public static PosClassSetTable CreateFrom(BinaryReader reader, long beginAt)
{
reader.BaseStream.Seek(beginAt, SeekOrigin.Begin);
//--------
var posClassSetTable = new PosClassSetTable();
posClassSetTable.ReadFrom(reader);
return(posClassSetTable);
}
/// <summary>
/// LookupType 8: Chaining Contextual Positioning Subtable
/// </summary>
/// <param name="reader"></param>
void ReadLookupType8(BinaryReader reader)
{
long thisLookupTablePos = reader.BaseStream.Position;
int j = subTableOffsets.Length;
for (int i = 0; i < j; ++i)
{
//move to read pos
long subTableStartAt = lookupTablePos + subTableOffsets[i];
reader.BaseStream.Seek(subTableStartAt, SeekOrigin.Begin);
//-----------------------
ushort format = reader.ReadUInt16();
switch (format)
{
default: throw new NotSupportedException();
case 1:
{
//Chaining Context Positioning Format 1: Simple Chaining Context Glyph Positioning
// USHORT PosFormat Format identifier-format = 1
//Offset Coverage Offset to Coverage table-from beginning of ContextPos subtable
//USHORT ChainPosRuleSetCount Number of ChainPosRuleSet tables
//Offset ChainPosRuleSet
//[ChainPosRuleSetCount] Array of offsets to ChainPosRuleSet tables-from beginning of ContextPos subtable-ordered by Coverage Index
short coverageOffset = reader.ReadInt16();
ushort chainPosRuleSetCount = reader.ReadUInt16();
short[] chainPosRuleSetOffsetList = Utils.ReadInt16Array(reader, chainPosRuleSetCount);
LkSubTableType8Fmt1 subTable = new LkSubTableType8Fmt1();
subTable.PosRuleSetTables = CreateMultiplePosRuleSetTables(subTableStartAt, chainPosRuleSetOffsetList, reader);
subTable.CoverageTable = CoverageTable.CreateFrom(reader, subTableStartAt + coverageOffset);
//----------
subTables.Add(subTable);
} break;
case 2:
{
//Chaining Context Positioning Format 2: Class-based Chaining Context Glyph Positioning
//USHORT PosFormat Format identifier-format = 2
//Offset Coverage Offset to Coverage table-from beginning of ChainContextPos subtable
//Offset BacktrackClassDef Offset to ClassDef table containing backtrack sequence context-from beginning of ChainContextPos subtable
//Offset InputClassDef Offset to ClassDef table containing input sequence context-from beginning of ChainContextPos subtable
//Offset LookaheadClassDef Offset to ClassDef table containing lookahead sequence context-from beginning of ChainContextPos subtable
//USHORT ChainPosClassSetCnt Number of ChainPosClassSet tables
//Offset ChainPosClassSet
//[ChainPosClassSetCnt] Array of offsets to ChainPosClassSet tables-from beginning of ChainContextPos subtable-ordered by input class-may be NULL
short coverageOffset = reader.ReadInt16();
short backTrackClassDefOffset = reader.ReadInt16();
short inpuClassDefOffset = reader.ReadInt16();
short lookadheadClassDefOffset = reader.ReadInt16();
ushort chainPosClassSetCnt = reader.ReadUInt16();
short[] chainPosClassSetOffsetArray = Utils.ReadInt16Array(reader, chainPosClassSetCnt);
LkSubTableType8Fmt2 subTable = new LkSubTableType8Fmt2(chainPosClassSetOffsetArray);
subTable.BacktrackClassDefOffset = backTrackClassDefOffset;
subTable.InputClassDefOffset = inpuClassDefOffset;
subTable.LookaheadClassDefOffset = lookadheadClassDefOffset;
//----------
PosClassSetTable[] posClassSetTables = new PosClassSetTable[chainPosClassSetCnt];
subTable.PosClassSetTables = posClassSetTables;
for (int n = 0; n < chainPosClassSetCnt; ++n)
{
posClassSetTables[n] = PosClassSetTable.CreateFrom(reader, subTableStartAt + chainPosClassSetOffsetArray[i]);
}
//----------
subTable.CoverageTable = CoverageTable.CreateFrom(reader, subTableStartAt + coverageOffset);
//----------
subTables.Add(subTable);
//----------
} break;
case 3:
{
//Chaining Context Positioning Format 3: Coverage-based Chaining Context Glyph Positioning
//USHORT PosFormat Format identifier-format = 3
//USHORT BacktrackGlyphCount Number of glyphs in the backtracking sequence
//Offset Coverage[BacktrackGlyphCount] Array of offsets to coverage tables in backtracking sequence, in glyph sequence order
//USHORT InputGlyphCount Number of glyphs in input sequence
//Offset Coverage[InputGlyphCount] Array of offsets to coverage tables in input sequence, in glyph sequence order
//USHORT LookaheadGlyphCount Number of glyphs in lookahead sequence
//Offset Coverage[LookaheadGlyphCount] Array of offsets to coverage tables in lookahead sequence, in glyph sequence order
//USHORT PosCount Number of PosLookupRecords
//struct PosLookupRecord[PosCount] Array of PosLookupRecords,in design order
var subTable = new LkSubTableType8Fmt3();
//
ushort backtrackGlyphCount = reader.ReadUInt16();
short[] backtrackCoverageOffsets = Utils.ReadInt16Array(reader, backtrackGlyphCount);
ushort inputGlyphCount = reader.ReadUInt16();
short[] inputGlyphCoverageOffsets = Utils.ReadInt16Array(reader, inputGlyphCount);
//
ushort lookaheadGlyphCount = reader.ReadUInt16();
short[] lookaheadCoverageOffsets = Utils.ReadInt16Array(reader, lookaheadGlyphCount);
//
ushort posCount = reader.ReadUInt16();
subTable.PosLookupRecords = CreateMultiplePosLookupRecords(reader, posCount);
//--------------
subTable.BacktrackCoverages = CoverageTable.CreateMultipleCoverageTables(subTableStartAt, backtrackCoverageOffsets, reader);
subTable.InputGlyphCoverages = CoverageTable.CreateMultipleCoverageTables(subTableStartAt, inputGlyphCoverageOffsets, reader);
subTable.LookaheadCoverages = CoverageTable.CreateMultipleCoverageTables(subTableStartAt, lookaheadCoverageOffsets, reader);
subTables.Add(subTable);
} break;
}
}
}
/// <summary>
/// Lookup Type 7: Contextual Positioning Subtables
/// </summary>
/// <param name="reader"></param>
void ReadLookupType7(BinaryReader reader)
{
long thisLookupTablePos = reader.BaseStream.Position;
int j = subTableOffsets.Length;
for (int i = 0; i < j; ++i)
{
//move to read pos
long subTableStartAt = lookupTablePos + subTableOffsets[i];
reader.BaseStream.Seek(subTableStartAt, SeekOrigin.Begin);
//-----------------------
ushort format = reader.ReadUInt16();
switch (format)
{
default: throw new NotSupportedException();
case 1:
{
//Context Positioning Subtable: Format 1
//ContextPosFormat1 subtable: Simple context positioning
//Value Type Description
//USHORT PosFormat Format identifier-format = 1
//Offset Coverage Offset to Coverage table-from beginning of ContextPos subtable
//USHORT PosRuleSetCount Number of PosRuleSet tables
//Offset PosRuleSet[PosRuleSetCount]
//
short coverageOffset = reader.ReadInt16();
ushort posRuleSetCount = reader.ReadUInt16();
short[] posRuleSetOffsets = Utils.ReadInt16Array(reader, posRuleSetCount);
LkSubTableType7Fmt1 subTable = new LkSubTableType7Fmt1();
subTable.PosRuleSetTables = CreateMultiplePosRuleSetTables(subTableStartAt, posRuleSetOffsets, reader);
subTable.CoverageTable = CoverageTable.CreateFrom(reader, subTableStartAt + coverageOffset);
//-----------
subTables.Add(subTable);
} break;
case 2:
{
//Context Positioning Subtable: Format 2
//USHORT PosFormat Format identifier-format = 2
//Offset Coverage Offset to Coverage table-from beginning of ContextPos subtable
//Offset ClassDef Offset to ClassDef table-from beginning of ContextPos subtable
//USHORT PosClassSetCnt Number of PosClassSet tables
//Offset PosClassSet
//[PosClassSetCnt] Array of offsets to PosClassSet tables-from beginning of ContextPos subtable-ordered by class-may be NULL
short coverageOffset = reader.ReadInt16();
short classDefOffset = reader.ReadInt16();
ushort posClassSetCount = reader.ReadUInt16();
short[] posClassSetOffsets = Utils.ReadInt16Array(reader, posClassSetCount);
var subTable = new LkSubTableType7Fmt2();
subTable.ClassDefOffset = classDefOffset;
//----------
PosClassSetTable[] posClassSetTables = new PosClassSetTable[posClassSetCount];
subTable.PosClassSetTables = posClassSetTables;
for (int n = 0; n < posClassSetCount; ++n)
{
posClassSetTables[n] = PosClassSetTable.CreateFrom(reader, coverageOffset);
}
//----------
subTable.CoverageTable = CoverageTable.CreateFrom(reader, subTableStartAt + coverageOffset);
//----------
subTables.Add(subTable);
//----------
} break;
case 3:
{
//ContextPosFormat3 subtable: Coverage-based context glyph positioning
//Value Type Description
//USHORT PosFormat Format identifier-format = 3
//USHORT GlyphCount Number of glyphs in the input sequence
//USHORT PosCount Number of PosLookupRecords
//Offset Coverage[GlyphCount] Array of offsets to Coverage tables-from beginning of ContextPos subtable
//struct PosLookupRecord[PosCount] Array of positioning lookups-in design order
var subTable = new LkSubTableType7Fmt3();
ushort glyphCount = reader.ReadUInt16();
ushort posCount = reader.ReadUInt16();
//read each lookahead record
short[] coverageOffsets = Utils.ReadInt16Array(reader, glyphCount);
subTable.PosLookupRecords = CreateMultiplePosLookupRecords(reader, posCount);
subTable.CoverageTables = CoverageTable.CreateMultipleCoverageTables(subTableStartAt, coverageOffsets, reader);
//----------
subTables.Add(subTable);
//----------
} break;
}
}
}
public static PosClassSetTable CreateFrom(BinaryReader reader, long beginAt)
{
reader.BaseStream.Seek(beginAt, SeekOrigin.Begin);
//--------
var posClassSetTable = new PosClassSetTable();
posClassSetTable.ReadFrom(reader);
return posClassSetTable;
}
