document and add tests for SBIX color font support

.github/workflows/test-windows.yml

@@ -110,7 +110,7 @@ jobs:
       if: steps.build-cache.outputs.cache-hit != 'true'
       run: "& winbuild\\build\\build_dep_libwebp.cmd"
 
-    # for FreeType CBDT font support
+    # for FreeType CBDT/SBIX font support
     - name: Build dependencies / libpng
       if: steps.build-cache.outputs.cache-hit != 'true'
       run: "& winbuild\\build\\build_dep_libpng.cmd"

Tests/fonts/LICENSE.txt

@@ -15,6 +15,8 @@ FreeMono.ttf is licensed under GPLv3, with the GPL font exception.
 
 OpenSansCondensed-LightItalic.tt, from https://fonts.google.com/specimen/Open+Sans, under Apache License 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
 
+chromacheck-sbix.woff, from https://github.com/RoelN/ChromaCheck, under The MIT License (MIT), Copyright (c) 2018 Roel Nieskens, https://pixelambacht.nl Copyright (c) 2018 Google LLC
+
 DejaVuSans-24-{1,2,4,8}-stripped.ttf are based on DejaVuSans.ttf converted using FontForge to add bitmap strikes and keep only the ASCII range.
 
 

Tests/test_imagefont.py

@@ -897,6 +897,46 @@ class TestImageFont:
             assert str(e) in ("unimplemented feature", "unknown file format")
             pytest.skip("freetype compiled without libpng or unsupported")
 
+    @skip_unless_feature_version("freetype2", "2.5.1")
+    def test_sbix(self):
+        try:
+            font = ImageFont.truetype(
+                "Tests/fonts/chromacheck-sbix.woff",
+                size=300,
+                layout_engine=self.LAYOUT_ENGINE,
+            )
+
+            im = Image.new("RGB", (400, 400), "white")
+            d = ImageDraw.Draw(im)
+
+            d.text((50, 50), "\uE901", embedded_color=True, font=font)
+
+            with Image.open("Tests/images/chromacheck-sbix.png") as expected:
+                assert_image_similar(im, expected, 1)
+        except IOError as e:
+            assert str(e) in ("unimplemented feature", "unknown file format")
+            pytest.skip("freetype compiled without libpng or unsupported")
+
+    @skip_unless_feature_version("freetype2", "2.5.1")
+    def test_sbix_mask(self):
+        try:
+            font = ImageFont.truetype(
+                "Tests/fonts/chromacheck-sbix.woff",
+                size=300,
+                layout_engine=self.LAYOUT_ENGINE,
+            )
+
+            im = Image.new("RGB", (400, 400), "white")
+            d = ImageDraw.Draw(im)
+
+            d.text((50, 50), "\uE901", (100, 0, 0), font=font)
+
+            with Image.open("Tests/images/chromacheck-sbix_mask.png") as expected:
+                assert_image_similar(im, expected, 1)
+        except IOError as e:
+            assert str(e) in ("unimplemented feature", "unknown file format")
+            pytest.skip("freetype compiled without libpng or unsupported")
+
     @skip_unless_feature_version("freetype2", "2.10.0")
     def test_colr(self):
         font = ImageFont.truetype(

docs/reference/ImageDraw.rst

@@ -352,7 +352,7 @@ Methods
 
         .. versionadded:: 6.2.0
 
-    :param embedded_color: Whether to use font embedded color glyphs (COLR or CBDT).
+    :param embedded_color: Whether to use font embedded color glyphs (COLR, CBDT, SBIX).
 
                     .. versionadded:: 8.0.0
 
@@ -413,7 +413,7 @@ Methods
 
                      .. versionadded:: 6.2.0
 
-    :param embedded_color: Whether to use font embedded color glyphs (COLR or CBDT).
+    :param embedded_color: Whether to use font embedded color glyphs (COLR, CBDT, SBIX).
 
                      .. versionadded:: 8.0.0
 
@@ -577,7 +577,7 @@ Methods
                      correct substitutions as appropriate, if available.
                      It should be a `BCP 47 language code`_.
                      Requires libraqm.
-    :param embedded_color: Whether to use font embedded color glyphs (COLR or CBDT).
+    :param embedded_color: Whether to use font embedded color glyphs (COLR, CBDT, SBIX).
 
 .. py:method:: ImageDraw.textbbox(xy, text, font=None, anchor=None, spacing=4, align="left", direction=None, features=None, language=None, stroke_width=0, embedded_color=False)
 
@@ -626,7 +626,7 @@ Methods
                      It should be a `BCP 47 language code`_.
                      Requires libraqm.
     :param stroke_width: The width of the text stroke.
-    :param embedded_color: Whether to use font embedded color glyphs (COLR or CBDT).
+    :param embedded_color: Whether to use font embedded color glyphs (COLR, CBDT, SBIX).
 
 .. py:method:: ImageDraw.multiline_textbbox(xy, text, font=None, anchor=None, spacing=4, align="left", direction=None, features=None, language=None, stroke_width=0, embedded_color=False)
 
@@ -669,7 +669,7 @@ Methods
                      It should be a `BCP 47 language code`_.
                      Requires libraqm.
     :param stroke_width: The width of the text stroke.
-    :param embedded_color: Whether to use font embedded color glyphs (COLR or CBDT).
+    :param embedded_color: Whether to use font embedded color glyphs (COLR, CBDT, SBIX).
 
 .. py:method:: getdraw(im=None, hints=None)
 

docs/releasenotes/8.0.0.rst

@@ -115,8 +115,9 @@ now support fonts with embedded color data.
 To render text with embedded color data, use the parameter ``embedded_color=True``.
 
 Support for CBDT fonts requires FreeType 2.5 compiled with libpng.
+Support for SBIX fonts requires FreeType 2.5.1 compiled with libpng.
 Support for COLR fonts requires FreeType 2.10.
-SBIX and SVG fonts are not yet supported.
+SVG fonts are not yet supported.
 
 ImageDraw.textlength
 ^^^^^^^^^^^^^^^^^^^^