1 files changed, 129 insertions, 0 deletions
diff --git a/Lib/fontTools/merge/cmap.py b/Lib/fontTools/merge/cmap.py
new file mode 100644
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+++ b/Lib/fontTools/merge/cmap.py
@@ -0,0 +1,129 @@
+# Copyright 2013 Google, Inc. All Rights Reserved.
+#
+# Google Author(s): Behdad Esfahbod, Roozbeh Pournader
+
+from fontTools.merge.unicode import is_Default_Ignorable
+from fontTools.pens.recordingPen import DecomposingRecordingPen
+import logging
+
+
+log = logging.getLogger("fontTools.merge")
+
+
+def computeMegaGlyphOrder(merger, glyphOrders):
+	"""Modifies passed-in glyphOrders to reflect new glyph names.
+    Stores merger.glyphOrder."""
+	megaOrder = {}
+	for glyphOrder in glyphOrders:
+		for i,glyphName in enumerate(glyphOrder):
+			if glyphName in megaOrder:
+				n = megaOrder[glyphName]
+				while (glyphName + "#" + repr(n)) in megaOrder:
+					n += 1
+				megaOrder[glyphName] = n
+				glyphName += "#" + repr(n)
+				glyphOrder[i] = glyphName
+			megaOrder[glyphName] = 1
+	merger.glyphOrder = megaOrder = list(megaOrder.keys())
+
+
+def _glyphsAreSame(glyphSet1, glyphSet2, glyph1, glyph2,
+				   advanceTolerance=.05,
+				   advanceToleranceEmpty=.20):
+	pen1 = DecomposingRecordingPen(glyphSet1)
+	pen2 = DecomposingRecordingPen(glyphSet2)
+	g1 = glyphSet1[glyph1]
+	g2 = glyphSet2[glyph2]
+	g1.draw(pen1)
+	g2.draw(pen2)
+	if pen1.value != pen2.value:
+		return False
+	# Allow more width tolerance for glyphs with no ink
+	tolerance = advanceTolerance if pen1.value else advanceToleranceEmpty
+    # TODO Warn if advances not the same but within tolerance.
+	if abs(g1.width - g2.width) > g1.width * tolerance:
+		return False
+	if hasattr(g1, 'height') and g1.height is not None:
+		if abs(g1.height - g2.height) > g1.height * tolerance:
+			return False
+	return True
+
+# Valid (format, platformID, platEncID) triplets for cmap subtables containing
+# Unicode BMP-only and Unicode Full Repertoire semantics.
+# Cf. OpenType spec for "Platform specific encodings":
+# https://docs.microsoft.com/en-us/typography/opentype/spec/name
+class _CmapUnicodePlatEncodings:
+	BMP = {(4, 3, 1), (4, 0, 3), (4, 0, 4), (4, 0, 6)}
+	FullRepertoire = {(12, 3, 10), (12, 0, 4), (12, 0, 6)}
+
+def computeMegaCmap(merger, cmapTables):
+	"""Sets merger.cmap and merger.glyphOrder."""
+
+	# TODO Handle format=14.
+	# Only merge format 4 and 12 Unicode subtables, ignores all other subtables
+	# If there is a format 12 table for a font, ignore the format 4 table of it
+	chosenCmapTables = []
+	for fontIdx,table in enumerate(cmapTables):
+		format4 = None
+		format12 = None
+		for subtable in table.tables:
+			properties = (subtable.format, subtable.platformID, subtable.platEncID)
+			if properties in _CmapUnicodePlatEncodings.BMP:
+				format4 = subtable
+			elif properties in _CmapUnicodePlatEncodings.FullRepertoire:
+				format12 = subtable
+			else:
+				log.warning(
+					"Dropped cmap subtable from font '%s':\t"
+					"format %2s, platformID %2s, platEncID %2s",
+					fontIdx, subtable.format, subtable.platformID, subtable.platEncID
+				)
+		if format12 is not None:
+			chosenCmapTables.append((format12, fontIdx))
+		elif format4 is not None:
+			chosenCmapTables.append((format4, fontIdx))
+
+	# Build the unicode mapping
+	merger.cmap = cmap = {}
+	fontIndexForGlyph = {}
+	glyphSets = [None for f in merger.fonts] if hasattr(merger, 'fonts') else None
+
+	for table,fontIdx in chosenCmapTables:
+		# handle duplicates
+		for uni,gid in table.cmap.items():
+			oldgid = cmap.get(uni, None)
+			if oldgid is None:
+				cmap[uni] = gid
+				fontIndexForGlyph[gid] = fontIdx
+			elif is_Default_Ignorable(uni) or uni in (0x25CC,): # U+25CC DOTTED CIRCLE
+				continue
+			elif oldgid != gid:
+				# Char previously mapped to oldgid, now to gid.
+				# Record, to fix up in GSUB 'locl' later.
+				if merger.duplicateGlyphsPerFont[fontIdx].get(oldgid) is None:
+					if glyphSets is not None:
+						oldFontIdx = fontIndexForGlyph[oldgid]
+						for idx in (fontIdx, oldFontIdx):
+							if glyphSets[idx] is None:
+								glyphSets[idx] = merger.fonts[idx].getGlyphSet()
+						#if _glyphsAreSame(glyphSets[oldFontIdx], glyphSets[fontIdx], oldgid, gid):
+						#	continue
+					merger.duplicateGlyphsPerFont[fontIdx][oldgid] = gid
+				elif merger.duplicateGlyphsPerFont[fontIdx][oldgid] != gid:
+					# Char previously mapped to oldgid but oldgid is already remapped to a different
+					# gid, because of another Unicode character.
+					# TODO: Try harder to do something about these.
+					log.warning("Dropped mapping from codepoint %#06X to glyphId '%s'", uni, gid)
+
+
+def renameCFFCharStrings(merger, glyphOrder, cffTable):
+	"""Rename topDictIndex charStrings based on glyphOrder."""
+	td = cffTable.cff.topDictIndex[0]
+
+	charStrings = {}
+	for i, v in enumerate(td.CharStrings.charStrings.values()):
+		glyphName = glyphOrder[i]
+		charStrings[glyphName] = v
+	td.CharStrings.charStrings = charStrings
+
+	td.charset = list(glyphOrder)