Disable harfbuzz for color fonts.

Author: anntzer

src/_util.cpp

@@ -2,6 +2,7 @@
 
 #include "_raqm.h"
 
+#include FT_TRUETYPE_TABLES_H
 #include <regex>
 #include <stack>
 
@@ -33,7 +34,8 @@ ITER_CAIRO_OPTIONAL_API(DEFINE_API)
 
 // Other useful values.
 std::unordered_map<std::string, cairo_font_face_t*> FONT_CACHE{};
-cairo_user_data_key_t const REFS_KEY{}, STATE_KEY{}, FT_KEY{}, FEATURES_KEY{};
+cairo_user_data_key_t const
+  REFS_KEY{}, STATE_KEY{}, FT_KEY{}, FEATURES_KEY{}, IS_COLOR_FONT_KEY{};
 py::object RC_PARAMS{py::none{}},
            PIXEL_MARKER{py::none{}},
            UNIT_CIRCLE{py::none{}};
@@ -611,6 +613,26 @@ cairo_font_face_t* font_face_from_path(std::string pathspec)
       [](void* ptr) -> void {
         delete static_cast<std::vector<std::string>*>(ptr);
       });
+    // FIXME[harfbuzz] (#2428) Disable raqm for color fonts.
+    auto n_tables = FT_ULong{}, table_length = FT_ULong{};
+    FT_CHECK(FT_Sfnt_Table_Info, ft_face, 0, nullptr, &n_tables);
+    for (auto i = FT_ULong{}; i < n_tables; ++i) {
+      auto tag = FT_ULong{};
+      FT_CHECK(
+        FT_Sfnt_Table_Info, ft_face, i, &tag, &table_length);
+      if (tag == FT_MAKE_TAG('C', 'O', 'L', 'R')
+          || tag == FT_MAKE_TAG('C', 'P', 'A', 'L')
+          || tag == FT_MAKE_TAG('C', 'B', 'D', 'T')
+          || tag == FT_MAKE_TAG('C', 'B', 'L', 'C')
+          || tag == FT_MAKE_TAG('s', 'b', 'i', 'x')
+          || tag == FT_MAKE_TAG('S', 'V', 'G', ' ')) {
+        CAIRO_CLEANUP_CHECK(
+          { cairo_font_face_destroy(font_face); },
+          cairo_font_face_set_user_data,
+          font_face, &detail::IS_COLOR_FONT_KEY, font_face, nullptr);
+        break;
+      }
+    }
   }
   return font_face;
 }
@@ -671,7 +693,8 @@ GlyphsAndClusters text_to_glyphs_and_clusters(cairo_t* cr, std::string s)
 {
   auto const& scaled_font = cairo_get_scaled_font(cr);
   auto gac = GlyphsAndClusters{};
-  if (has_raqm()) {
+  if (has_raqm()
+      && !cairo_font_face_get_user_data(cairo_get_font_face(cr), &detail::IS_COLOR_FONT_KEY)) {
     auto const& ft_face = cairo_ft_scaled_font_lock_face(scaled_font);
     auto const& scaled_font_unlock_cleanup =
       std::unique_ptr<

src/_util.h

@@ -68,10 +68,11 @@ extern void (*cairo_ps_surface_dsc_comment)(cairo_surface_t*, char const*);
 // Other useful values.
 extern std::unordered_map<std::string, cairo_font_face_t*> FONT_CACHE;
 extern cairo_user_data_key_t const
-  REFS_KEY,      // cairo_t -> kept alive Python objects.
-  STATE_KEY,     // cairo_t -> additional state.
-  FT_KEY,        // cairo_font_face_t -> FT_Face.
-  FEATURES_KEY;  // cairo_font_face_t -> OpenType features.
+  REFS_KEY,           // cairo_t -> kept alive Python objects.
+  STATE_KEY,          // cairo_t -> additional state.
+  FT_KEY,             // cairo_font_face_t -> FT_Face.
+  FEATURES_KEY,       // cairo_font_face_t -> OpenType features.
+  IS_COLOR_FONT_KEY;  // cairo_font_face_t -> non-null if a color font.
 extern py::object RC_PARAMS;
 extern py::object PIXEL_MARKER;
 extern py::object UNIT_CIRCLE;