1""" TSI{0,1,2,3,5} are private tables used by Microsoft Visual TrueType (VTT)
2tool to store its hinting source data.
3
4TSI0 is the index table containing the lengths and offsets for the glyph
5programs and 'extra' programs ('fpgm', 'prep', and 'cvt') that are contained
6in the TSI1 table.
7"""
8from __future__ import print_function, division, absolute_import
9from fontTools.misc.py23 import *
10from . import DefaultTable
11import struct
12
13tsi0Format = '>HHL'
14
15def fixlongs(glyphID, textLength, textOffset):
16	return int(glyphID), int(textLength), textOffset
17
18
19class table_T_S_I__0(DefaultTable.DefaultTable):
20
21	dependencies = ["TSI1"]
22
23	def decompile(self, data, ttFont):
24		numGlyphs = ttFont['maxp'].numGlyphs
25		indices = []
26		size = struct.calcsize(tsi0Format)
27		for i in range(numGlyphs + 5):
28			glyphID, textLength, textOffset = fixlongs(*struct.unpack(tsi0Format, data[:size]))
29			indices.append((glyphID, textLength, textOffset))
30			data = data[size:]
31		assert len(data) == 0
32		assert indices[-5] == (0XFFFE, 0, 0xABFC1F34), "bad magic number"
33		self.indices = indices[:-5]
34		self.extra_indices = indices[-4:]
35
36	def compile(self, ttFont):
37		if not hasattr(self, "indices"):
38			# We have no corresponding table (TSI1 or TSI3); let's return
39			# no data, which effectively means "ignore us".
40			return b""
41		data = b""
42		for index, textLength, textOffset in self.indices:
43			data = data + struct.pack(tsi0Format, index, textLength, textOffset)
44		data = data + struct.pack(tsi0Format, 0XFFFE, 0, 0xABFC1F34)
45		for index, textLength, textOffset in self.extra_indices:
46			data = data + struct.pack(tsi0Format, index, textLength, textOffset)
47		return data
48
49	def set(self, indices, extra_indices):
50		# gets called by 'TSI1' or 'TSI3'
51		self.indices = indices
52		self.extra_indices = extra_indices
53
54	def toXML(self, writer, ttFont):
55		writer.comment("This table will be calculated by the compiler")
56		writer.newline()
57