_h_m_t_x.py revision 7842e56b97ce677b83bdab09cda48bc2d89ac75a 
1import DefaultTable
2import Numeric
3from fontTools import ttLib
4from fontTools.misc.textTools import safeEval
5
6
7class table__h_m_t_x(DefaultTable.DefaultTable):
8
9	headerTag = 'hhea'
10	advanceName = 'width'
11	sideBearingName = 'lsb'
12	numberOfMetricsName = 'numberOfHMetrics'
13
14	def decompile(self, data, ttFont):
15		numberOfMetrics = int(getattr(ttFont[self.headerTag], self.numberOfMetricsName))
16		metrics = Numeric.fromstring(data[:4 * numberOfMetrics],
17				Numeric.Int16)
18		if ttLib.endian <> "big":
19			metrics = metrics.byteswapped()
20		metrics.shape = (numberOfMetrics, 2)
21		data = data[4 * numberOfMetrics:]
22		numberOfSideBearings = ttFont['maxp'].numGlyphs - numberOfMetrics
23		numberOfSideBearings = int(numberOfSideBearings)
24		if numberOfSideBearings:
25			assert numberOfSideBearings > 0, "bad hmtx/vmtx table"
26			lastAdvance = metrics[-1][0]
27			advances = Numeric.array([lastAdvance] * numberOfSideBearings,
28					Numeric.Int16)
29			sideBearings = Numeric.fromstring(data[:2 * numberOfSideBearings],
30					Numeric.Int16)
31			if ttLib.endian <> "big":
32				sideBearings = sideBearings.byteswapped()
33			data = data[2 * numberOfSideBearings:]
34			additionalMetrics = Numeric.array([advances, sideBearings],
35					Numeric.Int16)
36			metrics = Numeric.concatenate((metrics,
37					Numeric.transpose(additionalMetrics)))
38		if data:
39			raise  ttLib.TTLibError, "too much data for hmtx/vmtx table"
40		metrics = metrics.tolist()
41		self.metrics = {}
42		for i in range(len(metrics)):
43			glyphName = ttFont.getGlyphName(i)
44			self.metrics[glyphName] = metrics[i]
45
46	def compile(self, ttFont):
47		metrics = []
48		for glyphName in ttFont.getGlyphOrder():
49			metrics.append(self.metrics[glyphName])
50		lastAdvance = metrics[-1][0]
51		lastIndex = len(metrics)
52		while metrics[lastIndex-2][0] == lastAdvance:
53			lastIndex = lastIndex - 1
54		additionalMetrics = metrics[lastIndex:]
55		additionalMetrics = map(lambda (advance, sb): sb, additionalMetrics)
56		metrics = metrics[:lastIndex]
57		setattr(ttFont[self.headerTag], self.numberOfMetricsName, len(metrics))
58
59		metrics = Numeric.array(metrics, Numeric.Int16)
60		if ttLib.endian <> "big":
61			metrics = metrics.byteswapped()
62		data = metrics.tostring()
63
64		additionalMetrics = Numeric.array(additionalMetrics, Numeric.Int16)
65		if ttLib.endian <> "big":
66			additionalMetrics = additionalMetrics.byteswapped()
67		data = data + additionalMetrics.tostring()
68		return data
69
70	def toXML(self, writer, ttFont):
71		names = self.metrics.keys()
72		names.sort()
73		for glyphName in names:
74			advance, sb = self.metrics[glyphName]
75			writer.simpletag("mtx", [
76					("name", glyphName),
77					(self.advanceName, advance),
78					(self.sideBearingName, sb),
79					])
80			writer.newline()
81
82	def fromXML(self, (name, attrs, content), ttFont):
83		if not hasattr(self, "metrics"):
84			self.metrics = {}
85		if name == "mtx":
86			self.metrics[attrs["name"]] = [safeEval(attrs[self.advanceName]),
87					safeEval(attrs[self.sideBearingName])]
88
89	def __getitem__(self, glyphName):
90		return self.metrics[glyphName]
91
92	def __setitem__(self, glyphName, (advance, sb)):
93		self.metrics[glyphName] = advance, sb
94
95