Change RendererAgg.draw_text to use FT2Font._render_glyph

QuLogic · QuLogic · commit 931bcf3f0341 · 2026-02-06T15:38:18.000-05:00
This makes it more similar to `draw_mathtext`, and is necessary for
colour fonts, where the previously-cached bitmap would have been
downgraded to black&amp;white strokes by FreeType when copied. It should
also reduce the necessary code paths with the other text drawing methods
as well.
diff --git a/lib/matplotlib/backends/backend_agg.py b/lib/matplotlib/backends/backend_agg.py
@@ -229,13 +229,25 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
         if ismath:
             return self.draw_mathtext(gc, x, y, s, prop, angle)
         font = self._prepare_font(prop)
-        font.set_text(s, angle, flags=get_hinting_flag(),
-                      features=mtext.get_fontfeatures() if mtext is not None else None,
-                      language=mtext.get_language() if mtext is not None else None)
-        for bitmap in font._render_glyphs(
-            x, self.height - y,
-            RenderMode.NORMAL if gc.get_antialiased() else RenderMode.MONO,
-        ):
+        cos = math.cos(math.radians(angle))
+        sin = math.sin(math.radians(angle))
+        load_flags = get_hinting_flag()
+        items = font._layout(
+            s, flags=load_flags,
+            features=mtext.get_fontfeatures() if mtext is not None else None,
+            language=mtext.get_language() if mtext is not None else None)
+        for item in items:
+            hf = item.ft_object._hinting_factor
+            item.ft_object._set_transform(
+                [[round(0x10000 * cos / hf), round(0x10000 * -sin)],
+                 [round(0x10000 * sin / hf), round(0x10000 * cos)]],
+                [round(0x40 * (x + item.x * cos - item.y * sin)),
+                 # FreeType's y is upwards.
+                 round(0x40 * (self.height - y + item.x * sin + item.y * cos))]
+            )
+            bitmap = item.ft_object._render_glyph(
+                item.glyph_index, load_flags,
+                RenderMode.NORMAL if gc.get_antialiased() else RenderMode.MONO)
             buffer = bitmap.buffer
             if not gc.get_antialiased():
                 buffer *= 0xff
diff --git a/src/ft2font_wrapper.cpp b/src/ft2font_wrapper.cpp
@@ -1933,16 +1933,6 @@ PYBIND11_MODULE(ft2font, m, py::mod_gil_not_used())
                 FT_CHECK(FT_Render_Glyph, face->glyph, render_mode);
                 return PyPositionedBitmap{face->glyph};
             })
-        .def("_render_glyphs",
-             [](PyFT2Font *self, double x, double y, FT_Render_Mode render_mode) {
-                auto origin = FT_Vector{std::lround(x * 64), std::lround(y * 64)};
-                auto pbs = std::vector<PyPositionedBitmap>{};
-                for (auto &g: self->get_glyphs()) {
-                    FT_CHECK(FT_Glyph_To_Bitmap, &g, render_mode, &origin, 1);
-                    pbs.emplace_back(reinterpret_cast<FT_BitmapGlyph>(g));
-                }
-                return pbs;
-            })
         ;
 
     m.attr("__freetype_version__") = version_string;
