_h_m_t_x.py revision 212ea147062ac1ba9c914836b25bb4a8a8463522 
1import sys
2import DefaultTable
3import Numeric
4from fontTools import ttLib
5from fontTools.misc.textTools import safeEval
6
7
8class table__h_m_t_x(DefaultTable.DefaultTable):
9
10	headerTag = 'hhea'
11	advanceName = 'width'
12	sideBearingName = 'lsb'
13	numberOfMetricsName = 'numberOfHMetrics'
14
15	def decompile(self, data, ttFont):
16		numberOfMetrics = int(getattr(ttFont[self.headerTag], self.numberOfMetricsName))
17		metrics = Numeric.fromstring(data[:4 * numberOfMetrics],
18				Numeric.Int16)
19		if sys.byteorder <> "big":
20			metrics = metrics.byteswapped()
21		metrics.shape = (numberOfMetrics, 2)
22		data = data[4 * numberOfMetrics:]
23		numberOfSideBearings = ttFont['maxp'].numGlyphs - numberOfMetrics
24		numberOfSideBearings = int(numberOfSideBearings)
25		if numberOfSideBearings:
26			assert numberOfSideBearings > 0, "bad hmtx/vmtx table"
27			lastAdvance = metrics[-1][0]
28			advances = Numeric.array([lastAdvance] * numberOfSideBearings,
29					Numeric.Int16)
30			sideBearings = Numeric.fromstring(data[:2 * numberOfSideBearings],
31					Numeric.Int16)
32			if sys.byteorder <> "big":
33				sideBearings = sideBearings.byteswapped()
34			data = data[2 * numberOfSideBearings:]
35			additionalMetrics = Numeric.array([advances, sideBearings],
36					Numeric.Int16)
37			metrics = Numeric.concatenate((metrics,
38					Numeric.transpose(additionalMetrics)))
39		if data:
40			sys.stderr.write("too much data for hmtx/vmtx table\n")
41		metrics = metrics.tolist()
42		self.metrics = {}
43		for i in range(len(metrics)):
44			glyphName = ttFont.getGlyphName(i)
45			self.metrics[glyphName] = metrics[i]
46
47	def compile(self, ttFont):
48		metrics = []
49		for glyphName in ttFont.getGlyphOrder():
50			metrics.append(self.metrics[glyphName])
51		lastAdvance = metrics[-1][0]
52		lastIndex = len(metrics)
53		while metrics[lastIndex-2][0] == lastAdvance:
54			lastIndex = lastIndex - 1
55			if lastIndex <= 1:
56				# all advances are equal
57				lastIndex = 1
58				break
59		additionalMetrics = metrics[lastIndex:]
60		additionalMetrics = map(lambda (advance, sb): sb, additionalMetrics)
61		metrics = metrics[:lastIndex]
62		setattr(ttFont[self.headerTag], self.numberOfMetricsName, len(metrics))
63
64		metrics = Numeric.array(metrics, Numeric.Int16)
65		if sys.byteorder <> "big":
66			metrics = metrics.byteswapped()
67		data = metrics.tostring()
68
69		additionalMetrics = Numeric.array(additionalMetrics, Numeric.Int16)
70		if sys.byteorder <> "big":
71			additionalMetrics = additionalMetrics.byteswapped()
72		data = data + additionalMetrics.tostring()
73		return data
74
75	def toXML(self, writer, ttFont):
76		names = self.metrics.keys()
77		names.sort()
78		for glyphName in names:
79			advance, sb = self.metrics[glyphName]
80			writer.simpletag("mtx", [
81					("name", glyphName),
82					(self.advanceName, advance),
83					(self.sideBearingName, sb),
84					])
85			writer.newline()
86
87	def fromXML(self, (name, attrs, content), ttFont):
88		if not hasattr(self, "metrics"):
89			self.metrics = {}
90		if name == "mtx":
91			self.metrics[attrs["name"]] = [safeEval(attrs[self.advanceName]),
92					safeEval(attrs[self.sideBearingName])]
93
94	def __getitem__(self, glyphName):
95		return self.metrics[glyphName]
96
97	def __setitem__(self, glyphName, (advance, sb)):
98		self.metrics[glyphName] = advance, sb
99
100