Lib/fontTools/ttLib/tables/T_S_I__1.py

""" TSI{0,1,2,3,5} are private tables used by Microsoft Visual TrueType (VTT)
tool to store its hinting source data.

TSI1 contains the text of the glyph programs in the form of low-level assembly
code, as well as the 'extra' programs 'fpgm', 'ppgm' (i.e. 'prep'), and 'cvt'.
"""
from __future__ import print_function, division, absolute_import
from fontTools.misc.py23 import *
from . import DefaultTable
from fontTools.misc.loggingTools import LogMixin


class table_T_S_I__1(LogMixin, DefaultTable.DefaultTable):

	extras = {0xfffa: "ppgm", 0xfffb: "cvt", 0xfffc: "reserved", 0xfffd: "fpgm"}

	indextable = "TSI0"

	def decompile(self, data, ttFont):
		totalLength = len(data)
		indextable = ttFont[self.indextable]
		for indices, isExtra in zip(
				(indextable.indices, indextable.extra_indices), (False, True)):
			programs = {}
			for i, (glyphID, textLength, textOffset) in enumerate(indices):
				if isExtra:
					name = self.extras[glyphID]
				else:
					name = ttFont.getGlyphName(glyphID)
				if textOffset > totalLength:
					self.log.warning("textOffset > totalLength; %r skipped" % name)
					continue
				if textLength < 0x8000:
					# If the length stored in the record is less than 32768, then use
					# that as the length of the record.
					pass
				elif textLength == 0x8000:
					# If the length is 32768, compute the actual length as follows:
					isLast = i == (len(indices)-1)
					if isLast:
						if isExtra:
							# For the last "extra" record (the very last record of the
							# table), the length is the difference between the total
							# length of the TSI1 table and the textOffset of the final
							# record.
							nextTextOffset = totalLength
						else:
							# For the last "normal" record (the last record just prior
							# to the record containing the "magic number"), the length
							# is the difference between the textOffset of the record
							# following the "magic number" (0xFFFE) record (i.e. the
							# first "extra" record), and the textOffset of the last
							# "normal" record.
							nextTextOffset = indextable.extra_indices[0][2]
					else:
						# For all other records with a length of 0x8000, the length is
						# the difference between the textOffset of the record in
						# question and the textOffset of the next record.
						nextTextOffset = indices[i+1][2]
					assert nextTextOffset >= textOffset, "entries not sorted by offset"
					if nextTextOffset > totalLength:
						self.log.warning(
							"nextTextOffset > totalLength; %r truncated" % name)
						nextTextOffset = totalLength
					textLength = nextTextOffset - textOffset
				else:
					from fontTools import ttLib
					raise ttLib.TTLibError(
						"%r textLength (%d) must not be > 32768" % (name, textLength))
				text = data[textOffset:textOffset+textLength]
				assert len(text) == textLength
				text = tounicode(text, encoding='utf-8')
				if text:
					programs[name] = text
			if isExtra:
				self.extraPrograms = programs
			else:
				self.glyphPrograms = programs

	def compile(self, ttFont):
		if not hasattr(self, "glyphPrograms"):
			self.glyphPrograms = {}
			self.extraPrograms = {}
		data = b''
		indextable = ttFont[self.indextable]
		glyphNames = ttFont.getGlyphOrder()

		indices = []
		for i in range(len(glyphNames)):
			if len(data) % 2:
				data = data + b"\015"  # align on 2-byte boundaries, fill with return chars. Yum.
			name = glyphNames[i]
			if name in self.glyphPrograms:
				text = tobytes(self.glyphPrograms[name], encoding="utf-8")
			else:
				text = b""
			textLength = len(text)
			if textLength >= 0x8000:
				textLength = 0x8000
			indices.append((i, textLength, len(data)))
			data = data + text

		extra_indices = []
		codes = sorted(self.extras.items())
		for i in range(len(codes)):
			if len(data) % 2:
				data = data + b"\015"  # align on 2-byte boundaries, fill with return chars.
			code, name = codes[i]
			if name in self.extraPrograms:
				text = tobytes(self.extraPrograms[name], encoding="utf-8")
			else:
				text = b""
			textLength = len(text)
			if textLength >= 0x8000:
				textLength = 0x8000
			extra_indices.append((code, textLength, len(data)))
			data = data + text
		indextable.set(indices, extra_indices)
		return data

	def toXML(self, writer, ttFont):
		names = sorted(self.glyphPrograms.keys())
		writer.newline()
		for name in names:
			text = self.glyphPrograms[name]
			if not text:
				continue
			writer.begintag("glyphProgram", name=name)
			writer.newline()
			writer.write_noindent(text.replace("\r", "\n"))
			writer.newline()
			writer.endtag("glyphProgram")
			writer.newline()
			writer.newline()
		extra_names = sorted(self.extraPrograms.keys())
		for name in extra_names:
			text = self.extraPrograms[name]
			if not text:
				continue
			writer.begintag("extraProgram", name=name)
			writer.newline()
			writer.write_noindent(text.replace("\r", "\n"))
			writer.newline()
			writer.endtag("extraProgram")
			writer.newline()
			writer.newline()

	def fromXML(self, name, attrs, content, ttFont):
		if not hasattr(self, "glyphPrograms"):
			self.glyphPrograms = {}
			self.extraPrograms = {}
		lines = strjoin(content).replace("\r", "\n").split("\n")
		text = '\r'.join(lines[1:-1])
		if name == "glyphProgram":
			self.glyphPrograms[attrs["name"]] = text
		elif name == "extraProgram":
			self.extraPrograms[attrs["name"]] = text