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from fontTools.misc.py23 import bytesjoin
from fontTools.misc import sstruct
from fontTools.misc.fixedTools import (
fixedToFloat as fi2fl,
floatToFixed as fl2fi,
floatToFixedToStr as fl2str,
strToFixedToFloat as str2fl,
)
from fontTools.ttLib import TTLibError
from . import DefaultTable
import struct
import logging
log = logging.getLogger(__name__)
# Apple's documentation of 'avar':
# https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6avar.html
AVAR_HEADER_FORMAT = """
> # big endian
majorVersion: H
minorVersion: H
reserved: H
axisCount: H
"""
assert sstruct.calcsize(AVAR_HEADER_FORMAT) == 8, sstruct.calcsize(AVAR_HEADER_FORMAT)
class table__a_v_a_r(DefaultTable.DefaultTable):
dependencies = ["fvar"]
def __init__(self, tag=None):
DefaultTable.DefaultTable.__init__(self, tag)
self.segments = {}
def compile(self, ttFont):
axisTags = [axis.axisTag for axis in ttFont["fvar"].axes]
header = {
"majorVersion": 1,
"minorVersion": 0,
"reserved": 0,
"axisCount": len(axisTags)
}
result = [sstruct.pack(AVAR_HEADER_FORMAT, header)]
for axis in axisTags:
mappings = sorted(self.segments[axis].items())
result.append(struct.pack(">H", len(mappings)))
for key, value in mappings:
fixedKey = fl2fi(key, 14)
fixedValue = fl2fi(value, 14)
result.append(struct.pack(">hh", fixedKey, fixedValue))
return bytesjoin(result)
def decompile(self, data, ttFont):
axisTags = [axis.axisTag for axis in ttFont["fvar"].axes]
header = {}
headerSize = sstruct.calcsize(AVAR_HEADER_FORMAT)
header = sstruct.unpack(AVAR_HEADER_FORMAT, data[0:headerSize])
majorVersion = header["majorVersion"]
if majorVersion != 1:
raise TTLibError("unsupported 'avar' version %d" % majorVersion)
pos = headerSize
for axis in axisTags:
segments = self.segments[axis] = {}
numPairs = struct.unpack(">H", data[pos:pos+2])[0]
pos = pos + 2
for _ in range(numPairs):
fromValue, toValue = struct.unpack(">hh", data[pos:pos+4])
segments[fi2fl(fromValue, 14)] = fi2fl(toValue, 14)
pos = pos + 4
def toXML(self, writer, ttFont):
axisTags = [axis.axisTag for axis in ttFont["fvar"].axes]
for axis in axisTags:
writer.begintag("segment", axis=axis)
writer.newline()
for key, value in sorted(self.segments[axis].items()):
key = fl2str(key, 14)
value = fl2str(value, 14)
writer.simpletag("mapping", **{"from": key, "to": value})
writer.newline()
writer.endtag("segment")
writer.newline()
def fromXML(self, name, attrs, content, ttFont):
if name == "segment":
axis = attrs["axis"]
segment = self.segments[axis] = {}
for element in content:
if isinstance(element, tuple):
elementName, elementAttrs, _ = element
if elementName == "mapping":
fromValue = str2fl(elementAttrs["from"], 14)
toValue = str2fl(elementAttrs["to"], 14)
if fromValue in segment:
log.warning("duplicate entry for %s in axis '%s'",
fromValue, axis)
segment[fromValue] = toValue
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