1 files changed, 267 insertions, 0 deletions
diff --git a/src/display/cairo-utils.h b/src/display/cairo-utils.h
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+++ b/src/display/cairo-utils.h
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+// 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 *);
+void convert_pixbuf_argb32_to_normal(GdkPixbuf *pb);
+
+namespace Inkscape {
+
+/**
+ * RAII idiom for Cairo groups.
+ * Groups are temporary surfaces used when rendering e.g. masks and opacity.
+ * Use this class to ensure that each group push is matched with a pop.
+ */
+class CairoGroup {
+public:
+    CairoGroup(cairo_t *_ct);
+    ~CairoGroup();
+    void push();
+    void push_with_content(cairo_content_t content);
+    cairo_pattern_t *pop();
+    Cairo::RefPtr<Cairo::Pattern> popmm();
+    void pop_to_source();
+private:
+    cairo_t *ct;
+    bool pushed;
+};
+
+/** RAII idiom for Cairo state saving. */
+class CairoSave {
+public:
+    CairoSave(cairo_t *_ct, bool save=false)
+        : ct(_ct)
+        , saved(save)
+    {
+        if (save) {
+            cairo_save(ct);
+        }
+    }
+    void save() {
+        if (!saved) {
+            cairo_save(ct);
+            saved = true;
+        }
+    }
+    ~CairoSave() {
+        if (saved)
+            cairo_restore(ct);
+    }
+private:
+    cairo_t *ct;
+    bool saved;
+};
+
+/** Cairo context with Inkscape-specific operations. */
+class CairoContext : public Cairo::Context {
+public:
+    CairoContext(cairo_t *obj, bool ref = false);
+
+    void transform(Geom::Affine const &m);
+    void set_source_rgba32(guint32 color);
+    void append_path(Geom::PathVector const &pv);
+
+    static Cairo::RefPtr<CairoContext> create(Cairo::RefPtr<Cairo::Surface> const &target);
+};
+
+/** 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();
+
+    GdkPixbuf *getPixbufRaw(bool convert_format = true);
+    //Glib::RefPtr<Gdk::Pixbuf> getPixbuf(bool convert_format = true);
+
+    cairo_surface_t *getSurfaceRaw(bool convert_format = true);
+    Cairo::RefPtr<Cairo::Surface> getSurface(bool convert_format = true);
+
+    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 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 = "");
+
+    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
+
+// TODO: these declarations may not be needed in the header
+extern cairo_user_data_key_t ink_color_interpolation_key;
+extern cairo_user_data_key_t ink_pixbuf_key;
+
+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_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_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);
+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);
+
+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);
+
+G_GNUC_CONST guint32 argb32_from_pixbuf(guint32 in);
+G_GNUC_CONST guint32 pixbuf_from_argb32(guint32 in);
+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);
+
+
+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)
+{
+    // NOTE: you must check for alpha != 0 yourself.
+    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);
+
+#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 :