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from fontTools.misc.roundTools import noRound, otRound
from fontTools.ttLib.tables import otTables as ot
from fontTools.varLib.models import supportScalar
from fontTools.varLib.builder import (buildVarRegionList, buildVarStore,
buildVarRegion, buildVarData)
from functools import partial
from collections import defaultdict
from array import array
def _getLocationKey(loc):
return tuple(sorted(loc.items(), key=lambda kv: kv[0]))
class OnlineVarStoreBuilder(object):
def __init__(self, axisTags):
self._axisTags = axisTags
self._regionMap = {}
self._regionList = buildVarRegionList([], axisTags)
self._store = buildVarStore(self._regionList, [])
self._data = None
self._model = None
self._supports = None
self._varDataIndices = {}
self._varDataCaches = {}
self._cache = {}
def setModel(self, model):
self.setSupports(model.supports)
self._model = model
def setSupports(self, supports):
self._model = None
self._supports = list(supports)
if not self._supports[0]:
del self._supports[0] # Drop base master support
self._cache = {}
self._data = None
def finish(self, optimize=True):
self._regionList.RegionCount = len(self._regionList.Region)
self._store.VarDataCount = len(self._store.VarData)
for data in self._store.VarData:
data.ItemCount = len(data.Item)
data.calculateNumShorts(optimize=optimize)
return self._store
def _add_VarData(self):
regionMap = self._regionMap
regionList = self._regionList
regions = self._supports
regionIndices = []
for region in regions:
key = _getLocationKey(region)
idx = regionMap.get(key)
if idx is None:
varRegion = buildVarRegion(region, self._axisTags)
idx = regionMap[key] = len(regionList.Region)
regionList.Region.append(varRegion)
regionIndices.append(idx)
# Check if we have one already...
key = tuple(regionIndices)
varDataIdx = self._varDataIndices.get(key)
if varDataIdx is not None:
self._outer = varDataIdx
self._data = self._store.VarData[varDataIdx]
self._cache = self._varDataCaches[key]
if len(self._data.Item) == 0xFFFF:
# This is full. Need new one.
varDataIdx = None
if varDataIdx is None:
self._data = buildVarData(regionIndices, [], optimize=False)
self._outer = len(self._store.VarData)
self._store.VarData.append(self._data)
self._varDataIndices[key] = self._outer
if key not in self._varDataCaches:
self._varDataCaches[key] = {}
self._cache = self._varDataCaches[key]
def storeMasters(self, master_values):
deltas = self._model.getDeltas(master_values, round=round)
base = deltas.pop(0)
return base, self.storeDeltas(deltas, round=noRound)
def storeDeltas(self, deltas, *, round=round):
deltas = [round(d) for d in deltas]
if len(deltas) == len(self._supports) + 1:
deltas = tuple(deltas[1:])
else:
assert len(deltas) == len(self._supports)
deltas = tuple(deltas)
varIdx = self._cache.get(deltas)
if varIdx is not None:
return varIdx
if not self._data:
self._add_VarData()
inner = len(self._data.Item)
if inner == 0xFFFF:
# Full array. Start new one.
self._add_VarData()
return self.storeDeltas(deltas)
self._data.addItem(deltas, round=noRound)
varIdx = (self._outer << 16) + inner
self._cache[deltas] = varIdx
return varIdx
def VarData_addItem(self, deltas, *, round=round):
deltas = [round(d) for d in deltas]
countUs = self.VarRegionCount
countThem = len(deltas)
if countUs + 1 == countThem:
deltas = tuple(deltas[1:])
else:
assert countUs == countThem, (countUs, countThem)
deltas = tuple(deltas)
self.Item.append(list(deltas))
self.ItemCount = len(self.Item)
ot.VarData.addItem = VarData_addItem
def VarRegion_get_support(self, fvar_axes):
return {
fvar_axes[i].axisTag: (reg.StartCoord,reg.PeakCoord,reg.EndCoord)
for i, reg in enumerate(self.VarRegionAxis)
if reg.PeakCoord != 0
}
ot.VarRegion.get_support = VarRegion_get_support
class VarStoreInstancer(object):
def __init__(self, varstore, fvar_axes, location={}):
self.fvar_axes = fvar_axes
assert varstore is None or varstore.Format == 1
self._varData = varstore.VarData if varstore else []
self._regions = varstore.VarRegionList.Region if varstore else []
self.setLocation(location)
def setLocation(self, location):
self.location = dict(location)
self._clearCaches()
def _clearCaches(self):
self._scalars = {}
def _getScalar(self, regionIdx):
scalar = self._scalars.get(regionIdx)
if scalar is None:
support = self._regions[regionIdx].get_support(self.fvar_axes)
scalar = supportScalar(self.location, support)
self._scalars[regionIdx] = scalar
return scalar
@staticmethod
def interpolateFromDeltasAndScalars(deltas, scalars):
delta = 0.
for d,s in zip(deltas, scalars):
if not s: continue
delta += d * s
return delta
def __getitem__(self, varidx):
major, minor = varidx >> 16, varidx & 0xFFFF
varData = self._varData
scalars = [self._getScalar(ri) for ri in varData[major].VarRegionIndex]
deltas = varData[major].Item[minor]
return self.interpolateFromDeltasAndScalars(deltas, scalars)
def interpolateFromDeltas(self, varDataIndex, deltas):
varData = self._varData
scalars = [self._getScalar(ri) for ri in
varData[varDataIndex].VarRegionIndex]
return self.interpolateFromDeltasAndScalars(deltas, scalars)
#
# Optimizations
#
# retainFirstMap - If true, major 0 mappings are retained. Deltas for unused indices are zeroed
# advIdxes - Set of major 0 indices for advance deltas to be listed first. Other major 0 indices follow.
def VarStore_subset_varidxes(self, varIdxes, optimize=True, retainFirstMap=False, advIdxes=set()):
# Sort out used varIdxes by major/minor.
used = {}
for varIdx in varIdxes:
major = varIdx >> 16
minor = varIdx & 0xFFFF
d = used.get(major)
if d is None:
d = used[major] = set()
d.add(minor)
del varIdxes
#
# Subset VarData
#
varData = self.VarData
newVarData = []
varDataMap = {}
for major,data in enumerate(varData):
usedMinors = used.get(major)
if usedMinors is None:
continue
newMajor = len(newVarData)
newVarData.append(data)
items = data.Item
newItems = []
if major == 0 and retainFirstMap:
for minor in range(len(items)):
newItems.append(items[minor] if minor in usedMinors else [0] * len(items[minor]))
varDataMap[minor] = minor
else:
if major == 0:
minors = sorted(advIdxes) + sorted(usedMinors - advIdxes)
else:
minors = sorted(usedMinors)
for minor in minors:
newMinor = len(newItems)
newItems.append(items[minor])
varDataMap[(major<<16)+minor] = (newMajor<<16)+newMinor
data.Item = newItems
data.ItemCount = len(data.Item)
data.calculateNumShorts(optimize=optimize)
self.VarData = newVarData
self.VarDataCount = len(self.VarData)
self.prune_regions()
return varDataMap
ot.VarStore.subset_varidxes = VarStore_subset_varidxes
def VarStore_prune_regions(self):
"""Remove unused VarRegions."""
#
# Subset VarRegionList
#
# Collect.
usedRegions = set()
for data in self.VarData:
usedRegions.update(data.VarRegionIndex)
# Subset.
regionList = self.VarRegionList
regions = regionList.Region
newRegions = []
regionMap = {}
for i in sorted(usedRegions):
regionMap[i] = len(newRegions)
newRegions.append(regions[i])
regionList.Region = newRegions
regionList.RegionCount = len(regionList.Region)
# Map.
for data in self.VarData:
data.VarRegionIndex = [regionMap[i] for i in data.VarRegionIndex]
ot.VarStore.prune_regions = VarStore_prune_regions
def _visit(self, func):
"""Recurse down from self, if type of an object is ot.Device,
call func() on it. Works on otData-style classes."""
if type(self) == ot.Device:
func(self)
elif isinstance(self, list):
for that in self:
_visit(that, func)
elif hasattr(self, 'getConverters') and not hasattr(self, 'postRead'):
for conv in self.getConverters():
that = getattr(self, conv.name, None)
if that is not None:
_visit(that, func)
elif isinstance(self, ot.ValueRecord):
for that in self.__dict__.values():
_visit(that, func)
def _Device_recordVarIdx(self, s):
"""Add VarIdx in this Device table (if any) to the set s."""
if self.DeltaFormat == 0x8000:
s.add((self.StartSize<<16)+self.EndSize)
def Object_collect_device_varidxes(self, varidxes):
adder = partial(_Device_recordVarIdx, s=varidxes)
_visit(self, adder)
ot.GDEF.collect_device_varidxes = Object_collect_device_varidxes
ot.GPOS.collect_device_varidxes = Object_collect_device_varidxes
def _Device_mapVarIdx(self, mapping, done):
"""Map VarIdx in this Device table (if any) through mapping."""
if id(self) in done:
return
done.add(id(self))
if self.DeltaFormat == 0x8000:
varIdx = mapping[(self.StartSize<<16)+self.EndSize]
self.StartSize = varIdx >> 16
self.EndSize = varIdx & 0xFFFF
def Object_remap_device_varidxes(self, varidxes_map):
mapper = partial(_Device_mapVarIdx, mapping=varidxes_map, done=set())
_visit(self, mapper)
ot.GDEF.remap_device_varidxes = Object_remap_device_varidxes
ot.GPOS.remap_device_varidxes = Object_remap_device_varidxes
class _Encoding(object):
def __init__(self, chars):
self.chars = chars
self.width = self._popcount(chars)
self.overhead = self._characteristic_overhead(chars)
self.items = set()
def append(self, row):
self.items.add(row)
def extend(self, lst):
self.items.update(lst)
def get_room(self):
"""Maximum number of bytes that can be added to characteristic
while still being beneficial to merge it into another one."""
count = len(self.items)
return max(0, (self.overhead - 1) // count - self.width)
room = property(get_room)
@property
def gain(self):
"""Maximum possible byte gain from merging this into another
characteristic."""
count = len(self.items)
return max(0, self.overhead - count * (self.width + 1))
def sort_key(self):
return self.width, self.chars
def __len__(self):
return len(self.items)
def can_encode(self, chars):
return not (chars & ~self.chars)
def __sub__(self, other):
return self._popcount(self.chars & ~other.chars)
@staticmethod
def _popcount(n):
# Apparently this is the fastest native way to do it...
# https://stackoverflow.com/a/9831671
return bin(n).count('1')
@staticmethod
def _characteristic_overhead(chars):
"""Returns overhead in bytes of encoding this characteristic
as a VarData."""
c = 6
while chars:
if chars & 3:
c += 2
chars >>= 2
return c
def _find_yourself_best_new_encoding(self, done_by_width):
self.best_new_encoding = None
for new_width in range(self.width+1, self.width+self.room+1):
for new_encoding in done_by_width[new_width]:
if new_encoding.can_encode(self.chars):
break
else:
new_encoding = None
self.best_new_encoding = new_encoding
class _EncodingDict(dict):
def __missing__(self, chars):
r = self[chars] = _Encoding(chars)
return r
def add_row(self, row):
chars = self._row_characteristics(row)
self[chars].append(row)
@staticmethod
def _row_characteristics(row):
"""Returns encoding characteristics for a row."""
chars = 0
i = 1
for v in row:
if v:
chars += i
if not (-128 <= v <= 127):
chars += i * 2
i <<= 2
return chars
def VarStore_optimize(self):
"""Optimize storage. Returns mapping from old VarIdxes to new ones."""
# TODO
# Check that no two VarRegions are the same; if they are, fold them.
n = len(self.VarRegionList.Region) # Number of columns
zeroes = array('h', [0]*n)
front_mapping = {} # Map from old VarIdxes to full row tuples
encodings = _EncodingDict()
# Collect all items into a set of full rows (with lots of zeroes.)
for major,data in enumerate(self.VarData):
regionIndices = data.VarRegionIndex
for minor,item in enumerate(data.Item):
row = array('h', zeroes)
for regionIdx,v in zip(regionIndices, item):
row[regionIdx] += v
row = tuple(row)
encodings.add_row(row)
front_mapping[(major<<16)+minor] = row
# Separate encodings that have no gain (are decided) and those having
# possible gain (possibly to be merged into others.)
encodings = sorted(encodings.values(), key=_Encoding.__len__, reverse=True)
done_by_width = defaultdict(list)
todo = []
for encoding in encodings:
if not encoding.gain:
done_by_width[encoding.width].append(encoding)
else:
todo.append(encoding)
# For each encoding that is possibly to be merged, find the best match
# in the decided encodings, and record that.
todo.sort(key=_Encoding.get_room)
for encoding in todo:
encoding._find_yourself_best_new_encoding(done_by_width)
# Walk through todo encodings, for each, see if merging it with
# another todo encoding gains more than each of them merging with
# their best decided encoding. If yes, merge them and add resulting
# encoding back to todo queue. If not, move the enconding to decided
# list. Repeat till done.
while todo:
encoding = todo.pop()
best_idx = None
best_gain = 0
for i,other_encoding in enumerate(todo):
combined_chars = other_encoding.chars | encoding.chars
combined_width = _Encoding._popcount(combined_chars)
combined_overhead = _Encoding._characteristic_overhead(combined_chars)
combined_gain = (
+ encoding.overhead
+ other_encoding.overhead
- combined_overhead
- (combined_width - encoding.width) * len(encoding)
- (combined_width - other_encoding.width) * len(other_encoding)
)
this_gain = 0 if encoding.best_new_encoding is None else (
+ encoding.overhead
- (encoding.best_new_encoding.width - encoding.width) * len(encoding)
)
other_gain = 0 if other_encoding.best_new_encoding is None else (
+ other_encoding.overhead
- (other_encoding.best_new_encoding.width - other_encoding.width) * len(other_encoding)
)
separate_gain = this_gain + other_gain
if combined_gain > separate_gain:
best_idx = i
best_gain = combined_gain - separate_gain
if best_idx is None:
# Encoding is decided as is
done_by_width[encoding.width].append(encoding)
else:
other_encoding = todo[best_idx]
combined_chars = other_encoding.chars | encoding.chars
combined_encoding = _Encoding(combined_chars)
combined_encoding.extend(encoding.items)
combined_encoding.extend(other_encoding.items)
combined_encoding._find_yourself_best_new_encoding(done_by_width)
del todo[best_idx]
todo.append(combined_encoding)
# Assemble final store.
back_mapping = {} # Mapping from full rows to new VarIdxes
encodings = sum(done_by_width.values(), [])
encodings.sort(key=_Encoding.sort_key)
self.VarData = []
for major,encoding in enumerate(encodings):
data = ot.VarData()
self.VarData.append(data)
data.VarRegionIndex = range(n)
data.VarRegionCount = len(data.VarRegionIndex)
data.Item = sorted(encoding.items)
for minor,item in enumerate(data.Item):
back_mapping[item] = (major<<16)+minor
# Compile final mapping.
varidx_map = {}
for k,v in front_mapping.items():
varidx_map[k] = back_mapping[v]
# Remove unused regions.
self.prune_regions()
# Recalculate things and go home.
self.VarRegionList.RegionCount = len(self.VarRegionList.Region)
self.VarDataCount = len(self.VarData)
for data in self.VarData:
data.ItemCount = len(data.Item)
data.optimize()
return varidx_map
ot.VarStore.optimize = VarStore_optimize
def main(args=None):
"""Optimize a font's GDEF variation store"""
from argparse import ArgumentParser
from fontTools import configLogger
from fontTools.ttLib import TTFont
from fontTools.ttLib.tables.otBase import OTTableWriter
parser = ArgumentParser(prog='varLib.varStore', description= main.__doc__)
parser.add_argument('fontfile')
parser.add_argument('outfile', nargs='?')
options = parser.parse_args(args)
# TODO: allow user to configure logging via command-line options
configLogger(level="INFO")
fontfile = options.fontfile
outfile = options.outfile
font = TTFont(fontfile)
gdef = font['GDEF']
store = gdef.table.VarStore
writer = OTTableWriter()
store.compile(writer, font)
size = len(writer.getAllData())
print("Before: %7d bytes" % size)
varidx_map = store.optimize()
gdef.table.remap_device_varidxes(varidx_map)
if 'GPOS' in font:
font['GPOS'].table.remap_device_varidxes(varidx_map)
writer = OTTableWriter()
store.compile(writer, font)
size = len(writer.getAllData())
print("After: %7d bytes" % size)
if outfile is not None:
font.save(outfile)
if __name__ == "__main__":
import sys
if len(sys.argv) > 1:
sys.exit(main())
import doctest
sys.exit(doctest.testmod().failed)