Merge pull request #2275 from fonttools/subset-device

[subset] Fix hint-dropping

Lib/fontTools/subset/__init__.py

@@ -14,6 +14,7 @@ import struct
 import array
 import logging
 from collections import Counter, defaultdict
+from functools import reduce
 from types import MethodType
 
 __usage__ = "pyftsubset font-file [glyph...] [--option=value]..."
@@ -527,6 +528,17 @@ def subset_glyphs(self, s):
 	else:
 		assert 0, "unknown format: %s" % self.Format
 
+@_add_method(otTables.Device)
+def is_hinting(self):
+	return self.DeltaFormat in (1,2,3)
+
+@_add_method(otTables.ValueRecord)
+def prune_hints(self):
+	for name in ['XPlaDevice', 'YPlaDevice', 'XAdvDevice', 'YAdvDevice']:
+		v = getattr(self, name, None)
+		if v is not None and v.is_hinting():
+			delattr(self, name)
+
 @_add_method(otTables.SinglePos)
 def subset_glyphs(self, s):
 	if self.Format == 1:
@@ -543,15 +555,24 @@ def subset_glyphs(self, s):
 
 @_add_method(otTables.SinglePos)
 def prune_post_subset(self, font, options):
-	if not options.hinting:
-		# Drop device tables
-		self.ValueFormat &= ~0x00F0
+	# Shrink ValueFormat
+	if self.Format == 1:
+		if not options.hinting:
+			self.Value.prune_hints()
+		self.ValueFormat = self.Value.getEffectiveFormat()
+	elif self.Format == 2:
+		if not options.hinting:
+			for v in self.Value:
+				v.prune_hints()
+		self.ValueFormat = reduce(int.__or__, [v.getEffectiveFormat() for v in self.Value], 0)
+
 	# Downgrade to Format 1 if all ValueRecords are the same
 	if self.Format == 2 and all(v == self.Value[0] for v in self.Value):
 		self.Format = 1
 		self.Value = self.Value[0] if self.ValueFormat != 0 else None
 		del self.ValueCount
-	return True
+
+	return bool(self.ValueFormat)
 
 @_add_method(otTables.PairPos)
 def subset_glyphs(self, s):
@@ -587,10 +608,22 @@ def subset_glyphs(self, s):
 @_add_method(otTables.PairPos)
 def prune_post_subset(self, font, options):
 	if not options.hinting:
-		# Drop device tables
-		self.ValueFormat1 &= ~0x00F0
-		self.ValueFormat2 &= ~0x00F0
-	return True
+		attr1, attr2 = {
+			1: ('PairSet', 'PairValueRecord'),
+			2: ('Class1Record', 'Class2Record'),
+		}[self.Format]
+
+		self.ValueFormat1 = self.ValueFormat2 = 0
+		for row in getattr(self, attr1):
+			for r in getattr(row, attr2):
+				if r.Value1:
+					r.Value1.prune_hints()
+					self.ValueFormat1 |= r.Value1.getEffectiveFormat()
+				if r.Value2:
+					r.Value2.prune_hints()
+					self.ValueFormat2 |= r.Value2.getEffectiveFormat()
+
+	return bool(self.ValueFormat1 | self.ValueFormat2)
 
 @_add_method(otTables.CursivePos)
 def subset_glyphs(self, s):
@@ -606,9 +639,15 @@ def subset_glyphs(self, s):
 
 @_add_method(otTables.Anchor)
 def prune_hints(self):
-	# Drop device tables / contour anchor point
-	self.ensureDecompiled()
-	self.Format = 1
+	if self.Format == 2:
+		self.Format = 1
+	elif self.Format == 3:
+		for name in ('XDeviceTable', 'YDeviceTable'):
+			v = getattr(self, name, None)
+			if v is not None and v.is_hinting():
+				setattr(self, name, None)
+		if self.XDeviceTable is None and self.YDeviceTable is None:
+			self.Format = 1
 
 @_add_method(otTables.CursivePos)
 def prune_post_subset(self, font, options):
@@ -713,7 +752,6 @@ def subset_glyphs(self, s):
 @_add_method(otTables.MarkMarkPos)
 def prune_post_subset(self, font, options):
 		if not options.hinting:
-			# Drop device tables or contour anchor point
 			for m in self.Mark1Array.MarkRecord:
 				if m.MarkAnchor:
 					m.MarkAnchor.prune_hints()

Lib/fontTools/ttLib/tables/otBase.py

@@ -970,6 +970,13 @@ class ValueRecord(object):
 			format = format | valueRecordFormatDict[name][0]
 		return format
 
+	def getEffectiveFormat(self):
+		format = 0
+		for name,value in self.__dict__.items():
+			if value:
+				format = format | valueRecordFormatDict[name][0]
+		return format
+
 	def toXML(self, xmlWriter, font, valueName, attrs=None):
 		if attrs is None:
 			simpleItems = []

Lib/fontTools/varLib/merger.py

@@ -289,7 +289,7 @@ def merge(merger, self, lst):
 	# Merge everything else; though, there shouldn't be anything else. :)
 	merger.mergeObjects(self, lst,
 			    exclude=('Format', 'Coverage', 'Value', 'ValueCount'))
-	self.ValueFormat = reduce(int.__or__, [v.getFormat() for v in self.Value], 0)
+	self.ValueFormat = reduce(int.__or__, [v.getEffectiveFormat() for v in self.Value], 0)
 
 @AligningMerger.merger(ot.PairSet)
 def merge(merger, self, lst):