pyotlss.py

#!/usr/bin/python
#
# Python OpenType Layout Subsetter
# Later grown into a full OpenType subsetter...
#
# Copyright 2013 Google, Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# Google Author(s): Behdad Esfahbod
#

# Try running on PyPy
try:
	import numpypy
except ImportError:
	pass

import fontTools.ttx
import struct


def add_method (*clazzes):
	def wrapper(method):
		for clazz in clazzes:
			assert clazz.__name__ != 'DefaultTable', 'Oops, table class not found.'
			setattr (clazz, method.func_name, method)
	return wrapper

def unique_sorted (l):
	return sorted (set (l))

def safeEval(data, eval=eval):
	"""A (kindof) safe replacement for eval."""
	return eval(data, {"__builtins__":{}}, {})


@add_method(fontTools.ttLib.tables.otTables.Coverage)
def intersect (self, glyphs):
	"Returns ascending list of matching coverage values."
	return [i for (i,g) in enumerate (self.glyphs) if g in glyphs]

@add_method(fontTools.ttLib.tables.otTables.Coverage)
def intersect_glyphs (self, glyphs):
	"Returns set of intersecting glyphs."
	return set (g for g in self.glyphs if g in glyphs)

@add_method(fontTools.ttLib.tables.otTables.Coverage)
def subset (self, glyphs):
	"Returns ascending list of remaining coverage values."
	indices = self.intersect (glyphs)
	self.glyphs = [g for g in self.glyphs if g in glyphs]
	return indices

@add_method(fontTools.ttLib.tables.otTables.Coverage)
def remap (self, coverage_map):
	"Remaps coverage."
	self.glyphs = [self.glyphs[i] for i in coverage_map]

@add_method(fontTools.ttLib.tables.otTables.ClassDef)
def intersect (self, glyphs):
	"Returns ascending list of matching class values."
	return unique_sorted (([0] if any (g not in self.classDefs for g in glyphs) else []) + \
			      [v for g,v in self.classDefs.items() if g in glyphs])

@add_method(fontTools.ttLib.tables.otTables.ClassDef)
def intersect_class (self, glyphs, klass):
	"Returns set of glyphs matching class."
	if klass == 0:
		return set (g for g in glyphs if g not in self.classDefs)
	return set (g for g,v in self.classDefs.items() if v == klass and g in glyphs)

@add_method(fontTools.ttLib.tables.otTables.ClassDef)
def subset (self, glyphs, remap=False):
	"Returns ascending list of remaining classes."
	self.classDefs = {g:v for g,v in self.classDefs.items() if g in glyphs}
	# Note: while class 0 has the special meaning of "not matched", if no glyph will
	# ever /not match/, we can optimize class 0 out too.
	indices = unique_sorted (([0]  if any (g not in self.classDefs for g in glyphs) else []) + \
				 self.classDefs.values ())
	if remap:
		self.remap (indices)
	return indices

@add_method(fontTools.ttLib.tables.otTables.ClassDef)
def remap (self, class_map):
	"Remaps classes."
	self.classDefs = {g:class_map.index (v) for g,v in self.classDefs.items()}

@add_method(fontTools.ttLib.tables.otTables.SingleSubst)
def closure_glyphs (self, s, cur_glyphs=None):
	if cur_glyphs == None: cur_glyphs = s.glyphs
	if self.Format in [1, 2]:
		s.glyphs.update (v for g,v in self.mapping.items() if g in cur_glyphs)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.SingleSubst)
def subset_glyphs (self, s):
	if self.Format in [1, 2]:
		self.mapping = {g:v for g,v in self.mapping.items() if g in s.glyphs and v in s.glyphs}
		return bool (self.mapping)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.MultipleSubst)
def closure_glyphs (self, s, cur_glyphs=None):
	if cur_glyphs == None: cur_glyphs = s.glyphs
	if self.Format == 1:
		indices = self.Coverage.intersect (cur_glyphs)
		s.glyphs.update (*(self.Sequence[i].Substitute for i in indices))
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.MultipleSubst)
def subset_glyphs (self, s):
	if self.Format == 1:
		indices = self.Coverage.subset (s.glyphs)
		self.Sequence = [self.Sequence[i] for i in indices]
		# Now drop rules generating glyphs we don't want
		indices = [i for i,seq in enumerate (self.Sequence) \
			   if all (sub in s.glyphs for sub in seq.Substitute)]
		self.Sequence = [self.Sequence[i] for i in indices]
		self.Coverage.remap (indices)
		self.SequenceCount = len (self.Sequence)
		return bool (self.SequenceCount)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.AlternateSubst)
def closure_glyphs (self, s, cur_glyphs=None):
	if cur_glyphs == None: cur_glyphs = s.glyphs
	if self.Format == 1:
		s.glyphs.update (*(vlist for g,vlist in self.alternates.items() if g in cur_glyphs))
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.AlternateSubst)
def subset_glyphs (self, s):
	if self.Format == 1:
		self.alternates = {g:vlist for g,vlist in self.alternates.items() \
				   if g in s.glyphs and all (v in s.glyphs for v in vlist)}
		return bool (self.alternates)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.LigatureSubst)
def closure_glyphs (self, s, cur_glyphs=None):
	if cur_glyphs == None: cur_glyphs = s.glyphs
	if self.Format == 1:
		s.glyphs.update (*([seq.LigGlyph for seq in seqs if all(c in s.glyphs for c in seq.Component)]
				    for g,seqs in self.ligatures.items() if g in cur_glyphs))
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.LigatureSubst)
def subset_glyphs (self, s):
	if self.Format == 1:
		self.ligatures = {g:v for g,v in self.ligatures.items() if g in s.glyphs}
		self.ligatures = {g:[seq for seq in seqs \
				     if seq.LigGlyph in s.glyphs and \
				        all(c in s.glyphs for c in seq.Component)]
				  for g,seqs in self.ligatures.items()}
		self.ligatures = {g:v for g,v in self.ligatures.items() if v}
		return bool (self.ligatures)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.ReverseChainSingleSubst)
def closure_glyphs (self, s, cur_glyphs=None):
	if cur_glyphs == None: cur_glyphs = s.glyphs
	if self.Format == 1:
		indices = self.Coverage.intersect (cur_glyphs)
		if not indices or \
		   not all (c.intersect (s.glyphs) for c in self.LookAheadCoverage + self.BacktrackCoverage):
			return
		s.glyphs.update (self.Substitute[i] for i in indices)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.ReverseChainSingleSubst)
def subset_glyphs (self, s):
	if self.Format == 1:
		indices = self.Coverage.subset (s.glyphs)
		self.Substitute = [self.Substitute[i] for i in indices]
		# Now drop rules generating glyphs we don't want
		indices = [i for i,sub in enumerate (self.Substitute) \
			   if sub in s.glyphs]
		self.Substitute = [self.Substitute[i] for i in indices]
		self.Coverage.remap (indices)
		self.GlyphCount = len (self.Substitute)
		return bool (self.GlyphCount and all (c.subset (s.glyphs) for c in self.LookAheadCoverage + self.BacktrackCoverage))
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.SinglePos)
def subset_glyphs (self, s):
	if self.Format == 1:
		return len (self.Coverage.subset (s.glyphs))
	elif self.Format == 2:
		indices = self.Coverage.subset (s.glyphs)
		self.Value = [self.Value[i] for i in indices]
		self.ValueCount = len (self.Value)
		return bool (self.ValueCount)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.PairPos)
def subset_glyphs (self, s):
	if self.Format == 1:
		indices = self.Coverage.subset (s.glyphs)
		self.PairSet = [self.PairSet[i] for i in indices]
		for p in self.PairSet:
			p.PairValueRecord = [r for r in p.PairValueRecord if r.SecondGlyph in s.glyphs]
			p.PairValueCount = len (p.PairValueRecord)
		self.PairSet = [p for p in self.PairSet if p.PairValueCount]
		self.PairSetCount = len (self.PairSet)
		return bool (self.PairSetCount)
	elif self.Format == 2:
		class1_map = self.ClassDef1.subset (s.glyphs, remap=True)
		class2_map = self.ClassDef2.subset (s.glyphs, remap=True)
		self.Class1Record = [self.Class1Record[i] for i in class1_map]
		for c in self.Class1Record:
			c.Class2Record = [c.Class2Record[i] for i in class2_map]
		self.Class1Count = len (class1_map)
		self.Class2Count = len (class2_map)
		return bool (self.Class1Count and self.Class2Count and self.Coverage.subset (s.glyphs))
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.CursivePos)
def subset_glyphs (self, s):
	if self.Format == 1:
		indices = self.Coverage.subset (s.glyphs)
		self.EntryExitRecord = [self.EntryExitRecord[i] for i in indices]
		self.EntryExitCount = len (self.EntryExitRecord)
		return bool (self.EntryExitCount)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.MarkBasePos)
def subset_glyphs (self, s):
	if self.Format == 1:
		mark_indices = self.MarkCoverage.subset (s.glyphs)
		self.MarkArray.MarkRecord = [self.MarkArray.MarkRecord[i] for i in mark_indices]
		self.MarkArray.MarkCount = len (self.MarkArray.MarkRecord)
		base_indices = self.BaseCoverage.subset (s.glyphs)
		self.BaseArray.BaseRecord = [self.BaseArray.BaseRecord[i] for i in base_indices]
		self.BaseArray.BaseCount = len (self.BaseArray.BaseRecord)
		# Prune empty classes
		class_indices = unique_sorted (v.Class for v in self.MarkArray.MarkRecord)
		self.ClassCount = len (class_indices)
		for m in self.MarkArray.MarkRecord:
			m.Class = class_indices.index (m.Class)
		for b in self.BaseArray.BaseRecord:
			b.BaseAnchor = [b.BaseAnchor[i] for i in class_indices]
		return bool (self.ClassCount and self.MarkArray.MarkCount and self.BaseArray.BaseCount)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.MarkLigPos)
def subset_glyphs (self, s):
	if self.Format == 1:
		mark_indices = self.MarkCoverage.subset (s.glyphs)
		self.MarkArray.MarkRecord = [self.MarkArray.MarkRecord[i] for i in mark_indices]
		self.MarkArray.MarkCount = len (self.MarkArray.MarkRecord)
		ligature_indices = self.LigatureCoverage.subset (s.glyphs)
		self.LigatureArray.LigatureAttach = [self.LigatureArray.LigatureAttach[i] for i in ligature_indices]
		self.LigatureArray.LigatureCount = len (self.LigatureArray.LigatureAttach)
		# Prune empty classes
		class_indices = unique_sorted (v.Class for v in self.MarkArray.MarkRecord)
		self.ClassCount = len (class_indices)
		for m in self.MarkArray.MarkRecord:
			m.Class = class_indices.index (m.Class)
		for l in self.LigatureArray.LigatureAttach:
			for c in l.ComponentRecord:
				c.LigatureAnchor = [c.LigatureAnchor[i] for i in class_indices]
		return bool (self.ClassCount and self.MarkArray.MarkCount and self.LigatureArray.LigatureCount)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.MarkMarkPos)
def subset_glyphs (self, s):
	if self.Format == 1:
		mark1_indices = self.Mark1Coverage.subset (s.glyphs)
		self.Mark1Array.MarkRecord = [self.Mark1Array.MarkRecord[i] for i in mark1_indices]
		self.Mark1Array.MarkCount = len (self.Mark1Array.MarkRecord)
		mark2_indices = self.Mark2Coverage.subset (s.glyphs)
		self.Mark2Array.Mark2Record = [self.Mark2Array.Mark2Record[i] for i in mark2_indices]
		self.Mark2Array.MarkCount = len (self.Mark2Array.Mark2Record)
		# Prune empty classes
		class_indices = unique_sorted (v.Class for v in self.Mark1Array.MarkRecord)
		self.ClassCount = len (class_indices)
		for m in self.Mark1Array.MarkRecord:
			m.Class = class_indices.index (m.Class)
		for b in self.Mark2Array.Mark2Record:
			b.Mark2Anchor = [b.Mark2Anchor[i] for i in class_indices]
		return bool (self.ClassCount and self.Mark1Array.MarkCount and self.Mark2Array.MarkCount)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.SingleSubst,
	    fontTools.ttLib.tables.otTables.MultipleSubst,
	    fontTools.ttLib.tables.otTables.AlternateSubst,
	    fontTools.ttLib.tables.otTables.LigatureSubst,
	    fontTools.ttLib.tables.otTables.ReverseChainSingleSubst,
	    fontTools.ttLib.tables.otTables.SinglePos,
	    fontTools.ttLib.tables.otTables.PairPos,
	    fontTools.ttLib.tables.otTables.CursivePos,
	    fontTools.ttLib.tables.otTables.MarkBasePos,
	    fontTools.ttLib.tables.otTables.MarkLigPos,
	    fontTools.ttLib.tables.otTables.MarkMarkPos)
def subset_lookups (self, lookup_indices):
	pass

@add_method(fontTools.ttLib.tables.otTables.SingleSubst,
	    fontTools.ttLib.tables.otTables.MultipleSubst,
	    fontTools.ttLib.tables.otTables.AlternateSubst,
	    fontTools.ttLib.tables.otTables.LigatureSubst,
	    fontTools.ttLib.tables.otTables.ReverseChainSingleSubst,
	    fontTools.ttLib.tables.otTables.SinglePos,
	    fontTools.ttLib.tables.otTables.PairPos,
	    fontTools.ttLib.tables.otTables.CursivePos,
	    fontTools.ttLib.tables.otTables.MarkBasePos,
	    fontTools.ttLib.tables.otTables.MarkLigPos,
	    fontTools.ttLib.tables.otTables.MarkMarkPos)
def collect_lookups (self):
	return []

@add_method(fontTools.ttLib.tables.otTables.SingleSubst,
	    fontTools.ttLib.tables.otTables.AlternateSubst,
	    fontTools.ttLib.tables.otTables.ReverseChainSingleSubst)
def may_have_non_1to1 (self):
	return False

@add_method(fontTools.ttLib.tables.otTables.MultipleSubst,
	    fontTools.ttLib.tables.otTables.LigatureSubst,
	    fontTools.ttLib.tables.otTables.ContextSubst,
	    fontTools.ttLib.tables.otTables.ChainContextSubst)
def may_have_non_1to1 (self):
	return True

@add_method(fontTools.ttLib.tables.otTables.ContextSubst, fontTools.ttLib.tables.otTables.ChainContextSubst,
	    fontTools.ttLib.tables.otTables.ContextPos,   fontTools.ttLib.tables.otTables.ChainContextPos)
def __classify_context (self):

	class ContextHelper:
		def __init__ (self, klass, Format):
			if klass.__name__.endswith ('Subst'):
				Typ = 'Sub'
				Type = 'Subst'
			else:
				Typ = 'Pos'
				Type = 'Pos'
			if klass.__name__.startswith ('Chain'):
				Chain = 'Chain'
			else:
				Chain = ''
			ChainTyp = Chain+Typ

			self.Typ = Typ
			self.Type = Type
			self.Chain = Chain
			self.ChainTyp = ChainTyp

			self.LookupRecord = Type+'LookupRecord'

			if Format == 1:
				Coverage = lambda r: r.Coverage
				ChainCoverage = lambda r: r.Coverage
				ContextData = lambda r: (None,)
				ChainContextData = lambda r: (None, None, None)
				RuleData = lambda r: (r.Input,)
				ChainRuleData = lambda r: (r.Backtrack, r.Input, r.LookAhead)
				SetRuleData = None
				ChainSetRuleData = None
			elif Format == 2:
				Coverage = lambda r: r.Coverage
				ChainCoverage = lambda r: r.Coverage
				ContextData = lambda r: (r.ClassDef,)
				ChainContextData = lambda r: (r.LookAheadClassDef, r.InputClassDef, r.BacktrackClassDef)
				RuleData = lambda r: (r.Class,)
				ChainRuleData = lambda r: (r.LookAhead, r.Input, r.Backtrack)
				def SetRuleData (r, d): (r.Class,) = d
				def ChainSetRuleData (r, d): (r.LookAhead, r.Input, r.Backtrack) = d
			elif Format == 3:
				Coverage = lambda r: r.Coverage[0]
				ChainCoverage = lambda r: r.InputCoverage[0]
				ContextData = None
				ChainContextData = None
				RuleData = lambda r: r.Coverage
				ChainRuleData = lambda r: r.LookAheadCoverage + r.InputCoverage + r.BacktrackCoverage
				SetRuleData = None
				ChainSetRuleData = None
			else:
				assert 0, "unknown format: %s" % Format

			if Chain:
				self.Coverage = ChainCoverage
				self.ContextData = ChainContextData
				self.RuleData = ChainRuleData
				self.SetRuleData = ChainSetRuleData
			else:
				self.Coverage = Coverage
				self.ContextData = ContextData
				self.RuleData = RuleData
				self.SetRuleData = SetRuleData

			if Format == 1:
				self.Rule = ChainTyp+'Rule'
				self.RuleCount = ChainTyp+'RuleCount'
				self.RuleSet = ChainTyp+'RuleSet'
				self.RuleSetCount = ChainTyp+'RuleSetCount'
				self.Intersect = lambda glyphs, ContextData, RuleData: [RuleData] if RuleData in glyphs else []
			elif Format == 2:
				self.Rule = ChainTyp+'ClassRule'
				self.RuleCount = ChainTyp+'ClassRuleCount'
				self.RuleSet = ChainTyp+'ClassSet'
				self.RuleSetCount = ChainTyp+'ClassSetCount'
				self.Intersect = lambda glyphs, ContextData, RuleData: ContextData.intersect_class (glyphs, RuleData)

				self.ClassDef = 'InputClassDef' if Chain else 'ClassDef'

	if self.Format not in [1, 2, 3]:
		return None # Don't shoot the messenger; let it go
	if not hasattr (self.__class__, "__ContextHelpers"):
		self.__class__.__ContextHelpers = {}
	if self.Format not in self.__class__.__ContextHelpers:
		self.__class__.__ContextHelpers[self.Format] = ContextHelper (self.__class__, self.Format)
	return self.__class__.__ContextHelpers[self.Format]

@add_method(fontTools.ttLib.tables.otTables.ContextSubst, fontTools.ttLib.tables.otTables.ChainContextSubst)
def closure_glyphs (self, s, cur_glyphs=None):
	if cur_glyphs == None: cur_glyphs = s.glyphs
	c = self.__classify_context ()

	indices = c.Coverage (self).intersect (s.glyphs)
	if not indices:
		return []
	cur_glyphs = c.Coverage (self).intersect_glyphs (s.glyphs);

	if self.Format == 1:
		ContextData = c.ContextData (self)
		rss = getattr (self, c.RuleSet)
		for i in indices:
			if not rss[i]: continue
			for r in getattr (rss[i], c.Rule):
				if not r: continue
				if all (all (c.Intersect (s.glyphs, cd, k) for k in klist)
					for cd,klist in zip (ContextData, c.RuleData (r))):
					chaos = False
					for ll in getattr (r, c.LookupRecord):
						if not ll: continue
						seqi = ll.SequenceIndex
						if seqi == 0:
							pos_glyphs = set (c.Coverage (self).glyphs[i])
						else:
							if chaos:
								pos_glyphs = s.glyphs
							else:
								pos_glyphs = set (r.Input[seqi - 1])
						lookup = s.table.LookupList.Lookup[ll.LookupListIndex]
						chaos = chaos or lookup.may_have_non_1to1 ()
						lookup.closure_glyphs (s, cur_glyphs=pos_glyphs)
	elif self.Format == 2:
		ClassDef = getattr (self, c.ClassDef)
		indices = ClassDef.intersect (cur_glyphs)
		ContextData = c.ContextData (self)
		rss = getattr (self, c.RuleSet)
		for i in indices:
			if not rss[i]: continue
			for r in getattr (rss[i], c.Rule):
				if not r: continue
				if all (all (c.Intersect (s.glyphs, cd, k) for k in klist)
					for cd,klist in zip (ContextData, c.RuleData (r))):
					chaos = False
					for ll in getattr (r, c.LookupRecord):
						if not ll: continue
						seqi = ll.SequenceIndex
						if seqi == 0:
							pos_glyphs = ClassDef.intersect_class (cur_glyphs, i)
						else:
							if chaos:
								pos_glyphs = s.glyphs
							else:
								pos_glyphs = ClassDef.intersect_class (s.glyphs, r.Input[seqi - 1])
						lookup = s.table.LookupList.Lookup[ll.LookupListIndex]
						chaos = chaos or lookup.may_have_non_1to1 ()
						lookup.closure_glyphs (s, cur_glyphs=pos_glyphs)
	elif self.Format == 3:
		if not all (x.intersect (s.glyphs) for x in c.RuleData (self)):
			return []
		r = self
		chaos = False
		for ll in getattr (r, c.LookupRecord):
			if not ll: continue
			seqi = ll.SequenceIndex
			if seqi == 0:
				pos_glyphs = cur_glyphs
			else:
				if chaos:
					pos_glyphs = s.glyphs
				else:
					pos_glyphs = r.InputCoverage[seqi].intersect_glyphs (s.glyphs)
			lookup = s.table.LookupList.Lookup[ll.LookupListIndex]
			chaos = chaos or lookup.may_have_non_1to1 ()
			lookup.closure_glyphs (s, cur_glyphs=pos_glyphs)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.ContextSubst,      fontTools.ttLib.tables.otTables.ContextPos,
	    fontTools.ttLib.tables.otTables.ChainContextSubst, fontTools.ttLib.tables.otTables.ChainContextPos)
def subset_glyphs (self, s):
	c = self.__classify_context ()

	if self.Format == 1:
		indices = self.Coverage.subset (s.glyphs)
		rss = getattr (self, c.RuleSet)
		rss = [rss[i] for i in indices]
		for rs in rss:
			if not rs: continue
			ss = getattr (rs, c.Rule)
			ss = [r for r in ss \
			      if r and all (all (g in s.glyphs for g in glist) \
					    for glist in c.RuleData (r))]
			setattr (rs, c.Rule, ss)
			setattr (rs, c.RuleCount, len (ss))
		# Prune empty subrulesets
		rss = [rs for rs in rss if rs and getattr (rs, c.Rule)]
		setattr (self, c.RuleSet, rss)
		setattr (self, c.RuleSetCount, len (rss))
		return bool (rss)
	elif self.Format == 2:
		if not self.Coverage.subset (s.glyphs):
			return False
		indices = getattr (self, c.ClassDef).subset (self.Coverage.glyphs, remap=False)
		rss = getattr (self, c.RuleSet)
		rss = [rss[i] for i in indices]
		ContextData = c.ContextData (self)
		klass_maps = [x.subset (s.glyphs, remap=True) for x in ContextData]
		for rs in rss:
			if not rs: continue
			ss = getattr (rs, c.Rule)
			ss = [r for r in ss \
			      if r and all (all (k in klass_map for k in klist) \
					    for klass_map,klist in zip (klass_maps, c.RuleData (r)))]
			setattr (rs, c.Rule, ss)
			setattr (rs, c.RuleCount, len (ss))

			# Remap rule classes
			for r in ss:
				c.SetRuleData (r, [[klass_map.index (k) for k in klist] \
						   for klass_map,klist in zip (klass_maps, c.RuleData (r))])
		# Prune empty subrulesets
		rss = [rs for rs in rss if rs and getattr (rs, c.Rule)]
		setattr (self, c.RuleSet, rss)
		setattr (self, c.RuleSetCount, len (rss))
		return bool (rss)
	elif self.Format == 3:
		return all (x.subset (s.glyphs) for x in c.RuleData (self))
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.ContextSubst, fontTools.ttLib.tables.otTables.ChainContextSubst,
	    fontTools.ttLib.tables.otTables.ContextPos,   fontTools.ttLib.tables.otTables.ChainContextPos)
def subset_lookups (self, lookup_indices):
	c = self.__classify_context ()

	if self.Format in [1, 2]:
		for rs in getattr (self, c.RuleSet):
			if not rs: continue
			for r in getattr (rs, c.Rule):
				if not r: continue
				setattr (r, c.LookupRecord, [ll for ll in getattr (r, c.LookupRecord) if ll \
								if ll.LookupListIndex in lookup_indices])
				for ll in getattr (r, c.LookupRecord):
					if not ll: continue
					ll.LookupListIndex = lookup_indices.index (ll.LookupListIndex)
	elif self.Format == 3:
		setattr (self, c.LookupRecord, [ll for ll in getattr (self, c.LookupRecord) if ll \
						   if ll.LookupListIndex in lookup_indices])
		for ll in getattr (self, c.LookupRecord):
			if not ll: continue
			ll.LookupListIndex = lookup_indices.index (ll.LookupListIndex)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.ContextSubst, fontTools.ttLib.tables.otTables.ChainContextSubst,
	    fontTools.ttLib.tables.otTables.ContextPos,   fontTools.ttLib.tables.otTables.ChainContextPos)
def collect_lookups (self):
	c = self.__classify_context ()

	if self.Format in [1, 2]:
		return [ll.LookupListIndex \
			for rs in getattr (self, c.RuleSet) if rs \
			for r in getattr (rs, c.Rule) if r \
			for ll in getattr (r, c.LookupRecord) if ll]
	elif self.Format == 3:
		return [ll.LookupListIndex \
			for ll in getattr (self, c.LookupRecord) if ll]
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.ExtensionSubst)
def closure_glyphs (self, s, cur_glyphs=None):
	if self.Format == 1:
		self.ExtSubTable.closure_glyphs (s, cur_glyphs)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.ExtensionSubst)
def may_have_non_1to1 (self):
	if self.Format == 1:
		return self.ExtSubTable.may_have_non_1to1 ()
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.ExtensionSubst, fontTools.ttLib.tables.otTables.ExtensionPos)
def subset_glyphs (self, s):
	if self.Format == 1:
		return self.ExtSubTable.subset_glyphs (s)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.ExtensionSubst, fontTools.ttLib.tables.otTables.ExtensionPos)
def subset_lookups (self, lookup_indices):
	if self.Format == 1:
		return self.ExtSubTable.subset_lookups (lookup_indices)
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.ExtensionSubst, fontTools.ttLib.tables.otTables.ExtensionPos)
def collect_lookups (self):
	if self.Format == 1:
		return self.ExtSubTable.collect_lookups ()
	else:
		assert 0, "unknown format: %s" % self.Format

@add_method(fontTools.ttLib.tables.otTables.Lookup)
def closure_glyphs (self, s, cur_glyphs=None):
	for st in self.SubTable:
		if not st: continue
		st.closure_glyphs (s, cur_glyphs)

@add_method(fontTools.ttLib.tables.otTables.Lookup)
def subset_glyphs (self, s):
	self.SubTable = [st for st in self.SubTable if st and st.subset_glyphs (s)]
	self.SubTableCount = len (self.SubTable)
	return bool (self.SubTableCount)

@add_method(fontTools.ttLib.tables.otTables.Lookup)
def subset_lookups (self, lookup_indices):
	for s in self.SubTable:
		s.subset_lookups (lookup_indices)

@add_method(fontTools.ttLib.tables.otTables.Lookup)
def collect_lookups (self):
	return unique_sorted (sum ((st.collect_lookups () for st in self.SubTable if st), []))

@add_method(fontTools.ttLib.tables.otTables.Lookup)
def may_have_non_1to1 (self):
	return any (st.may_have_non_1to1 () for st in self.SubTable if st)

@add_method(fontTools.ttLib.tables.otTables.LookupList)
def subset_glyphs (self, s):
	"Returns the indices of nonempty lookups."
	return [i for (i,l) in enumerate (self.Lookup) if l and l.subset_glyphs (s)]

@add_method(fontTools.ttLib.tables.otTables.LookupList)
def subset_lookups (self, lookup_indices):
	self.Lookup = [self.Lookup[i] for i in lookup_indices if i < self.LookupCount]
	self.LookupCount = len (self.Lookup)
	for l in self.Lookup:
		l.subset_lookups (lookup_indices)

@add_method(fontTools.ttLib.tables.otTables.LookupList)
def closure_lookups (self, lookup_indices):
	lookup_indices = unique_sorted (lookup_indices)
	recurse = lookup_indices
	while True:
		recurse_lookups = sum ((self.Lookup[i].collect_lookups () for i in recurse if i < self.LookupCount), [])
		recurse_lookups = [l for l in recurse_lookups if l not in lookup_indices and l < self.LookupCount]
		if not recurse_lookups:
			return unique_sorted (lookup_indices)
		recurse_lookups = unique_sorted (recurse_lookups)
		lookup_indices.extend (recurse_lookups)
		recurse = recurse_lookups

@add_method(fontTools.ttLib.tables.otTables.Feature)
def subset_lookups (self, lookup_indices):
	self.LookupListIndex = [l for l in self.LookupListIndex if l in lookup_indices]
	# Now map them.
	self.LookupListIndex = [lookup_indices.index (l) for l in self.LookupListIndex]
	self.LookupCount = len (self.LookupListIndex)
	return self.LookupCount

@add_method(fontTools.ttLib.tables.otTables.Feature)
def collect_lookups (self):
	return self.LookupListIndex[:]

@add_method(fontTools.ttLib.tables.otTables.FeatureList)
def subset_lookups (self, lookup_indices):
	"Returns the indices of nonempty features."
	feature_indices = [i for (i,f) in enumerate (self.FeatureRecord) if f.Feature.subset_lookups (lookup_indices)]
	self.subset_features (feature_indices)
	return feature_indices

@add_method(fontTools.ttLib.tables.otTables.FeatureList)
def collect_lookups (self, feature_indices):
	return unique_sorted (sum ((self.FeatureRecord[i].Feature.collect_lookups () for i in feature_indices
				    if i < self.FeatureCount), []))

@add_method(fontTools.ttLib.tables.otTables.FeatureList)
def subset_features (self, feature_indices):
	self.FeatureRecord = [self.FeatureRecord[i] for i in feature_indices]
	self.FeatureCount = len (self.FeatureRecord)
	return bool (self.FeatureCount)

@add_method(fontTools.ttLib.tables.otTables.DefaultLangSys, fontTools.ttLib.tables.otTables.LangSys)
def subset_features (self, feature_indices):
	if self.ReqFeatureIndex in feature_indices:
		self.ReqFeatureIndex = feature_indices.index (self.ReqFeatureIndex)
	else:
		self.ReqFeatureIndex = 65535
	self.FeatureIndex = [f for f in self.FeatureIndex if f in feature_indices]
	# Now map them.
	self.FeatureIndex = [feature_indices.index (f) for f in self.FeatureIndex if f in feature_indices]
	self.FeatureCount = len (self.FeatureIndex)
	return bool (self.FeatureCount or self.ReqFeatureIndex != 65535)

@add_method(fontTools.ttLib.tables.otTables.DefaultLangSys, fontTools.ttLib.tables.otTables.LangSys)
def collect_features (self):
	feature_indices = self.FeatureIndex[:]
	if self.ReqFeatureIndex != 65535:
		feature_indices.append (self.ReqFeatureIndex)
	return unique_sorted (feature_indices)

@add_method(fontTools.ttLib.tables.otTables.Script)
def subset_features (self, feature_indices):
	if self.DefaultLangSys and not self.DefaultLangSys.subset_features (feature_indices):
		self.DefaultLangSys = None
	self.LangSysRecord = [l for l in self.LangSysRecord if l.LangSys.subset_features (feature_indices)]
	self.LangSysCount = len (self.LangSysRecord)
	return bool (self.LangSysCount or self.DefaultLangSys)

@add_method(fontTools.ttLib.tables.otTables.Script)
def collect_features (self):
	feature_indices = [l.LangSys.collect_features () for l in self.LangSysRecord]
	if self.DefaultLangSys:
		feature_indices.append (self.DefaultLangSys.collect_features ())
	return unique_sorted (sum (feature_indices, []))

@add_method(fontTools.ttLib.tables.otTables.ScriptList)
def subset_features (self, feature_indices):
	self.ScriptRecord = [s for s in self.ScriptRecord if s.Script.subset_features (feature_indices)]
	self.ScriptCount = len (self.ScriptRecord)
	return bool (self.ScriptCount)

@add_method(fontTools.ttLib.tables.otTables.ScriptList)
def collect_features (self):
	return unique_sorted (sum ((s.Script.collect_features () for s in self.ScriptRecord), []))

@add_method(fontTools.ttLib.getTableClass('GSUB'))
def closure_glyphs (self, s):
	s.table = self.table
	feature_indices = self.table.ScriptList.collect_features ()
	lookup_indices = self.table.FeatureList.collect_lookups (feature_indices)
	while True:
		orig_glyphs = s.glyphs.copy ()
		for i in lookup_indices:
			if i >= self.table.LookupList.LookupCount: continue
			if not self.table.LookupList.Lookup[i]: continue
			self.table.LookupList.Lookup[i].closure_glyphs (s)
		if orig_glyphs == s.glyphs:
			break
	del s.table

@add_method(fontTools.ttLib.getTableClass('GSUB'), fontTools.ttLib.getTableClass('GPOS'))
def subset_glyphs (self, s):
	s.glyphs = s.glyphs_gsubed
	lookup_indices = self.table.LookupList.subset_glyphs (s)
	self.subset_lookups (lookup_indices)
	self.prune_lookups ()
	return True

@add_method(fontTools.ttLib.getTableClass('GSUB'), fontTools.ttLib.getTableClass('GPOS'))
def subset_lookups (self, lookup_indices):
	"Retrains specified lookups, then removes empty features, language systems, and scripts."
	self.table.LookupList.subset_lookups (lookup_indices)
	feature_indices = self.table.FeatureList.subset_lookups (lookup_indices)
	self.table.ScriptList.subset_features (feature_indices)

@add_method(fontTools.ttLib.getTableClass('GSUB'), fontTools.ttLib.getTableClass('GPOS'))
def prune_lookups (self):
	"Remove unreferenced lookups"
	feature_indices = self.table.ScriptList.collect_features ()
	lookup_indices = self.table.FeatureList.collect_lookups (feature_indices)
	lookup_indices = self.table.LookupList.closure_lookups (lookup_indices)
	self.subset_lookups (lookup_indices)

@add_method(fontTools.ttLib.getTableClass('GSUB'), fontTools.ttLib.getTableClass('GPOS'))
def subset_feature_tags (self, feature_tags):
	feature_indices = [i for (i,f) in enumerate (self.table.FeatureList.FeatureRecord) if f.FeatureTag in feature_tags]
	self.table.FeatureList.subset_features (feature_indices)
	self.table.ScriptList.subset_features (feature_indices)

@add_method(fontTools.ttLib.getTableClass('GSUB'), fontTools.ttLib.getTableClass('GPOS'))
def prune_pre_subset (self, options):
	if options.layout_features and '*' not in options.layout_features:
		self.subset_feature_tags (options.layout_features)
	self.prune_lookups ()
	return True

@add_method(fontTools.ttLib.getTableClass('GDEF'))
def subset_glyphs (self, s):
	glyphs = s.glyphs_gsubed
	table = self.table
	if table.LigCaretList:
		indices = table.LigCaretList.Coverage.subset (glyphs)
		table.LigCaretList.LigGlyph = [table.LigCaretList.LigGlyph[i] for i in indices]
		table.LigCaretList.LigGlyphCount = len (table.LigCaretList.LigGlyph)
		if not table.LigCaretList.LigGlyphCount:
			table.LigCaretList = None
	if table.MarkAttachClassDef:
		table.MarkAttachClassDef.classDefs = {g:v for g,v in table.MarkAttachClassDef.classDefs.items() if g in glyphs}
		if not table.MarkAttachClassDef.classDefs:
			table.MarkAttachClassDef = None
	if table.GlyphClassDef:
		table.GlyphClassDef.classDefs = {g:v for g,v in table.GlyphClassDef.classDefs.items() if g in glyphs}
		if not table.GlyphClassDef.classDefs:
			table.GlyphClassDef = None
	if table.AttachList:
		indices = table.AttachList.Coverage.subset (glyphs)
		table.AttachList.AttachPoint = [table.AttachList.AttachPoint[i] for i in indices]
		table.AttachList.GlyphCount = len (table.AttachList.AttachPoint)
		if not table.AttachList.GlyphCount:
			table.AttachList = None
	return bool (table.LigCaretList or table.MarkAttachClassDef or table.GlyphClassDef or table.AttachList)

@add_method(fontTools.ttLib.getTableClass('kern'))
def prune_pre_subset (self, options):
	# Prune unknown kern table types
	self.kernTables = [t for t in self.kernTables if hasattr (t, 'kernTable')]
	return bool (self.kernTables)

@add_method(fontTools.ttLib.getTableClass('kern'))
def subset_glyphs (self, s):
	glyphs = s.glyphs_gsubed
	for t in self.kernTables:
		t.kernTable = {(a,b):v for ((a,b),v) in t.kernTable.items() if a in glyphs and b in glyphs}
	self.kernTables = [t for t in self.kernTables if t.kernTable]
	return bool (self.kernTables)

@add_method(fontTools.ttLib.getTableClass('hmtx'), fontTools.ttLib.getTableClass('vmtx'))
def subset_glyphs (self, s):
	self.metrics = {g:v for g,v in self.metrics.items() if g in s.glyphs}
	return bool (self.metrics)

@add_method(fontTools.ttLib.getTableClass('hdmx'))
def subset_glyphs (self, s):
	self.hdmx = {sz:{g:v for g,v in l.items() if g in s.glyphs} for (sz,l) in self.hdmx.items()}
	return bool (self.hdmx)

@add_method(fontTools.ttLib.getTableClass('VORG'))
def subset_glyphs (self, s):
	self.VOriginRecords = {g:v for g,v in self.VOriginRecords.items() if g in s.glyphs}
	self.numVertOriginYMetrics = len (self.VOriginRecords)
	return True # Never drop; has default metrics

@add_method(fontTools.ttLib.getTableClass('post'))
def prune_pre_subset (self, options):
	if not options.glyph_names:
		self.formatType = 3.0
	return True

@add_method(fontTools.ttLib.getTableClass('post'))
def subset_glyphs (self, s):
	self.extraNames = [] # This seems to do it
	return True

# Copied from _g_l_y_f.py
ARG_1_AND_2_ARE_WORDS      = 0x0001  # if set args are words otherwise they are bytes
ARGS_ARE_XY_VALUES         = 0x0002  # if set args are xy values, otherwise they are points
ROUND_XY_TO_GRID           = 0x0004  # for the xy values if above is true
WE_HAVE_A_SCALE            = 0x0008  # Sx = Sy, otherwise scale == 1.0
NON_OVERLAPPING            = 0x0010  # set to same value for all components (obsolete!)
MORE_COMPONENTS            = 0x0020  # indicates at least one more glyph after this one
WE_HAVE_AN_X_AND_Y_SCALE   = 0x0040  # Sx, Sy
WE_HAVE_A_TWO_BY_TWO       = 0x0080  # t00, t01, t10, t11
WE_HAVE_INSTRUCTIONS       = 0x0100  # instructions follow
USE_MY_METRICS             = 0x0200  # apply these metrics to parent glyph
OVERLAP_COMPOUND           = 0x0400  # used by Apple in GX fonts
SCALED_COMPONENT_OFFSET    = 0x0800  # composite designed to have the component offset scaled (designed for Apple)
UNSCALED_COMPONENT_OFFSET  = 0x1000  # composite designed not to have the component offset scaled (designed for MS)

@add_method(fontTools.ttLib.getTableModule('glyf').Glyph)
def getComponentNamesFast (self, glyfTable):
	if struct.unpack(">h", self.data[:2])[0] >= 0:
		return [] # Not composite
	data = self.data
	i = 10
	components = []
	more = 1
	while more:
		flags, glyphID = struct.unpack(">HH", data[i:i+4])
		i += 4
		flags = int(flags)
		components.append (glyfTable.getGlyphName (int (glyphID)))

		if flags & ARG_1_AND_2_ARE_WORDS:	i += 4
		else:					i += 2
		if flags & WE_HAVE_A_SCALE:		i += 2
		elif flags & WE_HAVE_AN_X_AND_Y_SCALE:	i += 4
		elif flags & WE_HAVE_A_TWO_BY_TWO:	i += 8
		more = flags & MORE_COMPONENTS
	return components

@add_method(fontTools.ttLib.getTableModule('glyf').Glyph)
def remapComponentsFast (self, indices):
	if struct.unpack(">h", self.data[:2])[0] >= 0:
		return # Not composite
	data = bytearray (self.data)
	i = 10
	more = 1
	while more:
		flags = (data[i] << 8) | data[i+1]
		glyphID = (data[i+2] << 8) | data[i+3]
		# Remap
		glyphID = indices.index (glyphID)
		data[i+2] = glyphID >> 8
		data[i+3] = glyphID & 0xFF
		i += 4
		flags = int(flags)

		if flags & ARG_1_AND_2_ARE_WORDS:	i += 4
		else:					i += 2
		if flags & WE_HAVE_A_SCALE:		i += 2
		elif flags & WE_HAVE_AN_X_AND_Y_SCALE:	i += 4
		elif flags & WE_HAVE_A_TWO_BY_TWO:	i += 8
		more = flags & MORE_COMPONENTS
	self.data = str (data)

@add_method(fontTools.ttLib.getTableModule('glyf').Glyph)
def dropInstructionsFast (self):
	numContours = struct.unpack(">h", self.data[:2])[0]
	data = bytearray (self.data)
	i = 10
	if numContours >= 0:
		i += 2 * numContours # endPtsOfContours
		instructionLen = (data[i] << 8) | data[i+1]
		# Zero it
		data[i] = data [i+1] = 0
		i += 2
		if instructionLen:
			# Splice it out
			data = data[:i] + data[i+instructionLen:]
	else:
		more = 1
		while more:
			flags = (data[i] << 8) | data[i+1]
			# Turn instruction flag off
			flags &= ~WE_HAVE_INSTRUCTIONS
			data[i+0] = flags >> 8
			data[i+1] = flags & 0xFF
			i += 4
			flags = int(flags)

			if flags & ARG_1_AND_2_ARE_WORDS:	i += 4
			else:					i += 2
			if flags & WE_HAVE_A_SCALE:		i += 2
			elif flags & WE_HAVE_AN_X_AND_Y_SCALE:	i += 4
			elif flags & WE_HAVE_A_TWO_BY_TWO:	i += 8
			more = flags & MORE_COMPONENTS
		# Cut off
		data = data[:i]
	if len(data) % 4:
		# add pad bytes
		nPadBytes = 4 - (len(data) % 4)
		for i in range (nPadBytes):
			data.append (0)
	self.data = str (data)

@add_method(fontTools.ttLib.getTableClass('glyf'))
def closure_glyphs (self, s):
	decompose = s.glyphs
	# I don't know if component glyphs can be composite themselves.
	# We handle them anyway.
	while True:
		components = set ()
		for g in decompose:
			if g not in self.glyphs:
				continue
			gl = self.glyphs[g]
			if hasattr (gl, "data"):
				for c in gl.getComponentNamesFast (self):
					if c not in s.glyphs:
						components.add (c)
			else:
				# TTX seems to expand gid0..3 always
				if gl.isComposite ():
					for c in gl.components:
						if c.glyphName not in s.glyphs:
							components.add (c.glyphName)
		components = set (c for c in components if c not in s.glyphs)
		if not components:
			break
		decompose = components
		s.glyphs.update (components)

@add_method(fontTools.ttLib.getTableClass('glyf'))
def subset_glyphs (self, s):
	self.glyphs = {g:v for g,v in self.glyphs.items() if g in s.glyphs}
	indices = [i for i,g in enumerate (self.glyphOrder) if g in s.glyphs]
	for v in self.glyphs.values ():
		if hasattr (v, "data"):
			v.remapComponentsFast (indices)
		else:
			pass # No need
	self.glyphOrder = [g for g in self.glyphOrder if g in s.glyphs]
	return bool (self.glyphs)

@add_method(fontTools.ttLib.getTableClass('glyf'))
def prune_post_subset (self, options):
	if not options.hinting:
		for v in self.glyphs.values ():
			if hasattr (v, "data"):
				v.dropInstructionsFast ()
			else:
				v.program = fontTools.ttLib.tables.ttProgram.Program()
				v.program.fromBytecode([])
	return True

@add_method(fontTools.ttLib.getTableClass('CFF '))
def subset_glyphs (self, s):
	assert 0, "unimplemented"

@add_method(fontTools.ttLib.getTableClass('cmap'))
def closure_glyphs (self, s):
	tables = [t for t in self.tables if t.platformID == 3 and t.platEncID in [1, 10]]
	for u in s.unicodes_requested:
		found = False
		for table in tables:
			if u in table.cmap:
				s.glyphs.add (table.cmap[u])
				found = True
				break
		if not found:
			s.log ("No glyph for Unicode value %s; skipping." % u)

@add_method(fontTools.ttLib.getTableClass('cmap'))
def prune_pre_subset (self, options):
	if not options.legacy_cmap:
		# Drop non-Unicode / non-Symbol cmaps
		self.tables = [t for t in self.tables if t.platformID == 3 and t.platEncID in [0, 1, 10]]
	if not options.symbol_cmap:
		self.tables = [t for t in self.tables if t.platformID == 3 and t.platEncID in [1, 10]]
	# TODO Only keep one subtable?
	# For now, drop format=0 which can't be subset_glyphs easily?
	self.tables = [t for t in self.tables if t.format != 0]
	return bool (self.tables)

@add_method(fontTools.ttLib.getTableClass('cmap'))
def subset_glyphs (self, s):
	s.glyphs = s.glyphs_cmaped
	for t in self.tables:
		# For reasons I don't understand I need this here
		# to force decompilation of the cmap format 14.
		try:
			getattr (t, "asdf")
		except AttributeError:
			pass
		if t.format == 14:
			# XXX We drop all the default-UVS mappings (g==None)
			t.uvsDict = {v:[(u,g) for (u,g) in l if g in s.glyphs] for (v,l) in t.uvsDict.items()}
			t.uvsDict = {v:l for (v,l) in t.uvsDict.items() if l}
		else:
			t.cmap = {u:g for (u,g) in t.cmap.items() if g in s.glyphs_requested or u in s.unicodes_requested}
	self.tables = [t for t in self.tables if (t.cmap if t.format != 14 else t.uvsDict)]
	# XXX Convert formats when needed
	# In particular, if we have a format=12 without non-BMP
	# characters, either drop format=12 one or convert it
	# to format=4 if there's not one.
	return bool (self.tables)

@add_method(fontTools.ttLib.getTableClass('name'))
def prune_pre_subset (self, options):
	if '*' not in options.name_IDs:
		self.names = [n for n in self.names if n.nameID in options.name_IDs]
	if not options.name_legacy:
		self.names = [n for n in self.names if n.platformID == 3 and n.platEncID == 1]
	if '*' not in options.name_languages:
		self.names = [n for n in self.names if n.langID in options.name_languages]
	return True # Retain even if empty


drop_tables_default = ['BASE', 'JSTF', 'DSIG', 'EBDT', 'EBLC', 'EBSC', 'PCLT', 'LTSH']
drop_tables_default += ['Feat', 'Glat', 'Gloc', 'Silf', 'Sill'] # Graphite
drop_tables_default += ['CBLC', 'CBDT', 'sbix', 'COLR', 'CPAL'] # Color
no_subset_tables_default = ['gasp', 'head', 'hhea', 'maxp', 'vhea', 'OS/2', 'loca', 'name', 'cvt ', 'fpgm', 'prep']
hinting_tables_default = ['cvt ', 'fpgm', 'prep', 'hdmx', 'VDMX']

# Based on HarfBuzz shapers
layout_features_dict = {
	# Default shaper
	'common':	['ccmp', 'liga', 'locl', 'mark', 'mkmk', 'rlig'],
	'horizontal':	['calt', 'clig', 'curs', 'kern', 'rclt'],
	'vertical':	['valt', 'vert', 'vkrn', 'vpal', 'vrt2'],
	'ltr':		['ltra', 'ltrm'],
	'rtl':		['rtla', 'rtlm'],
	# Complex shapers
	'arabic':	['init', 'medi', 'fina', 'isol', 'med2', 'fin2', 'fin3', 'cswh', 'mset'],
	'hangul':	['ljmo', 'vjmo', 'tjmo'],
	'tibetal':	['abvs', 'blws', 'abvm', 'blwm'],
	'indic':	['nukt', 'akhn', 'rphf', 'rkrf', 'pref', 'blwf', 'half', 'abvf', 'pstf', 'cfar', 'vatu', 'cjct',
		         'init', 'pres', 'abvs', 'blws', 'psts', 'haln', 'dist', 'abvm', 'blwm'],
}
layout_features_all = unique_sorted (sum (layout_features_dict.values (), []))

# TODO OS/2 ulUnicodeRange / ulCodePageRange?
# TODO Drop unneeded GSUB/GPOS Script/LangSys entries
# TODO Avoid recursing too much
# TODO Text direction considerations
# TODO Text script / language considerations
# TODO Drop unknown tables?  Using DefaultTable.prune?
# TODO Drop GPOS Device records if not hinting?
# TODO Move font name loading hack to Subsetter?


class Subsetter:

	class Options:
		drop_tables = drop_tables_default
		no_subset_tables = no_subset_tables_default
		hinting_tables = hinting_tables_default
		layout_features = layout_features_all
		hinting = False
		glyph_names = False
		legacy_cmap = False
		symbol_cmap = False
		name_IDs = [1, 2] # Family and Style
		name_legacy = False
		name_languages = [0x0409] # English
		mandatory_glyphs = True # First four for TrueType, .notdef for CFF
		recalc_bboxes = False # Slows us down

		def __init__ (self, **kwargs):

			self.set (**kwargs)

		def set (self, **kwargs):
			for k,v in kwargs.items ():
				if not hasattr (self, k):
					raise Exception ("Unknown option '%s'" % k)
				setattr (self, k, v)

		def parse_opts (self, argv, ignore_unknown=False):
			ret = []
			opts = {}
			for a in argv:
				if not a.startswith ('--'):
					ret.append (a)
					continue
				a = a[2:]
				i = a.find ('=')
				if i == -1:
					if a.startswith ("no-"):
						k = a[3:]
						v = False
					else:
						k = a
						v = True
				else:
					k = a[:i]
					v = a[i+1:]
				k = k.replace ('-', '_')
				if not hasattr (self, k):
					if ignore_unknown:
						ret.append (a)
						continue
					else:
						raise Exception ("Unknown option '%s'" % a)

				ov = getattr (self, k)
				if isinstance (ov, bool):
					v = bool (v)
				elif isinstance (ov, int):
					v = int (v)
				elif isinstance (ov, list):
					v = v.split (',')
					v = [int (x, 0) if x[0] in range (10) else x for x in v]

				opts[k] = v
			self.set (**opts)

			return ret


	def __init__ (self, options=None, log=None):

		if not log:
			log = Logger()
		if not options:
			options = Options()

		self.options = options
		self.log = log
		self.unicodes_requested = set ()
		self.glyphs_requested = set ()

	def populate (self, glyphs=[], unicodes=[], text=""):
		self.unicodes_requested.update (unicodes)
		if isinstance (text, str):
			text = text.decode ("utf8")
		for u in text:
			self.unicodes_requested.add (ord (u))
		self.glyphs_requested.update (glyphs)

	def pre_prune (self, font):

		for tag in font.keys():
			if tag == 'GlyphOrder': continue

			if tag in self.options.drop_tables or \
			   (tag in self.options.hinting_tables and not self.options.hinting):
				self.log (tag, "dropped")
				del font[tag]
				continue

			clazz = fontTools.ttLib.getTableClass(tag)

			if hasattr (clazz, 'prune_pre_subset'):
				table = font[tag]
				retain = table.prune_pre_subset (self.options)
				self.log.lapse ("prune  '%s'" % tag)
				if not retain:
					self.log (tag, "pruned to empty; dropped")
					del font[tag]
					continue
				else:
					self.log (tag, "pruned")

	def closure_glyphs (self, font):

		self.glyphs = self.glyphs_requested.copy ()

		if 'cmap' in font:
			font['cmap'].closure_glyphs (self)
		self.glyphs_cmaped = self.glyphs

		if self.options.mandatory_glyphs:
			if 'glyf' in font:
				for i in range (4):
					self.glyphs.add (font.getGlyphName (i))
				self.log ("Added first four glyphs to subset")
			else:
				self.glyphs.add ('.notdef')
				self.log ("Added .notdef glyph to subset")

		if 'GSUB' in font:
			self.log ("Closing glyph list over 'GSUB': %d glyphs before" % len (self.glyphs))
			self.log.glyphs (self.glyphs, font=font)
			font['GSUB'].closure_glyphs (self)
			self.log ("Closed  glyph list over 'GSUB': %d glyphs after" % len (self.glyphs))
			self.log.glyphs (self.glyphs, font=font)
			self.log.lapse ("close glyph list over 'GSUB'")
		self.glyphs_gsubed = self.glyphs.copy ()

		if 'glyf' in font:
			self.log ("Closing glyph list over 'glyf': %d glyphs before" % len (self.glyphs))
			self.log.glyphs (self.glyphs, font=font)
			font['glyf'].closure_glyphs (self)
			self.log ("Closed  glyph list over 'glyf': %d glyphs after" % len (self.glyphs))
			self.log.glyphs (self.glyphs, font=font)
			self.log.lapse ("close glyph list over 'glyf'")
		self.glyphs_glyfed = self.glyphs.copy ()

		self.glyphs_all = self.glyphs.copy ()

		self.log ("Retaining %d glyphs: " % len (self.glyphs_all))

	def subset_glyphs (self, font):
		for tag in font.keys():
			if tag == 'GlyphOrder': continue
			clazz = fontTools.ttLib.getTableClass(tag)

			if tag in self.options.no_subset_tables:
				self.log (tag, "subsetting not needed")
			elif hasattr (clazz, 'subset_glyphs'):
				table = font[tag]
				self.glyphs = self.glyphs_all
				retain = table.subset_glyphs (self)
				self.glyphs = self.glyphs_all
				self.log.lapse ("subset '%s'" % tag)
				if not retain:
					self.log (tag, "subsetted to empty; dropped")
					del font[tag]
				else:
					self.log (tag, "subsetted")
			else:
				self.log (tag, "NOT subset; don't know how to subset; dropped")
				del font[tag]

		glyphOrder = font.getGlyphOrder()
		glyphOrder = [g for g in glyphOrder if g in self.glyphs_all]
		font.setGlyphOrder (glyphOrder)
		font._buildReverseGlyphOrderDict ()
		self.log.lapse ("subset GlyphOrder")

	def post_prune (self, font):
		for tag in font.keys():
			if tag == 'GlyphOrder': continue
			clazz = fontTools.ttLib.getTableClass(tag)
			if hasattr (clazz, 'prune_post_subset'):
				table = font[tag]
				retain = table.prune_post_subset (self.options)
				self.log.lapse ("prune  '%s'" % tag)
				if not retain:
					self.log (tag, "pruned to empty; dropped")
					del font[tag]
				else:
					self.log (tag, "pruned")

	def subset (self, font):

		font.recalcBBoxes = self.options.recalc_bboxes

		self.pre_prune (font)
		self.closure_glyphs (font)
		self.subset_glyphs (font)
		self.post_prune (font)


import sys, time

class Logger:

	def __init__ (self, verbose=False, xml=False, timing=False):
		self.verbose = verbose
		self.xml = xml
		self.timing = timing
		self.last_time = self.start_time = time.time ()

	def parse_opts (self, argv):
		argv = argv[:]
		for v in ['verbose', 'xml', 'timing']:
			if "--"+v in argv:
				setattr (self, v, True)
				argv.remove ("--"+v)
		return argv

	def __call__ (self, *things):
		if not self.verbose:
			return
		print ' '.join (str (x) for x in things)

	def lapse (self, *things):
		if not self.timing:
			return
		new_time = time.time ()
		print "Took %0.3fs to %s" % (new_time - self.last_time, ' '.join (str (x) for x in things))
		self.last_time = new_time

	def glyphs (self, glyphs, glyph_names=True, font=None):
		self ("Names: ", sorted (glyphs))
		if font:
			reverseGlyphMap = font.getReverseGlyphMap ()
			self ("Gids : ", sorted (reverseGlyphMap[g] for g in glyphs))

	def font (self, font, file=sys.stdout):
		if not self.xml:
			return
		import xmlWriter, sys
		writer = xmlWriter.XMLWriter (file)
		font.disassembleInstructions = False # Work around ttx bug
		for tag in font.keys():
			writer.begintag (tag)
			writer.newline ()
			font[tag].toXML(writer, font)
			writer.endtag (tag)
			writer.newline ()


def load_font (fontfile, dont_load_glyph_names=False):

	# TODO Option for ignoreDecompileErrors?

	font = fontTools.ttx.TTFont (fontfile)

	# Hack:
	#
	# If we don't need glyph names, change 'post' class to not try to
	# load them.  It avoid lots of headache with broken fonts as well
	# as loading time.
	#
	# Ideally ttLib should provide a way to ask it to skip loading
	# glyph names.  But it currently doesn't provide such a thing.
	#
	if dont_load_glyph_names:
		post = fontTools.ttLib.getTableClass('post')
		saved = post.decode_format_2_0
		post.decode_format_2_0 = post.decode_format_3_0
		f = font['post']
		if f.formatType == 2.0:
			f.formatType = 3.0
		post.decode_format_2_0 = saved

	return font


def main (args):

	log = Logger ()
	args = log.parse_opts (args)

	options = Subsetter.Options ()
	args = options.parse_opts (args)

	if len (args) < 2:
		import sys
		print >>sys.stderr, "usage: pyotlss.py font-file glyph..."
		sys.exit (1)

	fontfile = args[0]
	args = args[1:]

	dont_load_glyph_names = not options.glyph_names and \
				all (any (g.startswith (p) \
					  for p in ['gid', 'glyph', 'uni', 'U+']) \
				     for g in args)

	font = load_font (fontfile, dont_load_glyph_names=dont_load_glyph_names)
	subsetter = Subsetter (options=options, log=log)
	log.lapse ("load font")

	names = font.getGlyphNames()
	log.lapse ("loading glyph names")

	glyphs = []
	unicodes = []
	for g in args:
		if g in names:
			glyphs.append (g)
			continue
		if g.startswith ('uni') or g.startswith ('U+'):
			if g.startswith ('uni') and len (g) > 3:
				g = g[3:]
			elif g.startswith ('U+') and len (g) > 2:
				g = g[2:]
			u = int (g, 16)
			unicodes.append (u)
			continue
		if g.startswith ('gid') or g.startswith ('glyph'):
			if g.startswith ('gid') and len (g) > 3:
				g = g[3:]
			elif g.startswith ('glyph') and len (g) > 5:
				g = g[5:]
			try:
				glyphs.append (font.getGlyphName (int (g), requireReal=1))
			except ValueError:
				raise Exception ("Invalid glyph identifier %s" % g)
			continue
		raise Exception ("Invalid glyph identifier %s" % g)
	log.lapse ("compile glyph list")
	log ("Unicodes:", unicodes)
	log ("Glyphs:", glyphs)

	subsetter.populate (glyphs=glyphs, unicodes=unicodes)
	subsetter.subset (font)

	font.save (fontfile + '.subset')
	log.lapse ("compile and save font")

	log.last_time = log.start_time
	log.lapse ("make one with everything (TOTAL TIME)")

	log.font (font)

if __name__ == '__main__':
	import sys
	main (sys.argv[1:])