1 files changed, 499 insertions, 0 deletions

diff --git a/src/display/nr-filter.cpp b/src/display/nr-filter.cpp
new file mode 100644
index 0000000..eec7c1a
--- /dev/null
+++ b/src/display/nr-filter.cpp
@@ -0,0 +1,499 @@
+// 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"
+#include "preferences.h"
+
+namespace Inkscape {
+namespace Filters {
+
+using Geom::X;
+using Geom::Y;
+
+Filter::Filter()
+{
+    _common_init();
+}
+
+Filter::Filter(int n)
+{
+    if (n > 0) _primitive.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;
+}
+
+Filter::~Filter()
+{
+    clear_primitives();
+}
+
+
+int Filter::render(Inkscape::DrawingItem const *item, DrawingContext &graphic, DrawingContext *bgdc)
+{
+    // 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 (_primitive.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;
+    }
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    item->drawing().setFilterQuality(prefs->getInt("/options/filterquality/value", 0));
+    item->drawing().setBlurQuality(prefs->getInt("/options/blurquality/value", 0));
+    FilterQuality const filterquality = (FilterQuality)item->drawing().filterQuality();
+    int const 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);
+
+    std::pair<double,double> 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 : _primitive) {
+        if (!i->can_handle_affine(pbtrans)) {
+            units.set_paraller(true);
+            break;
+        }
+    }
+
+    FilterSlot slot(const_cast<Inkscape::DrawingItem*>(item), bgdc, graphic, units);
+    slot.set_quality(filterquality);
+    slot.set_blurquality(blurquality);
+    slot.set_device_scale(graphic.surface()->device_scale());
+
+    for (auto & i : _primitive) {
+        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::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 i : _primitive) {
+        if (i) i->area_enlarge(bbox, item->ctm());
+    }
+
+/*
+  TODO: something. See images at the bottom of filters.svg with medium-low
+  filtering quality.
+
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    FilterQuality const filterquality = (FilterQuality)prefs->getInt("/options/filterquality/value");
+
+    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)
+{
+    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
+        _region_x.update(12, 6, len_x);
+        _region_y.update(12, 6, len_y);
+        _region_width.update(12, 6, len_x);
+        _region_height.update(12, 6, 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_width.computed;
+        } else {
+            maxp[X] = minp[X] + _region_width.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_height.computed;
+        } else {
+            maxp[Y] = minp[Y] + _region_height.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)
+{
+    double factor = 1.0;
+    for (auto & i : _primitive) {
+        if (i) {
+            double f = i->complexity(ctm);
+            factor += (f - 1.0);
+        }
+    }
+    return factor;
+}
+
+bool Filter::uses_background()
+{
+    for (auto & i : _primitive) {
+        if (i && i->uses_background()) {
+            return true;
+        }
+    }
+    return false;
+}
+
+/* Constructor table holds pointers to static methods returning filter
+ * primitives. This table is indexed with FilterPrimitiveType, so that
+ * for example method in _constructor[NR_FILTER_GAUSSIANBLUR]
+ * returns a filter object of type Inkscape::Filters::FilterGaussian.
+ */
+typedef FilterPrimitive*(*FilterConstructor)();
+static FilterConstructor _constructor[NR_FILTER_ENDPRIMITIVETYPE];
+
+void Filter::_create_constructor_table()
+{
+    // Constructor table won't change in run-time, so no need to recreate
+    static bool created = false;
+    if(created) return;
+
+/* Some filter classes are not implemented yet.
+   Some of them still have only boilerplate code.*/
+    _constructor[NR_FILTER_BLEND] = &FilterBlend::create;
+    _constructor[NR_FILTER_COLORMATRIX] = &FilterColorMatrix::create;
+    _constructor[NR_FILTER_COMPONENTTRANSFER] = &FilterComponentTransfer::create;
+    _constructor[NR_FILTER_COMPOSITE] = &FilterComposite::create;
+    _constructor[NR_FILTER_CONVOLVEMATRIX] = &FilterConvolveMatrix::create;
+    _constructor[NR_FILTER_DIFFUSELIGHTING] = &FilterDiffuseLighting::create;
+    _constructor[NR_FILTER_DISPLACEMENTMAP] = &FilterDisplacementMap::create;
+    _constructor[NR_FILTER_FLOOD] = &FilterFlood::create;
+    _constructor[NR_FILTER_GAUSSIANBLUR] = &FilterGaussian::create;
+    _constructor[NR_FILTER_IMAGE] = &FilterImage::create;
+    _constructor[NR_FILTER_MERGE] = &FilterMerge::create;
+    _constructor[NR_FILTER_MORPHOLOGY] = &FilterMorphology::create;
+    _constructor[NR_FILTER_OFFSET] = &FilterOffset::create;
+    _constructor[NR_FILTER_SPECULARLIGHTING] = &FilterSpecularLighting::create;
+    _constructor[NR_FILTER_TILE] = &FilterTile::create;
+    _constructor[NR_FILTER_TURBULENCE] = &FilterTurbulence::create;
+    created = true;
+}
+
+int Filter::add_primitive(FilterPrimitiveType type)
+{
+    _create_constructor_table();
+
+    // Check that we can create a new filter of specified type
+    if (type < 0 || type >= NR_FILTER_ENDPRIMITIVETYPE)
+        return -1;
+    if (!_constructor[type]) return -1;
+    FilterPrimitive *created = _constructor[type]();
+
+    int handle = _primitive.size();
+    _primitive.push_back(created);
+    return handle;
+}
+
+int Filter::replace_primitive(int target, FilterPrimitiveType type)
+{
+    _create_constructor_table();
+
+    // Check that target is valid primitive inside this filter
+    if (target < 0) return -1;
+    if (static_cast<unsigned>(target) >= _primitive.size()) return -1;
+
+    // Check that we can create a new filter of specified type
+    if (type < 0 || type >= NR_FILTER_ENDPRIMITIVETYPE)
+        return -1;
+    if (!_constructor[type]) return -1;
+    FilterPrimitive *created = _constructor[type]();
+
+    delete _primitive[target];
+    _primitive[target] = created;
+    return target;
+}
+
+FilterPrimitive *Filter::get_primitive(int handle) {
+    if (handle < 0 || handle >= static_cast<int>(_primitive.size())) return nullptr;
+    return _primitive[handle];
+}
+
+void Filter::clear_primitives()
+{
+    for (auto & i : _primitive) {
+        delete i;
+    }
+    _primitive.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 const pixels) {
+    if (pixels > 0) {
+        _x_pixels = pixels;
+        _y_pixels = pixels;
+    }
+}
+
+void Filter::set_resolution(double const x_pixels, double const 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 const quality) const {
+    int limit = -1;
+    switch (quality) {
+        case FILTER_QUALITY_WORST:
+            limit = 32;
+            break;
+        case FILTER_QUALITY_WORSE:
+            limit = 64;
+            break;
+        case FILTER_QUALITY_NORMAL:
+            limit = 256;
+            break;
+        case FILTER_QUALITY_BETTER:
+        case FILTER_QUALITY_BEST:
+        default:
+            break;
+    }
+    return limit;
+}
+
+std::pair<double,double> Filter::_filter_resolution(
+    Geom::Rect const &area, Geom::Affine const &trans,
+    FilterQuality const 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 {
+        Geom::Point origo = area.min();
+        origo *= trans;
+        Geom::Point max_i(area.max()[X], area.min()[Y]);
+        max_i *= trans;
+        Geom::Point max_j(area.min()[X], area.max()[Y]);
+        max_j *= trans;
+        double i_len = sqrt((origo[X] - max_i[X]) * (origo[X] - max_i[X])
+                            + (origo[Y] - max_i[Y]) * (origo[Y] - max_i[Y]));
+        double j_len = sqrt((origo[X] - max_j[X]) * (origo[X] - max_j[X])
+                            + (origo[Y] - max_j[Y]) * (origo[Y] - max_j[Y]));
+        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 :