1 files changed, 311 insertions, 0 deletions
diff --git a/Lib/fontTools/merge/tables.py b/Lib/fontTools/merge/tables.py
new file mode 100644
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+++ b/Lib/fontTools/merge/tables.py
@@ -0,0 +1,311 @@
+# Copyright 2013 Google, Inc. All Rights Reserved.
+#
+# Google Author(s): Behdad Esfahbod, Roozbeh Pournader
+
+from fontTools import ttLib, cffLib
+from fontTools.ttLib.tables.DefaultTable import DefaultTable
+from fontTools.merge.base import add_method, mergeObjects
+from fontTools.merge.cmap import computeMegaCmap
+from fontTools.merge.util import *
+import logging
+
+
+log = logging.getLogger("fontTools.merge")
+
+
+ttLib.getTableClass('maxp').mergeMap = {
+	'*': max,
+	'tableTag': equal,
+	'tableVersion': equal,
+	'numGlyphs': sum,
+	'maxStorage': first,
+	'maxFunctionDefs': first,
+	'maxInstructionDefs': first,
+	# TODO When we correctly merge hinting data, update these values:
+	# maxFunctionDefs, maxInstructionDefs, maxSizeOfInstructions
+}
+
+headFlagsMergeBitMap = {
+	'size': 16,
+	'*': bitwise_or,
+	1: bitwise_and, # Baseline at y = 0
+	2: bitwise_and, # lsb at x = 0
+	3: bitwise_and, # Force ppem to integer values. FIXME?
+	5: bitwise_and, # Font is vertical
+	6: lambda bit: 0, # Always set to zero
+	11: bitwise_and, # Font data is 'lossless'
+	13: bitwise_and, # Optimized for ClearType
+	14: bitwise_and, # Last resort font. FIXME? equal or first may be better
+	15: lambda bit: 0, # Always set to zero
+}
+
+ttLib.getTableClass('head').mergeMap = {
+	'tableTag': equal,
+	'tableVersion': max,
+	'fontRevision': max,
+	'checkSumAdjustment': lambda lst: 0, # We need *something* here
+	'magicNumber': equal,
+	'flags': mergeBits(headFlagsMergeBitMap),
+	'unitsPerEm': equal,
+	'created': current_time,
+	'modified': current_time,
+	'xMin': min,
+	'yMin': min,
+	'xMax': max,
+	'yMax': max,
+	'macStyle': first,
+	'lowestRecPPEM': max,
+	'fontDirectionHint': lambda lst: 2,
+	'indexToLocFormat': first,
+	'glyphDataFormat': equal,
+}
+
+ttLib.getTableClass('hhea').mergeMap = {
+	'*': equal,
+	'tableTag': equal,
+	'tableVersion': max,
+	'ascent': max,
+	'descent': min,
+	'lineGap': max,
+	'advanceWidthMax': max,
+	'minLeftSideBearing': min,
+	'minRightSideBearing': min,
+	'xMaxExtent': max,
+	'caretSlopeRise': first,
+	'caretSlopeRun': first,
+	'caretOffset': first,
+	'numberOfHMetrics': recalculate,
+}
+
+ttLib.getTableClass('vhea').mergeMap = {
+	'*': equal,
+	'tableTag': equal,
+	'tableVersion': max,
+	'ascent': max,
+	'descent': min,
+	'lineGap': max,
+	'advanceHeightMax': max,
+	'minTopSideBearing': min,
+	'minBottomSideBearing': min,
+	'yMaxExtent': max,
+	'caretSlopeRise': first,
+	'caretSlopeRun': first,
+	'caretOffset': first,
+	'numberOfVMetrics': recalculate,
+}
+
+os2FsTypeMergeBitMap = {
+	'size': 16,
+	'*': lambda bit: 0,
+	1: bitwise_or, # no embedding permitted
+	2: bitwise_and, # allow previewing and printing documents
+	3: bitwise_and, # allow editing documents
+	8: bitwise_or, # no subsetting permitted
+	9: bitwise_or, # no embedding of outlines permitted
+}
+
+def mergeOs2FsType(lst):
+	lst = list(lst)
+	if all(item == 0 for item in lst):
+		return 0
+
+	# Compute least restrictive logic for each fsType value
+	for i in range(len(lst)):
+		# unset bit 1 (no embedding permitted) if either bit 2 or 3 is set
+		if lst[i] & 0x000C:
+			lst[i] &= ~0x0002
+		# set bit 2 (allow previewing) if bit 3 is set (allow editing)
+		elif lst[i] & 0x0008:
+			lst[i] |= 0x0004
+		# set bits 2 and 3 if everything is allowed
+		elif lst[i] == 0:
+			lst[i] = 0x000C
+
+	fsType = mergeBits(os2FsTypeMergeBitMap)(lst)
+	# unset bits 2 and 3 if bit 1 is set (some font is "no embedding")
+	if fsType & 0x0002:
+		fsType &= ~0x000C
+	return fsType
+
+
+ttLib.getTableClass('OS/2').mergeMap = {
+	'*': first,
+	'tableTag': equal,
+	'version': max,
+	'xAvgCharWidth': avg_int, # Apparently fontTools doesn't recalc this
+	'fsType': mergeOs2FsType, # Will be overwritten
+	'panose': first, # FIXME: should really be the first Latin font
+	'ulUnicodeRange1': bitwise_or,
+	'ulUnicodeRange2': bitwise_or,
+	'ulUnicodeRange3': bitwise_or,
+	'ulUnicodeRange4': bitwise_or,
+	'fsFirstCharIndex': min,
+	'fsLastCharIndex': max,
+	'sTypoAscender': max,
+	'sTypoDescender': min,
+	'sTypoLineGap': max,
+	'usWinAscent': max,
+	'usWinDescent': max,
+	# Version 1
+	'ulCodePageRange1': onlyExisting(bitwise_or),
+	'ulCodePageRange2': onlyExisting(bitwise_or),
+	# Version 2, 3, 4
+	'sxHeight': onlyExisting(max),
+	'sCapHeight': onlyExisting(max),
+	'usDefaultChar': onlyExisting(first),
+	'usBreakChar': onlyExisting(first),
+	'usMaxContext': onlyExisting(max),
+	# version 5
+	'usLowerOpticalPointSize': onlyExisting(min),
+	'usUpperOpticalPointSize': onlyExisting(max),
+}
+
+@add_method(ttLib.getTableClass('OS/2'))
+def merge(self, m, tables):
+	DefaultTable.merge(self, m, tables)
+	if self.version < 2:
+		# bits 8 and 9 are reserved and should be set to zero
+		self.fsType &= ~0x0300
+	if self.version >= 3:
+		# Only one of bits 1, 2, and 3 may be set. We already take
+		# care of bit 1 implications in mergeOs2FsType. So unset
+		# bit 2 if bit 3 is already set.
+		if self.fsType & 0x0008:
+			self.fsType &= ~0x0004
+	return self
+
+ttLib.getTableClass('post').mergeMap = {
+	'*': first,
+	'tableTag': equal,
+	'formatType': max,
+	'isFixedPitch': min,
+	'minMemType42': max,
+	'maxMemType42': lambda lst: 0,
+	'minMemType1': max,
+	'maxMemType1': lambda lst: 0,
+	'mapping': onlyExisting(sumDicts),
+	'extraNames': lambda lst: [],
+}
+
+ttLib.getTableClass('vmtx').mergeMap = ttLib.getTableClass('hmtx').mergeMap = {
+	'tableTag': equal,
+	'metrics': sumDicts,
+}
+
+ttLib.getTableClass('name').mergeMap = {
+	'tableTag': equal,
+	'names': first, # FIXME? Does mixing name records make sense?
+}
+
+ttLib.getTableClass('loca').mergeMap = {
+	'*': recalculate,
+	'tableTag': equal,
+}
+
+ttLib.getTableClass('glyf').mergeMap = {
+	'tableTag': equal,
+	'glyphs': sumDicts,
+	'glyphOrder': sumLists,
+}
+
+@add_method(ttLib.getTableClass('glyf'))
+def merge(self, m, tables):
+	for i,table in enumerate(tables):
+		for g in table.glyphs.values():
+			if i:
+				# Drop hints for all but first font, since
+				# we don't map functions / CVT values.
+				g.removeHinting()
+			# Expand composite glyphs to load their
+			# composite glyph names.
+			if g.isComposite():
+				g.expand(table)
+	return DefaultTable.merge(self, m, tables)
+
+ttLib.getTableClass('prep').mergeMap = lambda self, lst: first(lst)
+ttLib.getTableClass('fpgm').mergeMap = lambda self, lst: first(lst)
+ttLib.getTableClass('cvt ').mergeMap = lambda self, lst: first(lst)
+ttLib.getTableClass('gasp').mergeMap = lambda self, lst: first(lst) # FIXME? Appears irreconcilable
+
+@add_method(ttLib.getTableClass('CFF '))
+def merge(self, m, tables):
+
+	if any(hasattr(table, "FDSelect") for table in tables):
+		raise NotImplementedError(
+			"Merging CID-keyed CFF tables is not supported yet"
+		)
+
+	for table in tables:
+		table.cff.desubroutinize()
+
+	newcff = tables[0]
+	newfont = newcff.cff[0]
+	private = newfont.Private
+	storedNamesStrings = []
+	glyphOrderStrings = []
+	glyphOrder = set(newfont.getGlyphOrder())
+
+	for name in newfont.strings.strings:
+		if name not in glyphOrder:
+			storedNamesStrings.append(name)
+		else:
+			glyphOrderStrings.append(name)
+
+	chrset = list(newfont.charset)
+	newcs = newfont.CharStrings
+	log.debug("FONT 0 CharStrings: %d.", len(newcs))
+
+	for i, table in enumerate(tables[1:], start=1):
+		font = table.cff[0]
+		font.Private = private
+		fontGlyphOrder = set(font.getGlyphOrder())
+		for name in font.strings.strings:
+			if name in fontGlyphOrder:
+				glyphOrderStrings.append(name)
+		cs = font.CharStrings
+		gs = table.cff.GlobalSubrs
+		log.debug("Font %d CharStrings: %d.", i, len(cs))
+		chrset.extend(font.charset)
+		if newcs.charStringsAreIndexed:
+			for i, name in enumerate(cs.charStrings, start=len(newcs)):
+				newcs.charStrings[name] = i
+				newcs.charStringsIndex.items.append(None)
+		for name in cs.charStrings:
+			newcs[name] = cs[name]
+
+	newfont.charset = chrset
+	newfont.numGlyphs = len(chrset)
+	newfont.strings.strings = glyphOrderStrings + storedNamesStrings
+
+	return newcff
+
+@add_method(ttLib.getTableClass('cmap'))
+def merge(self, m, tables):
+
+	# TODO Handle format=14.
+	if not hasattr(m, 'cmap'):
+		computeMegaCmap(m, tables)
+	cmap = m.cmap
+
+	cmapBmpOnly = {uni: gid for uni,gid in cmap.items() if uni <= 0xFFFF}
+	self.tables = []
+	module = ttLib.getTableModule('cmap')
+	if len(cmapBmpOnly) != len(cmap):
+		# format-12 required.
+		cmapTable = module.cmap_classes[12](12)
+		cmapTable.platformID = 3
+		cmapTable.platEncID = 10
+		cmapTable.language = 0
+		cmapTable.cmap = cmap
+		self.tables.append(cmapTable)
+	# always create format-4
+	cmapTable = module.cmap_classes[4](4)
+	cmapTable.platformID = 3
+	cmapTable.platEncID = 1
+	cmapTable.language = 0
+	cmapTable.cmap = cmapBmpOnly
+	# ordered by platform then encoding
+	self.tables.insert(0, cmapTable)
+	self.tableVersion = 0
+	self.numSubTables = len(self.tables)
+	return self