gsk: Use harfbuzz for color fonts

harfbuzz has all the information we need, so we
can avoid poking directly at freetype apis. Also
drop the caching of color glyph information until
it turns out to be a problem.

1 files changed, 45 insertions, 105 deletions

diff --git a/gsk/gskrendernodeimpl.c b/gsk/gskrendernodeimpl.c
index c44ce88784..5e07a8f92a 100644
--- a/gsk/gskrendernodeimpl.c
+++ b/gsk/gskrendernodeimpl.c
@@ -30,7 +30,7 @@
 #include "gdk/gdktextureprivate.h"
 #include "gdk/gdk-private.h"
 
-#include <cairo-ft.h>
+#include <hb-ot.h>
 
 static inline void
 gsk_cairo_rectangle (cairo_t               *cr,
@@ -4425,119 +4425,45 @@ gsk_text_node_diff (GskRenderNode  *node1,
 }
 
 static gboolean
-font_has_color_glyphs (const PangoFont *font)
+font_has_color_glyphs (PangoFont *font)
 {
-  cairo_scaled_font_t *scaled_font;
-  gboolean has_color = FALSE;
+  hb_face_t *face = hb_font_get_face (pango_font_get_hb_font (font));
 
-  scaled_font = pango_cairo_font_get_scaled_font ((PangoCairoFont *)font);
-  if (cairo_scaled_font_get_type (scaled_font) == CAIRO_FONT_TYPE_FT)
-    {
-      FT_Face ft_face = cairo_ft_scaled_font_lock_face (scaled_font);
-      has_color = (FT_HAS_COLOR (ft_face) != 0);
-      cairo_ft_scaled_font_unlock_face (scaled_font);
-    }
-
-  return has_color;
+  return hb_ot_color_has_layers (face) ||
+         hb_ot_color_has_png (face) ||
+         hb_ot_color_has_svg (face);
 }
 
 static gboolean
-glyph_has_color (FT_Face face,
-                 guint   glyph)
+glyph_has_color (PangoFont *font,
+                 guint      glyph)
 {
-  FT_Error error;
+  hb_font_t *hb_font = pango_font_get_hb_font (font);
+  hb_face_t *face = hb_font_get_face (hb_font);
+  hb_blob_t *blob;
 
-  error = FT_Load_Glyph (face, glyph, FT_LOAD_COLOR);
-  if (error != 0)
-    return FALSE;
-
-  error = FT_Render_Glyph (face->glyph, FT_RENDER_MODE_NORMAL);
-  if (error != 0)
-    return FALSE;
-
-  if (face->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_BGRA)
+  if (hb_ot_color_glyph_get_layers (face, glyph, 0, NULL, NULL) > 0)
     return TRUE;
 
-  return FALSE;
-}
-
-static GHashTable *
-ensure_color_glyph_cache (const PangoFont *font)
-{
-  GHashTable *cache;
-
-  cache = (GHashTable *) g_object_get_data (G_OBJECT (font), "gsk-color-glyph-cache");
-  if (!cache)
+  blob = hb_ot_color_glyph_reference_png (hb_font, glyph);
+  if (blob)
     {
-      cache = g_hash_table_new (NULL, NULL);
-      g_object_set_data_full (G_OBJECT (font), "gsk-color-glyph-cache",
-                              cache, (GDestroyNotify) g_hash_table_unref);
+      guint length = hb_blob_get_length (blob);
+      hb_blob_destroy (blob);
+      return length > 0;
     }
 
-  return cache;
-}
-
-static inline gboolean
-lookup_color_glyph_cache (GHashTable *cache,
-                          PangoGlyph  glyph,
-                          gboolean   *has_color)
-{
-  gpointer value;
-
-  if (g_hash_table_lookup_extended (cache, GUINT_TO_POINTER (glyph), NULL, &value))
+  blob = hb_ot_color_glyph_reference_svg (face, glyph);
+  if (blob)
     {
-      *has_color = GPOINTER_TO_UINT (value);
-      return TRUE;
+      guint length = hb_blob_get_length (blob);
+      hb_blob_destroy (blob);
+      return length > 0;
     }
 
   return FALSE;
 }
 
-static inline void
-insert_color_glyph_cache (GHashTable *cache,
-                          PangoGlyph  glyph,
-                          gboolean has_color)
-{
-  g_hash_table_insert (cache, GUINT_TO_POINTER (glyph), GUINT_TO_POINTER (has_color));
-}
-
-static void
-mark_color_glyphs (const PangoFont *font,
-                   PangoGlyphInfo  *glyphs,
-                   int              num_glyphs)
-{
-  cairo_scaled_font_t *scaled_font;
-  FT_Face ft_face;
-  GHashTable *cache;
-
-  scaled_font = pango_cairo_font_get_scaled_font ((PangoCairoFont *)font);
-  if (cairo_scaled_font_get_type (scaled_font) != CAIRO_FONT_TYPE_FT)
-    return;
-
-  ft_face = cairo_ft_scaled_font_lock_face (scaled_font);
-  if (!FT_HAS_COLOR (ft_face))
-    goto out;
-
-  cache = ensure_color_glyph_cache (font);
-
-  for (int i = 0; i < num_glyphs; i++)
-    {
-      gboolean has_color;
-
-      if (!lookup_color_glyph_cache (cache, glyphs[i].glyph, &has_color))
-        {
-          has_color = glyph_has_color (ft_face, glyphs[i].glyph);
-          insert_color_glyph_cache (cache, glyphs[i].glyph, has_color);
-        }
-
-      if (has_color)
-        GLYPH_SET_COLOR (&glyphs[i]);
-    }
-
-out:
-  cairo_ft_scaled_font_unlock_face (scaled_font);
-}
-
 /**
  * gsk_text_node_new:
  * @font: the `PangoFont` containing the glyphs
@@ -4561,6 +4487,9 @@ gsk_text_node_new (PangoFont              *font,
   GskTextNode *self;
   GskRenderNode *node;
   PangoRectangle ink_rect;
+  PangoGlyphInfo *glyph_infos;
+  gboolean has_color_glyphs;
+  int n;
 
   pango_glyph_string_extents (glyphs, font, &ink_rect, NULL);
   pango_extents_to_pixels (&ink_rect, NULL);
@@ -4573,24 +4502,35 @@ gsk_text_node_new (PangoFont              *font,
   node = (GskRenderNode *) self;
 
   self->font = g_object_ref (font);
-  self->has_color_glyphs = font_has_color_glyphs (font);
   self->color = *color;
   self->offset = *offset;
-  self->glyphs = g_malloc_n (glyphs->num_glyphs, sizeof (PangoGlyphInfo));
+  self->has_color_glyphs = FALSE;
 
-  /* skip empty glyphs */
-  self->num_glyphs = 0;
+  glyph_infos = g_malloc_n (glyphs->num_glyphs, sizeof (PangoGlyphInfo));
+  has_color_glyphs = font_has_color_glyphs (font);
+
+  n = 0;
   for (int i = 0; i < glyphs->num_glyphs; i++)
     {
-      if (glyphs->glyphs[i].glyph != PANGO_GLYPH_EMPTY)
+      /* skip empty glyphs */
+      if (glyphs->glyphs[i].glyph == PANGO_GLYPH_EMPTY)
+        continue;
+
+      glyph_infos[n] = glyphs->glyphs[i];
+      GLYPH_CLEAR_COLOR (&glyph_infos[n]);
+
+      if (has_color_glyphs &&
+          glyph_has_color (font, glyph_infos[n].glyph))
         {
-          self->glyphs[self->num_glyphs] = glyphs->glyphs[i];
-          GLYPH_CLEAR_COLOR (&self->glyphs[self->num_glyphs]);
-          self->num_glyphs++;
+          self->has_color_glyphs = TRUE;
+          GLYPH_SET_COLOR (&glyph_infos[n]);
         }
+
+      n++;
     }
 
-  mark_color_glyphs (font, self->glyphs, self->num_glyphs);
+  self->glyphs = glyph_infos;
+  self->num_glyphs = n;
 
   graphene_rect_init (&node->bounds,
                       offset->x + ink_rect.x - 1,