[ot] Add support for long counts

Lib/fontTools/ttLib/tables/otBase.py

@@ -466,8 +466,8 @@ class OTTableWriter(object):
 	def writeSubTable(self, subWriter):
 		self.items.append(subWriter)
 
-	def writeCountReference(self, table, name):
-		ref = CountReference(table, name)
+	def writeCountReference(self, table, name, size=2):
+		ref = CountReference(table, name, size=size)
 		self.items.append(ref)
 		return ref
 
@@ -514,9 +514,10 @@ class OTTableWriter(object):
 
 class CountReference(object):
 	"""A reference to a Count value, not a count of references."""
-	def __init__(self, table, name):
+	def __init__(self, table, name, size=None):
 		self.table = table
 		self.name = name
+		self.size = size
 	def setValue(self, value):
 		table = self.table
 		name = self.name
@@ -525,9 +526,10 @@ class CountReference(object):
 		else:
 			assert table[name] == value, (name, table[name], value)
 	def getCountData(self):
+		assert self.size in (2, 4)
 		v = self.table[self.name]
 		if v is None: v = 0
-		return packUShort(v)
+		return packUShort(v) if self.size == 2 else packULong(v)
 
 
 def packUShort(value):
@@ -657,12 +659,12 @@ class BaseTable(object):
 				# table. We will later store it here.
 				# We add a reference: by the time the data is assembled
 				# the Count value will be filled in.
-				ref = writer.writeCountReference(table, conv.name)
+				ref = writer.writeCountReference(table, conv.name, conv.staticSize)
 				table[conv.name] = None
 				if conv.isPropagated:
 					writer[conv.name] = ref
 			elif conv.isLookupType:
-				ref = writer.writeCountReference(table, conv.name)
+				ref = writer.writeCountReference(table, conv.name, conv.staticSize)
 				table[conv.name] = None
 				writer['LookupType'] = ref
 			else:

Lib/fontTools/ttLib/tables/otConverters.py

@@ -22,8 +22,8 @@ def buildConverters(tableSpec, tableNamespace):
 			assert tp == "uint16"
 			converterClass = ValueFormat
 		elif name.endswith("Count") or name.endswith("LookupType"):
-			assert tp == "uint16"
-			converterClass = ComputedUShort
+			assert tp in ("uint16", "uint32")
+			converterClass = ComputedUShort if tp == 'uint16' else ComputedULong
 		elif name == "SubTable":
 			converterClass = SubTable
 		elif name == "ExtSubTable":
@@ -203,11 +203,16 @@ class UInt24(IntValue):
 	def write(self, writer, font, tableDict, value, repeatIndex=None):
 		writer.writeUInt24(value)
 
-class ComputedUShort(UShort):
+class ComputedInt(IntValue):
 	def xmlWrite(self, xmlWriter, font, value, name, attrs):
 		xmlWriter.comment("%s=%s" % (name, value))
 		xmlWriter.newline()
 
+class ComputedUShort(ComputedInt, UShort):
+	pass
+class ComputedULong(ComputedInt, ULong):
+	pass
+
 class Tag(SimpleValue):
 	staticSize = 4
 	def read(self, reader, font, tableDict):