690 lines
25 KiB
Python
690 lines
25 KiB
Python
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"""Module to build FeatureVariation tables:
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https://docs.microsoft.com/en-us/typography/opentype/spec/chapter2#featurevariations-table
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NOTE: The API is experimental and subject to change.
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"""
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from fontTools.misc.dictTools import hashdict
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from fontTools.misc.intTools import bit_count
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from fontTools.ttLib import newTable
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from fontTools.ttLib.tables import otTables as ot
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from fontTools.ttLib.ttVisitor import TTVisitor
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from fontTools.otlLib.builder import buildLookup, buildSingleSubstSubtable
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from collections import OrderedDict
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from .errors import VarLibError, VarLibValidationError
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def addFeatureVariations(font, conditionalSubstitutions, featureTag="rvrn"):
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"""Add conditional substitutions to a Variable Font.
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The `conditionalSubstitutions` argument is a list of (Region, Substitutions)
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tuples.
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A Region is a list of Boxes. A Box is a dict mapping axisTags to
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(minValue, maxValue) tuples. Irrelevant axes may be omitted and they are
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interpretted as extending to end of axis in each direction. A Box represents
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an orthogonal 'rectangular' subset of an N-dimensional design space.
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A Region represents a more complex subset of an N-dimensional design space,
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ie. the union of all the Boxes in the Region.
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For efficiency, Boxes within a Region should ideally not overlap, but
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functionality is not compromised if they do.
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The minimum and maximum values are expressed in normalized coordinates.
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A Substitution is a dict mapping source glyph names to substitute glyph names.
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Example:
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# >>> f = TTFont(srcPath)
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# >>> condSubst = [
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# ... # A list of (Region, Substitution) tuples.
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# ... ([{"wdth": (0.5, 1.0)}], {"cent": "cent.rvrn"}),
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# ... ([{"wght": (0.5, 1.0)}], {"dollar": "dollar.rvrn"}),
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# ... ]
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# >>> addFeatureVariations(f, condSubst)
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# >>> f.save(dstPath)
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The `featureTag` parameter takes either a str or a iterable of str (the single str
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is kept for backwards compatibility), and defines which feature(s) will be
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associated with the feature variations.
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Note, if this is "rvrn", then the substitution lookup will be inserted at the
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beginning of the lookup list so that it is processed before others, otherwise
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for any other feature tags it will be appended last.
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"""
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# process first when "rvrn" is the only listed tag
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featureTags = [featureTag] if isinstance(featureTag, str) else sorted(featureTag)
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processLast = "rvrn" not in featureTags or len(featureTags) > 1
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_checkSubstitutionGlyphsExist(
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glyphNames=set(font.getGlyphOrder()),
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substitutions=conditionalSubstitutions,
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)
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substitutions = overlayFeatureVariations(conditionalSubstitutions)
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# turn substitution dicts into tuples of tuples, so they are hashable
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conditionalSubstitutions, allSubstitutions = makeSubstitutionsHashable(
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substitutions
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)
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if "GSUB" not in font:
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font["GSUB"] = buildGSUB()
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else:
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existingTags = _existingVariableFeatures(font["GSUB"].table).intersection(
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featureTags
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)
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if existingTags:
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raise VarLibError(
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f"FeatureVariations already exist for feature tag(s): {existingTags}"
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)
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# setup lookups
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lookupMap = buildSubstitutionLookups(
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font["GSUB"].table, allSubstitutions, processLast
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)
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# addFeatureVariationsRaw takes a list of
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# ( {condition}, [ lookup indices ] )
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# so rearrange our lookups to match
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conditionsAndLookups = []
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for conditionSet, substitutions in conditionalSubstitutions:
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conditionsAndLookups.append(
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(conditionSet, [lookupMap[s] for s in substitutions])
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)
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addFeatureVariationsRaw(font, font["GSUB"].table, conditionsAndLookups, featureTags)
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def _existingVariableFeatures(table):
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existingFeatureVarsTags = set()
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if hasattr(table, "FeatureVariations") and table.FeatureVariations is not None:
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features = table.FeatureList.FeatureRecord
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for fvr in table.FeatureVariations.FeatureVariationRecord:
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for ftsr in fvr.FeatureTableSubstitution.SubstitutionRecord:
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existingFeatureVarsTags.add(features[ftsr.FeatureIndex].FeatureTag)
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return existingFeatureVarsTags
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def _checkSubstitutionGlyphsExist(glyphNames, substitutions):
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referencedGlyphNames = set()
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for _, substitution in substitutions:
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referencedGlyphNames |= substitution.keys()
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referencedGlyphNames |= set(substitution.values())
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missing = referencedGlyphNames - glyphNames
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if missing:
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raise VarLibValidationError(
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"Missing glyphs are referenced in conditional substitution rules:"
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f" {', '.join(missing)}"
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)
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def overlayFeatureVariations(conditionalSubstitutions):
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"""Compute overlaps between all conditional substitutions.
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The `conditionalSubstitutions` argument is a list of (Region, Substitutions)
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tuples.
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A Region is a list of Boxes. A Box is a dict mapping axisTags to
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(minValue, maxValue) tuples. Irrelevant axes may be omitted and they are
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interpretted as extending to end of axis in each direction. A Box represents
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an orthogonal 'rectangular' subset of an N-dimensional design space.
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A Region represents a more complex subset of an N-dimensional design space,
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ie. the union of all the Boxes in the Region.
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For efficiency, Boxes within a Region should ideally not overlap, but
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functionality is not compromised if they do.
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The minimum and maximum values are expressed in normalized coordinates.
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A Substitution is a dict mapping source glyph names to substitute glyph names.
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Returns data is in similar but different format. Overlaps of distinct
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substitution Boxes (*not* Regions) are explicitly listed as distinct rules,
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and rules with the same Box merged. The more specific rules appear earlier
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in the resulting list. Moreover, instead of just a dictionary of substitutions,
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a list of dictionaries is returned for substitutions corresponding to each
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unique space, with each dictionary being identical to one of the input
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substitution dictionaries. These dictionaries are not merged to allow data
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sharing when they are converted into font tables.
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Example::
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>>> condSubst = [
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... # A list of (Region, Substitution) tuples.
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... ([{"wght": (0.5, 1.0)}], {"dollar": "dollar.rvrn"}),
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... ([{"wght": (0.5, 1.0)}], {"dollar": "dollar.rvrn"}),
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... ([{"wdth": (0.5, 1.0)}], {"cent": "cent.rvrn"}),
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... ([{"wght": (0.5, 1.0), "wdth": (-1, 1.0)}], {"dollar": "dollar.rvrn"}),
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... ]
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>>> from pprint import pprint
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>>> pprint(overlayFeatureVariations(condSubst))
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[({'wdth': (0.5, 1.0), 'wght': (0.5, 1.0)},
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[{'dollar': 'dollar.rvrn'}, {'cent': 'cent.rvrn'}]),
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({'wdth': (0.5, 1.0)}, [{'cent': 'cent.rvrn'}]),
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({'wght': (0.5, 1.0)}, [{'dollar': 'dollar.rvrn'}])]
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"""
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# Merge same-substitutions rules, as this creates fewer number oflookups.
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merged = OrderedDict()
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for value, key in conditionalSubstitutions:
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key = hashdict(key)
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if key in merged:
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merged[key].extend(value)
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else:
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merged[key] = value
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conditionalSubstitutions = [(v, dict(k)) for k, v in merged.items()]
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del merged
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# Merge same-region rules, as this is cheaper.
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# Also convert boxes to hashdict()
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#
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# Reversing is such that earlier entries win in case of conflicting substitution
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# rules for the same region.
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merged = OrderedDict()
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for key, value in reversed(conditionalSubstitutions):
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key = tuple(
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sorted(
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(hashdict(cleanupBox(k)) for k in key),
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key=lambda d: tuple(sorted(d.items())),
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)
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)
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if key in merged:
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merged[key].update(value)
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else:
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merged[key] = dict(value)
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conditionalSubstitutions = list(reversed(merged.items()))
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del merged
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# Overlay
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#
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# Rank is the bit-set of the index of all contributing layers.
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initMapInit = ((hashdict(), 0),) # Initializer representing the entire space
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boxMap = OrderedDict(initMapInit) # Map from Box to Rank
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for i, (currRegion, _) in enumerate(conditionalSubstitutions):
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newMap = OrderedDict(initMapInit)
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currRank = 1 << i
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for box, rank in boxMap.items():
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for currBox in currRegion:
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intersection, remainder = overlayBox(currBox, box)
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if intersection is not None:
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intersection = hashdict(intersection)
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newMap[intersection] = newMap.get(intersection, 0) | rank | currRank
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if remainder is not None:
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remainder = hashdict(remainder)
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newMap[remainder] = newMap.get(remainder, 0) | rank
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boxMap = newMap
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# Generate output
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items = []
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for box, rank in sorted(
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boxMap.items(), key=(lambda BoxAndRank: -bit_count(BoxAndRank[1]))
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):
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# Skip any box that doesn't have any substitution.
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if rank == 0:
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continue
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substsList = []
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i = 0
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while rank:
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if rank & 1:
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substsList.append(conditionalSubstitutions[i][1])
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rank >>= 1
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i += 1
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items.append((dict(box), substsList))
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return items
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#
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# Terminology:
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#
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# A 'Box' is a dict representing an orthogonal "rectangular" bit of N-dimensional space.
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# The keys in the dict are axis tags, the values are (minValue, maxValue) tuples.
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# Missing dimensions (keys) are substituted by the default min and max values
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# from the corresponding axes.
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#
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def overlayBox(top, bot):
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"""Overlays ``top`` box on top of ``bot`` box.
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Returns two items:
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* Box for intersection of ``top`` and ``bot``, or None if they don't intersect.
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* Box for remainder of ``bot``. Remainder box might not be exact (since the
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remainder might not be a simple box), but is inclusive of the exact
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remainder.
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"""
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# Intersection
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intersection = {}
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intersection.update(top)
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intersection.update(bot)
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for axisTag in set(top) & set(bot):
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min1, max1 = top[axisTag]
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min2, max2 = bot[axisTag]
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minimum = max(min1, min2)
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maximum = min(max1, max2)
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if not minimum < maximum:
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return None, bot # Do not intersect
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intersection[axisTag] = minimum, maximum
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# Remainder
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#
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# Remainder is empty if bot's each axis range lies within that of intersection.
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#
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# Remainder is shrank if bot's each, except for exactly one, axis range lies
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# within that of intersection, and that one axis, it extrudes out of the
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# intersection only on one side.
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#
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# Bot is returned in full as remainder otherwise, as true remainder is not
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# representable as a single box.
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remainder = dict(bot)
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extruding = False
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fullyInside = True
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for axisTag in top:
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if axisTag in bot:
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continue
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extruding = True
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fullyInside = False
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break
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for axisTag in bot:
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if axisTag not in top:
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continue # Axis range lies fully within
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min1, max1 = intersection[axisTag]
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min2, max2 = bot[axisTag]
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if min1 <= min2 and max2 <= max1:
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continue # Axis range lies fully within
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# Bot's range doesn't fully lie within that of top's for this axis.
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# We know they intersect, so it cannot lie fully without either; so they
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# overlap.
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# If we have had an overlapping axis before, remainder is not
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# representable as a box, so return full bottom and go home.
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if extruding:
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return intersection, bot
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extruding = True
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fullyInside = False
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# Otherwise, cut remainder on this axis and continue.
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if min1 <= min2:
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# Right side survives.
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minimum = max(max1, min2)
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maximum = max2
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elif max2 <= max1:
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# Left side survives.
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minimum = min2
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maximum = min(min1, max2)
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else:
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# Remainder leaks out from both sides. Can't cut either.
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return intersection, bot
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remainder[axisTag] = minimum, maximum
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if fullyInside:
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# bot is fully within intersection. Remainder is empty.
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return intersection, None
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return intersection, remainder
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def cleanupBox(box):
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"""Return a sparse copy of `box`, without redundant (default) values.
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>>> cleanupBox({})
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{}
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>>> cleanupBox({'wdth': (0.0, 1.0)})
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{'wdth': (0.0, 1.0)}
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>>> cleanupBox({'wdth': (-1.0, 1.0)})
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{}
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"""
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return {tag: limit for tag, limit in box.items() if limit != (-1.0, 1.0)}
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#
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# Low level implementation
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#
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def addFeatureVariationsRaw(font, table, conditionalSubstitutions, featureTag="rvrn"):
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"""Low level implementation of addFeatureVariations that directly
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models the possibilities of the FeatureVariations table."""
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featureTags = [featureTag] if isinstance(featureTag, str) else sorted(featureTag)
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processLast = "rvrn" not in featureTags or len(featureTags) > 1
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#
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# if a <featureTag> feature is not present:
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# make empty <featureTag> feature
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# sort features, get <featureTag> feature index
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# add <featureTag> feature to all scripts
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# if a <featureTag> feature is present:
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# reuse <featureTag> feature index
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# make lookups
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# add feature variations
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#
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if table.Version < 0x00010001:
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table.Version = 0x00010001 # allow table.FeatureVariations
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varFeatureIndices = set()
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||
|
|
|
||
|
|
existingTags = {
|
||
|
|
feature.FeatureTag
|
||
|
|
for feature in table.FeatureList.FeatureRecord
|
||
|
|
if feature.FeatureTag in featureTags
|
||
|
|
}
|
||
|
|
|
||
|
|
newTags = set(featureTags) - existingTags
|
||
|
|
if newTags:
|
||
|
|
varFeatures = []
|
||
|
|
for featureTag in sorted(newTags):
|
||
|
|
varFeature = buildFeatureRecord(featureTag, [])
|
||
|
|
table.FeatureList.FeatureRecord.append(varFeature)
|
||
|
|
varFeatures.append(varFeature)
|
||
|
|
table.FeatureList.FeatureCount = len(table.FeatureList.FeatureRecord)
|
||
|
|
|
||
|
|
sortFeatureList(table)
|
||
|
|
|
||
|
|
for varFeature in varFeatures:
|
||
|
|
varFeatureIndex = table.FeatureList.FeatureRecord.index(varFeature)
|
||
|
|
|
||
|
|
for scriptRecord in table.ScriptList.ScriptRecord:
|
||
|
|
if scriptRecord.Script.DefaultLangSys is None:
|
||
|
|
raise VarLibError(
|
||
|
|
"Feature variations require that the script "
|
||
|
|
f"'{scriptRecord.ScriptTag}' defines a default language system."
|
||
|
|
)
|
||
|
|
langSystems = [lsr.LangSys for lsr in scriptRecord.Script.LangSysRecord]
|
||
|
|
for langSys in [scriptRecord.Script.DefaultLangSys] + langSystems:
|
||
|
|
langSys.FeatureIndex.append(varFeatureIndex)
|
||
|
|
langSys.FeatureCount = len(langSys.FeatureIndex)
|
||
|
|
varFeatureIndices.add(varFeatureIndex)
|
||
|
|
|
||
|
|
if existingTags:
|
||
|
|
# indices may have changed if we inserted new features and sorted feature list
|
||
|
|
# so we must do this after the above
|
||
|
|
varFeatureIndices.update(
|
||
|
|
index
|
||
|
|
for index, feature in enumerate(table.FeatureList.FeatureRecord)
|
||
|
|
if feature.FeatureTag in existingTags
|
||
|
|
)
|
||
|
|
|
||
|
|
axisIndices = {
|
||
|
|
axis.axisTag: axisIndex for axisIndex, axis in enumerate(font["fvar"].axes)
|
||
|
|
}
|
||
|
|
|
||
|
|
hasFeatureVariations = (
|
||
|
|
hasattr(table, "FeatureVariations") and table.FeatureVariations is not None
|
||
|
|
)
|
||
|
|
|
||
|
|
featureVariationRecords = []
|
||
|
|
for conditionSet, lookupIndices in conditionalSubstitutions:
|
||
|
|
conditionTable = []
|
||
|
|
for axisTag, (minValue, maxValue) in sorted(conditionSet.items()):
|
||
|
|
if minValue > maxValue:
|
||
|
|
raise VarLibValidationError(
|
||
|
|
"A condition set has a minimum value above the maximum value."
|
||
|
|
)
|
||
|
|
ct = buildConditionTable(axisIndices[axisTag], minValue, maxValue)
|
||
|
|
conditionTable.append(ct)
|
||
|
|
records = []
|
||
|
|
for varFeatureIndex in sorted(varFeatureIndices):
|
||
|
|
existingLookupIndices = table.FeatureList.FeatureRecord[
|
||
|
|
varFeatureIndex
|
||
|
|
].Feature.LookupListIndex
|
||
|
|
combinedLookupIndices = (
|
||
|
|
existingLookupIndices + lookupIndices
|
||
|
|
if processLast
|
||
|
|
else lookupIndices + existingLookupIndices
|
||
|
|
)
|
||
|
|
|
||
|
|
records.append(
|
||
|
|
buildFeatureTableSubstitutionRecord(
|
||
|
|
varFeatureIndex, combinedLookupIndices
|
||
|
|
)
|
||
|
|
)
|
||
|
|
if hasFeatureVariations and (
|
||
|
|
fvr := findFeatureVariationRecord(table.FeatureVariations, conditionTable)
|
||
|
|
):
|
||
|
|
fvr.FeatureTableSubstitution.SubstitutionRecord.extend(records)
|
||
|
|
fvr.FeatureTableSubstitution.SubstitutionCount = len(
|
||
|
|
fvr.FeatureTableSubstitution.SubstitutionRecord
|
||
|
|
)
|
||
|
|
else:
|
||
|
|
featureVariationRecords.append(
|
||
|
|
buildFeatureVariationRecord(conditionTable, records)
|
||
|
|
)
|
||
|
|
|
||
|
|
if hasFeatureVariations:
|
||
|
|
if table.FeatureVariations.Version != 0x00010000:
|
||
|
|
raise VarLibError(
|
||
|
|
"Unsupported FeatureVariations table version: "
|
||
|
|
f"0x{table.FeatureVariations.Version:08x} (expected 0x00010000)."
|
||
|
|
)
|
||
|
|
table.FeatureVariations.FeatureVariationRecord.extend(featureVariationRecords)
|
||
|
|
table.FeatureVariations.FeatureVariationCount = len(
|
||
|
|
table.FeatureVariations.FeatureVariationRecord
|
||
|
|
)
|
||
|
|
else:
|
||
|
|
table.FeatureVariations = buildFeatureVariations(featureVariationRecords)
|
||
|
|
|
||
|
|
|
||
|
|
#
|
||
|
|
# Building GSUB/FeatureVariations internals
|
||
|
|
#
|
||
|
|
|
||
|
|
|
||
|
|
def buildGSUB():
|
||
|
|
"""Build a GSUB table from scratch."""
|
||
|
|
fontTable = newTable("GSUB")
|
||
|
|
gsub = fontTable.table = ot.GSUB()
|
||
|
|
gsub.Version = 0x00010001 # allow gsub.FeatureVariations
|
||
|
|
|
||
|
|
gsub.ScriptList = ot.ScriptList()
|
||
|
|
gsub.ScriptList.ScriptRecord = []
|
||
|
|
gsub.FeatureList = ot.FeatureList()
|
||
|
|
gsub.FeatureList.FeatureRecord = []
|
||
|
|
gsub.LookupList = ot.LookupList()
|
||
|
|
gsub.LookupList.Lookup = []
|
||
|
|
|
||
|
|
srec = ot.ScriptRecord()
|
||
|
|
srec.ScriptTag = "DFLT"
|
||
|
|
srec.Script = ot.Script()
|
||
|
|
srec.Script.DefaultLangSys = None
|
||
|
|
srec.Script.LangSysRecord = []
|
||
|
|
srec.Script.LangSysCount = 0
|
||
|
|
|
||
|
|
langrec = ot.LangSysRecord()
|
||
|
|
langrec.LangSys = ot.LangSys()
|
||
|
|
langrec.LangSys.ReqFeatureIndex = 0xFFFF
|
||
|
|
langrec.LangSys.FeatureIndex = []
|
||
|
|
srec.Script.DefaultLangSys = langrec.LangSys
|
||
|
|
|
||
|
|
gsub.ScriptList.ScriptRecord.append(srec)
|
||
|
|
gsub.ScriptList.ScriptCount = 1
|
||
|
|
gsub.FeatureVariations = None
|
||
|
|
|
||
|
|
return fontTable
|
||
|
|
|
||
|
|
|
||
|
|
def makeSubstitutionsHashable(conditionalSubstitutions):
|
||
|
|
"""Turn all the substitution dictionaries in sorted tuples of tuples so
|
||
|
|
they are hashable, to detect duplicates so we don't write out redundant
|
||
|
|
data."""
|
||
|
|
allSubstitutions = set()
|
||
|
|
condSubst = []
|
||
|
|
for conditionSet, substitutionMaps in conditionalSubstitutions:
|
||
|
|
substitutions = []
|
||
|
|
for substitutionMap in substitutionMaps:
|
||
|
|
subst = tuple(sorted(substitutionMap.items()))
|
||
|
|
substitutions.append(subst)
|
||
|
|
allSubstitutions.add(subst)
|
||
|
|
condSubst.append((conditionSet, substitutions))
|
||
|
|
return condSubst, sorted(allSubstitutions)
|
||
|
|
|
||
|
|
|
||
|
|
class ShifterVisitor(TTVisitor):
|
||
|
|
def __init__(self, shift):
|
||
|
|
self.shift = shift
|
||
|
|
|
||
|
|
|
||
|
|
@ShifterVisitor.register_attr(ot.Feature, "LookupListIndex") # GSUB/GPOS
|
||
|
|
def visit(visitor, obj, attr, value):
|
||
|
|
shift = visitor.shift
|
||
|
|
value = [l + shift for l in value]
|
||
|
|
setattr(obj, attr, value)
|
||
|
|
|
||
|
|
|
||
|
|
@ShifterVisitor.register_attr(
|
||
|
|
(ot.SubstLookupRecord, ot.PosLookupRecord), "LookupListIndex"
|
||
|
|
)
|
||
|
|
def visit(visitor, obj, attr, value):
|
||
|
|
setattr(obj, attr, visitor.shift + value)
|
||
|
|
|
||
|
|
|
||
|
|
def buildSubstitutionLookups(gsub, allSubstitutions, processLast=False):
|
||
|
|
"""Build the lookups for the glyph substitutions, return a dict mapping
|
||
|
|
the substitution to lookup indices."""
|
||
|
|
|
||
|
|
# Insert lookups at the beginning of the lookup vector
|
||
|
|
# https://github.com/googlefonts/fontmake/issues/950
|
||
|
|
|
||
|
|
firstIndex = len(gsub.LookupList.Lookup) if processLast else 0
|
||
|
|
lookupMap = {}
|
||
|
|
for i, substitutionMap in enumerate(allSubstitutions):
|
||
|
|
lookupMap[substitutionMap] = firstIndex + i
|
||
|
|
|
||
|
|
if not processLast:
|
||
|
|
# Shift all lookup indices in gsub by len(allSubstitutions)
|
||
|
|
shift = len(allSubstitutions)
|
||
|
|
visitor = ShifterVisitor(shift)
|
||
|
|
visitor.visit(gsub.FeatureList.FeatureRecord)
|
||
|
|
visitor.visit(gsub.LookupList.Lookup)
|
||
|
|
|
||
|
|
for i, subst in enumerate(allSubstitutions):
|
||
|
|
substMap = dict(subst)
|
||
|
|
lookup = buildLookup([buildSingleSubstSubtable(substMap)])
|
||
|
|
if processLast:
|
||
|
|
gsub.LookupList.Lookup.append(lookup)
|
||
|
|
else:
|
||
|
|
gsub.LookupList.Lookup.insert(i, lookup)
|
||
|
|
assert gsub.LookupList.Lookup[lookupMap[subst]] is lookup
|
||
|
|
gsub.LookupList.LookupCount = len(gsub.LookupList.Lookup)
|
||
|
|
return lookupMap
|
||
|
|
|
||
|
|
|
||
|
|
def buildFeatureVariations(featureVariationRecords):
|
||
|
|
"""Build the FeatureVariations subtable."""
|
||
|
|
fv = ot.FeatureVariations()
|
||
|
|
fv.Version = 0x00010000
|
||
|
|
fv.FeatureVariationRecord = featureVariationRecords
|
||
|
|
fv.FeatureVariationCount = len(featureVariationRecords)
|
||
|
|
return fv
|
||
|
|
|
||
|
|
|
||
|
|
def buildFeatureRecord(featureTag, lookupListIndices):
|
||
|
|
"""Build a FeatureRecord."""
|
||
|
|
fr = ot.FeatureRecord()
|
||
|
|
fr.FeatureTag = featureTag
|
||
|
|
fr.Feature = ot.Feature()
|
||
|
|
fr.Feature.LookupListIndex = lookupListIndices
|
||
|
|
fr.Feature.populateDefaults()
|
||
|
|
return fr
|
||
|
|
|
||
|
|
|
||
|
|
def buildFeatureVariationRecord(conditionTable, substitutionRecords):
|
||
|
|
"""Build a FeatureVariationRecord."""
|
||
|
|
fvr = ot.FeatureVariationRecord()
|
||
|
|
fvr.ConditionSet = ot.ConditionSet()
|
||
|
|
fvr.ConditionSet.ConditionTable = conditionTable
|
||
|
|
fvr.ConditionSet.ConditionCount = len(conditionTable)
|
||
|
|
fvr.FeatureTableSubstitution = ot.FeatureTableSubstitution()
|
||
|
|
fvr.FeatureTableSubstitution.Version = 0x00010000
|
||
|
|
fvr.FeatureTableSubstitution.SubstitutionRecord = substitutionRecords
|
||
|
|
fvr.FeatureTableSubstitution.SubstitutionCount = len(substitutionRecords)
|
||
|
|
return fvr
|
||
|
|
|
||
|
|
|
||
|
|
def buildFeatureTableSubstitutionRecord(featureIndex, lookupListIndices):
|
||
|
|
"""Build a FeatureTableSubstitutionRecord."""
|
||
|
|
ftsr = ot.FeatureTableSubstitutionRecord()
|
||
|
|
ftsr.FeatureIndex = featureIndex
|
||
|
|
ftsr.Feature = ot.Feature()
|
||
|
|
ftsr.Feature.LookupListIndex = lookupListIndices
|
||
|
|
ftsr.Feature.LookupCount = len(lookupListIndices)
|
||
|
|
return ftsr
|
||
|
|
|
||
|
|
|
||
|
|
def buildConditionTable(axisIndex, filterRangeMinValue, filterRangeMaxValue):
|
||
|
|
"""Build a ConditionTable."""
|
||
|
|
ct = ot.ConditionTable()
|
||
|
|
ct.Format = 1
|
||
|
|
ct.AxisIndex = axisIndex
|
||
|
|
ct.FilterRangeMinValue = filterRangeMinValue
|
||
|
|
ct.FilterRangeMaxValue = filterRangeMaxValue
|
||
|
|
return ct
|
||
|
|
|
||
|
|
|
||
|
|
def findFeatureVariationRecord(featureVariations, conditionTable):
|
||
|
|
"""Find a FeatureVariationRecord that has the same conditionTable."""
|
||
|
|
if featureVariations.Version != 0x00010000:
|
||
|
|
raise VarLibError(
|
||
|
|
"Unsupported FeatureVariations table version: "
|
||
|
|
f"0x{featureVariations.Version:08x} (expected 0x00010000)."
|
||
|
|
)
|
||
|
|
|
||
|
|
for fvr in featureVariations.FeatureVariationRecord:
|
||
|
|
if conditionTable == fvr.ConditionSet.ConditionTable:
|
||
|
|
return fvr
|
||
|
|
|
||
|
|
return None
|
||
|
|
|
||
|
|
|
||
|
|
def sortFeatureList(table):
|
||
|
|
"""Sort the feature list by feature tag, and remap the feature indices
|
||
|
|
elsewhere. This is needed after the feature list has been modified.
|
||
|
|
"""
|
||
|
|
# decorate, sort, undecorate, because we need to make an index remapping table
|
||
|
|
tagIndexFea = [
|
||
|
|
(fea.FeatureTag, index, fea)
|
||
|
|
for index, fea in enumerate(table.FeatureList.FeatureRecord)
|
||
|
|
]
|
||
|
|
tagIndexFea.sort()
|
||
|
|
table.FeatureList.FeatureRecord = [fea for tag, index, fea in tagIndexFea]
|
||
|
|
featureRemap = dict(
|
||
|
|
zip([index for tag, index, fea in tagIndexFea], range(len(tagIndexFea)))
|
||
|
|
)
|
||
|
|
|
||
|
|
# Remap the feature indices
|
||
|
|
remapFeatures(table, featureRemap)
|
||
|
|
|
||
|
|
|
||
|
|
def remapFeatures(table, featureRemap):
|
||
|
|
"""Go through the scripts list, and remap feature indices."""
|
||
|
|
for scriptIndex, script in enumerate(table.ScriptList.ScriptRecord):
|
||
|
|
defaultLangSys = script.Script.DefaultLangSys
|
||
|
|
if defaultLangSys is not None:
|
||
|
|
_remapLangSys(defaultLangSys, featureRemap)
|
||
|
|
for langSysRecordIndex, langSysRec in enumerate(script.Script.LangSysRecord):
|
||
|
|
langSys = langSysRec.LangSys
|
||
|
|
_remapLangSys(langSys, featureRemap)
|
||
|
|
|
||
|
|
if hasattr(table, "FeatureVariations") and table.FeatureVariations is not None:
|
||
|
|
for fvr in table.FeatureVariations.FeatureVariationRecord:
|
||
|
|
for ftsr in fvr.FeatureTableSubstitution.SubstitutionRecord:
|
||
|
|
ftsr.FeatureIndex = featureRemap[ftsr.FeatureIndex]
|
||
|
|
|
||
|
|
|
||
|
|
def _remapLangSys(langSys, featureRemap):
|
||
|
|
if langSys.ReqFeatureIndex != 0xFFFF:
|
||
|
|
langSys.ReqFeatureIndex = featureRemap[langSys.ReqFeatureIndex]
|
||
|
|
langSys.FeatureIndex = [featureRemap[index] for index in langSys.FeatureIndex]
|
||
|
|
|
||
|
|
|
||
|
|
if __name__ == "__main__":
|
||
|
|
import doctest, sys
|
||
|
|
|
||
|
|
sys.exit(doctest.testmod().failed)
|