Add support for Google CBLC/CBDT color bitmaps

Doc/documentation.html

@@ -42,7 +42,11 @@ When using TTX from the command line there are a bunch of extra options, these a
 The following tables are currently supported:
 <BLOCKQUOTE><TT>
 <!-- begin table list -->
+<<<<<<< HEAD
 BASE, CFF, DSIG, EBDT, EBLC, GDEF, GMAP, GPKG, GPOS, GSUB, JSTF, LTSH, META, OS/2, SING, TSI0, TSI1, TSI2, TSI3, TSI5, TSIB, TSID, TSIJ, TSIP, TSIS, TSIV, VORG, cmap, cvt, fpgm, gasp, glyf, hdmx, head, hhea, hmtx, kern, loca, maxp, name, post, prep, vhea and vmtx
+=======
+BASE, CBDT, CBLC, CFF, COLR, CPAL, DSIG, EBDT, EBLC, GDEF, GMAP, GPKG, GPOS, GSUB, JSTF, LTSH, META, OS/2, SING, TSI0, TSI1, TSI2, TSI3, TSI5, TSIB, TSID, TSIJ, TSIP, TSIS, TSIV, VORG, cmap, cvt, fpgm, gasp, glyf, hdmx, head, hhea, hmtx, kern, loca, maxp, name, post, prep, vhea and vmtx
+>>>>>>> 305bad8... Add support for Google CBLC/CBDT color bitmaps
 <!-- end table list -->
 </TT></BLOCKQUOTE>
 Other tables are dumped as hexadecimal data.

Lib/fontTools/ttLib/tables/C_B_D_T_.py

@@ -0,0 +1,88 @@
+
+import E_B_D_T_
+import string
+import struct
+import sstruct
+from BitmapGlyphMetrics import BigGlyphMetrics, bigGlyphMetricsFormat, SmallGlyphMetrics, smallGlyphMetricsFormat
+from E_B_D_T_ import BitmapGlyph, BitmapPlusSmallMetricsMixin, BitmapPlusBigMetricsMixin
+
+class table_C_B_D_T_(E_B_D_T_.table_E_B_D_T_):
+
+	# Change the data locator table being referenced.
+	locatorName = 'CBLC'
+
+	# Modify the format class accessor for color bitmap use.
+	def getImageFormatClass(self, imageFormat):
+		try:
+			return E_B_D_T_.table_E_B_D_T_.getImageFormatClass(self, imageFormat)
+		except KeyError:
+			return cbdt_bitmap_classes[imageFormat]
+
+# Helper method for removing export features not supported by color bitmaps.
+# Write data in the parent class will default to raw if an option is unsupported.
+def _removeUnsupportedForColor(dataFunctions):
+	dataFunctions = dict(dataFunctions)
+	del dataFunctions['row']
+	return dataFunctions
+
+class ColorBitmapGlyph(BitmapGlyph):
+
+	fileExtension = '.png'
+	xmlDataFunctions = _removeUnsupportedForColor(BitmapGlyph.xmlDataFunctions)
+
+class cbdt_bitmap_format_17(BitmapPlusSmallMetricsMixin, ColorBitmapGlyph):
+
+	def decompile(self):
+		self.metrics = SmallGlyphMetrics()
+		dummy, data = sstruct.unpack2(smallGlyphMetricsFormat, self.data, self.metrics)
+		(dataLen,) = struct.unpack(">L", data[:4])
+		data = data[4:]
+
+		# For the image data cut it to the size specified by dataLen.
+		assert dataLen <= len(data), "Data overun in format 17"
+		self.imageData = data[:dataLen]
+
+	def compile(self, ttFont):
+		dataList = []
+		dataList.append(sstruct.pack(smallGlyphMetricsFormat, self.metrics))
+		dataList.append(struct.pack(">L", len(self.imageData)))
+		dataList.append(self.imageData)
+		return string.join(dataList, "")
+
+class cbdt_bitmap_format_18(BitmapPlusBigMetricsMixin, ColorBitmapGlyph):
+
+	def decompile(self):
+		self.metrics = BigGlyphMetrics()
+		dummy, data = sstruct.unpack2(bigGlyphMetricsFormat, self.data, self.metrics)
+		(dataLen,) = struct.unpack(">L", data[:4])
+		data = data[4:]
+
+		# For the image data cut it to the size specified by dataLen.
+		assert dataLen <= len(data), "Data overun in format 18"
+		self.imageData = data[:dataLen]
+
+	def compile(self, ttFont):
+		dataList = []
+		dataList.append(sstruct.pack(bigGlyphMetricsFormat, self.metrics))
+		dataList.append(struct.pack(">L", len(self.imageData)))
+		dataList.append(self.imageData)
+		return string.join(dataList, "")
+
+class cbdt_bitmap_format_19(ColorBitmapGlyph):
+
+	def decompile(self):
+		(dataLen,) = struct.unpack(">L", self.data[:4])
+		data = self.data[4:]
+
+		assert dataLen <= len(data), "Data overun in format 19"
+		self.imageData = data[:dataLen]
+
+	def compile(self, ttFont):
+		return struct.pack(">L", len(self.imageData)) + self.imageData
+
+# Dict for CBDT extended formats.
+cbdt_bitmap_classes = {
+	17: cbdt_bitmap_format_17,
+	18: cbdt_bitmap_format_18,
+	19: cbdt_bitmap_format_19,
+}

Lib/fontTools/ttLib/tables/C_B_L_C_.py

@@ -0,0 +1,6 @@
+
+import E_B_L_C_
+
+class table_C_B_L_C_(E_B_L_C_.table_E_B_L_C_):
+
+	dependencies = ['CBDT']

Lib/fontTools/ttLib/tables/__init__.py

@@ -4,6 +4,8 @@ def _moduleFinderHint():
 	dynamically imported. Generated by MetaTools/buildTableList.py.
 	"""
 	import B_A_S_E_
+	import C_B_D_T_
+	import C_B_L_C_
 	import C_F_F_
 	import D_S_I_G_
 	import E_B_D_T_