1 files changed, 163 insertions, 0 deletions
diff --git a/src/display/drawing-context.cpp b/src/display/drawing-context.cpp
new file mode 100644
index 0000000..75922d7
--- /dev/null
+++ b/src/display/drawing-context.cpp
@@ -0,0 +1,163 @@
+// 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]);
+}
+void DrawingContext::setSourceCheckerboard() {
+    cairo_pattern_t *check = ink_cairo_pattern_create_checkerboard();
+    cairo_set_source(_ct, check);
+    cairo_pattern_destroy(check);
+}
+
+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 :