"""
Instantiate a variation font. Run, eg:
$ fonttools varLib.mutator ./NotoSansArabic-VF.ttf wght=140 wdth=85
"""
from fontTools.misc.fixedTools import floatToFixedToFloat, floatToFixed
from fontTools.misc.roundTools import otRound
from fontTools.pens.boundsPen import BoundsPen
from fontTools.ttLib import TTFont, newTable
from fontTools.ttLib.tables import ttProgram
from fontTools.ttLib.tables._g_l_y_f import (
GlyphCoordinates,
flagOverlapSimple,
OVERLAP_COMPOUND,
)
from fontTools.varLib.models import (
supportScalar,
normalizeLocation,
piecewiseLinearMap,
)
from fontTools.varLib.merger import MutatorMerger
from fontTools.varLib.varStore import VarStoreInstancer
from fontTools.varLib.mvar import MVAR_ENTRIES
from fontTools.varLib.iup import iup_delta
import fontTools.subset.cff
import os.path
import logging
from io import BytesIO
log = logging.getLogger("fontTools.varlib.mutator")
# map 'wdth' axis (1..200) to OS/2.usWidthClass (1..9), rounding to closest
OS2_WIDTH_CLASS_VALUES = {}
percents = [50.0, 62.5, 75.0, 87.5, 100.0, 112.5, 125.0, 150.0, 200.0]
for i, (prev, curr) in enumerate(zip(percents[:-1], percents[1:]), start=1):
half = (prev + curr) / 2
OS2_WIDTH_CLASS_VALUES[half] = i
[docs]
def interpolate_cff2_PrivateDict(topDict, interpolateFromDeltas):
pd_blend_lists = (
"BlueValues",
"OtherBlues",
"FamilyBlues",
"FamilyOtherBlues",
"StemSnapH",
"StemSnapV",
)
pd_blend_values = ("BlueScale", "BlueShift", "BlueFuzz", "StdHW", "StdVW")
for fontDict in topDict.FDArray:
pd = fontDict.Private
vsindex = pd.vsindex if (hasattr(pd, "vsindex")) else 0
for key, value in pd.rawDict.items():
if (key in pd_blend_values) and isinstance(value, list):
delta = interpolateFromDeltas(vsindex, value[1:])
pd.rawDict[key] = otRound(value[0] + delta)
elif (key in pd_blend_lists) and isinstance(value[0], list):
"""If any argument in a BlueValues list is a blend list,
then they all are. The first value of each list is an
absolute value. The delta tuples are calculated from
relative master values, hence we need to append all the
deltas to date to each successive absolute value."""
delta = 0
for i, val_list in enumerate(value):
delta += otRound(interpolateFromDeltas(vsindex, val_list[1:]))
value[i] = val_list[0] + delta
[docs]
def interpolate_cff2_charstrings(topDict, interpolateFromDeltas, glyphOrder):
charstrings = topDict.CharStrings
for gname in glyphOrder:
# Interpolate charstring
# e.g replace blend op args with regular args,
# and use and discard vsindex op.
charstring = charstrings[gname]
new_program = []
vsindex = 0
last_i = 0
for i, token in enumerate(charstring.program):
if token == "vsindex":
vsindex = charstring.program[i - 1]
if last_i != 0:
new_program.extend(charstring.program[last_i : i - 1])
last_i = i + 1
elif token == "blend":
num_regions = charstring.getNumRegions(vsindex)
numMasters = 1 + num_regions
num_args = charstring.program[i - 1]
# The program list starting at program[i] is now:
# ..args for following operations
# num_args values from the default font
# num_args tuples, each with numMasters-1 delta values
# num_blend_args
# 'blend'
argi = i - (num_args * numMasters + 1)
end_args = tuplei = argi + num_args
while argi < end_args:
next_ti = tuplei + num_regions
deltas = charstring.program[tuplei:next_ti]
delta = interpolateFromDeltas(vsindex, deltas)
charstring.program[argi] += otRound(delta)
tuplei = next_ti
argi += 1
new_program.extend(charstring.program[last_i:end_args])
last_i = i + 1
if last_i != 0:
new_program.extend(charstring.program[last_i:])
charstring.program = new_program
[docs]
def interpolate_cff2_metrics(varfont, topDict, glyphOrder, loc):
"""Unlike TrueType glyphs, neither advance width nor bounding box
info is stored in a CFF2 charstring. The width data exists only in
the hmtx and HVAR tables. Since LSB data cannot be interpolated
reliably from the master LSB values in the hmtx table, we traverse
the charstring to determine the actual bound box."""
charstrings = topDict.CharStrings
boundsPen = BoundsPen(glyphOrder)
hmtx = varfont["hmtx"]
hvar_table = None
if "HVAR" in varfont:
hvar_table = varfont["HVAR"].table
fvar = varfont["fvar"]
varStoreInstancer = VarStoreInstancer(hvar_table.VarStore, fvar.axes, loc)
for gid, gname in enumerate(glyphOrder):
entry = list(hmtx[gname])
# get width delta.
if hvar_table:
if hvar_table.AdvWidthMap:
width_idx = hvar_table.AdvWidthMap.mapping[gname]
else:
width_idx = gid
width_delta = otRound(varStoreInstancer[width_idx])
else:
width_delta = 0
# get LSB.
boundsPen.init()
charstring = charstrings[gname]
charstring.draw(boundsPen)
if boundsPen.bounds is None:
# Happens with non-marking glyphs
lsb_delta = 0
else:
lsb = otRound(boundsPen.bounds[0])
lsb_delta = entry[1] - lsb
if lsb_delta or width_delta:
if width_delta:
entry[0] = max(0, entry[0] + width_delta)
if lsb_delta:
entry[1] = lsb
hmtx[gname] = tuple(entry)
[docs]
def instantiateVariableFont(varfont, location, inplace=False, overlap=True):
"""Generate a static instance from a variable TTFont and a dictionary
defining the desired location along the variable font's axes.
The location values must be specified as user-space coordinates, e.g.:
{'wght': 400, 'wdth': 100}
By default, a new TTFont object is returned. If ``inplace`` is True, the
input varfont is modified and reduced to a static font.
When the overlap parameter is defined as True,
OVERLAP_SIMPLE and OVERLAP_COMPOUND bits are set to 1. See
https://docs.microsoft.com/en-us/typography/opentype/spec/glyf
"""
if not inplace:
# make a copy to leave input varfont unmodified
stream = BytesIO()
varfont.save(stream)
stream.seek(0)
varfont = TTFont(stream)
fvar = varfont["fvar"]
axes = {a.axisTag: (a.minValue, a.defaultValue, a.maxValue) for a in fvar.axes}
loc = normalizeLocation(location, axes)
if "avar" in varfont:
maps = varfont["avar"].segments
loc = {k: piecewiseLinearMap(v, maps[k]) for k, v in loc.items()}
# Quantize to F2Dot14, to avoid surprise interpolations.
loc = {k: floatToFixedToFloat(v, 14) for k, v in loc.items()}
# Location is normalized now
log.info("Normalized location: %s", loc)
if "gvar" in varfont:
log.info("Mutating glyf/gvar tables")
gvar = varfont["gvar"]
glyf = varfont["glyf"]
hMetrics = varfont["hmtx"].metrics
vMetrics = getattr(varfont.get("vmtx"), "metrics", None)
# get list of glyph names in gvar sorted by component depth
glyphnames = sorted(
gvar.variations.keys(),
key=lambda name: (
(
glyf[name].getCompositeMaxpValues(glyf).maxComponentDepth
if glyf[name].isComposite() or glyf[name].isVarComposite()
else 0
),
name,
),
)
for glyphname in glyphnames:
variations = gvar.variations[glyphname]
coordinates, _ = glyf._getCoordinatesAndControls(
glyphname, hMetrics, vMetrics
)
origCoords, endPts = None, None
for var in variations:
scalar = supportScalar(loc, var.axes)
if not scalar:
continue
delta = var.coordinates
if None in delta:
if origCoords is None:
origCoords, g = glyf._getCoordinatesAndControls(
glyphname, hMetrics, vMetrics
)
delta = iup_delta(delta, origCoords, g.endPts)
coordinates += GlyphCoordinates(delta) * scalar
glyf._setCoordinates(glyphname, coordinates, hMetrics, vMetrics)
else:
glyf = None
if "DSIG" in varfont:
del varfont["DSIG"]
if "cvar" in varfont:
log.info("Mutating cvt/cvar tables")
cvar = varfont["cvar"]
cvt = varfont["cvt "]
deltas = {}
for var in cvar.variations:
scalar = supportScalar(loc, var.axes)
if not scalar:
continue
for i, c in enumerate(var.coordinates):
if c is not None:
deltas[i] = deltas.get(i, 0) + scalar * c
for i, delta in deltas.items():
cvt[i] += otRound(delta)
if "CFF2" in varfont:
log.info("Mutating CFF2 table")
glyphOrder = varfont.getGlyphOrder()
CFF2 = varfont["CFF2"]
topDict = CFF2.cff.topDictIndex[0]
vsInstancer = VarStoreInstancer(topDict.VarStore.otVarStore, fvar.axes, loc)
interpolateFromDeltas = vsInstancer.interpolateFromDeltas
interpolate_cff2_PrivateDict(topDict, interpolateFromDeltas)
CFF2.desubroutinize()
interpolate_cff2_charstrings(topDict, interpolateFromDeltas, glyphOrder)
interpolate_cff2_metrics(varfont, topDict, glyphOrder, loc)
del topDict.rawDict["VarStore"]
del topDict.VarStore
if "MVAR" in varfont:
log.info("Mutating MVAR table")
mvar = varfont["MVAR"].table
varStoreInstancer = VarStoreInstancer(mvar.VarStore, fvar.axes, loc)
records = mvar.ValueRecord
for rec in records:
mvarTag = rec.ValueTag
if mvarTag not in MVAR_ENTRIES:
continue
tableTag, itemName = MVAR_ENTRIES[mvarTag]
delta = otRound(varStoreInstancer[rec.VarIdx])
if not delta:
continue
setattr(
varfont[tableTag],
itemName,
getattr(varfont[tableTag], itemName) + delta,
)
log.info("Mutating FeatureVariations")
for tableTag in "GSUB", "GPOS":
if not tableTag in varfont:
continue
table = varfont[tableTag].table
if not getattr(table, "FeatureVariations", None):
continue
variations = table.FeatureVariations
for record in variations.FeatureVariationRecord:
applies = True
for condition in record.ConditionSet.ConditionTable:
if condition.Format == 1:
axisIdx = condition.AxisIndex
axisTag = fvar.axes[axisIdx].axisTag
Min = condition.FilterRangeMinValue
Max = condition.FilterRangeMaxValue
v = loc[axisTag]
if not (Min <= v <= Max):
applies = False
else:
applies = False
if not applies:
break
if applies:
assert record.FeatureTableSubstitution.Version == 0x00010000
for rec in record.FeatureTableSubstitution.SubstitutionRecord:
table.FeatureList.FeatureRecord[rec.FeatureIndex].Feature = (
rec.Feature
)
break
del table.FeatureVariations
if "GDEF" in varfont and varfont["GDEF"].table.Version >= 0x00010003:
log.info("Mutating GDEF/GPOS/GSUB tables")
gdef = varfont["GDEF"].table
instancer = VarStoreInstancer(gdef.VarStore, fvar.axes, loc)
merger = MutatorMerger(varfont, instancer)
merger.mergeTables(varfont, [varfont], ["GDEF", "GPOS"])
# Downgrade GDEF.
del gdef.VarStore
gdef.Version = 0x00010002
if gdef.MarkGlyphSetsDef is None:
del gdef.MarkGlyphSetsDef
gdef.Version = 0x00010000
if not (
gdef.LigCaretList
or gdef.MarkAttachClassDef
or gdef.GlyphClassDef
or gdef.AttachList
or (gdef.Version >= 0x00010002 and gdef.MarkGlyphSetsDef)
):
del varfont["GDEF"]
addidef = False
if glyf:
for glyph in glyf.glyphs.values():
if hasattr(glyph, "program"):
instructions = glyph.program.getAssembly()
# If GETVARIATION opcode is used in bytecode of any glyph add IDEF
addidef = any(op.startswith("GETVARIATION") for op in instructions)
if addidef:
break
if overlap:
for glyph_name in glyf.keys():
glyph = glyf[glyph_name]
# Set OVERLAP_COMPOUND bit for compound glyphs
if glyph.isComposite():
glyph.components[0].flags |= OVERLAP_COMPOUND
# Set OVERLAP_SIMPLE bit for simple glyphs
elif glyph.numberOfContours > 0:
glyph.flags[0] |= flagOverlapSimple
if addidef:
log.info("Adding IDEF to fpgm table for GETVARIATION opcode")
asm = []
if "fpgm" in varfont:
fpgm = varfont["fpgm"]
asm = fpgm.program.getAssembly()
else:
fpgm = newTable("fpgm")
fpgm.program = ttProgram.Program()
varfont["fpgm"] = fpgm
asm.append("PUSHB[000] 145")
asm.append("IDEF[ ]")
args = [str(len(loc))]
for a in fvar.axes:
args.append(str(floatToFixed(loc[a.axisTag], 14)))
asm.append("NPUSHW[ ] " + " ".join(args))
asm.append("ENDF[ ]")
fpgm.program.fromAssembly(asm)
# Change maxp attributes as IDEF is added
if "maxp" in varfont:
maxp = varfont["maxp"]
setattr(
maxp, "maxInstructionDefs", 1 + getattr(maxp, "maxInstructionDefs", 0)
)
setattr(
maxp,
"maxStackElements",
max(len(loc), getattr(maxp, "maxStackElements", 0)),
)
if "name" in varfont:
log.info("Pruning name table")
exclude = {a.axisNameID for a in fvar.axes}
for i in fvar.instances:
exclude.add(i.subfamilyNameID)
exclude.add(i.postscriptNameID)
if "ltag" in varfont:
# Drop the whole 'ltag' table if all its language tags are referenced by
# name records to be pruned.
# TODO: prune unused ltag tags and re-enumerate langIDs accordingly
excludedUnicodeLangIDs = [
n.langID
for n in varfont["name"].names
if n.nameID in exclude and n.platformID == 0 and n.langID != 0xFFFF
]
if set(excludedUnicodeLangIDs) == set(range(len((varfont["ltag"].tags)))):
del varfont["ltag"]
varfont["name"].names[:] = [
n for n in varfont["name"].names if n.nameID not in exclude
]
if "wght" in location and "OS/2" in varfont:
varfont["OS/2"].usWeightClass = otRound(max(1, min(location["wght"], 1000)))
if "wdth" in location:
wdth = location["wdth"]
for percent, widthClass in sorted(OS2_WIDTH_CLASS_VALUES.items()):
if wdth < percent:
varfont["OS/2"].usWidthClass = widthClass
break
else:
varfont["OS/2"].usWidthClass = 9
if "slnt" in location and "post" in varfont:
varfont["post"].italicAngle = max(-90, min(location["slnt"], 90))
log.info("Removing variable tables")
for tag in ("avar", "cvar", "fvar", "gvar", "HVAR", "MVAR", "VVAR", "STAT"):
if tag in varfont:
del varfont[tag]
return varfont
[docs]
def main(args=None):
"""Instantiate a variation font"""
from fontTools import configLogger
import argparse
parser = argparse.ArgumentParser(
"fonttools varLib.mutator", description="Instantiate a variable font"
)
parser.add_argument("input", metavar="INPUT.ttf", help="Input variable TTF file.")
parser.add_argument(
"locargs",
metavar="AXIS=LOC",
nargs="*",
help="List of space separated locations. A location consist in "
"the name of a variation axis, followed by '=' and a number. E.g.: "
" wght=700 wdth=80. The default is the location of the base master.",
)
parser.add_argument(
"-o",
"--output",
metavar="OUTPUT.ttf",
default=None,
help="Output instance TTF file (default: INPUT-instance.ttf).",
)
parser.add_argument(
"--no-recalc-timestamp",
dest="recalc_timestamp",
action="store_false",
help="Don't set the output font's timestamp to the current time.",
)
logging_group = parser.add_mutually_exclusive_group(required=False)
logging_group.add_argument(
"-v", "--verbose", action="store_true", help="Run more verbosely."
)
logging_group.add_argument(
"-q", "--quiet", action="store_true", help="Turn verbosity off."
)
parser.add_argument(
"--no-overlap",
dest="overlap",
action="store_false",
help="Don't set OVERLAP_SIMPLE/OVERLAP_COMPOUND glyf flags.",
)
options = parser.parse_args(args)
varfilename = options.input
outfile = (
os.path.splitext(varfilename)[0] + "-instance.ttf"
if not options.output
else options.output
)
configLogger(
level=("DEBUG" if options.verbose else "ERROR" if options.quiet else "INFO")
)
loc = {}
for arg in options.locargs:
try:
tag, val = arg.split("=")
assert len(tag) <= 4
loc[tag.ljust(4)] = float(val)
except (ValueError, AssertionError):
parser.error("invalid location argument format: %r" % arg)
log.info("Location: %s", loc)
log.info("Loading variable font")
varfont = TTFont(varfilename, recalcTimestamp=options.recalc_timestamp)
instantiateVariableFont(varfont, loc, inplace=True, overlap=options.overlap)
log.info("Saving instance font %s", outfile)
varfont.save(outfile)
if __name__ == "__main__":
import sys
if len(sys.argv) > 1:
sys.exit(main())
import doctest
sys.exit(doctest.testmod().failed)