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ai-content-maker/.venv/Lib/site-packages/fontTools/ttLib/woff2.py

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first commit
2024-05-03 04:18:51 +03:00
from io import BytesIO
import sys
import array
import struct
from collections import OrderedDict
from fontTools.misc import sstruct
from fontTools.misc.arrayTools import calcIntBounds
from fontTools.misc.textTools import Tag, bytechr, byteord, bytesjoin, pad
from fontTools.ttLib import (
TTFont,
TTLibError,
getTableModule,
getTableClass,
getSearchRange,
)
from fontTools.ttLib.sfnt import (
SFNTReader,
SFNTWriter,
DirectoryEntry,
WOFFFlavorData,
sfntDirectoryFormat,
sfntDirectorySize,
SFNTDirectoryEntry,
sfntDirectoryEntrySize,
calcChecksum,
)
from fontTools.ttLib.tables import ttProgram, _g_l_y_f
import logging
log = logging.getLogger("fontTools.ttLib.woff2")
haveBrotli = False
try:
try:
import brotlicffi as brotli
except ImportError:
import brotli
haveBrotli = True
except ImportError:
pass
class WOFF2Reader(SFNTReader):
flavor = "woff2"
def __init__(self, file, checkChecksums=0, fontNumber=-1):
if not haveBrotli:
log.error(
"The WOFF2 decoder requires the Brotli Python extension, available at: "
"https://github.com/google/brotli"
)
raise ImportError("No module named brotli")
self.file = file
signature = Tag(self.file.read(4))
if signature != b"wOF2":
raise TTLibError("Not a WOFF2 font (bad signature)")
self.file.seek(0)
self.DirectoryEntry = WOFF2DirectoryEntry
data = self.file.read(woff2DirectorySize)
if len(data) != woff2DirectorySize:
raise TTLibError("Not a WOFF2 font (not enough data)")
sstruct.unpack(woff2DirectoryFormat, data, self)
self.tables = OrderedDict()
offset = 0
for i in range(self.numTables):
entry = self.DirectoryEntry()
entry.fromFile(self.file)
tag = Tag(entry.tag)
self.tables[tag] = entry
entry.offset = offset
offset += entry.length
totalUncompressedSize = offset
compressedData = self.file.read(self.totalCompressedSize)
decompressedData = brotli.decompress(compressedData)
if len(decompressedData) != totalUncompressedSize:
raise TTLibError(
"unexpected size for decompressed font data: expected %d, found %d"
% (totalUncompressedSize, len(decompressedData))
)
self.transformBuffer = BytesIO(decompressedData)
self.file.seek(0, 2)
if self.length != self.file.tell():
raise TTLibError("reported 'length' doesn't match the actual file size")
self.flavorData = WOFF2FlavorData(self)
# make empty TTFont to store data while reconstructing tables
self.ttFont = TTFont(recalcBBoxes=False, recalcTimestamp=False)
def __getitem__(self, tag):
"""Fetch the raw table data. Reconstruct transformed tables."""
entry = self.tables[Tag(tag)]
if not hasattr(entry, "data"):
if entry.transformed:
entry.data = self.reconstructTable(tag)
else:
entry.data = entry.loadData(self.transformBuffer)
return entry.data
def reconstructTable(self, tag):
"""Reconstruct table named 'tag' from transformed data."""
entry = self.tables[Tag(tag)]
rawData = entry.loadData(self.transformBuffer)
if tag == "glyf":
# no need to pad glyph data when reconstructing
padding = self.padding if hasattr(self, "padding") else None
data = self._reconstructGlyf(rawData, padding)
elif tag == "loca":
data = self._reconstructLoca()
elif tag == "hmtx":
data = self._reconstructHmtx(rawData)
else:
raise TTLibError("transform for table '%s' is unknown" % tag)
return data
def _reconstructGlyf(self, data, padding=None):
"""Return recostructed glyf table data, and set the corresponding loca's
locations. Optionally pad glyph offsets to the specified number of bytes.
"""
self.ttFont["loca"] = WOFF2LocaTable()
glyfTable = self.ttFont["glyf"] = WOFF2GlyfTable()
glyfTable.reconstruct(data, self.ttFont)
if padding:
glyfTable.padding = padding
data = glyfTable.compile(self.ttFont)
return data
def _reconstructLoca(self):
"""Return reconstructed loca table data."""
if "loca" not in self.ttFont:
# make sure glyf is reconstructed first
self.tables["glyf"].data = self.reconstructTable("glyf")
locaTable = self.ttFont["loca"]
data = locaTable.compile(self.ttFont)
if len(data) != self.tables["loca"].origLength:
raise TTLibError(
"reconstructed 'loca' table doesn't match original size: "
"expected %d, found %d" % (self.tables["loca"].origLength, len(data))
)
return data
def _reconstructHmtx(self, data):
"""Return reconstructed hmtx table data."""
# Before reconstructing 'hmtx' table we need to parse other tables:
# 'glyf' is required for reconstructing the sidebearings from the glyphs'
# bounding box; 'hhea' is needed for the numberOfHMetrics field.
if "glyf" in self.flavorData.transformedTables:
# transformed 'glyf' table is self-contained, thus 'loca' not needed
tableDependencies = ("maxp", "hhea", "glyf")
else:
# decompiling untransformed 'glyf' requires 'loca', which requires 'head'
tableDependencies = ("maxp", "head", "hhea", "loca", "glyf")
for tag in tableDependencies:
self._decompileTable(tag)
hmtxTable = self.ttFont["hmtx"] = WOFF2HmtxTable()
hmtxTable.reconstruct(data, self.ttFont)
data = hmtxTable.compile(self.ttFont)
return data
def _decompileTable(self, tag):
"""Decompile table data and store it inside self.ttFont."""
data = self[tag]
if self.ttFont.isLoaded(tag):
return self.ttFont[tag]
tableClass = getTableClass(tag)
table = tableClass(tag)
self.ttFont.tables[tag] = table
table.decompile(data, self.ttFont)
class WOFF2Writer(SFNTWriter):
flavor = "woff2"
def __init__(
self,
file,
numTables,
sfntVersion="\000\001\000\000",
flavor=None,
flavorData=None,
):
if not haveBrotli:
log.error(
"The WOFF2 encoder requires the Brotli Python extension, available at: "
"https://github.com/google/brotli"
)
raise ImportError("No module named brotli")
self.file = file
self.numTables = numTables
self.sfntVersion = Tag(sfntVersion)
self.flavorData = WOFF2FlavorData(data=flavorData)
self.directoryFormat = woff2DirectoryFormat
self.directorySize = woff2DirectorySize
self.DirectoryEntry = WOFF2DirectoryEntry
self.signature = Tag("wOF2")
self.nextTableOffset = 0
self.transformBuffer = BytesIO()
self.tables = OrderedDict()
# make empty TTFont to store data while normalising and transforming tables
self.ttFont = TTFont(recalcBBoxes=False, recalcTimestamp=False)
def __setitem__(self, tag, data):
"""Associate new entry named 'tag' with raw table data."""
if tag in self.tables:
raise TTLibError("cannot rewrite '%s' table" % tag)
if tag == "DSIG":
# always drop DSIG table, since the encoding process can invalidate it
self.numTables -= 1
return
entry = self.DirectoryEntry()
entry.tag = Tag(tag)
entry.flags = getKnownTagIndex(entry.tag)
# WOFF2 table data are written to disk only on close(), after all tags
# have been specified
entry.data = data
self.tables[tag] = entry
def close(self):
"""All tags must have been specified. Now write the table data and directory."""
if len(self.tables) != self.numTables:
raise TTLibError(
"wrong number of tables; expected %d, found %d"
% (self.numTables, len(self.tables))
)
if self.sfntVersion in ("\x00\x01\x00\x00", "true"):
isTrueType = True
elif self.sfntVersion == "OTTO":
isTrueType = False
else:
raise TTLibError("Not a TrueType or OpenType font (bad sfntVersion)")
# The WOFF2 spec no longer requires the glyph offsets to be 4-byte aligned.
# However, the reference WOFF2 implementation still fails to reconstruct
# 'unpadded' glyf tables, therefore we need to 'normalise' them.
# See:
# https://github.com/khaledhosny/ots/issues/60
# https://github.com/google/woff2/issues/15
if (
isTrueType
and "glyf" in self.flavorData.transformedTables
and "glyf" in self.tables
):
self._normaliseGlyfAndLoca(padding=4)
self._setHeadTransformFlag()
# To pass the legacy OpenType Sanitiser currently included in browsers,
# we must sort the table directory and data alphabetically by tag.
# See:
# https://github.com/google/woff2/pull/3
# https://lists.w3.org/Archives/Public/public-webfonts-wg/2015Mar/0000.html
#
# 2023: We rely on this in _transformTables where we expect that
# "loca" comes after "glyf" table.
self.tables = OrderedDict(sorted(self.tables.items()))
self.totalSfntSize = self._calcSFNTChecksumsLengthsAndOffsets()
fontData = self._transformTables()
compressedFont = brotli.compress(fontData, mode=brotli.MODE_FONT)
self.totalCompressedSize = len(compressedFont)
self.length = self._calcTotalSize()
self.majorVersion, self.minorVersion = self._getVersion()
self.reserved = 0
directory = self._packTableDirectory()
self.file.seek(0)
self.file.write(pad(directory + compressedFont, size=4))
self._writeFlavorData()
def _normaliseGlyfAndLoca(self, padding=4):
"""Recompile glyf and loca tables, aligning glyph offsets to multiples of
'padding' size. Update the head table's 'indexToLocFormat' accordingly while
compiling loca.
"""
if self.sfntVersion == "OTTO":
return
for tag in ("maxp", "head", "loca", "glyf", "fvar"):
if tag in self.tables:
self._decompileTable(tag)
self.ttFont["glyf"].padding = padding
for tag in ("glyf", "loca"):
self._compileTable(tag)
def _setHeadTransformFlag(self):
"""Set bit 11 of 'head' table flags to indicate that the font has undergone
a lossless modifying transform. Re-compile head table data."""
self._decompileTable("head")
self.ttFont["head"].flags |= 1 << 11
self._compileTable("head")
def _decompileTable(self, tag):
"""Fetch table data, decompile it, and store it inside self.ttFont."""
tag = Tag(tag)
if tag not in self.tables:
raise TTLibError("missing required table: %s" % tag)
if self.ttFont.isLoaded(tag):
return
data = self.tables[tag].data
if tag == "loca":
tableClass = WOFF2LocaTable
elif tag == "glyf":
tableClass = WOFF2GlyfTable
elif tag == "hmtx":
tableClass = WOFF2HmtxTable
else:
tableClass = getTableClass(tag)
table = tableClass(tag)
self.ttFont.tables[tag] = table
table.decompile(data, self.ttFont)
def _compileTable(self, tag):
"""Compile table and store it in its 'data' attribute."""
self.tables[tag].data = self.ttFont[tag].compile(self.ttFont)
def _calcSFNTChecksumsLengthsAndOffsets(self):
"""Compute the 'original' SFNT checksums, lengths and offsets for checksum
adjustment calculation. Return the total size of the uncompressed font.
"""
offset = sfntDirectorySize + sfntDirectoryEntrySize * len(self.tables)
for tag, entry in self.tables.items():
data = entry.data
entry.origOffset = offset
entry.origLength = len(data)
if tag == "head":
entry.checkSum = calcChecksum(data[:8] + b"\0\0\0\0" + data[12:])
else:
entry.checkSum = calcChecksum(data)
offset += (entry.origLength + 3) & ~3
return offset
def _transformTables(self):
"""Return transformed font data."""
transformedTables = self.flavorData.transformedTables
for tag, entry in self.tables.items():
data = None
if tag in transformedTables:
data = self.transformTable(tag)
if data is not None:
entry.transformed = True
if data is None:
if tag == "glyf":
# Currently we always sort table tags so
# 'loca' comes after 'glyf'.
transformedTables.discard("loca")
# pass-through the table data without transformation
data = entry.data
entry.transformed = False
entry.offset = self.nextTableOffset
entry.saveData(self.transformBuffer, data)
self.nextTableOffset += entry.length
self.writeMasterChecksum()
fontData = self.transformBuffer.getvalue()
return fontData
def transformTable(self, tag):
"""Return transformed table data, or None if some pre-conditions aren't
met -- in which case, the non-transformed table data will be used.
"""
if tag == "loca":
data = b""
elif tag == "glyf":
for tag in ("maxp", "head", "loca", "glyf"):
self._decompileTable(tag)
glyfTable = self.ttFont["glyf"]
data = glyfTable.transform(self.ttFont)
elif tag == "hmtx":
if "glyf" not in self.tables:
return
for tag in ("maxp", "head", "hhea", "loca", "glyf", "hmtx"):
self._decompileTable(tag)
hmtxTable = self.ttFont["hmtx"]
data = hmtxTable.transform(self.ttFont) # can be None
else:
raise TTLibError("Transform for table '%s' is unknown" % tag)
return data
def _calcMasterChecksum(self):
"""Calculate checkSumAdjustment."""
tags = list(self.tables.keys())
checksums = []
for i in range(len(tags)):
checksums.append(self.tables[tags[i]].checkSum)
# Create a SFNT directory for checksum calculation purposes
self.searchRange, self.entrySelector, self.rangeShift = getSearchRange(
self.numTables, 16
)
directory = sstruct.pack(sfntDirectoryFormat, self)
tables = sorted(self.tables.items())
for tag, entry in tables:
sfntEntry = SFNTDirectoryEntry()
sfntEntry.tag = entry.tag
sfntEntry.checkSum = entry.checkSum
sfntEntry.offset = entry.origOffset
sfntEntry.length = entry.origLength
directory = directory + sfntEntry.toString()
directory_end = sfntDirectorySize + len(self.tables) * sfntDirectoryEntrySize
assert directory_end == len(directory)
checksums.append(calcChecksum(directory))
checksum = sum(checksums) & 0xFFFFFFFF
# BiboAfba!
checksumadjustment = (0xB1B0AFBA - checksum) & 0xFFFFFFFF
return checksumadjustment
def writeMasterChecksum(self):
"""Write checkSumAdjustment to the transformBuffer."""
checksumadjustment = self._calcMasterChecksum()
self.transformBuffer.seek(self.tables["head"].offset + 8)
self.transformBuffer.write(struct.pack(">L", checksumadjustment))
def _calcTotalSize(self):
"""Calculate total size of WOFF2 font, including any meta- and/or private data."""
offset = self.directorySize
for entry in self.tables.values():
offset += len(entry.toString())
offset += self.totalCompressedSize
offset = (offset + 3) & ~3
offset = self._calcFlavorDataOffsetsAndSize(offset)
return offset
def _calcFlavorDataOffsetsAndSize(self, start):
"""Calculate offsets and lengths for any meta- and/or private data."""
offset = start
data = self.flavorData
if data.metaData:
self.metaOrigLength = len(data.metaData)
self.metaOffset = offset
self.compressedMetaData = brotli.compress(
data.metaData, mode=brotli.MODE_TEXT
)
self.metaLength = len(self.compressedMetaData)
offset += self.metaLength
else:
self.metaOffset = self.metaLength = self.metaOrigLength = 0
self.compressedMetaData = b""
if data.privData:
# make sure private data is padded to 4-byte boundary
offset = (offset + 3) & ~3
self.privOffset = offset
self.privLength = len(data.privData)
offset += self.privLength
else:
self.privOffset = self.privLength = 0
return offset
def _getVersion(self):
"""Return the WOFF2 font's (majorVersion, minorVersion) tuple."""
data = self.flavorData
if data.majorVersion is not None and data.minorVersion is not None:
return data.majorVersion, data.minorVersion
else:
# if None, return 'fontRevision' from 'head' table
if "head" in self.tables:
return struct.unpack(">HH", self.tables["head"].data[4:8])
else:
return 0, 0
def _packTableDirectory(self):
"""Return WOFF2 table directory data."""
directory = sstruct.pack(self.directoryFormat, self)
for entry in self.tables.values():
directory = directory + entry.toString()
return directory
def _writeFlavorData(self):
"""Write metadata and/or private data using appropiate padding."""
compressedMetaData = self.compressedMetaData
privData = self.flavorData.privData
if compressedMetaData and privData:
compressedMetaData = pad(compressedMetaData, size=4)
if compressedMetaData:
self.file.seek(self.metaOffset)
assert self.file.tell() == self.metaOffset
self.file.write(compressedMetaData)
if privData:
self.file.seek(self.privOffset)
assert self.file.tell() == self.privOffset
self.file.write(privData)
def reordersTables(self):
return True
# -- woff2 directory helpers and cruft
woff2DirectoryFormat = """
> # big endian
signature: 4s # "wOF2"
sfntVersion: 4s
length: L # total woff2 file size
numTables: H # number of tables
reserved: H # set to 0
totalSfntSize: L # uncompressed size
totalCompressedSize: L # compressed size
majorVersion: H # major version of WOFF file
minorVersion: H # minor version of WOFF file
metaOffset: L # offset to metadata block
metaLength: L # length of compressed metadata
metaOrigLength: L # length of uncompressed metadata
privOffset: L # offset to private data block
privLength: L # length of private data block
"""
woff2DirectorySize = sstruct.calcsize(woff2DirectoryFormat)
woff2KnownTags = (
"cmap",
"head",
"hhea",
"hmtx",
"maxp",
"name",
"OS/2",
"post",
"cvt ",
"fpgm",
"glyf",
"loca",
"prep",
"CFF ",
"VORG",
"EBDT",
"EBLC",
"gasp",
"hdmx",
"kern",
"LTSH",
"PCLT",
"VDMX",
"vhea",
"vmtx",
"BASE",
"GDEF",
"GPOS",
"GSUB",
"EBSC",
"JSTF",
"MATH",
"CBDT",
"CBLC",
"COLR",
"CPAL",
"SVG ",
"sbix",
"acnt",
"avar",
"bdat",
"bloc",
"bsln",
"cvar",
"fdsc",
"feat",
"fmtx",
"fvar",
"gvar",
"hsty",
"just",
"lcar",
"mort",
"morx",
"opbd",
"prop",
"trak",
"Zapf",
"Silf",
"Glat",
"Gloc",
"Feat",
"Sill",
)
woff2FlagsFormat = """
> # big endian
flags: B # table type and flags
"""
woff2FlagsSize = sstruct.calcsize(woff2FlagsFormat)
woff2UnknownTagFormat = """
> # big endian
tag: 4s # 4-byte tag (optional)
"""
woff2UnknownTagSize = sstruct.calcsize(woff2UnknownTagFormat)
woff2UnknownTagIndex = 0x3F
woff2Base128MaxSize = 5
woff2DirectoryEntryMaxSize = (
woff2FlagsSize + woff2UnknownTagSize + 2 * woff2Base128MaxSize
)
woff2TransformedTableTags = ("glyf", "loca")
woff2GlyfTableFormat = """
> # big endian
version: H # = 0x0000
optionFlags: H # Bit 0: we have overlapSimpleBitmap[], Bits 1-15: reserved
numGlyphs: H # Number of glyphs
indexFormat: H # Offset format for loca table
nContourStreamSize: L # Size of nContour stream
nPointsStreamSize: L # Size of nPoints stream
flagStreamSize: L # Size of flag stream
glyphStreamSize: L # Size of glyph stream
compositeStreamSize: L # Size of composite stream
bboxStreamSize: L # Comnined size of bboxBitmap and bboxStream
instructionStreamSize: L # Size of instruction stream
"""
woff2GlyfTableFormatSize = sstruct.calcsize(woff2GlyfTableFormat)
bboxFormat = """
> # big endian
xMin: h
yMin: h
xMax: h
yMax: h
"""
woff2OverlapSimpleBitmapFlag = 0x0001
def getKnownTagIndex(tag):
"""Return index of 'tag' in woff2KnownTags list. Return 63 if not found."""
for i in range(len(woff2KnownTags)):
if tag == woff2KnownTags[i]:
return i
return woff2UnknownTagIndex
class WOFF2DirectoryEntry(DirectoryEntry):
def fromFile(self, file):
pos = file.tell()
data = file.read(woff2DirectoryEntryMaxSize)
left = self.fromString(data)
consumed = len(data) - len(left)
file.seek(pos + consumed)
def fromString(self, data):
if len(data) < 1:
raise TTLibError("can't read table 'flags': not enough data")
dummy, data = sstruct.unpack2(woff2FlagsFormat, data, self)
if self.flags & 0x3F == 0x3F:
# if bits [0..5] of the flags byte == 63, read a 4-byte arbitrary tag value
if len(data) < woff2UnknownTagSize:
raise TTLibError("can't read table 'tag': not enough data")
dummy, data = sstruct.unpack2(woff2UnknownTagFormat, data, self)
else:
# otherwise, tag is derived from a fixed 'Known Tags' table
self.tag = woff2KnownTags[self.flags & 0x3F]
self.tag = Tag(self.tag)
self.origLength, data = unpackBase128(data)
self.length = self.origLength
if self.transformed:
self.length, data = unpackBase128(data)
if self.tag == "loca" and self.length != 0:
raise TTLibError("the transformLength of the 'loca' table must be 0")
# return left over data
return data
def toString(self):
data = bytechr(self.flags)
if (self.flags & 0x3F) == 0x3F:
data += struct.pack(">4s", self.tag.tobytes())
data += packBase128(self.origLength)
if self.transformed:
data += packBase128(self.length)
return data
@property
def transformVersion(self):
"""Return bits 6-7 of table entry's flags, which indicate the preprocessing
transformation version number (between 0 and 3).
"""
return self.flags >> 6
@transformVersion.setter
def transformVersion(self, value):
assert 0 <= value <= 3
self.flags |= value << 6
@property
def transformed(self):
"""Return True if the table has any transformation, else return False."""
# For all tables in a font, except for 'glyf' and 'loca', the transformation
# version 0 indicates the null transform (where the original table data is
# passed directly to the Brotli compressor). For 'glyf' and 'loca' tables,
# transformation version 3 indicates the null transform
if self.tag in {"glyf", "loca"}:
return self.transformVersion != 3
else:
return self.transformVersion != 0
@transformed.setter
def transformed(self, booleanValue):
# here we assume that a non-null transform means version 0 for 'glyf' and
# 'loca' and 1 for every other table (e.g. hmtx); but that may change as
# new transformation formats are introduced in the future (if ever).
if self.tag in {"glyf", "loca"}:
self.transformVersion = 3 if not booleanValue else 0
else:
self.transformVersion = int(booleanValue)
class WOFF2LocaTable(getTableClass("loca")):
"""Same as parent class. The only difference is that it attempts to preserve
the 'indexFormat' as encoded in the WOFF2 glyf table.
"""
def __init__(self, tag=None):
self.tableTag = Tag(tag or "loca")
def compile(self, ttFont):
try:
max_location = max(self.locations)
except AttributeError:
self.set([])
max_location = 0
if "glyf" in ttFont and hasattr(ttFont["glyf"], "indexFormat"):
# copile loca using the indexFormat specified in the WOFF2 glyf table
indexFormat = ttFont["glyf"].indexFormat
if indexFormat == 0:
if max_location >= 0x20000:
raise TTLibError("indexFormat is 0 but local offsets > 0x20000")
if not all(l % 2 == 0 for l in self.locations):
raise TTLibError(
"indexFormat is 0 but local offsets not multiples of 2"
)
locations = array.array("H")
for i in range(len(self.locations)):
locations.append(self.locations[i] // 2)
else:
locations = array.array("I", self.locations)
if sys.byteorder != "big":
locations.byteswap()
data = locations.tobytes()
else:
# use the most compact indexFormat given the current glyph offsets
data = super(WOFF2LocaTable, self).compile(ttFont)
return data
class WOFF2GlyfTable(getTableClass("glyf")):
"""Decoder/Encoder for WOFF2 'glyf' table transform."""
subStreams = (
"nContourStream",
"nPointsStream",
"flagStream",
"glyphStream",
"compositeStream",
"bboxStream",
"instructionStream",
)
def __init__(self, tag=None):
self.tableTag = Tag(tag or "glyf")
def reconstruct(self, data, ttFont):
"""Decompile transformed 'glyf' data."""
inputDataSize = len(data)
if inputDataSize < woff2GlyfTableFormatSize:
raise TTLibError("not enough 'glyf' data")
dummy, data = sstruct.unpack2(woff2GlyfTableFormat, data, self)
offset = woff2GlyfTableFormatSize
for stream in self.subStreams:
size = getattr(self, stream + "Size")
setattr(self, stream, data[:size])
data = data[size:]
offset += size
hasOverlapSimpleBitmap = self.optionFlags & woff2OverlapSimpleBitmapFlag
self.overlapSimpleBitmap = None
if hasOverlapSimpleBitmap:
overlapSimpleBitmapSize = (self.numGlyphs + 7) >> 3
self.overlapSimpleBitmap = array.array("B", data[:overlapSimpleBitmapSize])
offset += overlapSimpleBitmapSize
if offset != inputDataSize:
raise TTLibError(
"incorrect size of transformed 'glyf' table: expected %d, received %d bytes"
% (offset, inputDataSize)
)
bboxBitmapSize = ((self.numGlyphs + 31) >> 5) << 2
bboxBitmap = self.bboxStream[:bboxBitmapSize]
self.bboxBitmap = array.array("B", bboxBitmap)
self.bboxStream = self.bboxStream[bboxBitmapSize:]
self.nContourStream = array.array("h", self.nContourStream)
if sys.byteorder != "big":
self.nContourStream.byteswap()
assert len(self.nContourStream) == self.numGlyphs
if "head" in ttFont:
ttFont["head"].indexToLocFormat = self.indexFormat
try:
self.glyphOrder = ttFont.getGlyphOrder()
except:
self.glyphOrder = None
if self.glyphOrder is None:
self.glyphOrder = [".notdef"]
self.glyphOrder.extend(["glyph%.5d" % i for i in range(1, self.numGlyphs)])
else:
if len(self.glyphOrder) != self.numGlyphs:
raise TTLibError(
"incorrect glyphOrder: expected %d glyphs, found %d"
% (len(self.glyphOrder), self.numGlyphs)
)
glyphs = self.glyphs = {}
for glyphID, glyphName in enumerate(self.glyphOrder):
glyph = self._decodeGlyph(glyphID)
glyphs[glyphName] = glyph
def transform(self, ttFont):
"""Return transformed 'glyf' data"""
self.numGlyphs = len(self.glyphs)
assert len(self.glyphOrder) == self.numGlyphs
if "maxp" in ttFont:
ttFont["maxp"].numGlyphs = self.numGlyphs
self.indexFormat = ttFont["head"].indexToLocFormat
for stream in self.subStreams:
setattr(self, stream, b"")
bboxBitmapSize = ((self.numGlyphs + 31) >> 5) << 2
self.bboxBitmap = array.array("B", [0] * bboxBitmapSize)
self.overlapSimpleBitmap = array.array("B", [0] * ((self.numGlyphs + 7) >> 3))
for glyphID in range(self.numGlyphs):
try:
self._encodeGlyph(glyphID)
except NotImplementedError:
return None
hasOverlapSimpleBitmap = any(self.overlapSimpleBitmap)
self.bboxStream = self.bboxBitmap.tobytes() + self.bboxStream
for stream in self.subStreams:
setattr(self, stream + "Size", len(getattr(self, stream)))
self.version = 0
self.optionFlags = 0
if hasOverlapSimpleBitmap:
self.optionFlags |= woff2OverlapSimpleBitmapFlag
data = sstruct.pack(woff2GlyfTableFormat, self)
data += bytesjoin([getattr(self, s) for s in self.subStreams])
if hasOverlapSimpleBitmap:
data += self.overlapSimpleBitmap.tobytes()
return data
def _decodeGlyph(self, glyphID):
glyph = getTableModule("glyf").Glyph()
glyph.numberOfContours = self.nContourStream[glyphID]
if glyph.numberOfContours == 0:
return glyph
elif glyph.isComposite():
self._decodeComponents(glyph)
else:
self._decodeCoordinates(glyph)
self._decodeOverlapSimpleFlag(glyph, glyphID)
self._decodeBBox(glyphID, glyph)
return glyph
def _decodeComponents(self, glyph):
data = self.compositeStream
glyph.components = []
more = 1
haveInstructions = 0
while more:
component = getTableModule("glyf").GlyphComponent()
more, haveInstr, data = component.decompile(data, self)
haveInstructions = haveInstructions | haveInstr
glyph.components.append(component)
self.compositeStream = data
if haveInstructions:
self._decodeInstructions(glyph)
def _decodeCoordinates(self, glyph):
data = self.nPointsStream
endPtsOfContours = []
endPoint = -1
for i in range(glyph.numberOfContours):
ptsOfContour, data = unpack255UShort(data)
endPoint += ptsOfContour
endPtsOfContours.append(endPoint)
glyph.endPtsOfContours = endPtsOfContours
self.nPointsStream = data
self._decodeTriplets(glyph)
self._decodeInstructions(glyph)
def _decodeOverlapSimpleFlag(self, glyph, glyphID):
if self.overlapSimpleBitmap is None or glyph.numberOfContours <= 0:
return
byte = glyphID >> 3
bit = glyphID & 7
if self.overlapSimpleBitmap[byte] & (0x80 >> bit):
glyph.flags[0] |= _g_l_y_f.flagOverlapSimple
def _decodeInstructions(self, glyph):
glyphStream = self.glyphStream
instructionStream = self.instructionStream
instructionLength, glyphStream = unpack255UShort(glyphStream)
glyph.program = ttProgram.Program()
glyph.program.fromBytecode(instructionStream[:instructionLength])
self.glyphStream = glyphStream
self.instructionStream = instructionStream[instructionLength:]
def _decodeBBox(self, glyphID, glyph):
haveBBox = bool(self.bboxBitmap[glyphID >> 3] & (0x80 >> (glyphID & 7)))
if glyph.isComposite() and not haveBBox:
raise TTLibError("no bbox values for composite glyph %d" % glyphID)
if haveBBox:
dummy, self.bboxStream = sstruct.unpack2(bboxFormat, self.bboxStream, glyph)
else:
glyph.recalcBounds(self)
def _decodeTriplets(self, glyph):
def withSign(flag, baseval):
assert 0 <= baseval and baseval < 65536, "integer overflow"
return baseval if flag & 1 else -baseval
nPoints = glyph.endPtsOfContours[-1] + 1
flagSize = nPoints
if flagSize > len(self.flagStream):
raise TTLibError("not enough 'flagStream' data")
flagsData = self.flagStream[:flagSize]
self.flagStream = self.flagStream[flagSize:]
flags = array.array("B", flagsData)
triplets = array.array("B", self.glyphStream)
nTriplets = len(triplets)
assert nPoints <= nTriplets
x = 0
y = 0
glyph.coordinates = getTableModule("glyf").GlyphCoordinates.zeros(nPoints)
glyph.flags = array.array("B")
tripletIndex = 0
for i in range(nPoints):
flag = flags[i]
onCurve = not bool(flag >> 7)
flag &= 0x7F
if flag < 84:
nBytes = 1
elif flag < 120:
nBytes = 2
elif flag < 124:
nBytes = 3
else:
nBytes = 4
assert (tripletIndex + nBytes) <= nTriplets
if flag < 10:
dx = 0
dy = withSign(flag, ((flag & 14) << 7) + triplets[tripletIndex])
elif flag < 20:
dx = withSign(flag, (((flag - 10) & 14) << 7) + triplets[tripletIndex])
dy = 0
elif flag < 84:
b0 = flag - 20
b1 = triplets[tripletIndex]
dx = withSign(flag, 1 + (b0 & 0x30) + (b1 >> 4))
dy = withSign(flag >> 1, 1 + ((b0 & 0x0C) << 2) + (b1 & 0x0F))
elif flag < 120:
b0 = flag - 84
dx = withSign(flag, 1 + ((b0 // 12) << 8) + triplets[tripletIndex])
dy = withSign(
flag >> 1, 1 + (((b0 % 12) >> 2) << 8) + triplets[tripletIndex + 1]
)
elif flag < 124:
b2 = triplets[tripletIndex + 1]
dx = withSign(flag, (triplets[tripletIndex] << 4) + (b2 >> 4))
dy = withSign(
flag >> 1, ((b2 & 0x0F) << 8) + triplets[tripletIndex + 2]
)
else:
dx = withSign(
flag, (triplets[tripletIndex] << 8) + triplets[tripletIndex + 1]
)
dy = withSign(
flag >> 1,
(triplets[tripletIndex + 2] << 8) + triplets[tripletIndex + 3],
)
tripletIndex += nBytes
x += dx
y += dy
glyph.coordinates[i] = (x, y)
glyph.flags.append(int(onCurve))
bytesConsumed = tripletIndex
self.glyphStream = self.glyphStream[bytesConsumed:]
def _encodeGlyph(self, glyphID):
glyphName = self.getGlyphName(glyphID)
glyph = self[glyphName]
self.nContourStream += struct.pack(">h", glyph.numberOfContours)
if glyph.numberOfContours == 0:
return
elif glyph.isComposite():
self._encodeComponents(glyph)
elif glyph.isVarComposite():
raise NotImplementedError
else:
self._encodeCoordinates(glyph)
self._encodeOverlapSimpleFlag(glyph, glyphID)
self._encodeBBox(glyphID, glyph)
def _encodeComponents(self, glyph):
lastcomponent = len(glyph.components) - 1
more = 1
haveInstructions = 0
for i in range(len(glyph.components)):
if i == lastcomponent:
haveInstructions = hasattr(glyph, "program")
more = 0
component = glyph.components[i]
self.compositeStream += component.compile(more, haveInstructions, self)
if haveInstructions:
self._encodeInstructions(glyph)
def _encodeCoordinates(self, glyph):
lastEndPoint = -1
if _g_l_y_f.flagCubic in glyph.flags:
raise NotImplementedError
for endPoint in glyph.endPtsOfContours:
ptsOfContour = endPoint - lastEndPoint
self.nPointsStream += pack255UShort(ptsOfContour)
lastEndPoint = endPoint
self._encodeTriplets(glyph)
self._encodeInstructions(glyph)
def _encodeOverlapSimpleFlag(self, glyph, glyphID):
if glyph.numberOfContours <= 0:
return
if glyph.flags[0] & _g_l_y_f.flagOverlapSimple:
byte = glyphID >> 3
bit = glyphID & 7
self.overlapSimpleBitmap[byte] |= 0x80 >> bit
def _encodeInstructions(self, glyph):
instructions = glyph.program.getBytecode()
self.glyphStream += pack255UShort(len(instructions))
self.instructionStream += instructions
def _encodeBBox(self, glyphID, glyph):
assert glyph.numberOfContours != 0, "empty glyph has no bbox"
if not glyph.isComposite():
# for simple glyphs, compare the encoded bounding box info with the calculated
# values, and if they match omit the bounding box info
currentBBox = glyph.xMin, glyph.yMin, glyph.xMax, glyph.yMax
calculatedBBox = calcIntBounds(glyph.coordinates)
if currentBBox == calculatedBBox:
return
self.bboxBitmap[glyphID >> 3] |= 0x80 >> (glyphID & 7)
self.bboxStream += sstruct.pack(bboxFormat, glyph)
def _encodeTriplets(self, glyph):
assert len(glyph.coordinates) == len(glyph.flags)
coordinates = glyph.coordinates.copy()
coordinates.absoluteToRelative()
flags = array.array("B")
triplets = array.array("B")
for i in range(len(coordinates)):
onCurve = glyph.flags[i] & _g_l_y_f.flagOnCurve
x, y = coordinates[i]
absX = abs(x)
absY = abs(y)
onCurveBit = 0 if onCurve else 128
xSignBit = 0 if (x < 0) else 1
ySignBit = 0 if (y < 0) else 1
xySignBits = xSignBit + 2 * ySignBit
if x == 0 and absY < 1280:
flags.append(onCurveBit + ((absY & 0xF00) >> 7) + ySignBit)
triplets.append(absY & 0xFF)
elif y == 0 and absX < 1280:
flags.append(onCurveBit + 10 + ((absX & 0xF00) >> 7) + xSignBit)
triplets.append(absX & 0xFF)
elif absX < 65 and absY < 65:
flags.append(
onCurveBit
+ 20
+ ((absX - 1) & 0x30)
+ (((absY - 1) & 0x30) >> 2)
+ xySignBits
)
triplets.append((((absX - 1) & 0xF) << 4) | ((absY - 1) & 0xF))
elif absX < 769 and absY < 769:
flags.append(
onCurveBit
+ 84
+ 12 * (((absX - 1) & 0x300) >> 8)
+ (((absY - 1) & 0x300) >> 6)
+ xySignBits
)
triplets.append((absX - 1) & 0xFF)
triplets.append((absY - 1) & 0xFF)
elif absX < 4096 and absY < 4096:
flags.append(onCurveBit + 120 + xySignBits)
triplets.append(absX >> 4)
triplets.append(((absX & 0xF) << 4) | (absY >> 8))
triplets.append(absY & 0xFF)
else:
flags.append(onCurveBit + 124 + xySignBits)
triplets.append(absX >> 8)
triplets.append(absX & 0xFF)
triplets.append(absY >> 8)
triplets.append(absY & 0xFF)
self.flagStream += flags.tobytes()
self.glyphStream += triplets.tobytes()
class WOFF2HmtxTable(getTableClass("hmtx")):
def __init__(self, tag=None):
self.tableTag = Tag(tag or "hmtx")
def reconstruct(self, data, ttFont):
(flags,) = struct.unpack(">B", data[:1])
data = data[1:]
if flags & 0b11111100 != 0:
raise TTLibError("Bits 2-7 of '%s' flags are reserved" % self.tableTag)
# When bit 0 is _not_ set, the lsb[] array is present
hasLsbArray = flags & 1 == 0
# When bit 1 is _not_ set, the leftSideBearing[] array is present
hasLeftSideBearingArray = flags & 2 == 0
if hasLsbArray and hasLeftSideBearingArray:
raise TTLibError(
"either bits 0 or 1 (or both) must set in transformed '%s' flags"
% self.tableTag
)
glyfTable = ttFont["glyf"]
headerTable = ttFont["hhea"]
glyphOrder = glyfTable.glyphOrder
numGlyphs = len(glyphOrder)
numberOfHMetrics = min(int(headerTable.numberOfHMetrics), numGlyphs)
assert len(data) >= 2 * numberOfHMetrics
advanceWidthArray = array.array("H", data[: 2 * numberOfHMetrics])
if sys.byteorder != "big":
advanceWidthArray.byteswap()
data = data[2 * numberOfHMetrics :]
if hasLsbArray:
assert len(data) >= 2 * numberOfHMetrics
lsbArray = array.array("h", data[: 2 * numberOfHMetrics])
if sys.byteorder != "big":
lsbArray.byteswap()
data = data[2 * numberOfHMetrics :]
else:
# compute (proportional) glyphs' lsb from their xMin
lsbArray = array.array("h")
for i, glyphName in enumerate(glyphOrder):
if i >= numberOfHMetrics:
break
glyph = glyfTable[glyphName]
xMin = getattr(glyph, "xMin", 0)
lsbArray.append(xMin)
numberOfSideBearings = numGlyphs - numberOfHMetrics
if hasLeftSideBearingArray:
assert len(data) >= 2 * numberOfSideBearings
leftSideBearingArray = array.array("h", data[: 2 * numberOfSideBearings])
if sys.byteorder != "big":
leftSideBearingArray.byteswap()
data = data[2 * numberOfSideBearings :]
else:
# compute (monospaced) glyphs' leftSideBearing from their xMin
leftSideBearingArray = array.array("h")
for i, glyphName in enumerate(glyphOrder):
if i < numberOfHMetrics:
continue
glyph = glyfTable[glyphName]
xMin = getattr(glyph, "xMin", 0)
leftSideBearingArray.append(xMin)
if data:
raise TTLibError("too much '%s' table data" % self.tableTag)
self.metrics = {}
for i in range(numberOfHMetrics):
glyphName = glyphOrder[i]
advanceWidth, lsb = advanceWidthArray[i], lsbArray[i]
self.metrics[glyphName] = (advanceWidth, lsb)
lastAdvance = advanceWidthArray[-1]
for i in range(numberOfSideBearings):
glyphName = glyphOrder[i + numberOfHMetrics]
self.metrics[glyphName] = (lastAdvance, leftSideBearingArray[i])
def transform(self, ttFont):
glyphOrder = ttFont.getGlyphOrder()
glyf = ttFont["glyf"]
hhea = ttFont["hhea"]
numberOfHMetrics = hhea.numberOfHMetrics
# check if any of the proportional glyphs has left sidebearings that
# differ from their xMin bounding box values.
hasLsbArray = False
for i in range(numberOfHMetrics):
glyphName = glyphOrder[i]
lsb = self.metrics[glyphName][1]
if lsb != getattr(glyf[glyphName], "xMin", 0):
hasLsbArray = True
break
# do the same for the monospaced glyphs (if any) at the end of hmtx table
hasLeftSideBearingArray = False
for i in range(numberOfHMetrics, len(glyphOrder)):
glyphName = glyphOrder[i]
lsb = self.metrics[glyphName][1]
if lsb != getattr(glyf[glyphName], "xMin", 0):
hasLeftSideBearingArray = True
break
# if we need to encode both sidebearings arrays, then no transformation is
# applicable, and we must use the untransformed hmtx data
if hasLsbArray and hasLeftSideBearingArray:
return
# set bit 0 and 1 when the respective arrays are _not_ present
flags = 0
if not hasLsbArray:
flags |= 1 << 0
if not hasLeftSideBearingArray:
flags |= 1 << 1
data = struct.pack(">B", flags)
advanceWidthArray = array.array(
"H",
[
self.metrics[glyphName][0]
for i, glyphName in enumerate(glyphOrder)
if i < numberOfHMetrics
],
)
if sys.byteorder != "big":
advanceWidthArray.byteswap()
data += advanceWidthArray.tobytes()
if hasLsbArray:
lsbArray = array.array(
"h",
[
self.metrics[glyphName][1]
for i, glyphName in enumerate(glyphOrder)
if i < numberOfHMetrics
],
)
if sys.byteorder != "big":
lsbArray.byteswap()
data += lsbArray.tobytes()
if hasLeftSideBearingArray:
leftSideBearingArray = array.array(
"h",
[
self.metrics[glyphOrder[i]][1]
for i in range(numberOfHMetrics, len(glyphOrder))
],
)
if sys.byteorder != "big":
leftSideBearingArray.byteswap()
data += leftSideBearingArray.tobytes()
return data
class WOFF2FlavorData(WOFFFlavorData):
Flavor = "woff2"
def __init__(self, reader=None, data=None, transformedTables=None):
"""Data class that holds the WOFF2 header major/minor version, any
metadata or private data (as bytes strings), and the set of
table tags that have transformations applied (if reader is not None),
or will have once the WOFF2 font is compiled.
Args:
reader: an SFNTReader (or subclass) object to read flavor data from.
data: another WOFFFlavorData object to initialise data from.
transformedTables: set of strings containing table tags to be transformed.
Raises:
ImportError if the brotli module is not installed.
NOTE: The 'reader' argument, on the one hand, and the 'data' and
'transformedTables' arguments, on the other hand, are mutually exclusive.
"""
if not haveBrotli:
raise ImportError("No module named brotli")
if reader is not None:
if data is not None:
raise TypeError("'reader' and 'data' arguments are mutually exclusive")
if transformedTables is not None:
raise TypeError(
"'reader' and 'transformedTables' arguments are mutually exclusive"
)
if transformedTables is not None and (
"glyf" in transformedTables
and "loca" not in transformedTables
or "loca" in transformedTables
and "glyf" not in transformedTables
):
raise ValueError("'glyf' and 'loca' must be transformed (or not) together")
super(WOFF2FlavorData, self).__init__(reader=reader)
if reader:
transformedTables = [
tag for tag, entry in reader.tables.items() if entry.transformed
]
elif data:
self.majorVersion = data.majorVersion
self.majorVersion = data.minorVersion
self.metaData = data.metaData
self.privData = data.privData
if transformedTables is None and hasattr(data, "transformedTables"):
transformedTables = data.transformedTables
if transformedTables is None:
transformedTables = woff2TransformedTableTags
self.transformedTables = set(transformedTables)
def _decompress(self, rawData):
return brotli.decompress(rawData)
def unpackBase128(data):
r"""Read one to five bytes from UIntBase128-encoded input string, and return
a tuple containing the decoded integer plus any leftover data.
>>> unpackBase128(b'\x3f\x00\x00') == (63, b"\x00\x00")
True
>>> unpackBase128(b'\x8f\xff\xff\xff\x7f')[0] == 4294967295
True
>>> unpackBase128(b'\x80\x80\x3f') # doctest: +IGNORE_EXCEPTION_DETAIL
Traceback (most recent call last):
File "<stdin>", line 1, in ?
TTLibError: UIntBase128 value must not start with leading zeros
>>> unpackBase128(b'\x8f\xff\xff\xff\xff\x7f')[0] # doctest: +IGNORE_EXCEPTION_DETAIL
Traceback (most recent call last):
File "<stdin>", line 1, in ?
TTLibError: UIntBase128-encoded sequence is longer than 5 bytes
>>> unpackBase128(b'\x90\x80\x80\x80\x00')[0] # doctest: +IGNORE_EXCEPTION_DETAIL
Traceback (most recent call last):
File "<stdin>", line 1, in ?
TTLibError: UIntBase128 value exceeds 2**32-1
"""
if len(data) == 0:
raise TTLibError("not enough data to unpack UIntBase128")
result = 0
if byteord(data[0]) == 0x80:
# font must be rejected if UIntBase128 value starts with 0x80
raise TTLibError("UIntBase128 value must not start with leading zeros")
for i in range(woff2Base128MaxSize):
if len(data) == 0:
raise TTLibError("not enough data to unpack UIntBase128")
code = byteord(data[0])
data = data[1:]
# if any of the top seven bits are set then we're about to overflow
if result & 0xFE000000:
raise TTLibError("UIntBase128 value exceeds 2**32-1")
# set current value = old value times 128 bitwise-or (byte bitwise-and 127)
result = (result << 7) | (code & 0x7F)
# repeat until the most significant bit of byte is false
if (code & 0x80) == 0:
# return result plus left over data
return result, data
# make sure not to exceed the size bound
raise TTLibError("UIntBase128-encoded sequence is longer than 5 bytes")
def base128Size(n):
"""Return the length in bytes of a UIntBase128-encoded sequence with value n.
>>> base128Size(0)
1
>>> base128Size(24567)
3
>>> base128Size(2**32-1)
5
"""
assert n >= 0
size = 1
while n >= 128:
size += 1
n >>= 7
return size
def packBase128(n):
r"""Encode unsigned integer in range 0 to 2**32-1 (inclusive) to a string of
bytes using UIntBase128 variable-length encoding. Produce the shortest possible
encoding.
>>> packBase128(63) == b"\x3f"
True
>>> packBase128(2**32-1) == b'\x8f\xff\xff\xff\x7f'
True
"""
if n < 0 or n >= 2**32:
raise TTLibError("UIntBase128 format requires 0 <= integer <= 2**32-1")
data = b""
size = base128Size(n)
for i in range(size):
b = (n >> (7 * (size - i - 1))) & 0x7F
if i < size - 1:
b |= 0x80
data += struct.pack("B", b)
return data
def unpack255UShort(data):
"""Read one to three bytes from 255UInt16-encoded input string, and return a
tuple containing the decoded integer plus any leftover data.
>>> unpack255UShort(bytechr(252))[0]
252
Note that some numbers (e.g. 506) can have multiple encodings:
>>> unpack255UShort(struct.pack("BB", 254, 0))[0]
506
>>> unpack255UShort(struct.pack("BB", 255, 253))[0]
506
>>> unpack255UShort(struct.pack("BBB", 253, 1, 250))[0]
506
"""
code = byteord(data[:1])
data = data[1:]
if code == 253:
# read two more bytes as an unsigned short
if len(data) < 2:
raise TTLibError("not enough data to unpack 255UInt16")
(result,) = struct.unpack(">H", data[:2])
data = data[2:]
elif code == 254:
# read another byte, plus 253 * 2
if len(data) == 0:
raise TTLibError("not enough data to unpack 255UInt16")
result = byteord(data[:1])
result += 506
data = data[1:]
elif code == 255:
# read another byte, plus 253
if len(data) == 0:
raise TTLibError("not enough data to unpack 255UInt16")
result = byteord(data[:1])
result += 253
data = data[1:]
else:
# leave as is if lower than 253
result = code
# return result plus left over data
return result, data
def pack255UShort(value):
r"""Encode unsigned integer in range 0 to 65535 (inclusive) to a bytestring
using 255UInt16 variable-length encoding.
>>> pack255UShort(252) == b'\xfc'
True
>>> pack255UShort(506) == b'\xfe\x00'
True
>>> pack255UShort(762) == b'\xfd\x02\xfa'
True
"""
if value < 0 or value > 0xFFFF:
raise TTLibError("255UInt16 format requires 0 <= integer <= 65535")
if value < 253:
return struct.pack(">B", value)
elif value < 506:
return struct.pack(">BB", 255, value - 253)
elif value < 762:
return struct.pack(">BB", 254, value - 506)
else:
return struct.pack(">BH", 253, value)
def compress(input_file, output_file, transform_tables=None):
"""Compress OpenType font to WOFF2.
Args:
input_file: a file path, file or file-like object (open in binary mode)
containing an OpenType font (either CFF- or TrueType-flavored).
output_file: a file path, file or file-like object where to save the
compressed WOFF2 font.
transform_tables: Optional[Iterable[str]]: a set of table tags for which
to enable preprocessing transformations. By default, only 'glyf'
and 'loca' tables are transformed. An empty set means disable all
transformations.
"""
log.info("Processing %s => %s" % (input_file, output_file))
font = TTFont(input_file, recalcBBoxes=False, recalcTimestamp=False)
font.flavor = "woff2"
if transform_tables is not None:
font.flavorData = WOFF2FlavorData(
data=font.flavorData, transformedTables=transform_tables
)
font.save(output_file, reorderTables=False)
def decompress(input_file, output_file):
"""Decompress WOFF2 font to OpenType font.
Args:
input_file: a file path, file or file-like object (open in binary mode)
containing a compressed WOFF2 font.
output_file: a file path, file or file-like object where to save the
decompressed OpenType font.
"""
log.info("Processing %s => %s" % (input_file, output_file))
font = TTFont(input_file, recalcBBoxes=False, recalcTimestamp=False)
font.flavor = None
font.flavorData = None
font.save(output_file, reorderTables=True)
def main(args=None):
"""Compress and decompress WOFF2 fonts"""
import argparse
from fontTools import configLogger
from fontTools.ttx import makeOutputFileName
class _HelpAction(argparse._HelpAction):
def __call__(self, parser, namespace, values, option_string=None):
subparsers_actions = [
action
for action in parser._actions
if isinstance(action, argparse._SubParsersAction)
]
for subparsers_action in subparsers_actions:
for choice, subparser in subparsers_action.choices.items():
print(subparser.format_help())
parser.exit()
class _NoGlyfTransformAction(argparse.Action):
def __call__(self, parser, namespace, values, option_string=None):
namespace.transform_tables.difference_update({"glyf", "loca"})
class _HmtxTransformAction(argparse.Action):
def __call__(self, parser, namespace, values, option_string=None):
namespace.transform_tables.add("hmtx")
parser = argparse.ArgumentParser(
prog="fonttools ttLib.woff2", description=main.__doc__, add_help=False
)
parser.add_argument(
"-h", "--help", action=_HelpAction, help="show this help message and exit"
)
parser_group = parser.add_subparsers(title="sub-commands")
parser_compress = parser_group.add_parser(
"compress", description="Compress a TTF or OTF font to WOFF2"
)
parser_decompress = parser_group.add_parser(
"decompress", description="Decompress a WOFF2 font to OTF"
)
for subparser in (parser_compress, parser_decompress):
group = subparser.add_mutually_exclusive_group(required=False)
group.add_argument(
"-v",
"--verbose",
action="store_true",
help="print more messages to console",
)
group.add_argument(
"-q",
"--quiet",
action="store_true",
help="do not print messages to console",
)
parser_compress.add_argument(
"input_file",
metavar="INPUT",
help="the input OpenType font (.ttf or .otf)",
)
parser_decompress.add_argument(
"input_file",
metavar="INPUT",
help="the input WOFF2 font",
)
parser_compress.add_argument(
"-o",
"--output-file",
metavar="OUTPUT",
help="the output WOFF2 font",
)
parser_decompress.add_argument(
"-o",
"--output-file",
metavar="OUTPUT",
help="the output OpenType font",
)
transform_group = parser_compress.add_argument_group()
transform_group.add_argument(
"--no-glyf-transform",
dest="transform_tables",
nargs=0,
action=_NoGlyfTransformAction,
help="Do not transform glyf (and loca) tables",
)
transform_group.add_argument(
"--hmtx-transform",
dest="transform_tables",
nargs=0,
action=_HmtxTransformAction,
help="Enable optional transformation for 'hmtx' table",
)
parser_compress.set_defaults(
subcommand=compress,
transform_tables={"glyf", "loca"},
)
parser_decompress.set_defaults(subcommand=decompress)
options = vars(parser.parse_args(args))
subcommand = options.pop("subcommand", None)
if not subcommand:
parser.print_help()
return
quiet = options.pop("quiet")
verbose = options.pop("verbose")
configLogger(
level=("ERROR" if quiet else "DEBUG" if verbose else "INFO"),
)
if not options["output_file"]:
if subcommand is compress:
extension = ".woff2"
elif subcommand is decompress:
# choose .ttf/.otf file extension depending on sfntVersion
with open(options["input_file"], "rb") as f:
f.seek(4) # skip 'wOF2' signature
sfntVersion = f.read(4)
assert len(sfntVersion) == 4, "not enough data"
extension = ".otf" if sfntVersion == b"OTTO" else ".ttf"
else:
raise AssertionError(subcommand)
options["output_file"] = makeOutputFileName(
options["input_file"], outputDir=None, extension=extension
)
try:
subcommand(**options)
except TTLibError as e:
parser.error(e)
if __name__ == "__main__":
sys.exit(main())