Source code for fontTools.varLib.mutator

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 (
from fontTools.varLib.models import (
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
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 """ if not inplace: # make a copy to leave input varfont unmodified stream = BytesIO() 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"Normalized location: %s", loc) if "gvar" in varfont:"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:"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:"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:"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, )"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:"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:"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:"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))"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)"Location: %s", loc)"Loading variable font") varfont = TTFont(varfilename, recalcTimestamp=options.recalc_timestamp) instantiateVariableFont(varfont, loc, inplace=True, overlap=options.overlap)"Saving instance font %s", outfile)
if __name__ == "__main__": import sys if len(sys.argv) > 1: sys.exit(main()) import doctest sys.exit(doctest.testmod().failed)