WIP: add buildPaintColrLayers

Lib/fontTools/colorLib/builder.py

@@ -39,7 +39,7 @@ T = TypeVar("T")
 _Kwargs = Mapping[str, Any]
 _PaintInput = Union[int, _Kwargs, ot.Paint, Tuple[str, "_PaintInput"]]
 _PaintInputList = Sequence[_PaintInput]
-_ColorGlyphsDict = Dict[str, Union[_PaintInputList, ot.LayerV1List]]
+_ColorGlyphsDict = Dict[str, Union[_PaintInputList, _PaintInput]]
 _ColorGlyphsV0Dict = Dict[str, Sequence[Tuple[str, int]]]
 _Number = Union[int, float]
 _ScalarInput = Union[_Number, VariableValue, Tuple[_Number, int]]
@@ -55,7 +55,7 @@ _AffineTuple = Tuple[
 ]
 _AffineInput = Union[_AffineTuple, ot.Affine2x3]
 
-MAX_LAYER_V1_COUNT = 255
+MAX_PAINT_COLR_LAYER_COUNT = 255
 
 
 def populateCOLRv0(
@@ -571,15 +571,23 @@ def buildPaint(paint: _PaintInput) -> ot.Paint:
 def buildLayerV1List(layers: _PaintInputList) -> ot.LayerV1List:
     self = ot.LayerV1List()
     layerCount = len(layers)
-    if layerCount > MAX_LAYER_V1_COUNT:
-        raise OverflowError(
-            "LayerV1List.LayerCount: {layerCount} > {MAX_LAYER_V1_COUNT}"
-        )
     self.LayerCount = layerCount
     self.Paint = [buildPaint(layer) for layer in layers]
     return self
 
 
+def buildPaintColrLayers(firstLayerIndex: int, numLayers: int) -> ot.Paint:
+    self = ot.Paint()
+    self.Format = int(ot.Paint.Format.PaintColrLayers)
+    if numLayers > MAX_PAINT_COLR_LAYER_COUNT:
+        raise OverflowError(
+            "PaintColrLayers.NumLayers: {numLayers} > {MAX_PAINT_COLR_LAYER_COUNT}"
+        )
+    self.NumLayers = numLayers
+    self.FirstLayerIndex = firstLayerIndex
+    return self
+
+
 def buildBaseGlyphV1Record(
     baseGlyph: str, layers: Union[_PaintInputList, ot.LayerV1List]
 ) -> ot.BaseGlyphV1List:

Lib/fontTools/ttLib/tables/otData.py

@@ -1550,6 +1550,7 @@ otData = [
 		('LOffset', 'LayerRecordArray', None, None, 'Offset (from beginning of COLR table) to Layer Records.'),
 		('uint16', 'LayerRecordCount', None, None, 'Number of Layer Records.'),
 		('LOffset', 'BaseGlyphV1List', None, 'Version >= 1', 'Offset (from beginning of COLR table) to array of Version-1 Base Glyph records.'),
+		('LOffset', 'LayerV1List', None, 'Version >= 1', 'Offset (from beginning of COLR table) to LayerV1List.'),
 		('LOffset', 'VarStore', None, 'Version >= 1', 'Offset to variation store (may be NULL)'),
 	]),
 
@@ -1579,11 +1580,11 @@ otData = [
 
 	('BaseGlyphV1Record', [
 		('GlyphID', 'BaseGlyph', None, None, 'Glyph ID of reference glyph.'),
-		('LOffset', 'LayerV1List', None, None, 'Offset (from beginning of BaseGlyphV1List) to LayerV1List.'),
+		('LOffset', 'Paint', None, None, 'Offset (from beginning of BaseGlyphV1Record) to Paint, typically a PaintColrLayers.'),
 	]),
 
 	('LayerV1List', [
-		('uint8', 'LayerCount', None, None, 'Number of Version-1 Layers'),
+		('uint32', 'LayerCount', None, None, 'Number of Version-1 Layers'),
 		('LOffset', 'Paint', 'LayerCount', 0, 'Array of offsets to Paint tables, from the start of the LayerV1List table.'),
 	]),
 
@@ -1660,4 +1661,9 @@ otData = [
 		('CompositeMode', 'CompositeMode', None, None, 'A CompositeMode enumeration value.'),
 		('LOffset24To(Paint)', 'BackdropPaint', None, None, 'Offset (from beginning of PaintComposite table) to backdrop Paint subtable.'),
 	]),
+	('PaintFormat8', [
+		('uint8', 'PaintFormat', None, None, 'Format identifier-format = 8'),
+		('uint8', 'NumLayers', None, None, 'Number of offsets to Paint to read from LayerV1List.'),
+		('uint32', 'FirstLayerIndex', None, None, 'Index into LayerV1List.'),
+	]),
 ]

Lib/fontTools/ttLib/tables/otTables.py

@@ -1334,6 +1334,7 @@ class Paint(getFormatSwitchingBaseTableClass("uint8")):
 		PaintColrSlice = 5
 		PaintTransform = 6
 		PaintComposite = 7
+		PaintColrLayers = 8
 
 	def getFormatName(self):
 		try: