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

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

1 files changed, 315 insertions, 0 deletions

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 :