""" Partially instantiate a variable font. The module exports an `instantiateVariableFont` function and CLI that allow to create full instances (i.e. static fonts) from variable fonts, as well as "partial" variable fonts that only contain a subset of the original variation space. For example, if you wish to pin the width axis to a given location while also restricting the weight axis to 400..700 range, you can do:: $ fonttools varLib.instancer ./NotoSans-VF.ttf wdth=85 wght=400:700 See `fonttools varLib.instancer --help` for more info on the CLI options. The module's entry point is the `instantiateVariableFont` function, which takes a TTFont object and a dict specifying either axis coodinates or (min, max) ranges, and returns a new TTFont representing either a partial VF, or full instance if all the VF axes were given an explicit coordinate. E.g. here's how to pin the wght axis at a given location in a wght+wdth variable font, keeping only the deltas associated with the wdth axis:: | >>> from fontTools import ttLib | >>> from fontTools.varLib import instancer | >>> varfont = ttLib.TTFont("path/to/MyVariableFont.ttf") | >>> [a.axisTag for a in varfont["fvar"].axes] # the varfont's current axes | ['wght', 'wdth'] | >>> partial = instancer.instantiateVariableFont(varfont, {"wght": 300}) | >>> [a.axisTag for a in partial["fvar"].axes] # axes left after pinning 'wght' | ['wdth'] If the input location specifies all the axes, the resulting instance is no longer 'variable' (same as using fontools varLib.mutator): | >>> instance = instancer.instantiateVariableFont( | ... varfont, {"wght": 700, "wdth": 67.5} | ... ) | >>> "fvar" not in instance | True If one just want to drop an axis at the default location, without knowing in advance what the default value for that axis is, one can pass a `None` value: | >>> instance = instancer.instantiateVariableFont(varfont, {"wght": None}) | >>> len(varfont["fvar"].axes) | 1 From the console script, this is equivalent to passing `wght=drop` as input. This module is similar to fontTools.varLib.mutator, which it's intended to supersede. Note that, unlike varLib.mutator, when an axis is not mentioned in the input location, the varLib.instancer will keep the axis and the corresponding deltas, whereas mutator implicitly drops the axis at its default coordinate. The module supports all the following "levels" of instancing, which can of course be combined: L1 dropping one or more axes while leaving the default tables unmodified; | >>> font = instancer.instantiateVariableFont(varfont, {"wght": None}) L2 dropping one or more axes while pinning them at non-default locations; | >>> font = instancer.instantiateVariableFont(varfont, {"wght": 700}) L3 restricting the range of variation of one or more axes, by setting either a new minimum or maximum, potentially -- though not necessarily -- dropping entire regions of variations that fall completely outside this new range. | >>> font = instancer.instantiateVariableFont(varfont, {"wght": (100, 300)}) L4 moving the default location of an axis, by specifying (min,defalt,max) values: | >>> font = instancer.instantiateVariableFont(varfont, {"wght": (100, 300, 700)}) Currently only TrueType-flavored variable fonts (i.e. containing 'glyf' table) are supported, but support for CFF2 variable fonts will be added soon. The discussion and implementation of these features are tracked at https://github.com/fonttools/fonttools/issues/1537 """ from fontTools.misc.fixedTools import ( floatToFixedToFloat, strToFixedToFloat, otRound, ) from fontTools.varLib.models import normalizeValue, piecewiseLinearMap from fontTools.ttLib import TTFont from fontTools.ttLib.tables.TupleVariation import TupleVariation from fontTools.ttLib.tables import _g_l_y_f from fontTools import varLib # we import the `subset` module because we use the `prune_lookups` method on the GSUB # table class, and that method is only defined dynamically upon importing `subset` from fontTools import subset # noqa: F401 from fontTools.varLib import builder from fontTools.varLib.mvar import MVAR_ENTRIES from fontTools.varLib.merger import MutatorMerger from fontTools.varLib.instancer import names from .featureVars import instantiateFeatureVariations from fontTools.misc.cliTools import makeOutputFileName from fontTools.varLib.instancer import solver import collections import dataclasses from contextlib import contextmanager from copy import deepcopy from enum import IntEnum import logging import os import re from typing import Dict, Iterable, Mapping, Optional, Sequence, Tuple, Union import warnings log = logging.getLogger("fontTools.varLib.instancer") def AxisRange(minimum, maximum): warnings.warn( "AxisRange is deprecated; use AxisTriple instead", DeprecationWarning, stacklevel=2, ) return AxisTriple(minimum, None, maximum) def NormalizedAxisRange(minimum, maximum): warnings.warn( "NormalizedAxisRange is deprecated; use AxisTriple instead", DeprecationWarning, stacklevel=2, ) return NormalizedAxisTriple(minimum, None, maximum) @dataclasses.dataclass(frozen=True, order=True, repr=False) class AxisTriple(Sequence): """A triple of (min, default, max) axis values. Any of the values can be None, in which case the limitRangeAndPopulateDefaults() method can be used to fill in the missing values based on the fvar axis values. """ minimum: Optional[float] default: Optional[float] maximum: Optional[float] def __post_init__(self): if self.default is None and self.minimum == self.maximum: object.__setattr__(self, "default", self.minimum) if ( ( self.minimum is not None and self.default is not None and self.minimum > self.default ) or ( self.default is not None and self.maximum is not None and self.default > self.maximum ) or ( self.minimum is not None and self.maximum is not None and self.minimum > self.maximum ) ): raise ValueError( f"{type(self).__name__} minimum ({self.minimum}), default ({self.default}), maximum ({self.maximum}) must be in sorted order" ) def __getitem__(self, i): fields = dataclasses.fields(self) return getattr(self, fields[i].name) def __len__(self): return len(dataclasses.fields(self)) def _replace(self, **kwargs): return dataclasses.replace(self, **kwargs) def __repr__(self): return ( f"({', '.join(format(v, 'g') if v is not None else 'None' for v in self)})" ) @classmethod def expand( cls, v: Union[ "AxisTriple", float, # pin axis at single value, same as min==default==max Tuple[float, float], # (min, max), restrict axis and keep default Tuple[float, float, float], # (min, default, max) ], ) -> "AxisTriple": """Convert a single value or a tuple into an AxisTriple. If the input is a single value, it is interpreted as a pin at that value. If the input is a tuple, it is interpreted as (min, max) or (min, default, max). """ if isinstance(v, cls): return v if isinstance(v, (int, float)): return cls(v, v, v) try: n = len(v) except TypeError as e: raise ValueError( f"expected float, 2- or 3-tuple of floats; got {type(v)}: {v!r}" ) from e default = None if n == 2: minimum, maximum = v elif n >= 3: return cls(*v) else: raise ValueError(f"expected sequence of 2 or 3; got {n}: {v!r}") return cls(minimum, default, maximum) def limitRangeAndPopulateDefaults(self, fvarTriple) -> "AxisTriple": """Return a new AxisTriple with the default value filled in. Set default to fvar axis default if the latter is within the min/max range, otherwise set default to the min or max value, whichever is closer to the fvar axis default. If the default value is already set, return self. """ minimum = self.minimum if minimum is None: minimum = fvarTriple[0] default = self.default if default is None: default = fvarTriple[1] maximum = self.maximum if maximum is None: maximum = fvarTriple[2] minimum = max(minimum, fvarTriple[0]) maximum = max(maximum, fvarTriple[0]) minimum = min(minimum, fvarTriple[2]) maximum = min(maximum, fvarTriple[2]) default = max(minimum, min(maximum, default)) return AxisTriple(minimum, default, maximum) @dataclasses.dataclass(frozen=True, order=True, repr=False) class NormalizedAxisTriple(AxisTriple): """A triple of (min, default, max) normalized axis values.""" minimum: float default: float maximum: float def __post_init__(self): if self.default is None: object.__setattr__(self, "default", max(self.minimum, min(self.maximum, 0))) if not (-1.0 <= self.minimum <= self.default <= self.maximum <= 1.0): raise ValueError( "Normalized axis values not in -1..+1 range; got " f"minimum={self.minimum:g}, default={self.default:g}, maximum={self.maximum:g})" ) @dataclasses.dataclass(frozen=True, order=True, repr=False) class NormalizedAxisTripleAndDistances(AxisTriple): """A triple of (min, default, max) normalized axis values, with distances between min and default, and default and max, in the *pre-normalized* space.""" minimum: float default: float maximum: float distanceNegative: Optional[float] = 1 distancePositive: Optional[float] = 1 def __post_init__(self): if self.default is None: object.__setattr__(self, "default", max(self.minimum, min(self.maximum, 0))) if not (-1.0 <= self.minimum <= self.default <= self.maximum <= 1.0): raise ValueError( "Normalized axis values not in -1..+1 range; got " f"minimum={self.minimum:g}, default={self.default:g}, maximum={self.maximum:g})" ) def reverse_negate(self): v = self return self.__class__(-v[2], -v[1], -v[0], v[4], v[3]) def renormalizeValue(self, v, extrapolate=True): """Renormalizes a normalized value v to the range of this axis, considering the pre-normalized distances as well as the new axis limits.""" lower, default, upper, distanceNegative, distancePositive = self assert lower <= default <= upper if not extrapolate: v = max(lower, min(upper, v)) if v == default: return 0 if default < 0: return -self.reverse_negate().renormalizeValue(-v, extrapolate=extrapolate) # default >= 0 and v != default if v > default: return (v - default) / (upper - default) # v < default if lower >= 0: return (v - default) / (default - lower) # lower < 0 and v < default totalDistance = distanceNegative * -lower + distancePositive * default if v >= 0: vDistance = (default - v) * distancePositive else: vDistance = -v * distanceNegative + distancePositive * default return -vDistance / totalDistance class _BaseAxisLimits(Mapping[str, AxisTriple]): def __getitem__(self, key: str) -> AxisTriple: return self._data[key] def __iter__(self) -> Iterable[str]: return iter(self._data) def __len__(self) -> int: return len(self._data) def __repr__(self) -> str: return f"{type(self).__name__}({self._data!r})" def __str__(self) -> str: return str(self._data) def defaultLocation(self) -> Dict[str, float]: """Return a dict of default axis values.""" return {k: v.default for k, v in self.items()} def pinnedLocation(self) -> Dict[str, float]: """Return a location dict with only the pinned axes.""" return {k: v.default for k, v in self.items() if v.minimum == v.maximum} class AxisLimits(_BaseAxisLimits): """Maps axis tags (str) to AxisTriple values.""" def __init__(self, *args, **kwargs): self._data = data = {} for k, v in dict(*args, **kwargs).items(): if v is None: # will be filled in by limitAxesAndPopulateDefaults data[k] = v else: try: triple = AxisTriple.expand(v) except ValueError as e: raise ValueError(f"Invalid axis limits for {k!r}: {v!r}") from e data[k] = triple def limitAxesAndPopulateDefaults(self, varfont) -> "AxisLimits": """Return a new AxisLimits with defaults filled in from fvar table. If all axis limits already have defaults, return self. """ fvar = varfont["fvar"] fvarTriples = { a.axisTag: (a.minValue, a.defaultValue, a.maxValue) for a in fvar.axes } newLimits = {} for axisTag, triple in self.items(): fvarTriple = fvarTriples[axisTag] default = fvarTriple[1] if triple is None: newLimits[axisTag] = AxisTriple(default, default, default) else: newLimits[axisTag] = triple.limitRangeAndPopulateDefaults(fvarTriple) return type(self)(newLimits) def normalize(self, varfont, usingAvar=True) -> "NormalizedAxisLimits": """Return a new NormalizedAxisLimits with normalized -1..0..+1 values. If usingAvar is True, the avar table is used to warp the default normalization. """ fvar = varfont["fvar"] badLimits = set(self.keys()).difference(a.axisTag for a in fvar.axes) if badLimits: raise ValueError("Cannot limit: {} not present in fvar".format(badLimits)) axes = { a.axisTag: (a.minValue, a.defaultValue, a.maxValue) for a in fvar.axes if a.axisTag in self } avarSegments = {} if usingAvar and "avar" in varfont: avarSegments = varfont["avar"].segments normalizedLimits = {} for axis_tag, triple in axes.items(): distanceNegative = triple[1] - triple[0] distancePositive = triple[2] - triple[1] if self[axis_tag] is None: normalizedLimits[axis_tag] = NormalizedAxisTripleAndDistances( 0, 0, 0, distanceNegative, distancePositive ) continue minV, defaultV, maxV = self[axis_tag] if defaultV is None: defaultV = triple[1] avarMapping = avarSegments.get(axis_tag, None) normalizedLimits[axis_tag] = NormalizedAxisTripleAndDistances( *(normalize(v, triple, avarMapping) for v in (minV, defaultV, maxV)), distanceNegative, distancePositive, ) return NormalizedAxisLimits(normalizedLimits) class NormalizedAxisLimits(_BaseAxisLimits): """Maps axis tags (str) to NormalizedAxisTriple values.""" def __init__(self, *args, **kwargs): self._data = data = {} for k, v in dict(*args, **kwargs).items(): try: triple = NormalizedAxisTripleAndDistances.expand(v) except ValueError as e: raise ValueError(f"Invalid axis limits for {k!r}: {v!r}") from e data[k] = triple class OverlapMode(IntEnum): KEEP_AND_DONT_SET_FLAGS = 0 KEEP_AND_SET_FLAGS = 1 REMOVE = 2 REMOVE_AND_IGNORE_ERRORS = 3 def instantiateTupleVariationStore( variations, axisLimits, origCoords=None, endPts=None ): """Instantiate TupleVariation list at the given location, or limit axes' min/max. The 'variations' list of TupleVariation objects is modified in-place. The 'axisLimits' (dict) maps axis tags (str) to NormalizedAxisTriple namedtuples specifying (minimum, default, maximum) in the -1,0,+1 normalized space. Pinned axes have minimum == default == maximum. A 'full' instance (i.e. static font) is produced when all the axes are pinned to single coordinates; a 'partial' instance (i.e. a less variable font) is produced when some of the axes are omitted, or restricted with a new range. Tuples that do not participate are kept as they are. Those that have 0 influence at the given location are removed from the variation store. Those that are fully instantiated (i.e. all their axes are being pinned) are also removed from the variation store, their scaled deltas accummulated and returned, so that they can be added by the caller to the default instance's coordinates. Tuples that are only partially instantiated (i.e. not all the axes that they participate in are being pinned) are kept in the store, and their deltas multiplied by the scalar support of the axes to be pinned at the desired location. Args: variations: List[TupleVariation] from either 'gvar' or 'cvar'. axisLimits: NormalizedAxisLimits: map from axis tags to (min, default, max) normalized coordinates for the full or partial instance. origCoords: GlyphCoordinates: default instance's coordinates for computing 'gvar' inferred points (cf. table__g_l_y_f._getCoordinatesAndControls). endPts: List[int]: indices of contour end points, for inferring 'gvar' deltas. Returns: List[float]: the overall delta adjustment after applicable deltas were summed. """ newVariations = changeTupleVariationsAxisLimits(variations, axisLimits) mergedVariations = collections.OrderedDict() for var in newVariations: # compute inferred deltas only for gvar ('origCoords' is None for cvar) if origCoords is not None: var.calcInferredDeltas(origCoords, endPts) # merge TupleVariations with overlapping "tents" axes = frozenset(var.axes.items()) if axes in mergedVariations: mergedVariations[axes] += var else: mergedVariations[axes] = var # drop TupleVariation if all axes have been pinned (var.axes.items() is empty); # its deltas will be added to the default instance's coordinates defaultVar = mergedVariations.pop(frozenset(), None) for var in mergedVariations.values(): var.roundDeltas() variations[:] = list(mergedVariations.values()) return defaultVar.coordinates if defaultVar is not None else [] def changeTupleVariationsAxisLimits(variations, axisLimits): for axisTag, axisLimit in sorted(axisLimits.items()): newVariations = [] for var in variations: newVariations.extend(changeTupleVariationAxisLimit(var, axisTag, axisLimit)) variations = newVariations return variations def changeTupleVariationAxisLimit(var, axisTag, axisLimit): assert isinstance(axisLimit, NormalizedAxisTripleAndDistances) # Skip when current axis is missing (i.e. doesn't participate), lower, peak, upper = var.axes.get(axisTag, (-1, 0, 1)) if peak == 0: return [var] # Drop if the var 'tent' isn't well-formed if not (lower <= peak <= upper) or (lower < 0 and upper > 0): return [] if axisTag not in var.axes: return [var] tent = var.axes[axisTag] solutions = solver.rebaseTent(tent, axisLimit) out = [] for scalar, tent in solutions: newVar = ( TupleVariation(var.axes, var.coordinates) if len(solutions) > 1 else var ) if tent is None: newVar.axes.pop(axisTag) else: assert tent[1] != 0, tent newVar.axes[axisTag] = tent newVar *= scalar out.append(newVar) return out def _instantiateGvarGlyph( glyphname, glyf, gvar, hMetrics, vMetrics, axisLimits, optimize=True ): coordinates, ctrl = glyf._getCoordinatesAndControls(glyphname, hMetrics, vMetrics) endPts = ctrl.endPts # Not every glyph may have variations tupleVarStore = gvar.variations.get(glyphname) if tupleVarStore: defaultDeltas = instantiateTupleVariationStore( tupleVarStore, axisLimits, coordinates, endPts ) if defaultDeltas: coordinates += _g_l_y_f.GlyphCoordinates(defaultDeltas) glyph = glyf[glyphname] if glyph.isVarComposite(): for component in glyph.components: newLocation = {} for tag, loc in component.location.items(): if tag not in axisLimits: newLocation[tag] = loc continue if component.flags & _g_l_y_f.VarComponentFlags.AXES_HAVE_VARIATION: raise NotImplementedError( "Instancing accross VarComposite axes with variation is not supported." ) limits = axisLimits[tag] loc = limits.renormalizeValue(loc, extrapolate=False) newLocation[tag] = loc component.location = newLocation # _setCoordinates also sets the hmtx/vmtx advance widths and sidebearings from # the four phantom points and glyph bounding boxes. # We call it unconditionally even if a glyph has no variations or no deltas are # applied at this location, in case the glyph's xMin and in turn its sidebearing # have changed. E.g. a composite glyph has no deltas for the component's (x, y) # offset nor for the 4 phantom points (e.g. it's monospaced). Thus its entry in # gvar table is empty; however, the composite's base glyph may have deltas # applied, hence the composite's bbox and left/top sidebearings may need updating # in the instanced font. glyf._setCoordinates(glyphname, coordinates, hMetrics, vMetrics) if not tupleVarStore: if glyphname in gvar.variations: del gvar.variations[glyphname] return if optimize: isComposite = glyf[glyphname].isComposite() for var in tupleVarStore: var.optimize(coordinates, endPts, isComposite) def instantiateGvarGlyph(varfont, glyphname, axisLimits, optimize=True): """Remove? https://github.com/fonttools/fonttools/pull/2266""" gvar = varfont["gvar"] glyf = varfont["glyf"] hMetrics = varfont["hmtx"].metrics vMetrics = getattr(varfont.get("vmtx"), "metrics", None) _instantiateGvarGlyph( glyphname, glyf, gvar, hMetrics, vMetrics, axisLimits, optimize=optimize ) def instantiateGvar(varfont, axisLimits, optimize=True): log.info("Instantiating 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 sorted by component depth. # If a composite glyph is processed before its base glyph, the bounds may # be calculated incorrectly because deltas haven't been applied to the # base glyph yet. glyphnames = sorted( glyf.glyphOrder, key=lambda name: ( glyf[name].getCompositeMaxpValues(glyf).maxComponentDepth if glyf[name].isComposite() or glyf[name].isVarComposite() else 0, name, ), ) for glyphname in glyphnames: _instantiateGvarGlyph( glyphname, glyf, gvar, hMetrics, vMetrics, axisLimits, optimize=optimize ) if not gvar.variations: del varfont["gvar"] def setCvarDeltas(cvt, deltas): for i, delta in enumerate(deltas): if delta: cvt[i] += otRound(delta) def instantiateCvar(varfont, axisLimits): log.info("Instantiating cvt/cvar tables") cvar = varfont["cvar"] defaultDeltas = instantiateTupleVariationStore(cvar.variations, axisLimits) if defaultDeltas: setCvarDeltas(varfont["cvt "], defaultDeltas) if not cvar.variations: del varfont["cvar"] def setMvarDeltas(varfont, deltas): mvar = varfont["MVAR"].table records = mvar.ValueRecord for rec in records: mvarTag = rec.ValueTag if mvarTag not in MVAR_ENTRIES: continue tableTag, itemName = MVAR_ENTRIES[mvarTag] delta = deltas[rec.VarIdx] if delta != 0: setattr( varfont[tableTag], itemName, getattr(varfont[tableTag], itemName) + otRound(delta), ) @contextmanager def verticalMetricsKeptInSync(varfont): """Ensure hhea vertical metrics stay in sync with OS/2 ones after instancing. When applying MVAR deltas to the OS/2 table, if the ascender, descender and line gap change but they were the same as the respective hhea metrics in the original font, this context manager ensures that hhea metrcs also get updated accordingly. The MVAR spec only has tags for the OS/2 metrics, but it is common in fonts to have the hhea metrics be equal to those for compat reasons. https://learn.microsoft.com/en-us/typography/opentype/spec/mvar https://googlefonts.github.io/gf-guide/metrics.html#7-hhea-and-typo-metrics-should-be-equal https://github.com/fonttools/fonttools/issues/3297 """ current_os2_vmetrics = [ getattr(varfont["OS/2"], attr) for attr in ("sTypoAscender", "sTypoDescender", "sTypoLineGap") ] metrics_are_synced = current_os2_vmetrics == [ getattr(varfont["hhea"], attr) for attr in ("ascender", "descender", "lineGap") ] yield metrics_are_synced if metrics_are_synced: new_os2_vmetrics = [ getattr(varfont["OS/2"], attr) for attr in ("sTypoAscender", "sTypoDescender", "sTypoLineGap") ] if current_os2_vmetrics != new_os2_vmetrics: for attr, value in zip( ("ascender", "descender", "lineGap"), new_os2_vmetrics ): setattr(varfont["hhea"], attr, value) def instantiateMVAR(varfont, axisLimits): log.info("Instantiating MVAR table") mvar = varfont["MVAR"].table fvarAxes = varfont["fvar"].axes varStore = mvar.VarStore defaultDeltas = instantiateItemVariationStore(varStore, fvarAxes, axisLimits) with verticalMetricsKeptInSync(varfont): setMvarDeltas(varfont, defaultDeltas) if varStore.VarRegionList.Region: varIndexMapping = varStore.optimize() for rec in mvar.ValueRecord: rec.VarIdx = varIndexMapping[rec.VarIdx] else: del varfont["MVAR"] def _remapVarIdxMap(table, attrName, varIndexMapping, glyphOrder): oldMapping = getattr(table, attrName).mapping newMapping = [varIndexMapping[oldMapping[glyphName]] for glyphName in glyphOrder] setattr(table, attrName, builder.buildVarIdxMap(newMapping, glyphOrder)) # TODO(anthrotype) Add support for HVAR/VVAR in CFF2 def _instantiateVHVAR(varfont, axisLimits, tableFields): location = axisLimits.pinnedLocation() tableTag = tableFields.tableTag fvarAxes = varfont["fvar"].axes # Deltas from gvar table have already been applied to the hmtx/vmtx. For full # instances (i.e. all axes pinned), we can simply drop HVAR/VVAR and return if set(location).issuperset(axis.axisTag for axis in fvarAxes): log.info("Dropping %s table", tableTag) del varfont[tableTag] return log.info("Instantiating %s table", tableTag) vhvar = varfont[tableTag].table varStore = vhvar.VarStore # since deltas were already applied, the return value here is ignored instantiateItemVariationStore(varStore, fvarAxes, axisLimits) if varStore.VarRegionList.Region: # Only re-optimize VarStore if the HVAR/VVAR already uses indirect AdvWidthMap # or AdvHeightMap. If a direct, implicit glyphID->VariationIndex mapping is # used for advances, skip re-optimizing and maintain original VariationIndex. if getattr(vhvar, tableFields.advMapping): varIndexMapping = varStore.optimize(use_NO_VARIATION_INDEX=False) glyphOrder = varfont.getGlyphOrder() _remapVarIdxMap(vhvar, tableFields.advMapping, varIndexMapping, glyphOrder) if getattr(vhvar, tableFields.sb1): # left or top sidebearings _remapVarIdxMap(vhvar, tableFields.sb1, varIndexMapping, glyphOrder) if getattr(vhvar, tableFields.sb2): # right or bottom sidebearings _remapVarIdxMap(vhvar, tableFields.sb2, varIndexMapping, glyphOrder) if tableTag == "VVAR" and getattr(vhvar, tableFields.vOrigMapping): _remapVarIdxMap( vhvar, tableFields.vOrigMapping, varIndexMapping, glyphOrder ) def instantiateHVAR(varfont, axisLimits): return _instantiateVHVAR(varfont, axisLimits, varLib.HVAR_FIELDS) def instantiateVVAR(varfont, axisLimits): return _instantiateVHVAR(varfont, axisLimits, varLib.VVAR_FIELDS) class _TupleVarStoreAdapter(object): def __init__(self, regions, axisOrder, tupleVarData, itemCounts): self.regions = regions self.axisOrder = axisOrder self.tupleVarData = tupleVarData self.itemCounts = itemCounts @classmethod def fromItemVarStore(cls, itemVarStore, fvarAxes): axisOrder = [axis.axisTag for axis in fvarAxes] regions = [ region.get_support(fvarAxes) for region in itemVarStore.VarRegionList.Region ] tupleVarData = [] itemCounts = [] for varData in itemVarStore.VarData: variations = [] varDataRegions = (regions[i] for i in varData.VarRegionIndex) for axes, coordinates in zip(varDataRegions, zip(*varData.Item)): variations.append(TupleVariation(axes, list(coordinates))) tupleVarData.append(variations) itemCounts.append(varData.ItemCount) return cls(regions, axisOrder, tupleVarData, itemCounts) def rebuildRegions(self): # Collect the set of all unique region axes from the current TupleVariations. # We use an OrderedDict to de-duplicate regions while keeping the order. uniqueRegions = collections.OrderedDict.fromkeys( ( frozenset(var.axes.items()) for variations in self.tupleVarData for var in variations ) ) # Maintain the original order for the regions that pre-existed, appending # the new regions at the end of the region list. newRegions = [] for region in self.regions: regionAxes = frozenset(region.items()) if regionAxes in uniqueRegions: newRegions.append(region) del uniqueRegions[regionAxes] if uniqueRegions: newRegions.extend(dict(region) for region in uniqueRegions) self.regions = newRegions def instantiate(self, axisLimits): defaultDeltaArray = [] for variations, itemCount in zip(self.tupleVarData, self.itemCounts): defaultDeltas = instantiateTupleVariationStore(variations, axisLimits) if not defaultDeltas: defaultDeltas = [0] * itemCount defaultDeltaArray.append(defaultDeltas) # rebuild regions whose axes were dropped or limited self.rebuildRegions() pinnedAxes = set(axisLimits.pinnedLocation()) self.axisOrder = [ axisTag for axisTag in self.axisOrder if axisTag not in pinnedAxes ] return defaultDeltaArray def asItemVarStore(self): regionOrder = [frozenset(axes.items()) for axes in self.regions] varDatas = [] for variations, itemCount in zip(self.tupleVarData, self.itemCounts): if variations: assert len(variations[0].coordinates) == itemCount varRegionIndices = [ regionOrder.index(frozenset(var.axes.items())) for var in variations ] varDataItems = list(zip(*(var.coordinates for var in variations))) varDatas.append( builder.buildVarData(varRegionIndices, varDataItems, optimize=False) ) else: varDatas.append( builder.buildVarData([], [[] for _ in range(itemCount)]) ) regionList = builder.buildVarRegionList(self.regions, self.axisOrder) itemVarStore = builder.buildVarStore(regionList, varDatas) # remove unused regions from VarRegionList itemVarStore.prune_regions() return itemVarStore def instantiateItemVariationStore(itemVarStore, fvarAxes, axisLimits): """Compute deltas at partial location, and update varStore in-place. Remove regions in which all axes were instanced, or fall outside the new axis limits. Scale the deltas of the remaining regions where only some of the axes were instanced. The number of VarData subtables, and the number of items within each, are not modified, in order to keep the existing VariationIndex valid. One may call VarStore.optimize() method after this to further optimize those. Args: varStore: An otTables.VarStore object (Item Variation Store) fvarAxes: list of fvar's Axis objects axisLimits: NormalizedAxisLimits: mapping axis tags to normalized min/default/max axis coordinates. May not specify coordinates/ranges for all the fvar axes. Returns: defaultDeltas: to be added to the default instance, of type dict of floats keyed by VariationIndex compound values: i.e. (outer << 16) + inner. """ tupleVarStore = _TupleVarStoreAdapter.fromItemVarStore(itemVarStore, fvarAxes) defaultDeltaArray = tupleVarStore.instantiate(axisLimits) newItemVarStore = tupleVarStore.asItemVarStore() itemVarStore.VarRegionList = newItemVarStore.VarRegionList assert itemVarStore.VarDataCount == newItemVarStore.VarDataCount itemVarStore.VarData = newItemVarStore.VarData defaultDeltas = { ((major << 16) + minor): delta for major, deltas in enumerate(defaultDeltaArray) for minor, delta in enumerate(deltas) } defaultDeltas[itemVarStore.NO_VARIATION_INDEX] = 0 return defaultDeltas def instantiateOTL(varfont, axisLimits): # TODO(anthrotype) Support partial instancing of JSTF and BASE tables if ( "GDEF" not in varfont or varfont["GDEF"].table.Version < 0x00010003 or not varfont["GDEF"].table.VarStore ): return if "GPOS" in varfont: msg = "Instantiating GDEF and GPOS tables" else: msg = "Instantiating GDEF table" log.info(msg) gdef = varfont["GDEF"].table varStore = gdef.VarStore fvarAxes = varfont["fvar"].axes defaultDeltas = instantiateItemVariationStore(varStore, fvarAxes, axisLimits) # When VF are built, big lookups may overflow and be broken into multiple # subtables. MutatorMerger (which inherits from AligningMerger) reattaches # them upon instancing, in case they can now fit a single subtable (if not, # they will be split again upon compilation). # This 'merger' also works as a 'visitor' that traverses the OTL tables and # calls specific methods when instances of a given type are found. # Specifically, it adds default deltas to GPOS Anchors/ValueRecords and GDEF # LigatureCarets, and optionally deletes all VariationIndex tables if the # VarStore is fully instanced. merger = MutatorMerger( varfont, defaultDeltas, deleteVariations=(not varStore.VarRegionList.Region) ) merger.mergeTables(varfont, [varfont], ["GDEF", "GPOS"]) if varStore.VarRegionList.Region: varIndexMapping = varStore.optimize() gdef.remap_device_varidxes(varIndexMapping) if "GPOS" in varfont: varfont["GPOS"].table.remap_device_varidxes(varIndexMapping) else: # 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"] def _isValidAvarSegmentMap(axisTag, segmentMap): if not segmentMap: return True if not {(-1.0, -1.0), (0, 0), (1.0, 1.0)}.issubset(segmentMap.items()): log.warning( f"Invalid avar SegmentMap record for axis '{axisTag}': does not " "include all required value maps {-1.0: -1.0, 0: 0, 1.0: 1.0}" ) return False previousValue = None for fromCoord, toCoord in sorted(segmentMap.items()): if previousValue is not None and previousValue > toCoord: log.warning( f"Invalid avar AxisValueMap({fromCoord}, {toCoord}) record " f"for axis '{axisTag}': the toCoordinate value must be >= to " f"the toCoordinate value of the preceding record ({previousValue})." ) return False previousValue = toCoord return True def instantiateAvar(varfont, axisLimits): # 'axisLimits' dict must contain user-space (non-normalized) coordinates. segments = varfont["avar"].segments # drop table if we instantiate all the axes pinnedAxes = set(axisLimits.pinnedLocation()) if pinnedAxes.issuperset(segments): log.info("Dropping avar table") del varfont["avar"] return log.info("Instantiating avar table") for axis in pinnedAxes: if axis in segments: del segments[axis] # First compute the default normalization for axisLimits coordinates: i.e. # min = -1.0, default = 0, max = +1.0, and in between values interpolated linearly, # without using the avar table's mappings. # Then, for each SegmentMap, if we are restricting its axis, compute the new # mappings by dividing the key/value pairs by the desired new min/max values, # dropping any mappings that fall outside the restricted range. # The keys ('fromCoord') are specified in default normalized coordinate space, # whereas the values ('toCoord') are "mapped forward" using the SegmentMap. normalizedRanges = axisLimits.normalize(varfont, usingAvar=False) newSegments = {} for axisTag, mapping in segments.items(): if not _isValidAvarSegmentMap(axisTag, mapping): continue if mapping and axisTag in normalizedRanges: axisRange = normalizedRanges[axisTag] mappedMin = floatToFixedToFloat( piecewiseLinearMap(axisRange.minimum, mapping), 14 ) mappedDef = floatToFixedToFloat( piecewiseLinearMap(axisRange.default, mapping), 14 ) mappedMax = floatToFixedToFloat( piecewiseLinearMap(axisRange.maximum, mapping), 14 ) mappedAxisLimit = NormalizedAxisTripleAndDistances( mappedMin, mappedDef, mappedMax, axisRange.distanceNegative, axisRange.distancePositive, ) newMapping = {} for fromCoord, toCoord in mapping.items(): if fromCoord < axisRange.minimum or fromCoord > axisRange.maximum: continue fromCoord = axisRange.renormalizeValue(fromCoord) assert mappedMin <= toCoord <= mappedMax toCoord = mappedAxisLimit.renormalizeValue(toCoord) fromCoord = floatToFixedToFloat(fromCoord, 14) toCoord = floatToFixedToFloat(toCoord, 14) newMapping[fromCoord] = toCoord newMapping.update({-1.0: -1.0, 0.0: 0.0, 1.0: 1.0}) newSegments[axisTag] = newMapping else: newSegments[axisTag] = mapping varfont["avar"].segments = newSegments def isInstanceWithinAxisRanges(location, axisRanges): for axisTag, coord in location.items(): if axisTag in axisRanges: axisRange = axisRanges[axisTag] if coord < axisRange.minimum or coord > axisRange.maximum: return False return True def instantiateFvar(varfont, axisLimits): # 'axisLimits' dict must contain user-space (non-normalized) coordinates location = axisLimits.pinnedLocation() fvar = varfont["fvar"] # drop table if we instantiate all the axes if set(location).issuperset(axis.axisTag for axis in fvar.axes): log.info("Dropping fvar table") del varfont["fvar"] return log.info("Instantiating fvar table") axes = [] for axis in fvar.axes: axisTag = axis.axisTag if axisTag in location: continue if axisTag in axisLimits: triple = axisLimits[axisTag] if triple.default is None: triple = (triple.minimum, axis.defaultValue, triple.maximum) axis.minValue, axis.defaultValue, axis.maxValue = triple axes.append(axis) fvar.axes = axes # only keep NamedInstances whose coordinates == pinned axis location instances = [] for instance in fvar.instances: if any(instance.coordinates[axis] != value for axis, value in location.items()): continue for axisTag in location: del instance.coordinates[axisTag] if not isInstanceWithinAxisRanges(instance.coordinates, axisLimits): continue instances.append(instance) fvar.instances = instances def instantiateSTAT(varfont, axisLimits): # 'axisLimits' dict must contain user-space (non-normalized) coordinates stat = varfont["STAT"].table if not stat.DesignAxisRecord or not ( stat.AxisValueArray and stat.AxisValueArray.AxisValue ): return # STAT table empty, nothing to do log.info("Instantiating STAT table") newAxisValueTables = axisValuesFromAxisLimits(stat, axisLimits) stat.AxisValueCount = len(newAxisValueTables) if stat.AxisValueCount: stat.AxisValueArray.AxisValue = newAxisValueTables else: stat.AxisValueArray = None def axisValuesFromAxisLimits(stat, axisLimits): def isAxisValueOutsideLimits(axisTag, axisValue): if axisTag in axisLimits: triple = axisLimits[axisTag] if axisValue < triple.minimum or axisValue > triple.maximum: return True return False # only keep AxisValues whose axis is not pinned nor restricted, or is pinned at the # exact (nominal) value, or is restricted but the value is within the new range designAxes = stat.DesignAxisRecord.Axis newAxisValueTables = [] for axisValueTable in stat.AxisValueArray.AxisValue: axisValueFormat = axisValueTable.Format if axisValueFormat in (1, 2, 3): axisTag = designAxes[axisValueTable.AxisIndex].AxisTag if axisValueFormat == 2: axisValue = axisValueTable.NominalValue else: axisValue = axisValueTable.Value if isAxisValueOutsideLimits(axisTag, axisValue): continue elif axisValueFormat == 4: # drop 'non-analytic' AxisValue if _any_ AxisValueRecord doesn't match # the pinned location or is outside range dropAxisValueTable = False for rec in axisValueTable.AxisValueRecord: axisTag = designAxes[rec.AxisIndex].AxisTag axisValue = rec.Value if isAxisValueOutsideLimits(axisTag, axisValue): dropAxisValueTable = True break if dropAxisValueTable: continue else: log.warning("Unknown AxisValue table format (%s); ignored", axisValueFormat) newAxisValueTables.append(axisValueTable) return newAxisValueTables def setMacOverlapFlags(glyfTable): flagOverlapCompound = _g_l_y_f.OVERLAP_COMPOUND flagOverlapSimple = _g_l_y_f.flagOverlapSimple for glyphName in glyfTable.keys(): glyph = glyfTable[glyphName] # Set OVERLAP_COMPOUND bit for compound glyphs if glyph.isComposite(): glyph.components[0].flags |= flagOverlapCompound # Set OVERLAP_SIMPLE bit for simple glyphs elif glyph.numberOfContours > 0: glyph.flags[0] |= flagOverlapSimple def normalize(value, triple, avarMapping): value = normalizeValue(value, triple) if avarMapping: value = piecewiseLinearMap(value, avarMapping) # Quantize to F2Dot14, to avoid surprise interpolations. return floatToFixedToFloat(value, 14) def sanityCheckVariableTables(varfont): if "fvar" not in varfont: raise ValueError("Missing required table fvar") if "gvar" in varfont: if "glyf" not in varfont: raise ValueError("Can't have gvar without glyf") # TODO(anthrotype) Remove once we do support partial instancing CFF2 if "CFF2" in varfont: raise NotImplementedError("Instancing CFF2 variable fonts is not supported yet") def instantiateVariableFont( varfont, axisLimits, inplace=False, optimize=True, overlap=OverlapMode.KEEP_AND_SET_FLAGS, updateFontNames=False, ): """Instantiate variable font, either fully or partially. Depending on whether the `axisLimits` dictionary references all or some of the input varfont's axes, the output font will either be a full instance (static font) or a variable font with possibly less variation data. Args: varfont: a TTFont instance, which must contain at least an 'fvar' table. Note that variable fonts with 'CFF2' table are not supported yet. axisLimits: a dict keyed by axis tags (str) containing the coordinates (float) along one or more axes where the desired instance will be located. If the value is `None`, the default coordinate as per 'fvar' table for that axis is used. The limit values can also be (min, max) tuples for restricting an axis's variation range. The default axis value must be included in the new range. inplace (bool): whether to modify input TTFont object in-place instead of returning a distinct object. optimize (bool): if False, do not perform IUP-delta optimization on the remaining 'gvar' table's deltas. Possibly faster, and might work around rendering issues in some buggy environments, at the cost of a slightly larger file size. overlap (OverlapMode): variable fonts usually contain overlapping contours, and some font rendering engines on Apple platforms require that the `OVERLAP_SIMPLE` and `OVERLAP_COMPOUND` flags in the 'glyf' table be set to force rendering using a non-zero fill rule. Thus we always set these flags on all glyphs to maximise cross-compatibility of the generated instance. You can disable this by passing OverlapMode.KEEP_AND_DONT_SET_FLAGS. If you want to remove the overlaps altogether and merge overlapping contours and components, you can pass OverlapMode.REMOVE (or REMOVE_AND_IGNORE_ERRORS to not hard-fail on tricky glyphs). Note that this requires the skia-pathops package (available to pip install). The overlap parameter only has effect when generating full static instances. updateFontNames (bool): if True, update the instantiated font's name table using the Axis Value Tables from the STAT table. The name table and the style bits in the head and OS/2 table will be updated so they conform to the R/I/B/BI model. If the STAT table is missing or an Axis Value table is missing for a given axis coordinate, a ValueError will be raised. """ # 'overlap' used to be bool and is now enum; for backward compat keep accepting bool overlap = OverlapMode(int(overlap)) sanityCheckVariableTables(varfont) axisLimits = AxisLimits(axisLimits).limitAxesAndPopulateDefaults(varfont) log.info("Restricted limits: %s", axisLimits) normalizedLimits = axisLimits.normalize(varfont) log.info("Normalized limits: %s", normalizedLimits) if not inplace: varfont = deepcopy(varfont) if "DSIG" in varfont: del varfont["DSIG"] if updateFontNames: log.info("Updating name table") names.updateNameTable(varfont, axisLimits) if "gvar" in varfont: instantiateGvar(varfont, normalizedLimits, optimize=optimize) if "cvar" in varfont: instantiateCvar(varfont, normalizedLimits) if "MVAR" in varfont: instantiateMVAR(varfont, normalizedLimits) if "HVAR" in varfont: instantiateHVAR(varfont, normalizedLimits) if "VVAR" in varfont: instantiateVVAR(varfont, normalizedLimits) instantiateOTL(varfont, normalizedLimits) instantiateFeatureVariations(varfont, normalizedLimits) if "avar" in varfont: instantiateAvar(varfont, axisLimits) with names.pruningUnusedNames(varfont): if "STAT" in varfont: instantiateSTAT(varfont, axisLimits) instantiateFvar(varfont, axisLimits) if "fvar" not in varfont: if "glyf" in varfont: if overlap == OverlapMode.KEEP_AND_SET_FLAGS: setMacOverlapFlags(varfont["glyf"]) elif overlap in (OverlapMode.REMOVE, OverlapMode.REMOVE_AND_IGNORE_ERRORS): from fontTools.ttLib.removeOverlaps import removeOverlaps log.info("Removing overlaps from glyf table") removeOverlaps( varfont, ignoreErrors=(overlap == OverlapMode.REMOVE_AND_IGNORE_ERRORS), ) if "OS/2" in varfont: varfont["OS/2"].recalcAvgCharWidth(varfont) varLib.set_default_weight_width_slant( varfont, location=axisLimits.defaultLocation() ) if updateFontNames: # Set Regular/Italic/Bold/Bold Italic bits as appropriate, after the # name table has been updated. setRibbiBits(varfont) return varfont def setRibbiBits(font): """Set the `head.macStyle` and `OS/2.fsSelection` style bits appropriately.""" english_ribbi_style = font["name"].getName(names.NameID.SUBFAMILY_NAME, 3, 1, 0x409) if english_ribbi_style is None: return styleMapStyleName = english_ribbi_style.toStr().lower() if styleMapStyleName not in {"regular", "bold", "italic", "bold italic"}: return if styleMapStyleName == "bold": font["head"].macStyle = 0b01 elif styleMapStyleName == "bold italic": font["head"].macStyle = 0b11 elif styleMapStyleName == "italic": font["head"].macStyle = 0b10 selection = font["OS/2"].fsSelection # First clear... selection &= ~(1 << 0) selection &= ~(1 << 5) selection &= ~(1 << 6) # ...then re-set the bits. if styleMapStyleName == "regular": selection |= 1 << 6 elif styleMapStyleName == "bold": selection |= 1 << 5 elif styleMapStyleName == "italic": selection |= 1 << 0 elif styleMapStyleName == "bold italic": selection |= 1 << 0 selection |= 1 << 5 font["OS/2"].fsSelection = selection def parseLimits(limits: Iterable[str]) -> Dict[str, Optional[AxisTriple]]: result = {} for limitString in limits: match = re.match( r"^(\w{1,4})=(?:(drop)|(?:([^:]*)(?:[:]([^:]*))?(?:[:]([^:]*))?))$", limitString, ) if not match: raise ValueError("invalid location format: %r" % limitString) tag = match.group(1).ljust(4) if match.group(2): # 'drop' result[tag] = None continue triple = match.group(3, 4, 5) if triple[1] is None: # "value" syntax triple = (triple[0], triple[0], triple[0]) elif triple[2] is None: # "min:max" syntax triple = (triple[0], None, triple[1]) triple = tuple(float(v) if v else None for v in triple) result[tag] = AxisTriple(*triple) return result def parseArgs(args): """Parse argv. Returns: 3-tuple (infile, axisLimits, options) axisLimits is either a Dict[str, Optional[float]], for pinning variation axes to specific coordinates along those axes (with `None` as a placeholder for an axis' default value); or a Dict[str, Tuple(float, float)], meaning limit this axis to min/max range. Axes locations are in user-space coordinates, as defined in the "fvar" table. """ from fontTools import configLogger import argparse parser = argparse.ArgumentParser( "fonttools varLib.instancer", description="Partially 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 consists of " "the tag of a variation axis, followed by '=' and the literal, " "string 'drop', or comma-separate list of one to three values, " "each of which is the empty string, or a number. " "E.g.: wdth=100 or wght=75.0:125.0 or wght=100:400:700 or wght=:500: " "or wght=drop", ) parser.add_argument( "-o", "--output", metavar="OUTPUT.ttf", default=None, help="Output instance TTF file (default: INPUT-instance.ttf).", ) parser.add_argument( "--no-optimize", dest="optimize", action="store_false", help="Don't perform IUP optimization on the remaining gvar TupleVariations", ) parser.add_argument( "--no-overlap-flag", dest="overlap", action="store_false", help="Don't set OVERLAP_SIMPLE/OVERLAP_COMPOUND glyf flags (only applicable " "when generating a full instance)", ) parser.add_argument( "--remove-overlaps", dest="remove_overlaps", action="store_true", help="Merge overlapping contours and components (only applicable " "when generating a full instance). Requires skia-pathops", ) parser.add_argument( "--ignore-overlap-errors", dest="ignore_overlap_errors", action="store_true", help="Don't crash if the remove-overlaps operation fails for some glyphs.", ) parser.add_argument( "--update-name-table", action="store_true", help="Update the instantiated font's `name` table. Input font must have " "a STAT table with Axis Value Tables", ) 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.", ) parser.add_argument( "--no-recalc-bounds", dest="recalc_bounds", action="store_false", help="Don't recalculate font bounding boxes", ) loggingGroup = parser.add_mutually_exclusive_group(required=False) loggingGroup.add_argument( "-v", "--verbose", action="store_true", help="Run more verbosely." ) loggingGroup.add_argument( "-q", "--quiet", action="store_true", help="Turn verbosity off." ) options = parser.parse_args(args) if options.remove_overlaps: if options.ignore_overlap_errors: options.overlap = OverlapMode.REMOVE_AND_IGNORE_ERRORS else: options.overlap = OverlapMode.REMOVE else: options.overlap = OverlapMode(int(options.overlap)) infile = options.input if not os.path.isfile(infile): parser.error("No such file '{}'".format(infile)) configLogger( level=("DEBUG" if options.verbose else "ERROR" if options.quiet else "INFO") ) try: axisLimits = parseLimits(options.locargs) except ValueError as e: parser.error(str(e)) if len(axisLimits) != len(options.locargs): parser.error("Specified multiple limits for the same axis") return (infile, axisLimits, options) def main(args=None): """Partially instantiate a variable font""" infile, axisLimits, options = parseArgs(args) log.info("Restricting axes: %s", axisLimits) log.info("Loading variable font") varfont = TTFont( infile, recalcTimestamp=options.recalc_timestamp, recalcBBoxes=options.recalc_bounds, ) isFullInstance = { axisTag for axisTag, limit in axisLimits.items() if not isinstance(limit, tuple) }.issuperset(axis.axisTag for axis in varfont["fvar"].axes) instantiateVariableFont( varfont, axisLimits, inplace=True, optimize=options.optimize, overlap=options.overlap, updateFontNames=options.update_name_table, ) suffix = "-instance" if isFullInstance else "-partial" outfile = ( makeOutputFileName(infile, overWrite=True, suffix=suffix) if not options.output else options.output ) log.info( "Saving %s font %s", "instance" if isFullInstance else "partial variable", outfile, ) varfont.save(outfile)