public unsafe bool Apply( IOpenTypeFont Font, // Font access interface OpenTypeTags TableTag, // Layout table tag (GSUB or GPOS) FontTable Table, // Layout table (GSUB or GPOS) LayoutMetrics Metrics, // LayoutMetrics ClassDefTable inputClassDef, ClassDefTable backtrackClassDef, ClassDefTable lookaheadClassDef, int CharCount, // Characters count (i.e. Charmap.Length); UshortList Charmap, // Char to glyph mapping GlyphInfoList GlyphInfo, // List of GlyphInfo structs int* Advances, // Glyph adv.widths LayoutOffset* Offsets, // Glyph offsets ushort LookupFlags, // Lookup table flags int FirstGlyph, // where to apply it int AfterLastGlyph, // how long is a context we can use uint Parameter, // lookup parameter int nestingLevel, // Contextual lookup nesting level out int NextGlyph // out: next glyph index ) { bool match = true; NextGlyph = FirstGlyph + 1; //In case we don't match //We are moving through table. We can pick glyph count or glyph class id. int curOffset = offset; int glyphIndex; // //Check backtrack sequence // int backtrackGlyphCount = GlyphCount(Table,curOffset); curOffset += sizeCount; glyphIndex = FirstGlyph; for(ushort backtrackIndex = 0; backtrackIndex < backtrackGlyphCount && match; backtrackIndex++) { glyphIndex = LayoutEngine.GetNextGlyphInLookup(Font, GlyphInfo, glyphIndex-1, LookupFlags, LayoutEngine.LookBackward ); if (glyphIndex<0) { match = false; } else { ushort classId = ClassId(Table,curOffset); curOffset+=sizeClassId; ushort glyphClass = backtrackClassDef. GetClass(Table,GlyphInfo.Glyphs[glyphIndex]); match = (glyphClass == classId); } } if (!match) return false; // // Check input sequence // int inputGlyphCount = GlyphCount(Table,curOffset); curOffset += sizeCount; glyphIndex = FirstGlyph; for(ushort inputIndex = 1; //go from second glyph in the input inputIndex < inputGlyphCount && match; inputIndex++) { glyphIndex = LayoutEngine.GetNextGlyphInLookup(Font, GlyphInfo, glyphIndex+1, LookupFlags, LayoutEngine.LookForward ); if (glyphIndex >= AfterLastGlyph) { match = false; } else { ushort classId = ClassId(Table,curOffset); curOffset+=sizeClassId; ushort glyphClass = inputClassDef. GetClass(Table,GlyphInfo.Glyphs[glyphIndex]); match = (glyphClass == classId); } } if (!match) return false; int afterInputGlyph = glyphIndex + 1; // remember where we were after input seqence // // Check lookahead sequence // int lookaheadGlyphCount = GlyphCount(Table,curOffset); curOffset += sizeCount; // Lokahead sequence starting right after input, // no need to change current glyphIndex for(ushort lookaheadIndex = 0; lookaheadIndex < lookaheadGlyphCount && match; lookaheadIndex++) { glyphIndex = LayoutEngine.GetNextGlyphInLookup(Font, GlyphInfo, glyphIndex+1, LookupFlags, LayoutEngine.LookForward ); if (glyphIndex >= GlyphInfo.Length) { match = false; } else { ushort classId = ClassId(Table,curOffset); curOffset+=sizeClassId; ushort glyphClass = lookaheadClassDef. GetClass(Table,GlyphInfo.Glyphs[glyphIndex]); match = (glyphClass == classId); } } if (match) { ContextualLookups(Table,curOffset).ApplyContextualLookups( Font, TableTag, Table, Metrics, CharCount, Charmap, GlyphInfo, Advances, Offsets, LookupFlags, FirstGlyph, afterInputGlyph, //As AfterLastGlyph Parameter, nestingLevel, out NextGlyph ); } return match; }
public unsafe bool Apply( IOpenTypeFont Font, // Font access interface OpenTypeTags TableTag, // Layout table tag (GSUB or GPOS) FontTable Table, // Layout table (GSUB or GPOS) LayoutMetrics Metrics, // LayoutMetrics ClassDefTable ClassDef, int CharCount, // Characters count (i.e. Charmap.Length); UshortList Charmap, // Char to glyph mapping GlyphInfoList GlyphInfo, // List of GlyphInfo structs int* Advances, // Glyph adv.widths LayoutOffset* Offsets, // Glyph offsets ushort LookupFlags, // Lookup table flags int FirstGlyph, // where to apply it int AfterLastGlyph, // how long is a context we can use uint Parameter, // lookup parameter int nestingLevel, // Contextual lookup nesting level out int NextGlyph // out: next glyph index ) { NextGlyph = FirstGlyph + 1; //In case we don't match // // Check input sequence // bool match = true; int glyphIndex = FirstGlyph; int inputGlyphCount = GlyphCount(Table); for(ushort inputIndex = 1; // go from second glyph in the input inputIndex < inputGlyphCount && match; inputIndex++) { glyphIndex = LayoutEngine.GetNextGlyphInLookup(Font, GlyphInfo, glyphIndex+1, LookupFlags, LayoutEngine.LookForward ); if (glyphIndex>=AfterLastGlyph) { match = false; } else { ushort classId = ClassId(Table,inputIndex); ushort glyphClass = ClassDef.GetClass(Table,GlyphInfo.Glyphs[glyphIndex]); match = (glyphClass == classId); } } if (match) { ContextualLookups(Table).ApplyContextualLookups( Font, TableTag, Table, Metrics, CharCount, Charmap, GlyphInfo, Advances, Offsets, LookupFlags, FirstGlyph, glyphIndex + 1, //As AfterLastGlyph Parameter, nestingLevel, out NextGlyph ); } return match; }