Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

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

1 files changed, 1010 insertions, 0 deletions

diff --git a/gfx/harfbuzz/src/hb-cairo.cc b/gfx/harfbuzz/src/hb-cairo.cc
new file mode 100644
index 0000000000..f005afd17e
--- /dev/null
+++ b/gfx/harfbuzz/src/hb-cairo.cc
@@ -0,0 +1,1010 @@
+/*
+ * Copyright © 2022  Red Hat, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Red Hat Author(s): Matthias Clasen
+ */
+
+#include "hb.hh"
+
+#ifdef HAVE_CAIRO
+
+#include "hb-cairo.h"
+
+#include "hb-cairo-utils.hh"
+
+#include "hb-machinery.hh"
+#include "hb-utf.hh"
+
+
+/**
+ * SECTION:hb-cairo
+ * @title: hb-cairo
+ * @short_description: Cairo integration
+ * @include: hb-cairo.h
+ *
+ * Functions for using HarfBuzz with the cairo library.
+ *
+ * HarfBuzz supports using cairo for rendering.
+ **/
+
+static void
+hb_cairo_move_to (hb_draw_funcs_t *dfuncs HB_UNUSED,
+		  void *draw_data,
+		  hb_draw_state_t *st HB_UNUSED,
+		  float to_x, float to_y,
+		  void *user_data HB_UNUSED)
+{
+  cairo_t *cr = (cairo_t *) draw_data;
+
+  cairo_move_to (cr, (double) to_x, (double) to_y);
+}
+
+static void
+hb_cairo_line_to (hb_draw_funcs_t *dfuncs HB_UNUSED,
+		  void *draw_data,
+		  hb_draw_state_t *st HB_UNUSED,
+		  float to_x, float to_y,
+		  void *user_data HB_UNUSED)
+{
+  cairo_t *cr = (cairo_t *) draw_data;
+
+  cairo_line_to (cr, (double) to_x, (double) to_y);
+}
+
+static void
+hb_cairo_cubic_to (hb_draw_funcs_t *dfuncs HB_UNUSED,
+		   void *draw_data,
+		   hb_draw_state_t *st HB_UNUSED,
+		   float control1_x, float control1_y,
+		   float control2_x, float control2_y,
+		   float to_x, float to_y,
+		   void *user_data HB_UNUSED)
+{
+  cairo_t *cr = (cairo_t *) draw_data;
+
+  cairo_curve_to (cr,
+                  (double) control1_x, (double) control1_y,
+                  (double) control2_x, (double) control2_y,
+                  (double) to_x, (double) to_y);
+}
+
+static void
+hb_cairo_close_path (hb_draw_funcs_t *dfuncs HB_UNUSED,
+		     void *draw_data,
+		     hb_draw_state_t *st HB_UNUSED,
+		     void *user_data HB_UNUSED)
+{
+  cairo_t *cr = (cairo_t *) draw_data;
+
+  cairo_close_path (cr);
+}
+
+static inline void free_static_cairo_draw_funcs ();
+
+static struct hb_cairo_draw_funcs_lazy_loader_t : hb_draw_funcs_lazy_loader_t<hb_cairo_draw_funcs_lazy_loader_t>
+{
+  static hb_draw_funcs_t *create ()
+  {
+    hb_draw_funcs_t *funcs = hb_draw_funcs_create ();
+
+    hb_draw_funcs_set_move_to_func (funcs, hb_cairo_move_to, nullptr, nullptr);
+    hb_draw_funcs_set_line_to_func (funcs, hb_cairo_line_to, nullptr, nullptr);
+    hb_draw_funcs_set_cubic_to_func (funcs, hb_cairo_cubic_to, nullptr, nullptr);
+    hb_draw_funcs_set_close_path_func (funcs, hb_cairo_close_path, nullptr, nullptr);
+
+    hb_draw_funcs_make_immutable (funcs);
+
+    hb_atexit (free_static_cairo_draw_funcs);
+
+    return funcs;
+  }
+} static_cairo_draw_funcs;
+
+static inline
+void free_static_cairo_draw_funcs ()
+{
+  static_cairo_draw_funcs.free_instance ();
+}
+
+static hb_draw_funcs_t *
+hb_cairo_draw_get_funcs ()
+{
+  return static_cairo_draw_funcs.get_unconst ();
+}
+
+
+#ifdef HAVE_CAIRO_USER_FONT_FACE_SET_RENDER_COLOR_GLYPH_FUNC
+
+static void
+hb_cairo_push_transform (hb_paint_funcs_t *pfuncs HB_UNUSED,
+			 void *paint_data,
+			 float xx, float yx,
+			 float xy, float yy,
+			 float dx, float dy,
+			 void *user_data HB_UNUSED)
+{
+  hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data;
+  cairo_t *cr = c->cr;
+
+  cairo_matrix_t m;
+
+  cairo_save (cr);
+  cairo_matrix_init (&m, (double) xx, (double) yx,
+                         (double) xy, (double) yy,
+                         (double) dx, (double) dy);
+  cairo_transform (cr, &m);
+}
+
+static void
+hb_cairo_pop_transform (hb_paint_funcs_t *pfuncs HB_UNUSED,
+		        void *paint_data,
+		        void *user_data HB_UNUSED)
+{
+  hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data;
+  cairo_t *cr = c->cr;
+
+  cairo_restore (cr);
+}
+
+static void
+hb_cairo_push_clip_glyph (hb_paint_funcs_t *pfuncs HB_UNUSED,
+			  void *paint_data,
+			  hb_codepoint_t glyph,
+			  hb_font_t *font,
+			  void *user_data HB_UNUSED)
+{
+  hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data;
+  cairo_t *cr = c->cr;
+
+  cairo_save (cr);
+  cairo_new_path (cr);
+  hb_font_draw_glyph (font, glyph, hb_cairo_draw_get_funcs (), cr);
+  cairo_close_path (cr);
+  cairo_clip (cr);
+}
+
+static void
+hb_cairo_push_clip_rectangle (hb_paint_funcs_t *pfuncs HB_UNUSED,
+			      void *paint_data,
+			      float xmin, float ymin, float xmax, float ymax,
+			      void *user_data HB_UNUSED)
+{
+  hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data;
+  cairo_t *cr = c->cr;
+
+  cairo_save (cr);
+  cairo_rectangle (cr,
+                   (double) xmin, (double) ymin,
+                   (double) (xmax - xmin), (double) (ymax - ymin));
+  cairo_clip (cr);
+}
+
+static void
+hb_cairo_pop_clip (hb_paint_funcs_t *pfuncs HB_UNUSED,
+		   void *paint_data,
+		   void *user_data HB_UNUSED)
+{
+  hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data;
+  cairo_t *cr = c->cr;
+
+  cairo_restore (cr);
+}
+
+static void
+hb_cairo_push_group (hb_paint_funcs_t *pfuncs HB_UNUSED,
+		     void *paint_data,
+		     void *user_data HB_UNUSED)
+{
+  hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data;
+  cairo_t *cr = c->cr;
+
+  cairo_save (cr);
+  cairo_push_group (cr);
+}
+
+static void
+hb_cairo_pop_group (hb_paint_funcs_t *pfuncs HB_UNUSED,
+		    void *paint_data,
+		    hb_paint_composite_mode_t mode,
+		    void *user_data HB_UNUSED)
+{
+  hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data;
+  cairo_t *cr = c->cr;
+
+  cairo_pop_group_to_source (cr);
+  cairo_set_operator (cr, _hb_paint_composite_mode_to_cairo (mode));
+  cairo_paint (cr);
+
+  cairo_restore (cr);
+}
+
+static void
+hb_cairo_paint_color (hb_paint_funcs_t *pfuncs HB_UNUSED,
+		      void *paint_data,
+		      hb_bool_t use_foreground,
+		      hb_color_t color,
+		      void *user_data HB_UNUSED)
+{
+  hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data;
+  cairo_t *cr = c->cr;
+
+  if (use_foreground)
+  {
+#ifdef HAVE_CAIRO_USER_SCALED_FONT_GET_FOREGROUND_SOURCE
+    double r, g, b, a;
+    cairo_pattern_t *foreground = cairo_user_scaled_font_get_foreground_source (c->scaled_font);
+    if (cairo_pattern_get_rgba (foreground, &r, &g, &b, &a) == CAIRO_STATUS_SUCCESS)
+      cairo_set_source_rgba (cr, r, g, b, a * hb_color_get_alpha (color) / 255.);
+    else
+#endif
+      cairo_set_source_rgba (cr, 0, 0, 0, hb_color_get_alpha (color) / 255.);
+  }
+  else
+    cairo_set_source_rgba (cr,
+			   hb_color_get_red (color) / 255.,
+			   hb_color_get_green (color) / 255.,
+			   hb_color_get_blue (color) / 255.,
+			   hb_color_get_alpha (color) / 255.);
+  cairo_paint (cr);
+}
+
+static hb_bool_t
+hb_cairo_paint_image (hb_paint_funcs_t *pfuncs HB_UNUSED,
+		      void *paint_data,
+		      hb_blob_t *blob,
+		      unsigned width,
+		      unsigned height,
+		      hb_tag_t format,
+		      float slant,
+		      hb_glyph_extents_t *extents,
+		      void *user_data HB_UNUSED)
+{
+  hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data;
+
+  return _hb_cairo_paint_glyph_image (c, blob, width, height, format, slant, extents);
+}
+
+static void
+hb_cairo_paint_linear_gradient (hb_paint_funcs_t *pfuncs HB_UNUSED,
+				void *paint_data,
+				hb_color_line_t *color_line,
+				float x0, float y0,
+				float x1, float y1,
+				float x2, float y2,
+				void *user_data HB_UNUSED)
+{
+  hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data;
+
+  _hb_cairo_paint_linear_gradient (c, color_line, x0, y0, x1, y1, x2, y2);
+}
+
+static void
+hb_cairo_paint_radial_gradient (hb_paint_funcs_t *pfuncs HB_UNUSED,
+				void *paint_data,
+				hb_color_line_t *color_line,
+				float x0, float y0, float r0,
+				float x1, float y1, float r1,
+				void *user_data HB_UNUSED)
+{
+  hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data;
+
+  _hb_cairo_paint_radial_gradient (c, color_line, x0, y0, r0, x1, y1, r1);
+}
+
+static void
+hb_cairo_paint_sweep_gradient (hb_paint_funcs_t *pfuncs HB_UNUSED,
+			       void *paint_data,
+			       hb_color_line_t *color_line,
+			       float x0, float y0,
+			       float start_angle, float end_angle,
+			       void *user_data HB_UNUSED)
+{
+  hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data;
+
+  _hb_cairo_paint_sweep_gradient (c, color_line, x0, y0, start_angle, end_angle);
+}
+
+static const cairo_user_data_key_t color_cache_key = {0};
+
+static void
+_hb_cairo_destroy_map (void *p)
+{
+  hb_map_destroy ((hb_map_t *) p);
+}
+
+static hb_bool_t
+hb_cairo_paint_custom_palette_color (hb_paint_funcs_t *funcs,
+                                     void *paint_data,
+                                     unsigned int color_index,
+                                     hb_color_t *color,
+                                     void *user_data HB_UNUSED)
+{
+#ifdef HAVE_CAIRO_FONT_OPTIONS_GET_CUSTOM_PALETTE_COLOR
+  hb_cairo_context_t *c = (hb_cairo_context_t *) paint_data;
+  cairo_t *cr = c->cr;
+
+#define HB_DEADBEEF HB_TAG(0xDE,0xAD,0xBE,0xEF)
+
+  hb_map_t *color_cache = c->color_cache;
+  hb_codepoint_t *v;
+  if (likely (color_cache && color_cache->has (color_index, &v)))
+  {
+    if (*v == HB_DEADBEEF)
+      return false;
+    *color = *v;
+    return true;
+  }
+
+  cairo_font_options_t *options;
+  double red, green, blue, alpha;
+
+  options = cairo_font_options_create ();
+  cairo_get_font_options (cr, options);
+  if (CAIRO_STATUS_SUCCESS ==
+      cairo_font_options_get_custom_palette_color (options, color_index,
+                                                   &red, &green, &blue, &alpha))
+  {
+    cairo_font_options_destroy (options);
+    *color = HB_COLOR (round (255 * blue),
+		       round (255 * green),
+		       round (255 * red),
+		       round (255 * alpha));
+
+    if (likely (color_cache && *color != HB_DEADBEEF))
+      color_cache->set (color_index, *color);
+
+    return true;
+  }
+  cairo_font_options_destroy (options);
+
+  if (likely (color_cache))
+    color_cache->set (color_index, HB_DEADBEEF);
+
+#undef HB_DEADBEEF
+
+#endif
+
+  return false;
+}
+
+static inline void free_static_cairo_paint_funcs ();
+
+static struct hb_cairo_paint_funcs_lazy_loader_t : hb_paint_funcs_lazy_loader_t<hb_cairo_paint_funcs_lazy_loader_t>
+{
+  static hb_paint_funcs_t *create ()
+  {
+    hb_paint_funcs_t *funcs = hb_paint_funcs_create ();
+
+    hb_paint_funcs_set_push_transform_func (funcs, hb_cairo_push_transform, nullptr, nullptr);
+    hb_paint_funcs_set_pop_transform_func (funcs, hb_cairo_pop_transform, nullptr, nullptr);
+    hb_paint_funcs_set_push_clip_glyph_func (funcs, hb_cairo_push_clip_glyph, nullptr, nullptr);
+    hb_paint_funcs_set_push_clip_rectangle_func (funcs, hb_cairo_push_clip_rectangle, nullptr, nullptr);
+    hb_paint_funcs_set_pop_clip_func (funcs, hb_cairo_pop_clip, nullptr, nullptr);
+    hb_paint_funcs_set_push_group_func (funcs, hb_cairo_push_group, nullptr, nullptr);
+    hb_paint_funcs_set_pop_group_func (funcs, hb_cairo_pop_group, nullptr, nullptr);
+    hb_paint_funcs_set_color_func (funcs, hb_cairo_paint_color, nullptr, nullptr);
+    hb_paint_funcs_set_image_func (funcs, hb_cairo_paint_image, nullptr, nullptr);
+    hb_paint_funcs_set_linear_gradient_func (funcs, hb_cairo_paint_linear_gradient, nullptr, nullptr);
+    hb_paint_funcs_set_radial_gradient_func (funcs, hb_cairo_paint_radial_gradient, nullptr, nullptr);
+    hb_paint_funcs_set_sweep_gradient_func (funcs, hb_cairo_paint_sweep_gradient, nullptr, nullptr);
+    hb_paint_funcs_set_custom_palette_color_func (funcs, hb_cairo_paint_custom_palette_color, nullptr, nullptr);
+
+    hb_paint_funcs_make_immutable (funcs);
+
+    hb_atexit (free_static_cairo_paint_funcs);
+
+    return funcs;
+  }
+} static_cairo_paint_funcs;
+
+static inline
+void free_static_cairo_paint_funcs ()
+{
+  static_cairo_paint_funcs.free_instance ();
+}
+
+static hb_paint_funcs_t *
+hb_cairo_paint_get_funcs ()
+{
+  return static_cairo_paint_funcs.get_unconst ();
+}
+#endif
+
+static const cairo_user_data_key_t hb_cairo_face_user_data_key = {0};
+static const cairo_user_data_key_t hb_cairo_font_user_data_key = {0};
+static const cairo_user_data_key_t hb_cairo_font_init_func_user_data_key = {0};
+static const cairo_user_data_key_t hb_cairo_font_init_user_data_user_data_key = {0};
+static const cairo_user_data_key_t hb_cairo_scale_factor_user_data_key = {0};
+
+static void hb_cairo_face_destroy (void *p) { hb_face_destroy ((hb_face_t *) p); }
+static void hb_cairo_font_destroy (void *p) { hb_font_destroy ((hb_font_t *) p); }
+
+static cairo_status_t
+hb_cairo_init_scaled_font (cairo_scaled_font_t  *scaled_font,
+			   cairo_t              *cr HB_UNUSED,
+			   cairo_font_extents_t *extents)
+{
+  cairo_font_face_t *font_face = cairo_scaled_font_get_font_face (scaled_font);
+
+  hb_font_t *font = (hb_font_t *) cairo_font_face_get_user_data (font_face,
+								 &hb_cairo_font_user_data_key);
+
+  if (!font)
+  {
+    hb_face_t *face = (hb_face_t *) cairo_font_face_get_user_data (font_face,
+								   &hb_cairo_face_user_data_key);
+    font = hb_font_create (face);
+
+#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1,16,0)
+    cairo_font_options_t *font_options = cairo_font_options_create ();
+
+    // Set variations
+    cairo_scaled_font_get_font_options (scaled_font, font_options);
+    const char *variations = cairo_font_options_get_variations (font_options);
+    hb_vector_t<hb_variation_t> vars;
+    const char *p = variations;
+    while (p && *p)
+    {
+      const char *end = strpbrk ((char *) p, ", ");
+      hb_variation_t var;
+      if (hb_variation_from_string (p, end ? end - p : -1, &var))
+	vars.push (var);
+      p = end ? end + 1 : nullptr;
+    }
+    hb_font_set_variations (font, &vars[0], vars.length);
+
+    cairo_font_options_destroy (font_options);
+#endif
+
+    // Set scale; Note: should NOT set slant, or we'll double-slant.
+    unsigned scale_factor = hb_cairo_font_face_get_scale_factor (font_face);
+    if (scale_factor)
+    {
+      cairo_matrix_t font_matrix;
+      cairo_scaled_font_get_scale_matrix (scaled_font, &font_matrix);
+      hb_font_set_scale (font,
+			 round (font_matrix.xx * scale_factor),
+			 round (font_matrix.yy * scale_factor));
+    }
+
+    auto *init_func = (hb_cairo_font_init_func_t)
+		      cairo_font_face_get_user_data (font_face,
+						     &hb_cairo_font_init_func_user_data_key);
+    if (init_func)
+    {
+      void *user_data = cairo_font_face_get_user_data (font_face,
+						       &hb_cairo_font_init_user_data_user_data_key);
+      font = init_func (font, scaled_font, user_data);
+    }
+
+    hb_font_make_immutable (font);
+  }
+
+  cairo_scaled_font_set_user_data (scaled_font,
+				   &hb_cairo_font_user_data_key,
+				   (void *) hb_font_reference (font),
+				   hb_cairo_font_destroy);
+
+  hb_position_t x_scale, y_scale;
+  hb_font_get_scale (font, &x_scale, &y_scale);
+
+  hb_font_extents_t hb_extents;
+  hb_font_get_h_extents (font, &hb_extents);
+
+  extents->ascent  = (double)  hb_extents.ascender  / y_scale;
+  extents->descent = (double) -hb_extents.descender / y_scale;
+  extents->height  = extents->ascent + extents->descent;
+
+#ifdef HAVE_CAIRO_USER_FONT_FACE_SET_RENDER_COLOR_GLYPH_FUNC
+  hb_map_t *color_cache = hb_map_create ();
+  if (unlikely (CAIRO_STATUS_SUCCESS != cairo_scaled_font_set_user_data (scaled_font,
+									 &color_cache_key,
+									 color_cache,
+									 _hb_cairo_destroy_map)))
+    hb_map_destroy (color_cache);
+#endif
+
+  return CAIRO_STATUS_SUCCESS;
+}
+
+static cairo_status_t
+hb_cairo_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 *cluster_flags)
+{
+  hb_font_t *font = (hb_font_t *) cairo_scaled_font_get_user_data (scaled_font,
+								   &hb_cairo_font_user_data_key);
+
+  hb_buffer_t *buffer = hb_buffer_create ();
+  hb_buffer_add_utf8 (buffer, utf8, utf8_len, 0, utf8_len);
+  hb_buffer_guess_segment_properties (buffer);
+  hb_shape (font, buffer, nullptr, 0);
+
+  hb_cairo_glyphs_from_buffer (buffer,
+			       true,
+			       font->x_scale, font->y_scale,
+			       0., 0.,
+			       utf8, utf8_len,
+			       glyphs, (unsigned *) num_glyphs,
+			       clusters, (unsigned *) num_clusters,
+			       cluster_flags);
+
+  hb_buffer_destroy (buffer);
+
+  return CAIRO_STATUS_SUCCESS;
+}
+
+static cairo_status_t
+hb_cairo_render_glyph (cairo_scaled_font_t  *scaled_font,
+		       unsigned long         glyph,
+		       cairo_t              *cr,
+		       cairo_text_extents_t *extents)
+{
+  hb_font_t *font = (hb_font_t *) cairo_scaled_font_get_user_data (scaled_font,
+								   &hb_cairo_font_user_data_key);
+
+  hb_position_t x_scale, y_scale;
+  hb_font_get_scale (font, &x_scale, &y_scale);
+  cairo_scale (cr, +1./x_scale, -1./y_scale);
+
+  hb_font_draw_glyph (font, glyph, hb_cairo_draw_get_funcs (), cr);
+
+  cairo_fill (cr);
+
+  return CAIRO_STATUS_SUCCESS;
+}
+
+#ifdef HAVE_CAIRO_USER_FONT_FACE_SET_RENDER_COLOR_GLYPH_FUNC
+
+static cairo_status_t
+hb_cairo_render_color_glyph (cairo_scaled_font_t  *scaled_font,
+			     unsigned long         glyph,
+			     cairo_t              *cr,
+			     cairo_text_extents_t *extents)
+{
+  hb_font_t *font = (hb_font_t *) cairo_scaled_font_get_user_data (scaled_font,
+								   &hb_cairo_font_user_data_key);
+
+  unsigned int palette = 0;
+#ifdef CAIRO_COLOR_PALETTE_DEFAULT
+  cairo_font_options_t *options = cairo_font_options_create ();
+  cairo_scaled_font_get_font_options (scaled_font, options);
+  palette = cairo_font_options_get_color_palette (options);
+  cairo_font_options_destroy (options);
+#endif
+
+  hb_color_t color = HB_COLOR (0, 0, 0, 255);
+  hb_position_t x_scale, y_scale;
+  hb_font_get_scale (font, &x_scale, &y_scale);
+  cairo_scale (cr, +1./x_scale, -1./y_scale);
+
+  hb_cairo_context_t c;
+  c.scaled_font = scaled_font;
+  c.cr = cr;
+  c.color_cache = (hb_map_t *) cairo_scaled_font_get_user_data (scaled_font, &color_cache_key);
+
+  hb_font_paint_glyph (font, glyph, hb_cairo_paint_get_funcs (), &c, palette, color);
+
+
+  return CAIRO_STATUS_SUCCESS;
+}
+
+#endif
+
+static cairo_font_face_t *
+user_font_face_create (hb_face_t *face)
+{
+  cairo_font_face_t *cairo_face;
+
+  cairo_face = cairo_user_font_face_create ();
+  cairo_user_font_face_set_init_func (cairo_face, hb_cairo_init_scaled_font);
+  cairo_user_font_face_set_text_to_glyphs_func (cairo_face, hb_cairo_text_to_glyphs);
+  cairo_user_font_face_set_render_glyph_func (cairo_face, hb_cairo_render_glyph);
+#ifdef HAVE_CAIRO_USER_FONT_FACE_SET_RENDER_COLOR_GLYPH_FUNC
+  if (hb_ot_color_has_png (face) || hb_ot_color_has_layers (face) || hb_ot_color_has_paint (face))
+    cairo_user_font_face_set_render_color_glyph_func (cairo_face, hb_cairo_render_color_glyph);
+#endif
+
+  if (unlikely (CAIRO_STATUS_SUCCESS != cairo_font_face_set_user_data (cairo_face,
+								       &hb_cairo_face_user_data_key,
+								       (void *) hb_face_reference (face),
+								       hb_cairo_face_destroy)))
+    hb_face_destroy (face);
+
+  return cairo_face;
+}
+
+/**
+ * hb_cairo_font_face_create_for_font:
+ * @font: a #hb_font_t
+ *
+ * Creates a #cairo_font_face_t for rendering text according
+ * to @font.
+ *
+ * Note that the scale of @font does not affect the rendering,
+ * but the variations and slant that are set on @font do.
+ *
+ * Returns: (transfer full): a newly created #cairo_font_face_t
+ *
+ * Since: 7.0.0
+ */
+cairo_font_face_t *
+hb_cairo_font_face_create_for_font (hb_font_t *font)
+{
+  hb_font_make_immutable (font);
+
+  auto *cairo_face =  user_font_face_create (font->face);
+
+  if (unlikely (CAIRO_STATUS_SUCCESS != cairo_font_face_set_user_data (cairo_face,
+								       &hb_cairo_font_user_data_key,
+								       (void *) hb_font_reference (font),
+								       hb_cairo_font_destroy)))
+    hb_font_destroy (font);
+
+  return cairo_face;
+}
+
+/**
+ * hb_cairo_font_face_get_font:
+ * @font_face: a #cairo_font_face_t
+ *
+ * Gets the #hb_font_t that @font_face was created from.
+ *
+ * Returns: (nullable) (transfer none): the #hb_font_t that @font_face was created from
+ *
+ * Since: 7.0.0
+ */
+hb_font_t *
+hb_cairo_font_face_get_font (cairo_font_face_t *font_face)
+{
+  return (hb_font_t *) cairo_font_face_get_user_data (font_face,
+						      &hb_cairo_font_user_data_key);
+}
+
+/**
+ * hb_cairo_font_face_create_for_face:
+ * @face: a #hb_face_t
+ *
+ * Creates a #cairo_font_face_t for rendering text according
+ * to @face.
+ *
+ * Returns: (transfer full): a newly created #cairo_font_face_t
+ *
+ * Since: 7.0.0
+ */
+cairo_font_face_t *
+hb_cairo_font_face_create_for_face (hb_face_t *face)
+{
+  hb_face_make_immutable (face);
+
+  return user_font_face_create (face);
+}
+
+/**
+ * hb_cairo_font_face_get_face:
+ * @font_face: a #cairo_font_face_t
+ *
+ * Gets the #hb_face_t associated with @font_face.
+ *
+ * Returns: (nullable) (transfer none): the #hb_face_t associated with @font_face
+ *
+ * Since: 7.0.0
+ */
+hb_face_t *
+hb_cairo_font_face_get_face (cairo_font_face_t *font_face)
+{
+  return (hb_face_t *) cairo_font_face_get_user_data (font_face,
+						      &hb_cairo_face_user_data_key);
+}
+
+/**
+ * hb_cairo_font_face_set_font_init_func:
+ * @font_face: a #cairo_font_face_t
+ * @func: The virtual method to use
+ * @user_data: user data accompanying the method
+ * @destroy: function to call when @user_data is not needed anymore
+ *
+ * Set the virtual method to be called when a cairo
+ * face created using hb_cairo_font_face_create_for_face()
+ * creates an #hb_font_t for a #cairo_scaled_font_t.
+ *
+ * Since: 7.0.0
+ */
+void
+hb_cairo_font_face_set_font_init_func (cairo_font_face_t *font_face,
+				       hb_cairo_font_init_func_t func,
+				       void *user_data,
+				       hb_destroy_func_t destroy)
+{
+  cairo_font_face_set_user_data (font_face,
+				 &hb_cairo_font_init_func_user_data_key,
+				 (void *) func,
+				 nullptr);
+  if (unlikely (CAIRO_STATUS_SUCCESS != cairo_font_face_set_user_data (font_face,
+								       &hb_cairo_font_init_user_data_user_data_key,
+								       (void *) user_data,
+								       destroy)) && destroy)
+  {
+    destroy (user_data);
+    cairo_font_face_set_user_data (font_face,
+				   &hb_cairo_font_init_func_user_data_key,
+				   nullptr,
+				   nullptr);
+  }
+}
+
+/**
+ * hb_cairo_scaled_font_get_font:
+ * @scaled_font: a #cairo_scaled_font_t
+ *
+ * Gets the #hb_font_t associated with @scaled_font.
+ *
+ * Returns: (nullable) (transfer none): the #hb_font_t associated with @scaled_font
+ *
+ * Since: 7.0.0
+ */
+hb_font_t *
+hb_cairo_scaled_font_get_font (cairo_scaled_font_t *scaled_font)
+{
+  return (hb_font_t *) cairo_scaled_font_get_user_data (scaled_font, &hb_cairo_font_user_data_key);
+}
+
+
+/**
+ * hb_cairo_font_face_set_scale_factor:
+ * @scale_factor: The scale factor to use. See below
+ * @font_face: a #cairo_font_face_t
+ *
+ * Sets the scale factor of the @font_face. Default scale
+ * factor is zero.
+ *
+ * When a #cairo_font_face_t is created from a #hb_face_t using
+ * hb_cairo_font_face_create_for_face(), such face will create
+ * #hb_font_t objects during scaled-font creation.  The scale
+ * factor defines how the scale set on such #hb_font_t objects
+ * relates to the font-matrix (as such font size) of the cairo
+ * scaled-font.
+ *
+ * If the scale-factor is zero (default), then the scale of the
+ * #hb_font_t object will be left at default, which is the UPEM
+ * value of the respective #hb_face_t.
+ *
+ * If the scale-factor is set to non-zero, then the X and Y scale
+ * of the #hb_font_t object will be respectively set to the
+ * @scale_factor times the xx and yy elements of the scale-matrix
+ * of the cairo scaled-font being created.
+ *
+ * When using the hb_cairo_glyphs_from_buffer() API to convert the
+ * HarfBuzz glyph buffer that resulted from shaping with such a #hb_font_t,
+ * if the scale-factor was non-zero, you can pass it directly to
+ * that API as both X and Y scale factors.
+ *
+ * If the scale-factor was zero however, or the cairo face was
+ * created using the alternative constructor
+ * hb_cairo_font_face_create_for_font(), you need to calculate the
+ * correct X/Y scale-factors to pass to hb_cairo_glyphs_from_buffer()
+ * by dividing the #hb_font_t X/Y scale-factors by the
+ * cairo scaled-font's scale-matrix XX/YY components respectively
+ * and use those values.  Or if you know that relationship offhand
+ * (because you set the scale of the #hb_font_t yourself), use
+ * the conversion rate involved.
+ *
+ * Since: 7.0.0
+ */
+void
+hb_cairo_font_face_set_scale_factor (cairo_font_face_t *font_face,
+				     unsigned int scale_factor)
+{
+  cairo_font_face_set_user_data (font_face,
+				 &hb_cairo_scale_factor_user_data_key,
+				 (void *) (uintptr_t) scale_factor,
+				 nullptr);
+}
+
+/**
+ * hb_cairo_font_face_get_scale_factor:
+ * @font_face: a #cairo_font_face_t
+ *
+ * Gets the scale factor set on the @font_face. Defaults to zero.
+ * See hb_cairo_font_face_set_scale_factor() for details.
+ *
+ * Returns: the scale factor of @font_face
+ *
+ * Since: 7.0.0
+ */
+unsigned int
+hb_cairo_font_face_get_scale_factor (cairo_font_face_t *font_face)
+{
+  return (unsigned int) (uintptr_t)
+	 cairo_font_face_get_user_data (font_face,
+					&hb_cairo_scale_factor_user_data_key);
+}
+
+
+/**
+ * hb_cairo_glyphs_from_buffer:
+ * @buffer: a #hb_buffer_t containing glyphs
+ * @utf8_clusters: `true` if @buffer clusters are in bytes, instead of characters
+ * @x_scale_factor: scale factor to divide #hb_position_t Y values by
+ * @y_scale_factor: scale factor to divide #hb_position_t X values by
+ * @x: X position to place first glyph
+ * @y: Y position to place first glyph
+ * @utf8: (nullable): the text that was shaped in @buffer
+ * @utf8_len: the length of @utf8 in bytes
+ * @glyphs: (out): return location for an array of #cairo_glyph_t
+ * @num_glyphs: (inout): return location for the length of @glyphs
+ * @clusters: (out) (nullable): return location for an array of cluster positions
+ * @num_clusters: (inout) (nullable): return location for the length of @clusters
+ * @cluster_flags: (out) (nullable): return location for cluster flags
+ *
+ * Extracts information from @buffer in a form that can be
+ * passed to cairo_show_text_glyphs() or cairo_show_glyphs().
+ * This API is modeled after cairo_scaled_font_text_to_glyphs() and
+ * cairo_user_scaled_font_text_to_glyphs_func_t.
+ *
+ * The @num_glyphs argument should be preset to the number of glyph entries available
+ * in the @glyphs buffer. If the @glyphs buffer is `NULL`, the value of
+ * @num_glyphs must be zero.  If the provided glyph array is too short for
+ * the conversion (or for convenience), a new glyph array may be allocated
+ * using cairo_glyph_allocate() and placed in @glyphs.  Upon return,
+ * @num_glyphs should contain the number of generated glyphs.  If the value
+ * @glyphs points at has changed after the call, the caller will free the
+ * allocated glyph array using cairo_glyph_free().  The caller will also free
+ * the original value of @glyphs, so this function shouldn't do so.
+ *
+ * If @clusters is not `NULL`, then @num_clusters and @cluster_flags
+ * should not be either, and @utf8 must be provided, and cluster
+ * mapping will be computed. The semantics of how
+ * cluster array allocation works is similar to the glyph array.  That is,
+ * if @clusters initially points to a non-`NULL` value, that array may be used
+ * as a cluster buffer, and @num_clusters points to the number of cluster
+ * entries available there.  If the provided cluster array is too short for
+ * the conversion (or for convenience), a new cluster array may be allocated
+ * using cairo_text_cluster_allocate() and placed in @clusters.  In this case,
+ * the original value of @clusters will still be freed by the caller.  Upon
+ * return, @num_clusters will contain the number of generated clusters.
+ * If the value @clusters points at has changed after the call, the caller
+ * will free the allocated cluster array using cairo_text_cluster_free().
+ *
+ * See hb_cairo_font_face_set_scale_factor() for the details of
+ * the @scale_factor argument.
+ *
+ * The returned @glyphs vector actually has `@num_glyphs + 1` entries in
+ * it and the x,y values of the extra entry at the end add up the advance
+ * x,y of all the glyphs in the @buffer.
+ *
+ * Since: 7.0.0
+ */
+void
+hb_cairo_glyphs_from_buffer (hb_buffer_t *buffer,
+			     hb_bool_t utf8_clusters,
+			     double x_scale_factor,
+			     double y_scale_factor,
+			     double x,
+			     double y,
+			     const char *utf8,
+			     int utf8_len,
+			     cairo_glyph_t **glyphs,
+			     unsigned int *num_glyphs,
+			     cairo_text_cluster_t **clusters,
+			     unsigned int *num_clusters,
+			     cairo_text_cluster_flags_t *cluster_flags)
+{
+  if (utf8 && utf8_len < 0)
+    utf8_len = strlen (utf8);
+
+  unsigned orig_num_glyphs = *num_glyphs;
+  *num_glyphs = hb_buffer_get_length (buffer);
+  hb_glyph_info_t *hb_glyph = hb_buffer_get_glyph_infos (buffer, nullptr);
+  hb_glyph_position_t *hb_position = hb_buffer_get_glyph_positions (buffer, nullptr);
+  if (orig_num_glyphs < *num_glyphs + 1)
+    *glyphs = cairo_glyph_allocate (*num_glyphs + 1);
+
+  if (clusters && utf8)
+  {
+    unsigned orig_num_clusters = *num_clusters;
+    *num_clusters = *num_glyphs ? 1 : 0;
+    for (unsigned int i = 1; i < *num_glyphs; i++)
+      if (hb_glyph[i].cluster != hb_glyph[i-1].cluster)
+	(*num_clusters)++;
+    if (orig_num_clusters < *num_clusters)
+      *clusters = cairo_text_cluster_allocate (*num_clusters);
+  }
+
+  double x_scale = x_scale_factor ? 1. / x_scale_factor : 0.;
+  double y_scale = y_scale_factor ? 1. / y_scale_factor : 0.;
+  hb_position_t hx = 0, hy = 0;
+  int i;
+  for (i = 0; i < (int) *num_glyphs; i++)
+  {
+    (*glyphs)[i].index = hb_glyph[i].codepoint;
+    (*glyphs)[i].x = x + (+hb_position->x_offset + hx) * x_scale;
+    (*glyphs)[i].y = y + (-hb_position->y_offset + hy) * y_scale;
+    hx +=  hb_position->x_advance;
+    hy += -hb_position->y_advance;
+
+    hb_position++;
+  }
+  (*glyphs)[i].index = -1;
+  (*glyphs)[i].x = round (hx * x_scale);
+  (*glyphs)[i].y = round (hy * y_scale);
+
+  if (clusters && *num_clusters && utf8)
+  {
+    memset ((void *) *clusters, 0, *num_clusters * sizeof ((*clusters)[0]));
+    hb_bool_t backward = HB_DIRECTION_IS_BACKWARD (hb_buffer_get_direction (buffer));
+    *cluster_flags = backward ? CAIRO_TEXT_CLUSTER_FLAG_BACKWARD : (cairo_text_cluster_flags_t) 0;
+    unsigned int cluster = 0;
+    const char *start = utf8, *end;
+    (*clusters)[cluster].num_glyphs++;
+    if (backward)
+    {
+      for (i = *num_glyphs - 2; i >= 0; i--)
+      {
+	if (hb_glyph[i].cluster != hb_glyph[i+1].cluster)
+	{
+	  assert (hb_glyph[i].cluster > hb_glyph[i+1].cluster);
+	  if (utf8_clusters)
+	    end = start + hb_glyph[i].cluster - hb_glyph[i+1].cluster;
+	  else
+	    end = (const char *) hb_utf_offset_to_pointer<hb_utf8_t> ((const uint8_t *) start,
+								      (signed) (hb_glyph[i].cluster - hb_glyph[i+1].cluster));
+	  (*clusters)[cluster].num_bytes = end - start;
+	  start = end;
+	  cluster++;
+	}
+	(*clusters)[cluster].num_glyphs++;
+      }
+      (*clusters)[cluster].num_bytes = utf8 + utf8_len - start;
+    }
+    else
+    {
+      for (i = 1; i < (int) *num_glyphs; i++)
+      {
+	if (hb_glyph[i].cluster != hb_glyph[i-1].cluster)
+	{
+	  assert (hb_glyph[i].cluster > hb_glyph[i-1].cluster);
+	  if (utf8_clusters)
+	    end = start + hb_glyph[i].cluster - hb_glyph[i-1].cluster;
+	  else
+	    end = (const char *) hb_utf_offset_to_pointer<hb_utf8_t> ((const uint8_t *) start,
+								      (signed) (hb_glyph[i].cluster - hb_glyph[i-1].cluster));
+	  (*clusters)[cluster].num_bytes = end - start;
+	  start = end;
+	  cluster++;
+	}
+	(*clusters)[cluster].num_glyphs++;
+      }
+      (*clusters)[cluster].num_bytes = utf8 + utf8_len - start;
+    }
+  }
+  else if (num_clusters)
+    *num_clusters = 0;
+}
+
+#endif