Merge pull request #521 from googlefonts/colr-clip-boxes

define 'colrClipBoxes' lib key, pass it on to buildCOLR

Lib/ufo2ft/constants.py

@@ -19,6 +19,19 @@
 COLOR_LAYERS_KEY = UFO2FT_PREFIX + "colorLayers"
 COLOR_PALETTES_KEY = UFO2FT_PREFIX + "colorPalettes"
 COLOR_LAYER_MAPPING_KEY = UFO2FT_PREFIX + "colorLayerMapping"
+# sequence of [glyphs, clipBox], where 'glyphs' is in turn a sequence of
+# glyph names, and 'clipBox' a 5- or 4-item sequence of numbers:
+# Sequence[
+#   Sequence[
+#     Sequence[str, ...],  # glyph names
+#     Union[
+#       Sequence[float, float, float, float, float],  # variable box
+#       Sequence[float, float, float, float],  # non-variable box
+#     ]
+#   ],
+#   ...
+# ]
+COLR_CLIP_BOXES_KEY = UFO2FT_PREFIX + "colrClipBoxes"
 
 OPENTYPE_CATEGORIES_KEY = "public.openTypeCategories"
 OPENTYPE_META_KEY = "public.openTypeMeta"

Lib/ufo2ft/outlineCompiler.py

@@ -27,6 +27,7 @@
 from ufo2ft.constants import (
     COLOR_LAYERS_KEY,
     COLOR_PALETTES_KEY,
+    COLR_CLIP_BOXES_KEY,
     OPENTYPE_META_KEY,
     UNICODE_VARIATION_SEQUENCES_KEY,
 )
@@ -959,7 +960,18 @@ def setupTable_COLR(self):
         layerInfo = self.ufo.lib[COLOR_LAYERS_KEY]
         glyphMap = self.otf.getReverseGlyphMap()
         if layerInfo:
-            self.otf["COLR"] = buildCOLR(layerInfo, glyphMap=glyphMap)
+            # unpack (glyphs, clipBox) tuples to a flat dict keyed by glyph name,
+            # as colorLib buildCOLR expects
+            clipBoxes = {
+                glyphName: tuple(box)
+                for glyphs, box in self.ufo.lib.get(COLR_CLIP_BOXES_KEY, ())
+                for glyphName in glyphs
+            }
+            self.otf["COLR"] = buildCOLR(
+                layerInfo,
+                glyphMap=glyphMap,
+                clipBoxes=clipBoxes,
+            )
 
     def setupTable_CPAL(self):
         """