[ttFont] Remove allowVID

Leave the parameter intact for back compat.

Part of https://github.com/fonttools/fonttools/pull/2398
Fixes https://github.com/fonttools/fonttools/issues/2334

Lib/fontTools/ttLib/ttFont.py

@@ -20,7 +20,7 @@ class TTFont(object):
 
 	def __init__(self, file=None, res_name_or_index=None,
 			sfntVersion="\000\001\000\000", flavor=None, checkChecksums=0,
-			verbose=None, recalcBBoxes=True, allowVID=False, ignoreDecompileErrors=False,
+			verbose=None, recalcBBoxes=True, allowVID=NotImplemented, ignoreDecompileErrors=False,
 			recalcTimestamp=True, fontNumber=-1, lazy=None, quiet=None,
 			_tableCache=None):
 
@@ -61,16 +61,6 @@ class TTFont(object):
 		If the recalcTimestamp argument is false, the modified timestamp in the
 		'head' table will *not* be recalculated upon save/compile.
 
-		If the allowVID argument is set to true, then virtual GID's are
-		supported. Asking for a glyph ID with a glyph name or GID that is not in
-		the font will return a virtual GID.   This is valid for GSUB and cmap
-		tables. For SING glyphlets, the cmap table is used to specify Unicode
-		values for virtual GI's used in GSUB/GPOS rules. If the gid N is requested
-		and does not exist in the font, or the glyphname has the form glyphN
-		and does not exist in the font, then N is used as the virtual GID.
-		Else, the first virtual GID is assigned as 0x1000 -1; for subsequent new
-		virtual GIDs, the next is one less than the previous.
-
 		If ignoreDecompileErrors is set to True, exceptions raised in
 		individual tables during decompilation will be ignored, falling
 		back to the DefaultTable implementation, which simply keeps the
@@ -92,12 +82,6 @@ class TTFont(object):
 		self.recalcTimestamp = recalcTimestamp
 		self.tables = {}
 		self.reader = None
-
-		# Permit the user to reference glyphs that are not int the font.
-		self.last_vid = 0xFFFE # Can't make it be 0xFFFF, as the world is full unsigned short integer counters that get incremented after the last seen GID value.
-		self.reverseVIDDict = {}
-		self.VIDDict = {}
-		self.allowVID = allowVID
 		self.ignoreDecompileErrors = ignoreDecompileErrors
 
 		if not file:
@@ -548,20 +532,7 @@ class TTFont(object):
 		try:
 			return self.getGlyphOrder()[glyphID]
 		except IndexError:
-			if not self.allowVID:
-				# XXX The ??.W8.otf font that ships with OSX uses higher glyphIDs in
-				# the cmap table than there are glyphs. I don't think it's legal...
 			return "glyph%.5d" % glyphID
-			else:
-				# user intends virtual GID support
-				try:
-					glyphName = self.VIDDict[glyphID]
-				except KeyError:
-					glyphName  ="glyph%.5d" % glyphID
-					self.last_vid = min(glyphID, self.last_vid )
-					self.reverseVIDDict[glyphName] = glyphID
-					self.VIDDict[glyphID] = glyphName
-				return glyphName
 
 	def getGlyphID(self, glyphName):
 		if not hasattr(self, "_reverseGlyphOrderDict"):
@@ -573,30 +544,12 @@ class TTFont(object):
 				self._buildReverseGlyphOrderDict()
 				return self.getGlyphID(glyphName)
 			else:
-				if not self.allowVID:
 				# Handle glyphXXX only
 				if glyphName[:5] == "glyph":
 					try:
 						return int(glyphName[5:])
 					except (NameError, ValueError):
 						raise KeyError(glyphName)
-				else:
-					# user intends virtual GID support
-					try:
-						glyphID = self.reverseVIDDict[glyphName]
-					except KeyError:
-						# if name is in glyphXXX format, use the specified name.
-						if glyphName[:5] == "glyph":
-							try:
-								glyphID = int(glyphName[5:])
-							except (NameError, ValueError):
-								glyphID = None
-						if glyphID is None:
-							glyphID = self.last_vid -1
-							self.last_vid = glyphID
-						self.reverseVIDDict[glyphName] = glyphID
-						self.VIDDict[glyphID] = glyphName
-					return glyphID
 
 		glyphID = d[glyphName]
 		if glyphName != glyphOrder[glyphID]: