rendermode.h
new file mode 100644
index 0000000..dec852c
--- /dev/null
+++ b/src/display/rendermode.h
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * TODO: insert short description here
+ *//*
+ * Authors: see git history
+ *
+ * Copyright (C) 2011 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+/*
+ * RenderMode enumeration.
+ *
+ * Trivially public domain.
+ */
+
+#ifndef SEEN_INKSCAPE_DISPLAY_RENDERMODE_H
+#define SEEN_INKSCAPE_DISPLAY_RENDERMODE_H
+
+namespace Inkscape {
+
+enum class RenderMode {
+    NORMAL,
+    OUTLINE,
+    NO_FILTERS,
+    VISIBLE_HAIRLINES,
+    OUTLINE_OVERLAY,
+    size
+};
+
+enum class SplitMode {
+    NORMAL,
+    SPLIT,
+    XRAY,
+    size
+};
+
+enum class SplitDirection {
+    NONE,
+    NORTH,
+    EAST,
+    SOUTH,
+    WEST,
+    HORIZONTAL, // Only used when hovering
+    VERTICAL    // Only used when hovering
+};
+
+enum class ColorMode {
+    NORMAL,
+    GRAYSCALE,
+    PRINT_COLORS_PREVIEW
+};
+
+} // Namespace Inkscape
+
+#endif
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/display/tags.h b/src/display/tags.h
new file mode 100644
index 0000000..c09d361
--- /dev/null
+++ b/src/display/tags.h
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Author: PBS <pbs3141@gmail.com>
+ * Copyright (C) 2022 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef INKSCAPE_DRAWINGITEM_TAGS_H
+#define INKSCAPE_DRAWINGITEM_TAGS_H
+
+#include "util/cast.h"
+
+// Class hierarchy structure
+
+#define DRAWINGITEM_HIERARCHY_DATA(X)\
+X(DrawingItem,\
+    X(DrawingShape)\
+    X(DrawingImage)\
+    X(DrawingGroup,\
+        X(DrawingPattern)\
+        X(DrawingText)\
+    )\
+    X(DrawingGlyphs)\
+)
+
+namespace Inkscape {
+
+// Forward declarations
+
+#define X(n, ...) class n; __VA_ARGS__
+DRAWINGITEM_HIERARCHY_DATA(X)
+#undef X
+
+// Tag generation
+
+enum class DrawingItemTag : int
+{
+    #define X(n, ...) n##_first, __VA_ARGS__ n##_tmp, n##_last = n##_tmp - 1,
+    DRAWINGITEM_HIERARCHY_DATA(X)
+    #undef X
+};
+
+} // namespace Inkscape
+
+// Tag specialization
+
+#define X(n, ...) template <> inline constexpr int first_tag<Inkscape::n> = static_cast<int>(Inkscape::DrawingItemTag::n##_first); __VA_ARGS__
+DRAWINGITEM_HIERARCHY_DATA(X)
+#undef X
+
+#define X(n, ...) template <> inline constexpr int last_tag<Inkscape::n> = static_cast<int>(Inkscape::DrawingItemTag::n##_last); __VA_ARGS__
+DRAWINGITEM_HIERARCHY_DATA(X)
+#undef X
+
+#undef DRAWINGITEM_HIERARCHY_DATA
+
+#endif // INKSCAPE_DRAWINGITEM_TAGS_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :