422 lines
13 KiB
Python
422 lines
13 KiB
Python
from __future__ import print_function, division, absolute_import
|
|
from fontTools.misc.py23 import *
|
|
from fontTools.misc.fixedTools import fixedToFloat, floatToFixed
|
|
from fontTools.misc.textTools import safeEval
|
|
import array
|
|
import io
|
|
import logging
|
|
import struct
|
|
import sys
|
|
|
|
|
|
# https://www.microsoft.com/typography/otspec/otvarcommonformats.htm
|
|
|
|
EMBEDDED_PEAK_TUPLE = 0x8000
|
|
INTERMEDIATE_REGION = 0x4000
|
|
PRIVATE_POINT_NUMBERS = 0x2000
|
|
|
|
DELTAS_ARE_ZERO = 0x80
|
|
DELTAS_ARE_WORDS = 0x40
|
|
DELTA_RUN_COUNT_MASK = 0x3f
|
|
|
|
POINTS_ARE_WORDS = 0x80
|
|
POINT_RUN_COUNT_MASK = 0x7f
|
|
|
|
log = logging.getLogger(__name__)
|
|
|
|
|
|
class TupleVariation(object):
|
|
def __init__(self, axes, coordinates):
|
|
self.axes = axes
|
|
self.coordinates = coordinates
|
|
|
|
def __repr__(self):
|
|
axes = ",".join(sorted(["%s=%s" % (name, value) for (name, value) in self.axes.items()]))
|
|
return "<TupleVariation %s %s>" % (axes, self.coordinates)
|
|
|
|
def __eq__(self, other):
|
|
return self.coordinates == other.coordinates and self.axes == other.axes
|
|
|
|
def getUsedPoints(self):
|
|
result = set()
|
|
for i, point in enumerate(self.coordinates):
|
|
if point is not None:
|
|
result.add(i)
|
|
return result
|
|
|
|
def hasImpact(self):
|
|
"""Returns True if this TupleVariation has any visible impact.
|
|
|
|
If the result is False, the TupleVariation can be omitted from the font
|
|
without making any visible difference.
|
|
"""
|
|
for c in self.coordinates:
|
|
if c is not None:
|
|
return True
|
|
return False
|
|
|
|
def toXML(self, writer, axisTags):
|
|
writer.begintag("tuple")
|
|
writer.newline()
|
|
for axis in axisTags:
|
|
value = self.axes.get(axis)
|
|
if value is not None:
|
|
minValue, value, maxValue = value
|
|
defaultMinValue = min(value, 0.0) # -0.3 --> -0.3; 0.7 --> 0.0
|
|
defaultMaxValue = max(value, 0.0) # -0.3 --> 0.0; 0.7 --> 0.7
|
|
if minValue == defaultMinValue and maxValue == defaultMaxValue:
|
|
writer.simpletag("coord", axis=axis, value=value)
|
|
else:
|
|
writer.simpletag("coord", axis=axis, value=value, min=minValue, max=maxValue)
|
|
writer.newline()
|
|
wrote_any_points = False
|
|
for i, point in enumerate(self.coordinates):
|
|
if point is not None:
|
|
writer.simpletag("delta", pt=i, x=point[0], y=point[1])
|
|
writer.newline()
|
|
wrote_any_points = True
|
|
if not wrote_any_points:
|
|
writer.comment("no deltas")
|
|
writer.newline()
|
|
writer.endtag("tuple")
|
|
writer.newline()
|
|
|
|
def fromXML(self, name, attrs, _content):
|
|
if name == "coord":
|
|
axis = attrs["axis"]
|
|
value = float(attrs["value"])
|
|
defaultMinValue = min(value, 0.0) # -0.3 --> -0.3; 0.7 --> 0.0
|
|
defaultMaxValue = max(value, 0.0) # -0.3 --> 0.0; 0.7 --> 0.7
|
|
minValue = float(attrs.get("min", defaultMinValue))
|
|
maxValue = float(attrs.get("max", defaultMaxValue))
|
|
self.axes[axis] = (minValue, value, maxValue)
|
|
elif name == "delta":
|
|
point = safeEval(attrs["pt"])
|
|
x = safeEval(attrs["x"])
|
|
y = safeEval(attrs["y"])
|
|
self.coordinates[point] = (x, y)
|
|
|
|
def compile(self, axisTags, sharedCoordIndices, sharedPoints):
|
|
tupleData = []
|
|
|
|
assert all(tag in axisTags for tag in self.axes.keys()), ("Unknown axis tag found.", self.axes.keys(), axisTags)
|
|
|
|
coord = self.compileCoord(axisTags)
|
|
if coord in sharedCoordIndices:
|
|
flags = sharedCoordIndices[coord]
|
|
else:
|
|
flags = EMBEDDED_PEAK_TUPLE
|
|
tupleData.append(coord)
|
|
|
|
intermediateCoord = self.compileIntermediateCoord(axisTags)
|
|
if intermediateCoord is not None:
|
|
flags |= INTERMEDIATE_REGION
|
|
tupleData.append(intermediateCoord)
|
|
|
|
if sharedPoints is not None:
|
|
auxData = self.compileDeltas(sharedPoints)
|
|
else:
|
|
flags |= PRIVATE_POINT_NUMBERS
|
|
points = self.getUsedPoints()
|
|
numPointsInGlyph = len(self.coordinates)
|
|
auxData = self.compilePoints(points, numPointsInGlyph) + self.compileDeltas(points)
|
|
|
|
tupleData = struct.pack('>HH', len(auxData), flags) + bytesjoin(tupleData)
|
|
return (tupleData, auxData)
|
|
|
|
def compileCoord(self, axisTags):
|
|
result = []
|
|
for axis in axisTags:
|
|
_minValue, value, _maxValue = self.axes.get(axis, (0.0, 0.0, 0.0))
|
|
result.append(struct.pack(">h", floatToFixed(value, 14)))
|
|
return bytesjoin(result)
|
|
|
|
def compileIntermediateCoord(self, axisTags):
|
|
needed = False
|
|
for axis in axisTags:
|
|
minValue, value, maxValue = self.axes.get(axis, (0.0, 0.0, 0.0))
|
|
defaultMinValue = min(value, 0.0) # -0.3 --> -0.3; 0.7 --> 0.0
|
|
defaultMaxValue = max(value, 0.0) # -0.3 --> 0.0; 0.7 --> 0.7
|
|
if (minValue != defaultMinValue) or (maxValue != defaultMaxValue):
|
|
needed = True
|
|
break
|
|
if not needed:
|
|
return None
|
|
minCoords = []
|
|
maxCoords = []
|
|
for axis in axisTags:
|
|
minValue, value, maxValue = self.axes.get(axis, (0.0, 0.0, 0.0))
|
|
minCoords.append(struct.pack(">h", floatToFixed(minValue, 14)))
|
|
maxCoords.append(struct.pack(">h", floatToFixed(maxValue, 14)))
|
|
return bytesjoin(minCoords + maxCoords)
|
|
|
|
@staticmethod
|
|
def decompileCoord_(axisTags, data, offset):
|
|
coord = {}
|
|
pos = offset
|
|
for axis in axisTags:
|
|
coord[axis] = fixedToFloat(struct.unpack(">h", data[pos:pos+2])[0], 14)
|
|
pos += 2
|
|
return coord, pos
|
|
|
|
@staticmethod
|
|
def decompileCoords_(axisTags, numCoords, data, offset):
|
|
result = []
|
|
pos = offset
|
|
for _ in range(numCoords):
|
|
coord, pos = TupleVariation.decompileCoord_(axisTags, data, pos)
|
|
result.append(coord)
|
|
return result, pos
|
|
|
|
@staticmethod
|
|
def compilePoints(points, numPointsInGlyph):
|
|
# If the set consists of all points in the glyph, it gets encoded with
|
|
# a special encoding: a single zero byte.
|
|
if len(points) == numPointsInGlyph:
|
|
return b"\0"
|
|
|
|
# In the 'gvar' table, the packing of point numbers is a little surprising.
|
|
# It consists of multiple runs, each being a delta-encoded list of integers.
|
|
# For example, the point set {17, 18, 19, 20, 21, 22, 23} gets encoded as
|
|
# [6, 17, 1, 1, 1, 1, 1, 1]. The first value (6) is the run length minus 1.
|
|
# There are two types of runs, with values being either 8 or 16 bit unsigned
|
|
# integers.
|
|
points = list(points)
|
|
points.sort()
|
|
numPoints = len(points)
|
|
|
|
# The binary representation starts with the total number of points in the set,
|
|
# encoded into one or two bytes depending on the value.
|
|
if numPoints < 0x80:
|
|
result = [bytechr(numPoints)]
|
|
else:
|
|
result = [bytechr((numPoints >> 8) | 0x80) + bytechr(numPoints & 0xff)]
|
|
|
|
MAX_RUN_LENGTH = 127
|
|
pos = 0
|
|
lastValue = 0
|
|
while pos < numPoints:
|
|
run = io.BytesIO()
|
|
runLength = 0
|
|
useByteEncoding = None
|
|
while pos < numPoints and runLength <= MAX_RUN_LENGTH:
|
|
curValue = points[pos]
|
|
delta = curValue - lastValue
|
|
if useByteEncoding is None:
|
|
useByteEncoding = 0 <= delta <= 0xff
|
|
if useByteEncoding and (delta > 0xff or delta < 0):
|
|
# we need to start a new run (which will not use byte encoding)
|
|
break
|
|
# TODO This never switches back to a byte-encoding from a short-encoding.
|
|
# That's suboptimal.
|
|
if useByteEncoding:
|
|
run.write(bytechr(delta))
|
|
else:
|
|
run.write(bytechr(delta >> 8))
|
|
run.write(bytechr(delta & 0xff))
|
|
lastValue = curValue
|
|
pos += 1
|
|
runLength += 1
|
|
if useByteEncoding:
|
|
runHeader = bytechr(runLength - 1)
|
|
else:
|
|
runHeader = bytechr((runLength - 1) | POINTS_ARE_WORDS)
|
|
result.append(runHeader)
|
|
result.append(run.getvalue())
|
|
|
|
return bytesjoin(result)
|
|
|
|
@staticmethod
|
|
def decompilePoints_(numPointsInGlyph, data, offset):
|
|
"""(numPointsInGlyph, data, offset) --> ([point1, point2, ...], newOffset)"""
|
|
pos = offset
|
|
numPointsInData = byteord(data[pos])
|
|
pos += 1
|
|
if (numPointsInData & POINTS_ARE_WORDS) != 0:
|
|
numPointsInData = (numPointsInData & POINT_RUN_COUNT_MASK) << 8 | byteord(data[pos])
|
|
pos += 1
|
|
if numPointsInData == 0:
|
|
return (range(numPointsInGlyph), pos)
|
|
|
|
result = []
|
|
while len(result) < numPointsInData:
|
|
runHeader = byteord(data[pos])
|
|
pos += 1
|
|
numPointsInRun = (runHeader & POINT_RUN_COUNT_MASK) + 1
|
|
point = 0
|
|
if (runHeader & POINTS_ARE_WORDS) != 0:
|
|
points = array.array("H")
|
|
pointsSize = numPointsInRun * 2
|
|
else:
|
|
points = array.array("B")
|
|
pointsSize = numPointsInRun
|
|
points.fromstring(data[pos:pos+pointsSize])
|
|
if sys.byteorder != "big":
|
|
points.byteswap()
|
|
|
|
assert len(points) == numPointsInRun
|
|
pos += pointsSize
|
|
|
|
result.extend(points)
|
|
|
|
# Convert relative to absolute
|
|
absolute = []
|
|
current = 0
|
|
for delta in result:
|
|
current += delta
|
|
absolute.append(current)
|
|
result = absolute
|
|
del absolute
|
|
|
|
if max(result) >= numPointsInGlyph or min(result) < 0:
|
|
log.warning("point number out of range in 'gvar' table")
|
|
return (result, pos)
|
|
|
|
def compileDeltas(self, points):
|
|
deltaX = []
|
|
deltaY = []
|
|
for p in sorted(list(points)):
|
|
c = self.coordinates[p]
|
|
if c is not None:
|
|
deltaX.append(c[0])
|
|
deltaY.append(c[1])
|
|
return self.compileDeltaValues_(deltaX) + self.compileDeltaValues_(deltaY)
|
|
|
|
@staticmethod
|
|
def compileDeltaValues_(deltas):
|
|
"""[value1, value2, value3, ...] --> bytestring
|
|
|
|
Emits a sequence of runs. Each run starts with a
|
|
byte-sized header whose 6 least significant bits
|
|
(header & 0x3F) indicate how many values are encoded
|
|
in this run. The stored length is the actual length
|
|
minus one; run lengths are thus in the range [1..64].
|
|
If the header byte has its most significant bit (0x80)
|
|
set, all values in this run are zero, and no data
|
|
follows. Otherwise, the header byte is followed by
|
|
((header & 0x3F) + 1) signed values. If (header &
|
|
0x40) is clear, the delta values are stored as signed
|
|
bytes; if (header & 0x40) is set, the delta values are
|
|
signed 16-bit integers.
|
|
""" # Explaining the format because the 'gvar' spec is hard to understand.
|
|
stream = io.BytesIO()
|
|
pos = 0
|
|
while pos < len(deltas):
|
|
value = deltas[pos]
|
|
if value == 0:
|
|
pos = TupleVariation.encodeDeltaRunAsZeroes_(deltas, pos, stream)
|
|
elif value >= -128 and value <= 127:
|
|
pos = TupleVariation.encodeDeltaRunAsBytes_(deltas, pos, stream)
|
|
else:
|
|
pos = TupleVariation.encodeDeltaRunAsWords_(deltas, pos, stream)
|
|
return stream.getvalue()
|
|
|
|
@staticmethod
|
|
def encodeDeltaRunAsZeroes_(deltas, offset, stream):
|
|
runLength = 0
|
|
pos = offset
|
|
numDeltas = len(deltas)
|
|
while pos < numDeltas and runLength < 64 and deltas[pos] == 0:
|
|
pos += 1
|
|
runLength += 1
|
|
assert runLength >= 1 and runLength <= 64
|
|
stream.write(bytechr(DELTAS_ARE_ZERO | (runLength - 1)))
|
|
return pos
|
|
|
|
@staticmethod
|
|
def encodeDeltaRunAsBytes_(deltas, offset, stream):
|
|
runLength = 0
|
|
pos = offset
|
|
numDeltas = len(deltas)
|
|
while pos < numDeltas and runLength < 64:
|
|
value = deltas[pos]
|
|
if value < -128 or value > 127:
|
|
break
|
|
# Within a byte-encoded run of deltas, a single zero
|
|
# is best stored literally as 0x00 value. However,
|
|
# if are two or more zeroes in a sequence, it is
|
|
# better to start a new run. For example, the sequence
|
|
# of deltas [15, 15, 0, 15, 15] becomes 6 bytes
|
|
# (04 0F 0F 00 0F 0F) when storing the zero value
|
|
# literally, but 7 bytes (01 0F 0F 80 01 0F 0F)
|
|
# when starting a new run.
|
|
if value == 0 and pos+1 < numDeltas and deltas[pos+1] == 0:
|
|
break
|
|
pos += 1
|
|
runLength += 1
|
|
assert runLength >= 1 and runLength <= 64
|
|
stream.write(bytechr(runLength - 1))
|
|
for i in range(offset, pos):
|
|
stream.write(struct.pack('b', deltas[i]))
|
|
return pos
|
|
|
|
@staticmethod
|
|
def encodeDeltaRunAsWords_(deltas, offset, stream):
|
|
runLength = 0
|
|
pos = offset
|
|
numDeltas = len(deltas)
|
|
while pos < numDeltas and runLength < 64:
|
|
value = deltas[pos]
|
|
# Within a word-encoded run of deltas, it is easiest
|
|
# to start a new run (with a different encoding)
|
|
# whenever we encounter a zero value. For example,
|
|
# the sequence [0x6666, 0, 0x7777] needs 7 bytes when
|
|
# storing the zero literally (42 66 66 00 00 77 77),
|
|
# and equally 7 bytes when starting a new run
|
|
# (40 66 66 80 40 77 77).
|
|
if value == 0:
|
|
break
|
|
|
|
# Within a word-encoded run of deltas, a single value
|
|
# in the range (-128..127) should be encoded literally
|
|
# because it is more compact. For example, the sequence
|
|
# [0x6666, 2, 0x7777] becomes 7 bytes when storing
|
|
# the value literally (42 66 66 00 02 77 77), but 8 bytes
|
|
# when starting a new run (40 66 66 00 02 40 77 77).
|
|
isByteEncodable = lambda value: value >= -128 and value <= 127
|
|
if isByteEncodable(value) and pos+1 < numDeltas and isByteEncodable(deltas[pos+1]):
|
|
break
|
|
pos += 1
|
|
runLength += 1
|
|
assert runLength >= 1 and runLength <= 64
|
|
stream.write(bytechr(DELTAS_ARE_WORDS | (runLength - 1)))
|
|
for i in range(offset, pos):
|
|
stream.write(struct.pack('>h', deltas[i]))
|
|
return pos
|
|
|
|
@staticmethod
|
|
def decompileDeltas_(numDeltas, data, offset):
|
|
"""(numDeltas, data, offset) --> ([delta, delta, ...], newOffset)"""
|
|
result = []
|
|
pos = offset
|
|
while len(result) < numDeltas:
|
|
runHeader = byteord(data[pos])
|
|
pos += 1
|
|
numDeltasInRun = (runHeader & DELTA_RUN_COUNT_MASK) + 1
|
|
if (runHeader & DELTAS_ARE_ZERO) != 0:
|
|
result.extend([0] * numDeltasInRun)
|
|
else:
|
|
if (runHeader & DELTAS_ARE_WORDS) != 0:
|
|
deltas = array.array("h")
|
|
deltasSize = numDeltasInRun * 2
|
|
else:
|
|
deltas = array.array("b")
|
|
deltasSize = numDeltasInRun
|
|
deltas.fromstring(data[pos:pos+deltasSize])
|
|
if sys.byteorder != "big":
|
|
deltas.byteswap()
|
|
assert len(deltas) == numDeltasInRun
|
|
pos += deltasSize
|
|
result.extend(deltas)
|
|
assert len(result) == numDeltas
|
|
return (result, pos)
|
|
|
|
@staticmethod
|
|
def getTupleSize_(flags, axisCount):
|
|
size = 4
|
|
if (flags & EMBEDDED_PEAK_TUPLE) != 0:
|
|
size += axisCount * 2
|
|
if (flags & INTERMEDIATE_REGION) != 0:
|
|
size += axisCount * 4
|
|
return size
|