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 . import DefaultTable 9import struct 10 11tsi0Format = '>HHL' 12 13def fixlongs(glyphID, textLength, textOffset): 14 return int(glyphID), int(textLength), textOffset 15 16 17class table_T_S_I__0(DefaultTable.DefaultTable): 18 19 dependencies = ["TSI1"] 20 21 def decompile(self, data, ttFont): 22 numGlyphs = ttFont['maxp'].numGlyphs 23 indices = [] 24 size = struct.calcsize(tsi0Format) 25 for i in range(numGlyphs + 5): 26 glyphID, textLength, textOffset = fixlongs(*struct.unpack(tsi0Format, data[:size])) 27 indices.append((glyphID, textLength, textOffset)) 28 data = data[size:] 29 assert len(data) == 0 30 assert indices[-5] == (0XFFFE, 0, 0xABFC1F34), "bad magic number" 31 self.indices = indices[:-5] 32 self.extra_indices = indices[-4:] 33 34 def compile(self, ttFont): 35 if not hasattr(self, "indices"): 36 # We have no corresponding table (TSI1 or TSI3); let's return 37 # no data, which effectively means "ignore us". 38 return b"" 39 data = b"" 40 for index, textLength, textOffset in self.indices: 41 data = data + struct.pack(tsi0Format, index, textLength, textOffset) 42 data = data + struct.pack(tsi0Format, 0XFFFE, 0, 0xABFC1F34) 43 for index, textLength, textOffset in self.extra_indices: 44 data = data + struct.pack(tsi0Format, index, textLength, textOffset) 45 return data 46 47 def set(self, indices, extra_indices): 48 # gets called by 'TSI1' or 'TSI3' 49 self.indices = indices 50 self.extra_indices = extra_indices 51 52 def toXML(self, writer, ttFont): 53 writer.comment("This table will be calculated by the compiler") 54 writer.newline() 55