reconnect moved files to git repo

venv/lib/python3.11/site-packages/fontTools/varLib/instancer/featureVars.py

@@ -0,0 +1,190 @@
+from fontTools.ttLib.tables import otTables as ot
+from copy import deepcopy
+import logging
+
+
+log = logging.getLogger("fontTools.varLib.instancer")
+
+
+def _featureVariationRecordIsUnique(rec, seen):
+    conditionSet = []
+    conditionSets = (
+        rec.ConditionSet.ConditionTable if rec.ConditionSet is not None else []
+    )
+    for cond in conditionSets:
+        if cond.Format != 1:
+            # can't tell whether this is duplicate, assume is unique
+            return True
+        conditionSet.append(
+            (cond.AxisIndex, cond.FilterRangeMinValue, cond.FilterRangeMaxValue)
+        )
+    # besides the set of conditions, we also include the FeatureTableSubstitution
+    # version to identify unique FeatureVariationRecords, even though only one
+    # version is currently defined. It's theoretically possible that multiple
+    # records with same conditions but different substitution table version be
+    # present in the same font for backward compatibility.
+    recordKey = frozenset([rec.FeatureTableSubstitution.Version] + conditionSet)
+    if recordKey in seen:
+        return False
+    else:
+        seen.add(recordKey)  # side effect
+        return True
+
+
+def _limitFeatureVariationConditionRange(condition, axisLimit):
+    minValue = condition.FilterRangeMinValue
+    maxValue = condition.FilterRangeMaxValue
+
+    if (
+        minValue > maxValue
+        or minValue > axisLimit.maximum
+        or maxValue < axisLimit.minimum
+    ):
+        # condition invalid or out of range
+        return
+
+    return tuple(
+        axisLimit.renormalizeValue(v, extrapolate=False) for v in (minValue, maxValue)
+    )
+
+
+def _instantiateFeatureVariationRecord(
+    record, recIdx, axisLimits, fvarAxes, axisIndexMap
+):
+    applies = True
+    shouldKeep = False
+    newConditions = []
+    from fontTools.varLib.instancer import NormalizedAxisTripleAndDistances
+
+    default_triple = NormalizedAxisTripleAndDistances(-1, 0, +1)
+    if record.ConditionSet is None:
+        record.ConditionSet = ot.ConditionSet()
+        record.ConditionSet.ConditionTable = []
+        record.ConditionSet.ConditionCount = 0
+    for i, condition in enumerate(record.ConditionSet.ConditionTable):
+        if condition.Format == 1:
+            axisIdx = condition.AxisIndex
+            axisTag = fvarAxes[axisIdx].axisTag
+
+            minValue = condition.FilterRangeMinValue
+            maxValue = condition.FilterRangeMaxValue
+            triple = axisLimits.get(axisTag, default_triple)
+
+            if not (minValue <= triple.default <= maxValue):
+                applies = False
+
+            # if condition not met, remove entire record
+            if triple.minimum > maxValue or triple.maximum < minValue:
+                newConditions = None
+                break
+
+            if axisTag in axisIndexMap:
+                # remap axis index
+                condition.AxisIndex = axisIndexMap[axisTag]
+
+                # remap condition limits
+                newRange = _limitFeatureVariationConditionRange(condition, triple)
+                if newRange:
+                    # keep condition with updated limits
+                    minimum, maximum = newRange
+                    condition.FilterRangeMinValue = minimum
+                    condition.FilterRangeMaxValue = maximum
+                    shouldKeep = True
+                    if minimum != -1 or maximum != +1:
+                        newConditions.append(condition)
+                else:
+                    # condition out of range, remove entire record
+                    newConditions = None
+                    break
+
+        else:
+            log.warning(
+                "Condition table {0} of FeatureVariationRecord {1} has "
+                "unsupported format ({2}); ignored".format(i, recIdx, condition.Format)
+            )
+            applies = False
+            newConditions.append(condition)
+
+    if newConditions is not None and shouldKeep:
+        record.ConditionSet.ConditionTable = newConditions
+        if not newConditions:
+            record.ConditionSet = None
+        shouldKeep = True
+    else:
+        shouldKeep = False
+
+    # Does this *always* apply?
+    universal = shouldKeep and not newConditions
+
+    return applies, shouldKeep, universal
+
+
+def _instantiateFeatureVariations(table, fvarAxes, axisLimits):
+    pinnedAxes = set(axisLimits.pinnedLocation())
+    axisOrder = [axis.axisTag for axis in fvarAxes if axis.axisTag not in pinnedAxes]
+    axisIndexMap = {axisTag: axisOrder.index(axisTag) for axisTag in axisOrder}
+
+    featureVariationApplied = False
+    uniqueRecords = set()
+    newRecords = []
+    defaultsSubsts = None
+
+    for i, record in enumerate(table.FeatureVariations.FeatureVariationRecord):
+        applies, shouldKeep, universal = _instantiateFeatureVariationRecord(
+            record, i, axisLimits, fvarAxes, axisIndexMap
+        )
+
+        if shouldKeep and _featureVariationRecordIsUnique(record, uniqueRecords):
+            newRecords.append(record)
+
+        if applies and not featureVariationApplied:
+            assert record.FeatureTableSubstitution.Version == 0x00010000
+            defaultsSubsts = deepcopy(record.FeatureTableSubstitution)
+            for default, rec in zip(
+                defaultsSubsts.SubstitutionRecord,
+                record.FeatureTableSubstitution.SubstitutionRecord,
+            ):
+                default.Feature = deepcopy(
+                    table.FeatureList.FeatureRecord[rec.FeatureIndex].Feature
+                )
+                table.FeatureList.FeatureRecord[rec.FeatureIndex].Feature = deepcopy(
+                    rec.Feature
+                )
+            # Set variations only once
+            featureVariationApplied = True
+
+        # Further records don't have a chance to apply after a universal record
+        if universal:
+            break
+
+    # Insert a catch-all record to reinstate the old features if necessary
+    if featureVariationApplied and newRecords and not universal:
+        defaultRecord = ot.FeatureVariationRecord()
+        defaultRecord.ConditionSet = ot.ConditionSet()
+        defaultRecord.ConditionSet.ConditionTable = []
+        defaultRecord.ConditionSet.ConditionCount = 0
+        defaultRecord.FeatureTableSubstitution = defaultsSubsts
+
+        newRecords.append(defaultRecord)
+
+    if newRecords:
+        table.FeatureVariations.FeatureVariationRecord = newRecords
+        table.FeatureVariations.FeatureVariationCount = len(newRecords)
+    else:
+        del table.FeatureVariations
+        # downgrade table version if there are no FeatureVariations left
+        table.Version = 0x00010000
+
+
+def instantiateFeatureVariations(varfont, axisLimits):
+    for tableTag in ("GPOS", "GSUB"):
+        if tableTag not in varfont or not getattr(
+            varfont[tableTag].table, "FeatureVariations", None
+        ):
+            continue
+        log.info("Instantiating FeatureVariations of %s table", tableTag)
+        _instantiateFeatureVariations(
+            varfont[tableTag].table, varfont["fvar"].axes, axisLimits
+        )
+        # remove unreferenced lookups
+        varfont[tableTag].prune_lookups()