Merge pull request #443 from googlefonts/otsvg-to-colrv0

add --colr_version flag to maximum_color

.github/workflows/ci.yml

@@ -15,9 +15,7 @@ jobs:
     - name: Set up Python 3.9
       uses: actions/setup-python@v2
       with:
-        # typed_ast (used by pytype) has a problem when run under 3.9.8, pin to 3.9.7
-        # until resolved: https://github.com/python/typed_ast/issues/169
-        python-version: "3.9.7"
+        python-version: "3.9"
     - name: Install tox
       run: pip install tox
     - name: Run style and typing checks

src/nanoemoji/glue_together.py

@@ -46,9 +46,21 @@ class CbdtGlyphInfo(NamedTuple):
 
 def _copy_colr(target: ttLib.TTFont, donor: ttLib.TTFont):
     # Copy all glyphs used by COLR over
-    glyphs_to_copy = sorted(
-        {p.Glyph for p in paints_of_type(donor, ot.PaintFormat.PaintGlyph)}
-    )
+    colr_version = donor["COLR"].version
+    if colr_version == 1:
+        glyphs_to_copy = sorted(
+            {p.Glyph for p in paints_of_type(donor, ot.PaintFormat.PaintGlyph)}
+        )
+    elif colr_version == 0:
+        glyphs_to_copy = sorted(
+            {
+                rec.name
+                for layers in donor["COLR"].ColorLayers.values()
+                for rec in layers
+            }
+        )
+    else:
+        raise NotImplementedError(colr_version)
 
     # We avoid using the glyf table's `__setitem__` for it appends to the TTFont's
     # glyphOrder list without also invalidating the {glyphNames:glyphID} cache,

src/nanoemoji/maximum_color.py

@@ -43,7 +43,7 @@
 )
 from nanoemoji.util import only
 from pathlib import Path
-from typing import List, NamedTuple, Tuple
+from typing import List, NamedTuple, Optional, Tuple
 
 
 FLAGS = flags.FLAGS
@@ -59,6 +59,13 @@
     False,
     "If true, generate a bitmap table (specificaly CBDT)",
 )
+flags.DEFINE_integer(
+    "colr_version",
+    1,
+    "COLR table version to generate",
+    lower_bound=0,
+    upper_bound=1,
+)
 
 
 # attribute names need to match inputs to write_font rule
@@ -69,26 +76,43 @@ class WriteFontInputs(NamedTuple):
 
     @property
     def table_tag(self) -> str:
-        return f"{Path(self.glyphmap_file).stem:4}"
+        basename = Path(self.glyphmap_file).stem
+        table_tag, _, _ = basename.partition("_")
+        return f"{table_tag:4}"
+
+    @property
+    def table_version(self) -> Optional[int]:
+        basename = Path(self.glyphmap_file).stem
+        _, _, version = basename.partition("_")
+        return int(version) if version else None
 
     @property
     def color_format(self) -> str:
         identifier = self.table_tag.strip().lower()
+        table_version = self.table_version
 
         if identifier == "svg":
             # for good woff2 performance, at cost of inflated size
             return "picosvg"
         elif identifier == "colr":
             # optimize for woff2 performance
-            return "glyf_colr_1"
+            if table_version not in (0, 1):
+                raise ValueError(
+                    f"Invalid COLR version, expected 0 or 1, got {table_version}"
+                )
+            return f"glyf_colr_{table_version}"
         elif identifier == "cbdt":
             return "cbdt"
         else:
             raise ValueError(f"What is {identifier}?!")
 
     @classmethod
-    def for_tag(cls, table_tag: str) -> "WriteFontInputs":
+    def for_tag(
+        cls, table_tag: str, table_version: Optional[int] = None
+    ) -> "WriteFontInputs":
         basename = table_tag.strip()
+        if table_version is not None:
+            basename += f"_{table_version}"
         return cls(
             Path(basename + ".glyphmap"),
             Path(basename + ".toml"),
@@ -296,8 +320,9 @@ def _generate_additional_color_table(
     glyphmap_inputs: List[Path],
     table_tag: str,
     glue_target: Path,
+    table_version: Optional[int] = None,
 ) -> Path:
-    write_font_inputs = WriteFontInputs.for_tag(table_tag)
+    write_font_inputs = WriteFontInputs.for_tag(table_tag, table_version)
     identifier = write_font_inputs.color_format
     del table_tag
 
@@ -363,6 +388,7 @@ def _generate_colr_from_svg(
     font_config: config.FontConfig,
     input_font: Path,
     font: ttLib.TTFont,
+    colr_version: int,
 ) -> Tuple[Path, List[Path]]:
     # extract the svgs
     svg_files = [
@@ -376,7 +402,12 @@ def _generate_colr_from_svg(
     part_file = _part_file(nw, font_config, picosvgs)
 
     output_file = _generate_additional_color_table(
-        nw, input_font, picosvgs + [input_font], "COLR", input_font
+        nw,
+        input_font,
+        picosvgs + [input_font],
+        "COLR",
+        input_font,
+        table_version=colr_version,
     )
     return output_file, picosvgs
 
@@ -460,7 +491,7 @@ def _run(argv):
                 )
             else:
                 wip_file, picosvg_files = _generate_colr_from_svg(
-                    nw, font_config, wip_file, font
+                    nw, font_config, wip_file, font, FLAGS.colr_version
                 )
 
             if FLAGS.bitmaps:

tests/maximum_color_test.py

@@ -98,6 +98,24 @@ def test_build_maximum_font(color_format, expected_new_tables, bitmaps, input_fi
     assert set(maximum_font.keys()) - set(initial_font.keys()) == expected_new_tables
 
 
+@pytest.mark.parametrize("colr_version", [None, 0, 1])
+def test_build_colrv0_from_svg(colr_version):
+    initial_font_file = _build_initial_font("picosvg")
+
+    additional_flags = ()
+    if colr_version is not None:
+        additional_flags = ("--colr_version", str(colr_version))
+
+    maxmium_font_file = _maximize_color(initial_font_file, additional_flags)
+
+    initial_font = ttLib.TTFont(initial_font_file)
+    maximum_font = ttLib.TTFont(maxmium_font_file)
+    assert set(maximum_font.keys()) - set(initial_font.keys()) == {"COLR", "CPAL"}
+
+    expected_version = 1 if colr_version is None else colr_version
+    assert maximum_font["COLR"].version == expected_version
+
+
 @pytest.mark.parametrize("keep_names", [True, False])
 def test_keep_glyph_names(keep_names):
     initial_font_file = _build_initial_font("glyf_colr_1")