private IGlyphTransformationTable ParseCoverageChainingSubstitutionTable(int subTableOffset, dynamic fontTable, LookupFlags lookupFlags)
{
var type = typeof(GlyphTypeface).Assembly.GetType("MS.Internal.Shaping.CoverageChainingSubtable");
dynamic table = new AccessPrivateWrapper(TypeExtensions.Instantiate(type, fontTable.Wrapped, subTableOffset));
dynamic contextualLookupTable = new AccessPrivateWrapper(table.ContextualLookups(fontTable.Wrapped));
return(new ChainingCoverageContextSubstitutionTable
{
LookbackCoverages = this.GetEnumerableFromInternalList(
() => table.BacktrackGlyphCount(fontTable.Wrapped),
i => (ICoverageTable)this.ParseCoverageTable(fontTable, new AccessPrivateWrapper(table.BacktrackCoverage(fontTable.Wrapped, i)))).ToList(),
ContextCoverages = this.GetEnumerableFromInternalList(
() => table.InputGlyphCount(fontTable.Wrapped),
i => (ICoverageTable)this.ParseCoverageTable(fontTable, new AccessPrivateWrapper(table.InputCoverage(fontTable.Wrapped, i)))).ToList(),
LookaheadCoverages = this.GetEnumerableFromInternalList(
() => table.LookaheadGlyphCount(fontTable.Wrapped),
i => (ICoverageTable)this.ParseCoverageTable(fontTable, new AccessPrivateWrapper(table.LookaheadCoverage(fontTable.Wrapped, i)))).ToList(),
TransformationSets = this.GetEnumerableFromInternalList(
() => contextualLookupTable.recordCount,
i => new ContextTransformationSet
{
FirstGlyphIndex = contextualLookupTable.SequenceIndex(fontTable.Wrapped, i),
Transformations = this.GetTransformationTablesByLookupIndex(fontTable, contextualLookupTable.LookupIndex(fontTable.Wrapped, i))
}).ToList(),
LookupFlags = lookupFlags
});
}
private ChainingContextTransformationRule ParseChainingTransformationRule(dynamic fontTable, dynamic rule, Func <dynamic, int, ushort> idProjection, ushort firstInputId)
{
const int GlyphIdSize = 2;
// Load the lookback
var lookBackCount = rule.GlyphCount(fontTable.Wrapped, rule.offset);
int currentOffset = rule.offset + rule.sizeCount;
var lookBackGlyphIds = this.GetEnumerableFromInternalList(
() => lookBackCount,
i => (ushort)idProjection(rule, (i * GlyphIdSize) + currentOffset)).ToList();
currentOffset += lookBackCount * GlyphIdSize;
// Load the context
var contextCount = rule.GlyphCount(fontTable.Wrapped, currentOffset);
currentOffset += rule.sizeCount;
// The first element of the context comes from index of the rule set
var contextGlyphIds = this.GetEnumerableFromInternalList(
() => (ushort)(contextCount - 1),
i => (ushort)idProjection(rule, (i * GlyphIdSize) + currentOffset)).Prepend(firstInputId).ToList();
currentOffset += (contextCount - 1) * GlyphIdSize;
// Load the context
var lookAheadCount = rule.GlyphCount(fontTable.Wrapped, currentOffset);
currentOffset += rule.sizeCount;
var lookAheadGlyphIds = this.GetEnumerableFromInternalList(
() => lookAheadCount,
i => (ushort)idProjection(rule, (i * GlyphIdSize) + currentOffset)).ToList();
currentOffset += lookAheadCount * GlyphIdSize;
// Load the substitution lookup records
var lookupSubstitutionRecordCount = fontTable.GetUShort(currentOffset);
dynamic contextualLookupsTable = new AccessPrivateWrapper(rule.ContextualLookups(fontTable.Wrapped, currentOffset));
return(new ChainingContextTransformationRule
{
Lookback = lookBackGlyphIds,
Context = contextGlyphIds,
Lookahead = lookAheadGlyphIds,
TransformationSets = this.GetEnumerableFromInternalList(
() => lookupSubstitutionRecordCount,
i => new ContextTransformationSet
{
FirstGlyphIndex = contextualLookupsTable.SequenceIndex(fontTable.Wrapped, i),
Transformations = this.GetTransformationTablesByLookupIndex(fontTable, contextualLookupsTable.LookupIndex(fontTable.Wrapped, i))
}).ToList()
});
}
private ContextTransformationRule ParseContextTransformationRule(dynamic fontTable, dynamic rule, Func <dynamic, int, ushort> idProjection)
{
dynamic contextualLookupsTable = new AccessPrivateWrapper(rule.ContextualLookups(fontTable.Wrapped));
return(new ContextTransformationRule
{
Context = this.GetEnumerableFromInternalList(
() => rule.GlyphCount(fontTable.Wrapped),
i => (ushort)idProjection(rule, i)).ToList(),
TransformationSets = this.GetEnumerableFromInternalList(
() => rule.SubstCount(fontTable.Wrapped),
i => new ContextTransformationSet
{
FirstGlyphIndex = contextualLookupsTable.SequenceIndex(fontTable.Wrapped, i),
Transformations = this.GetTransformationTablesByLookupIndex(fontTable, contextualLookupsTable.LookupIndex(fontTable.Wrapped, i))
}).ToList()
});
}
