public bool Apply(
FontTable Table,
GlyphInfoList GlyphInfo, // List of GlyphInfo structs
int FirstGlyph, // where to apply it
out int NextGlyph // Next glyph to process
)
{
Invariant.Assert(FirstGlyph >= 0);
NextGlyph = FirstGlyph + 1; //In case we don't match;
ushort GlyphId = GlyphInfo.Glyphs[FirstGlyph];
int CoverageIndex = Coverage(Table).GetGlyphIndex(Table,GlyphId);
if (CoverageIndex == -1) return false;
switch(Format(Table))
{
case 1:
GlyphInfo.Glyphs[FirstGlyph] = (ushort)(GlyphId + Format1DeltaGlyphId(Table));
GlyphInfo.GlyphFlags[FirstGlyph] = (ushort)(GlyphFlags.Unresolved | GlyphFlags.Substituted);
NextGlyph = FirstGlyph + 1;
return true;
case 2:
GlyphInfo.Glyphs[FirstGlyph] = Format2SubstituteGlyphId(Table,(ushort)CoverageIndex);
GlyphInfo.GlyphFlags[FirstGlyph] = (ushort)(GlyphFlags.Unresolved | GlyphFlags.Substituted);
NextGlyph = FirstGlyph + 1;
return true;
default:
NextGlyph = FirstGlyph+1;
return false;
}
}
public bool Apply(
FontTable Table,
GlyphInfoList GlyphInfo, // List of GlyphInfo structs
int FirstGlyph, // where to apply it
out int NextGlyph // Next glyph to process
)
{
Invariant.Assert(FirstGlyph >= 0);
NextGlyph = FirstGlyph + 1; //In case we don't match;
ushort GlyphId = GlyphInfo.Glyphs[FirstGlyph];
int CoverageIndex = Coverage(Table).GetGlyphIndex(Table,GlyphId);
if (CoverageIndex == -1) return false;
switch(Format(Table))
{
case 1:
GlyphInfo.Glyphs[FirstGlyph] = (ushort)(GlyphId + Format1DeltaGlyphId(Table));
GlyphInfo.GlyphFlags[FirstGlyph] = (ushort)(GlyphFlags.Unresolved | GlyphFlags.Substituted);
NextGlyph = FirstGlyph + 1;
return true;
case 2:
GlyphInfo.Glyphs[FirstGlyph] = Format2SubstituteGlyphId(Table,(ushort)CoverageIndex);
GlyphInfo.GlyphFlags[FirstGlyph] = (ushort)(GlyphFlags.Unresolved | GlyphFlags.Substituted);
NextGlyph = FirstGlyph + 1;
return true;
default:
NextGlyph = FirstGlyph+1;
return false;
}
}
public unsafe bool Apply(
FontTable Table,
GlyphInfoList GlyphInfo, // List of GlyphInfo
uint FeatureParam, // For this lookup - index of glyph alternate
int FirstGlyph, // where to apply it
out int NextGlyph // Next glyph to process
)
{
NextGlyph = FirstGlyph + 1; // always move one glyph forward,
// doesn't matter whether we matched context
if (Format(Table) != 1) return false; //Unknown format
int oldGlyphCount=GlyphInfo.Length;
int coverageIndex = Coverage(Table).
GetGlyphIndex(Table,GlyphInfo.Glyphs[FirstGlyph]);
if (coverageIndex==-1) return false;
AlternateSetTable alternateSet = AlternateSet(Table,coverageIndex);
ushort alternateGlyph = alternateSet.Alternate(Table, FeatureParam);
if (alternateGlyph != InvalidAlternateGlyph)
{
GlyphInfo.Glyphs[FirstGlyph] = alternateGlyph;
GlyphInfo.GlyphFlags[FirstGlyph] = (ushort)(GlyphFlags.Unresolved | GlyphFlags.Substituted);
return true;
}
return false;
}
// Not used. This value should be equal to glyph count in Coverage.
// Keeping it for future reference
//private ushort AlternateSetCount(FontTable Table)
//{
// return Table.GetUShort(offset + offsetAlternateSetCount);
//}
private AlternateSetTable AlternateSet(FontTable Table, int index)
{
return(new AlternateSetTable(offset +
Table.GetUShort(offset +
offsetAlternateSets +
index * sizeAlternateSetOffset)
));
}
// Not used. This value should be equal to glyph count in Coverage.
// Keeping it for future reference
//private ushort SequenceCount(FontTable Table)
//{
// return Table.GetUShort(offset + offsetSequenceCount);
//}
private MultipleSubstitutionSequenceTable Sequence(FontTable Table, int Index)
{
return(new MultipleSubstitutionSequenceTable(
offset +
Table.GetUShort(offset +
offsetSequenceArray +
Index * sizeSequenceOffset)
));
}
public bool IsLookupCovered(
FontTable table,
uint[] glyphBits,
ushort minGlyphId,
ushort maxGlyphId)
{
return(Coverage(table).IsAnyGlyphCovered(table,
glyphBits,
minGlyphId,
maxGlyphId
));
}
public bool IsLookupCovered(
FontTable table,
uint[] glyphBits,
ushort minGlyphId,
ushort maxGlyphId)
{
if (!Coverage(table).IsAnyGlyphCovered(table,
glyphBits,
minGlyphId,
maxGlyphId
)
)
{
return(false);
}
ushort ligatureSetCount = LigatureSetCount(table);
for (ushort setIndex = 0; setIndex < ligatureSetCount; setIndex++)
{
LigatureSetTable ligatureSet = LigatureSet(table, setIndex);
ushort ligaCount = ligatureSet.LigatureCount(table);
for (ushort liga = 0; liga < ligaCount; liga++)
{
LigatureTable ligature = ligatureSet.Ligature(table, liga);
ushort compCount = ligature.ComponentCount(table);
bool ligatureIsComplex = true;
for (ushort compIndex = 1; compIndex < compCount; compIndex++)
{
ushort glyphId = ligature.Component(table, compIndex);
if (glyphId > maxGlyphId ||
glyphId < minGlyphId ||
(glyphBits[glyphId >> 5] & (1 << (glyphId % 32))) == 0
)
{
ligatureIsComplex = false;
break;
}
}
if (ligatureIsComplex)
{
return(true);
}
}
}
return(false);
}
private static bool AppendCoverageGlyphRecords(
FontTable table,
ushort lookupIndex,
CoverageTable coverage,
GlyphLookupRecord[] records,
ref int recordCount,
ref int maxLookupGlyph
)
{
switch (coverage.Format(table))
{
case 1:
ushort glyphCount = coverage.Format1GlyphCount(table);
for (ushort i = 0; i < glyphCount; i++)
{
ushort glyph = coverage.Format1Glyph(table, i);
if (!AppendGlyphRecord(glyph, lookupIndex, records, ref recordCount, ref maxLookupGlyph))
{
// We've failed to add another record.
return(false);
}
}
break;
case 2:
ushort rangeCount = coverage.Format2RangeCount(table);
for (ushort i = 0; i < rangeCount; i++)
{
ushort firstGlyph = coverage.Format2RangeStartGlyph(table, i);
ushort lastGlyph = coverage.Format2RangeEndGlyph(table, i);
for (int glyph = firstGlyph; glyph <= lastGlyph; glyph++)
{
if (!AppendGlyphRecord((ushort)glyph, lookupIndex, records, ref recordCount, ref maxLookupGlyph))
{
// We've failed to add another record.
return(false);
}
}
}
break;
}
return(true);
}
public ushort Alternate(FontTable Table, uint FeatureParam)
{
Invariant.Assert(FeatureParam > 0); // Parameter 0 means feautre is disabled.
//Should be filtered out in GetNextEnabledGlyphRange
// Off by one - alternate number 1 is stored under index 0
uint index = FeatureParam - 1;
if (index >= GlyphCount(Table))
{
return(AlternateSubstitutionSubtable.InvalidAlternateGlyph);
}
return(Table.GetUShort(offset + offsetGlyphs + (ushort)index * sizeGlyph));
}
/// <summary>
///
/// </summary>
/// <param name="Font">Font</param>
/// <param name="ScriptTag">Script to search in</param>
/// <param name="LangSysTag">LangGys to search for</param>
/// <returns>TagInfoFlags, if script not present == None</returns>
internal static TagInfoFlags FindLangSys(
IOpenTypeFont Font,
uint ScriptTag,
uint LangSysTag
)
{
TagInfoFlags flags = TagInfoFlags.None;
try
{
FontTable gsubTable = Font.GetFontTable(OpenTypeTags.GSUB);
if (gsubTable.IsPresent)
{
GSUBHeader gsubHeader = new GSUBHeader(0);
ScriptTable gsubScript = gsubHeader.GetScriptList(gsubTable).FindScript(gsubTable, ScriptTag);
if (!gsubScript.IsNull && !gsubScript.FindLangSys(gsubTable, LangSysTag).IsNull)
{
flags |= TagInfoFlags.Substitution;
}
}
}
catch (FileFormatException)
{
return(TagInfoFlags.None);
}
try
{
FontTable gposTable = Font.GetFontTable(OpenTypeTags.GPOS);
if (gposTable.IsPresent)
{
GPOSHeader gposHeader = new GPOSHeader(0);
ScriptTable gposScript = gposHeader.GetScriptList(gposTable).FindScript(gposTable, ScriptTag);
if (!gposScript.IsNull && !gposScript.FindLangSys(gposTable, LangSysTag).IsNull)
{
flags |= TagInfoFlags.Positioning;
}
}
}
catch (FileFormatException)
{
return(TagInfoFlags.None);
}
return(flags);
}
public ushort ComponentCount(FontTable Table)
{
return Table.GetUShort(offset + offsetComponentCount);
}
private LigatureSetTable LigatureSet(FontTable Table, ushort Index)
{
return new LigatureSetTable(offset+Table.GetUShort(offset+
offsetLigatureSetArray +
Index * sizeLigatureSet));
}
public LigatureTable Ligature(FontTable Table, ushort Index)
{
return new LigatureTable(offset + Table.GetUShort(offset +
offsetLigatureArray +
Index * sizeLigatureOffset));
}
public ushort ComponentCount(FontTable Table)
{
return(Table.GetUShort(offset + offsetComponentCount));
}
/// <summary>
/// Position glyphs according to features defined in the font.
/// </summary>
/// <param name="Font">In: Font access interface</param>
/// <param name="workspace">In: Workspace for layout engine</param>
/// <param name="ScriptTag">In: Script tag</param>
/// <param name="LangSysTag">In: LangSys tag</param>
/// <param name="Metrics">In: LayoutMetrics</param>
/// <param name="FeatureSet">In: List of features to apply</param>
/// <param name="featureCount">In: Actual number of features in <paramref name="FeatureSet"/></param>
/// <param name="featureSetOffset">In: offset of input characters inside FeatureSet</param>
/// <param name="CharCount">In: Characters count (i.e. <paramref name="Charmap"/>.Length);</param>
/// <param name="Charmap">In: Char to glyph mapping</param>
/// <param name="Glyphs">In/out: List of GlyphInfo structs</param>
/// <param name="Advances">In/out: Glyphs adv.widths</param>
/// <param name="Offsets">In/out: Glyph offsets</param>
/// <returns>Substitution result</returns>
internal static OpenTypeLayoutResult PositionGlyphs(
IOpenTypeFont Font,
OpenTypeLayoutWorkspace workspace,
uint ScriptTag,
uint LangSysTag,
LayoutMetrics Metrics,
Feature[] FeatureSet,
int featureCount,
int featureSetOffset,
int CharCount,
UshortList Charmap,
GlyphInfoList Glyphs,
int *Advances,
LayoutOffset *Offsets
)
{
try
{
FontTable GposTable = Font.GetFontTable(OpenTypeTags.GPOS);
if (!GposTable.IsPresent)
{
return(OpenTypeLayoutResult.ScriptNotFound);
}
GPOSHeader GposHeader = new GPOSHeader(0);
ScriptList ScriptList = GposHeader.GetScriptList(GposTable);
ScriptTable Script = ScriptList.FindScript(GposTable, ScriptTag);
if (Script.IsNull)
{
return(OpenTypeLayoutResult.ScriptNotFound);
}
LangSysTable LangSys = Script.FindLangSys(GposTable, LangSysTag);
if (LangSys.IsNull)
{
return(OpenTypeLayoutResult.LangSysNotFound);
}
FeatureList FeatureList = GposHeader.GetFeatureList(GposTable);
LookupList LookupList = GposHeader.GetLookupList(GposTable);
LayoutEngine.ApplyFeatures(
Font,
workspace,
OpenTypeTags.GPOS,
GposTable,
Metrics,
LangSys,
FeatureList,
LookupList,
FeatureSet,
featureCount,
featureSetOffset,
CharCount,
Charmap,
Glyphs,
Advances,
Offsets
);
}
catch (FileFormatException)
{
return(OpenTypeLayoutResult.BadFontTable);
}
return(OpenTypeLayoutResult.Success);
}
// Not used. This value should be equal to glyph count in Coverage.
// Keeping it for future reference
//private ushort SequenceCount(FontTable Table)
//{
// return Table.GetUShort(offset + offsetSequenceCount);
//}
private MultipleSubstitutionSequenceTable Sequence(FontTable Table, int Index)
{
return new MultipleSubstitutionSequenceTable(
offset +
Table.GetUShort(offset +
offsetSequenceArray +
Index * sizeSequenceOffset)
);
}
// Not used. This value should be equal to glyph count in Coverage.
// Keeping it for future reference
//private ushort Foramt2GlyphCount(FontTable Table)
//{
// Debug.Assert(Format(Table)==2);
// return Table.GetUShort(offset + offsetFormat2GlyphCount);
//}
private ushort Format2SubstituteGlyphId(FontTable Table,ushort Index)
{
Invariant.Assert(Format(Table)==2);
return Table.GetUShort(offset + offsetFormat2SubstitutehArray +
Index * sizeFormat2SubstituteSize);
}
private CoverageTable Coverage(FontTable Table)
{
return(new CoverageTable(offset + Table.GetUShort(offset + offsetCoverage)));
}
public LigatureTable Ligature(FontTable Table, ushort Index)
{
return(new LigatureTable(offset + Table.GetUShort(offset +
offsetLigatureArray +
Index * sizeLigatureOffset)));
}
public unsafe bool Apply(
IOpenTypeFont Font,
FontTable Table,
int CharCount,
UshortList Charmap, // Character to glyph map
GlyphInfoList GlyphInfo, // List of GlyphInfo
ushort LookupFlags, // Lookup flags for glyph lookups
int FirstGlyph, // where to apply it
int AfterLastGlyph, // how long is a context we can use
out int NextGlyph // Next glyph to process
)
{
NextGlyph = FirstGlyph + 1; // in case we don't match
if (Format(Table) != 1)
{
return(false); //unknown format
}
int oldGlyphCount = GlyphInfo.Length;
ushort glyphId = GlyphInfo.Glyphs[FirstGlyph];
int coverageIndex = Coverage(Table).GetGlyphIndex(Table, glyphId);
if (coverageIndex == -1)
{
return(false);
}
MultipleSubstitutionSequenceTable sequence = Sequence(Table, coverageIndex);
ushort sequenceLength = sequence.GlyphCount(Table);
int lengthDelta = sequenceLength - 1;
if (sequenceLength == 0)
{
// This is illegal, because mapping will be broken -
// corresponding char will be lost. Just leave it as it is.
// (char will be attached to the following glyph).
GlyphInfo.Remove(FirstGlyph, 1);
}
else
{
ushort firstChar = GlyphInfo.FirstChars[FirstGlyph];
ushort ligatureCount = GlyphInfo.LigatureCounts[FirstGlyph];
if (lengthDelta > 0)
{
GlyphInfo.Insert(FirstGlyph, lengthDelta);
}
//put glyphs in place
for (ushort gl = 0; gl < sequenceLength; gl++)
{
GlyphInfo.Glyphs[FirstGlyph + gl] = sequence.Glyph(Table, gl);
GlyphInfo.GlyphFlags[FirstGlyph + gl] =
(ushort)(GlyphFlags.Unresolved | GlyphFlags.Substituted);
GlyphInfo.FirstChars[FirstGlyph + gl] = firstChar;
GlyphInfo.LigatureCounts[FirstGlyph + gl] = ligatureCount;
}
}
// Fix char mapping - very simple for now.
// Works only for arabic base+mark -> base and marks decomposition
// Needs work for full mapping
for (int ch = 0; ch < CharCount; ch++)
{
if (Charmap[ch] > FirstGlyph)
{
Charmap[ch] = (ushort)(Charmap[ch] + lengthDelta);
}
}
NextGlyph = FirstGlyph + lengthDelta + 1;
return(true);
}
public ushort Format(FontTable Table)
{
return(Table.GetUShort(offset + offsetFormat));
}
// Not used. This value should be equal to glyph count in Coverage.
// Keeping it for future reference
//private ushort Foramt2GlyphCount(FontTable Table)
//{
// Debug.Assert(Format(Table)==2);
// return Table.GetUShort(offset + offsetFormat2GlyphCount);
//}
private ushort Format2SubstituteGlyphId(FontTable Table, ushort Index)
{
Invariant.Assert(Format(Table) == 2);
return(Table.GetUShort(offset + offsetFormat2SubstitutehArray +
Index * sizeFormat2SubstituteSize));
}
public ushort LigatureGlyph(FontTable Table)
{
return(Table.GetUShort(offset + offsetLigatureGlyph));
}
public ushort Glyph(FontTable Table, ushort index)
{
return(Table.GetUShort(offset + offsetGlyphArray + index * sizeGlyphId));
}
public unsafe bool Apply(
IOpenTypeFont Font,
FontTable Table,
int CharCount,
UshortList Charmap, // Character to glyph map
GlyphInfoList GlyphInfo, // List of GlyphInfo
ushort LookupFlags, // Lookup flags for glyph lookups
int FirstGlyph, // where to apply it
int AfterLastGlyph, // how long is a context we can use
out int NextGlyph // Next glyph to process
)
{
Invariant.Assert(FirstGlyph>=0);
Invariant.Assert(AfterLastGlyph<=GlyphInfo.Length);
NextGlyph = FirstGlyph + 1; //In case we don't match;
if (Format(Table) != 1) return false; // Unknown format
int glyphCount=GlyphInfo.Length;
ushort glyphId = GlyphInfo.Glyphs[FirstGlyph];
int CoverageIndex = Coverage(Table).GetGlyphIndex(Table,glyphId);
if (CoverageIndex==-1) return false;
int curGlyph;
ushort ligatureGlyph=0;
bool match = false;
ushort compCount=0;
LigatureSetTable ligatureSet = LigatureSet(Table,(ushort)CoverageIndex);
ushort ligaCount = ligatureSet.LigatureCount(Table);
for(ushort liga=0; liga<ligaCount; liga++)
{
LigatureTable ligature = ligatureSet.Ligature(Table,liga);
compCount = ligature.ComponentCount(Table);
if (compCount == 0)
{
throw new FileFormatException();
}
curGlyph=FirstGlyph;
ushort comp=1;
for(comp=1;comp<compCount;comp++)
{
curGlyph = LayoutEngine.GetNextGlyphInLookup(Font,GlyphInfo,curGlyph+1,LookupFlags,LayoutEngine.LookForward);
if (curGlyph>=AfterLastGlyph) break;
if (GlyphInfo.Glyphs[curGlyph]!=ligature.Component(Table,comp)) break;
}
if (comp==compCount) //liga matched
{
match=true;
ligatureGlyph = ligature.LigatureGlyph(Table);
break; //Liga found
}
}
//If no ligature found, match will remain false after last iteration
if (match)
{
//Fix character and glyph Mapping
//PERF: localize ligature character range
//Calculate Ligature CharCount
int totalLigaCharCount=0;
int firstLigaChar=int.MaxValue;
curGlyph=FirstGlyph;
for(ushort comp=0;comp<compCount;comp++)
{
Invariant.Assert(curGlyph<AfterLastGlyph);
int curFirstChar = GlyphInfo.FirstChars[curGlyph];
int curLigaCount = GlyphInfo.LigatureCounts[curGlyph];
totalLigaCharCount += curLigaCount;
if (curFirstChar<firstLigaChar) firstLigaChar=curFirstChar;
curGlyph = LayoutEngine.GetNextGlyphInLookup(Font,GlyphInfo,curGlyph+1,LookupFlags,LayoutEngine.LookForward);
}
curGlyph=FirstGlyph;
int prevGlyph=FirstGlyph;
ushort shift=0;
for(ushort comp=1;comp<=compCount;comp++)
{
prevGlyph=curGlyph;
if (comp<compCount)
{
curGlyph = LayoutEngine.
GetNextGlyphInLookup(Font,GlyphInfo,
curGlyph+1,
LookupFlags,
LayoutEngine.LookForward);
}
else curGlyph = GlyphInfo.Length; // to the end from last component
// Set charmap for ligature component
for(int curChar=0; curChar<CharCount; curChar++)
{
if (Charmap[curChar]==prevGlyph)
{
Charmap[curChar] = (ushort)FirstGlyph;
}
}
//Shift glyphInfo
if (shift>0)
{
for(int glyph=prevGlyph+1; glyph<curGlyph; glyph++)
{
GlyphInfo.Glyphs[glyph-shift] = GlyphInfo.Glyphs[glyph];
GlyphInfo.GlyphFlags[glyph-shift] = GlyphInfo.GlyphFlags[glyph];
GlyphInfo.FirstChars[glyph-shift] = GlyphInfo.FirstChars[glyph];
GlyphInfo.LigatureCounts[glyph-shift] = GlyphInfo.LigatureCounts[glyph];
}
if (curGlyph-prevGlyph>1) //do fixing only if have glyphs in between
{
for(int curChar=0; curChar<CharCount; curChar++)
{
ushort curCharmap = Charmap[curChar];
if (curCharmap>prevGlyph && curCharmap<curGlyph)
{
Charmap[curChar] -= shift;
}
}
}
}
++shift;
}
//Place new glyph into position of first ligature glyph
GlyphInfo.Glyphs[FirstGlyph] = ligatureGlyph;
GlyphInfo.GlyphFlags[FirstGlyph] = (ushort)(GlyphFlags.Unresolved | GlyphFlags.Substituted);
GlyphInfo.FirstChars[FirstGlyph] = (ushort)firstLigaChar;
GlyphInfo.LigatureCounts[FirstGlyph] = (ushort)totalLigaCharCount;
//remove empty space
if (compCount > 1)
{
GlyphInfo.Remove(GlyphInfo.Length-compCount+1,compCount-1);
}
NextGlyph=prevGlyph-(compCount-1)+1;
}
return match;
}
public ushort GlyphCount(FontTable Table)
{
return(Table.GetUShort(offset + offsetGlyphCount));
}
public ushort Glyph(FontTable Table, ushort index)
{
return Table.GetUShort(offset + offsetGlyphArray + index * sizeGlyphId);
}
public unsafe bool Apply(
FontTable Table,
GlyphInfoList GlyphInfo, // List of GlyphInfo
uint FeatureParam, // For this lookup - index of glyph alternate
int FirstGlyph, // where to apply it
out int NextGlyph // Next glyph to process
)
{
NextGlyph = FirstGlyph + 1; // always move one glyph forward,
// doesn't matter whether we matched context
if (Format(Table) != 1) return false; //Unknown format
int oldGlyphCount=GlyphInfo.Length;
int coverageIndex = Coverage(Table).
GetGlyphIndex(Table,GlyphInfo.Glyphs[FirstGlyph]);
if (coverageIndex==-1) return false;
AlternateSetTable alternateSet = AlternateSet(Table,coverageIndex);
ushort alternateGlyph = alternateSet.Alternate(Table, FeatureParam);
if (alternateGlyph != InvalidAlternateGlyph)
{
GlyphInfo.Glyphs[FirstGlyph] = alternateGlyph;
GlyphInfo.GlyphFlags[FirstGlyph] = (ushort)(GlyphFlags.Unresolved | GlyphFlags.Substituted);
return true;
}
return false;
}
public ushort Format(FontTable Table)
{
return Table.GetUShort(offset + offsetFormat);
}
public unsafe bool Apply(
IOpenTypeFont Font,
FontTable Table,
int CharCount,
UshortList Charmap, // Character to glyph map
GlyphInfoList GlyphInfo, // List of GlyphInfo
ushort LookupFlags, // Lookup flags for glyph lookups
int FirstGlyph, // where to apply it
int AfterLastGlyph, // how long is a context we can use
out int NextGlyph // Next glyph to process
)
{
Invariant.Assert(FirstGlyph >= 0);
Invariant.Assert(AfterLastGlyph <= GlyphInfo.Length);
NextGlyph = FirstGlyph + 1; //In case we don't match;
if (Format(Table) != 1)
{
return(false); // Unknown format
}
int glyphCount = GlyphInfo.Length;
ushort glyphId = GlyphInfo.Glyphs[FirstGlyph];
int CoverageIndex = Coverage(Table).GetGlyphIndex(Table, glyphId);
if (CoverageIndex == -1)
{
return(false);
}
int curGlyph;
ushort ligatureGlyph = 0;
bool match = false;
ushort compCount = 0;
LigatureSetTable ligatureSet = LigatureSet(Table, (ushort)CoverageIndex);
ushort ligaCount = ligatureSet.LigatureCount(Table);
for (ushort liga = 0; liga < ligaCount; liga++)
{
LigatureTable ligature = ligatureSet.Ligature(Table, liga);
compCount = ligature.ComponentCount(Table);
if (compCount == 0)
{
throw new FileFormatException();
}
curGlyph = FirstGlyph;
ushort comp = 1;
for (comp = 1; comp < compCount; comp++)
{
curGlyph = LayoutEngine.GetNextGlyphInLookup(Font, GlyphInfo, curGlyph + 1, LookupFlags, LayoutEngine.LookForward);
if (curGlyph >= AfterLastGlyph)
{
break;
}
if (GlyphInfo.Glyphs[curGlyph] != ligature.Component(Table, comp))
{
break;
}
}
if (comp == compCount) //liga matched
{
match = true;
ligatureGlyph = ligature.LigatureGlyph(Table);
break; //Liga found
}
}
//If no ligature found, match will remain false after last iteration
if (match)
{
//Fix character and glyph Mapping
//PERF: localize ligature character range
//Calculate Ligature CharCount
int totalLigaCharCount = 0;
int firstLigaChar = int.MaxValue;
curGlyph = FirstGlyph;
for (ushort comp = 0; comp < compCount; comp++)
{
Invariant.Assert(curGlyph < AfterLastGlyph);
int curFirstChar = GlyphInfo.FirstChars[curGlyph];
int curLigaCount = GlyphInfo.LigatureCounts[curGlyph];
totalLigaCharCount += curLigaCount;
if (curFirstChar < firstLigaChar)
{
firstLigaChar = curFirstChar;
}
curGlyph = LayoutEngine.GetNextGlyphInLookup(Font, GlyphInfo, curGlyph + 1, LookupFlags, LayoutEngine.LookForward);
}
curGlyph = FirstGlyph;
int prevGlyph = FirstGlyph;
ushort shift = 0;
for (ushort comp = 1; comp <= compCount; comp++)
{
prevGlyph = curGlyph;
if (comp < compCount)
{
curGlyph = LayoutEngine.
GetNextGlyphInLookup(Font, GlyphInfo,
curGlyph + 1,
LookupFlags,
LayoutEngine.LookForward);
}
else
{
curGlyph = GlyphInfo.Length; // to the end from last component
}
// Set charmap for ligature component
for (int curChar = 0; curChar < CharCount; curChar++)
{
if (Charmap[curChar] == prevGlyph)
{
Charmap[curChar] = (ushort)FirstGlyph;
}
}
//Shift glyphInfo
if (shift > 0)
{
for (int glyph = prevGlyph + 1; glyph < curGlyph; glyph++)
{
GlyphInfo.Glyphs[glyph - shift] = GlyphInfo.Glyphs[glyph];
GlyphInfo.GlyphFlags[glyph - shift] = GlyphInfo.GlyphFlags[glyph];
GlyphInfo.FirstChars[glyph - shift] = GlyphInfo.FirstChars[glyph];
GlyphInfo.LigatureCounts[glyph - shift] = GlyphInfo.LigatureCounts[glyph];
}
if (curGlyph - prevGlyph > 1) //do fixing only if have glyphs in between
{
for (int curChar = 0; curChar < CharCount; curChar++)
{
ushort curCharmap = Charmap[curChar];
if (curCharmap > prevGlyph && curCharmap < curGlyph)
{
Charmap[curChar] -= shift;
}
}
}
}
++shift;
}
//Place new glyph into position of first ligature glyph
GlyphInfo.Glyphs[FirstGlyph] = ligatureGlyph;
GlyphInfo.GlyphFlags[FirstGlyph] = (ushort)(GlyphFlags.Unresolved | GlyphFlags.Substituted);
GlyphInfo.FirstChars[FirstGlyph] = (ushort)firstLigaChar;
GlyphInfo.LigatureCounts[FirstGlyph] = (ushort)totalLigaCharCount;
//remove empty space
if (compCount > 1)
{
GlyphInfo.Remove(GlyphInfo.Length - compCount + 1, compCount - 1);
}
NextGlyph = prevGlyph - (compCount - 1) + 1;
}
return(match);
}
public ushort GlyphCount(FontTable Table)
{
return Table.GetUShort(offset + offsetGlyphCount);
}
private short Format1DeltaGlyphId(FontTable Table)
{
Invariant.Assert(Format(Table) == 1);
return(Table.GetShort(offset + offsetFormat1DeltaGlyphId));
}
public bool IsLookupCovered(
FontTable table,
uint[] glyphBits,
ushort minGlyphId,
ushort maxGlyphId)
{
return Coverage(table).IsAnyGlyphCovered(table,
glyphBits,
minGlyphId,
maxGlyphId
);
}
public CoverageTable GetPrimaryCoverage(FontTable table)
{
return(Coverage(table));
}
/* This is unused code, but will be used later so it is just commented out for now.
*
* /// <summary>
* /// Enumerates scripts in a font
* /// </summary>
* internal static OpenTypeLayoutResult GetScriptList (
* IOpenTypeFont Font, // In: Font access interface
* out TagInfo[] Scripts // Out: Array of scripts supported
* )
* {
* ushort i;
* ushort GposNewTags;
*
* Scripts=null; // Assignment required, because of out attribute.
* // This value should be owerwritten later.
*
* try
* {
* FontTable GsubTable = Font.GetFontTable(OpenTypeTags.GSUB);
* FontTable GposTable = Font.GetFontTable(OpenTypeTags.GPOS);
*
* GSUBHeader GsubHeader = new GSUBHeader(0);
* GPOSHeader GposHeader = new GPOSHeader(0);
*
* ScriptList GsubScriptList;
* ScriptList GposScriptList;
* ushort GsubScriptCount;
* ushort GposScriptCount;
*
* if (GsubTable.IsNotPresent && GposTable.IsNotPresent)
* {
* Scripts = Array.Empty<TagInfo>();
* return OpenTypeLayoutResult.Success;
* }
*
* if (GsubTable.IsPresent)
* {
* GsubScriptList = GsubHeader.GetScriptList(GsubTable);
* GsubScriptCount = GsubScriptList.GetScriptCount(GsubTable);
* }
* else
* {
* GsubScriptList = new ScriptList(FontTable.InvalidOffset);
* GsubScriptCount = 0;
* }
*
* if (GposTable.IsPresent)
* {
* GposScriptList = GposHeader.GetScriptList(GposTable);
* GposScriptCount = GposScriptList.GetScriptCount(GposTable);
* }
* else
* {
* GposScriptList = new ScriptList(FontTable.InvalidOffset);
* GposScriptCount = 0;
* }
*
* //This is true in most cases that there is no new tags in GPOS.
* //So, we allocate this array then check GPOS for new tags
* Scripts = new TagInfo[GsubScriptCount];
*
* for(i=0; i<GsubScriptCount; i++)
* {
* Scripts[i].Tag = GsubScriptList.GetScriptTag(GsubTable,i);
* Scripts[i].TagFlags = TagInfoFlags.Substitution;
* }
*
* //Check GPOS for tags that is not in GSUB
* GposNewTags=0;
*
* for(i=0;i<GposScriptCount;i++)
* {
* uint GposTag = GsubScriptList.GetScriptTag(GposTable,i);
* if (TagInfo.IsNewTag(Scripts,GposTag)) GposNewTags++;
* }
*
* //append new tags to ScriptTags if any exists
* if (GposNewTags>0)
* {
* int CurrentScriptIndex=GposScriptCount;
*
* //Allocate new array to fit all tags
* TagInfo[] tmp = Scripts;
* Scripts = new TagInfo[GsubScriptCount+GposNewTags];
* Array.Copy(tmp,0,Scripts,0,tmp.Length);
*
* for(i=0;i<GposScriptCount;i++)
* {
* uint GposTag = GsubScriptList.GetScriptTag(GposTable,i);
* if (TagInfo.IsNewTag(Scripts,GposTag))
* {
* Scripts[CurrentScriptIndex].Tag=GposTag;
* Scripts[CurrentScriptIndex].TagFlags
* = TagInfoFlags.Positioning;
++CurrentScriptIndex;
* }
* else
* {
* int ScriptIndex = TagInfo.GetTagIndex(Scripts,GposTag);
* Scripts[ScriptIndex].TagFlags |= TagInfoFlags.Positioning;
* }
* }
*
* Debug.Assert(CurrentScriptIndex==Scripts.Length);
* }
* }
* catch (FileFormatException)
* {
* return OpenTypeLayoutResult.BadFontTable;
* }
*
* return OpenTypeLayoutResult.Success;
* }
*
*
* ///<summary>
* /// Enumerates language systems for script
* /// </summary>
* internal static OpenTypeLayoutResult GetLangSysList (
* IOpenTypeFont Font, // In: Font access interface
* uint ScriptTag, // In: Script tag
* out TagInfo[] LangSystems // Out: Array of LangSystems for Script
* )
* {
* ushort i;
* ushort GposNewTags;
*
* LangSystems=null; // Assignment required, because of out attribute.
* // This value should be owerwritten later.
*
* try
* {
* FontTable GsubTable = Font.GetFontTable(OpenTypeTags.GSUB);
* FontTable GposTable = Font.GetFontTable(OpenTypeTags.GPOS);
*
* GSUBHeader GsubHeader = new GSUBHeader(0);
* GPOSHeader GposHeader = new GPOSHeader(0);
*
* ScriptList GsubScriptList;
* ScriptList GposScriptList;
* ScriptTable GsubScript;
* ScriptTable GposScript;
* ushort GsubLangSysCount;
* ushort GposLangSysCount;
*
* if (GsubTable.IsNotPresent && GposTable.IsNotPresent)
* {
* return OpenTypeLayoutResult.ScriptNotFound;
* }
*
* if (GsubTable.IsPresent)
* {
* GsubScriptList = GsubHeader.GetScriptList(GsubTable);
* GsubScript = GsubScriptList.FindScript(GsubTable,ScriptTag);
* }
* else
* {
* GsubScript = new ScriptTable(FontTable.InvalidOffset);
* }
*
* if (GposTable.IsPresent)
* {
* GposScriptList = GposHeader.GetScriptList(GposTable);
* GposScript = GposScriptList.FindScript(GposTable,ScriptTag);
* }
* else
* {
* GposScript = new ScriptTable(FontTable.InvalidOffset);
* }
*
* if (GsubScript.IsNull && GposScript.IsNull)
* {
* return OpenTypeLayoutResult.ScriptNotFound;
* }
*
* if (!GsubScript.IsNull)
* {
* GsubLangSysCount = GsubScript.GetLangSysCount(GsubTable);
* }
* else
* {
* GsubLangSysCount = 0;
* }
*
* if (!GposScript.IsNull)
* {
* GposLangSysCount = GposScript.GetLangSysCount(GposTable);
* }
* else
* {
* GposLangSysCount = 0;
* }
*
* //This is true in most cases that there is no new tags in GPOS.
* //So, we allocate this array then check GPOS for new tags
* ushort CurrentLangSysIndex;
*
* if (GsubScript.IsDefaultLangSysExists(GsubTable))
* {
* LangSystems = new TagInfo[GsubLangSysCount+1];
* LangSystems[0].Tag = (uint)OpenTypeTags.dflt;
* LangSystems[0].TagFlags = TagInfoFlags.Substitution;
* CurrentLangSysIndex = 1;
* }
* else
* {
* LangSystems = new TagInfo[GsubLangSysCount];
* CurrentLangSysIndex = 0;
* }
*
* for(i=0; i<GsubLangSysCount; i++)
* {
* LangSystems[CurrentLangSysIndex].Tag = GsubScript.GetLangSysTag(GsubTable,i);
* LangSystems[CurrentLangSysIndex].TagFlags = TagInfoFlags.Substitution;
++CurrentLangSysIndex;
* }
*
* //Check GPOS for tags that is not in GSUB
* GposNewTags=0;
*
* if (!GposScript.IsNull)
* {
* if (GposScript.IsDefaultLangSysExists(GposTable) &&
* TagInfo.IsNewTag(LangSystems,(uint)OpenTypeTags.dflt))
* {
++GposNewTags;
* }
*
* for(i=0;i<GposLangSysCount;i++)
* {
* uint GposTag = GsubScript.GetLangSysTag(GposTable,i);
* if (TagInfo.IsNewTag(LangSystems,GposTag))
* {
++GposNewTags;
* }
* }
* }
*
* Debug.Assert(CurrentLangSysIndex==LangSystems.Length);
*
* //append new tags to ScriptTags if any exists
* if (GposNewTags>0)
* {
* //Allocate new array to fit all tags
* TagInfo[] tmp = LangSystems;
* LangSystems = new TagInfo[GsubLangSysCount+GposNewTags];
* Array.Copy(tmp,0,LangSystems,0,tmp.Length);
*
* if (GposScript.IsDefaultLangSysExists(GposTable))
* {
* if (TagInfo.IsNewTag(LangSystems,(uint)OpenTypeTags.dflt))
* {
* LangSystems[CurrentLangSysIndex].Tag = (uint)OpenTypeTags.dflt;
* LangSystems[CurrentLangSysIndex].TagFlags = TagInfoFlags.Positioning;
++CurrentLangSysIndex;
* }
* else
* {
* int LangSysIndex = TagInfo.GetTagIndex(LangSystems,(uint)OpenTypeTags.dflt);
* LangSystems[LangSysIndex].TagFlags |= TagInfoFlags.Positioning;
* }
* }
*
* for(i=0;i<GposLangSysCount;i++)
* {
* uint GposTag = GposScript.GetLangSysTag(GposTable,i);
*
* if (TagInfo.IsNewTag(LangSystems,GposTag))
* {
* LangSystems[CurrentLangSysIndex].Tag = GposTag;
* LangSystems[CurrentLangSysIndex].TagFlags = TagInfoFlags.Positioning;
++CurrentLangSysIndex;
* }
* else
* {
* int LangSysIndex = TagInfo.GetTagIndex(LangSystems,GposTag);
* LangSystems[LangSysIndex].TagFlags |= TagInfoFlags.Positioning;
* }
* }
*
* Debug.Assert(CurrentLangSysIndex==LangSystems.Length);
* }
* }
* catch (FileFormatException)
* {
* return OpenTypeLayoutResult.BadFontTable;
* }
*
* return OpenTypeLayoutResult.Success;
* }
*
*
* /// <summary>
* /// Enumerates features in a language system
* /// </summary>
* internal static OpenTypeLayoutResult GetFeatureList (
* IOpenTypeFont Font, // In: Font access interface
* uint ScriptTag, // In: Script tag
* uint LangSysTag, // In: LangSys tag
* out TagInfo[] Features // Out: Array of features
* )
* {
* ushort i;
* ushort GposNewTags;
*
* Features=null; // Assignment required, because of out attribute.
* // This value should be owerwritten later.
*
* try
* {
* FontTable GsubTable = Font.GetFontTable(OpenTypeTags.GSUB);
* FontTable GposTable = Font.GetFontTable(OpenTypeTags.GPOS);
*
* GSUBHeader GsubHeader = new GSUBHeader(0);
* GPOSHeader GposHeader = new GPOSHeader(0);
*
* ScriptList GsubScriptList;
* ScriptList GposScriptList;
* ScriptTable GsubScript;
* ScriptTable GposScript;
* LangSysTable GsubLangSys;
* LangSysTable GposLangSys;
* ushort GsubFeatureCount;
* ushort GposFeatureCount;
* FeatureList GsubFeatureList;
* FeatureList GposFeatureList;
*
*
* if (GsubTable.IsNotPresent && GposTable.IsNotPresent)
* {
* return OpenTypeLayoutResult.ScriptNotFound;
* }
*
* if (GsubTable.IsPresent)
* {
* GsubScriptList = GsubHeader.GetScriptList(GsubTable);
* GsubScript = GsubScriptList.FindScript(GsubTable,ScriptTag);
* GsubLangSys = GsubScript.FindLangSys(GsubTable,LangSysTag);
* GsubFeatureList = GsubHeader.GetFeatureList(GsubTable);
* }
* else
* {
* GsubScript = new ScriptTable(FontTable.InvalidOffset);
* GsubLangSys = new LangSysTable(FontTable.InvalidOffset);
* GsubFeatureList = new FeatureList(FontTable.InvalidOffset);
* }
*
* if (GposTable.IsPresent)
* {
* GposScriptList = GposHeader.GetScriptList(GposTable);
* GposScript = GposScriptList.FindScript(GposTable,ScriptTag);
* GposLangSys = GposScript.FindLangSys(GposTable,LangSysTag);
* GposFeatureList = GposHeader.GetFeatureList(GposTable);
* }
* else
* {
* GposScript = new ScriptTable(FontTable.InvalidOffset);
* GposLangSys = new LangSysTable(FontTable.InvalidOffset);
* GposFeatureList = new FeatureList(FontTable.InvalidOffset);
* }
*
* if (GsubScript.IsNull && GposScript.IsNull)
* {
* return OpenTypeLayoutResult.ScriptNotFound;
* }
*
* if (GsubLangSys.IsNull && GposLangSys.IsNull)
* {
* return OpenTypeLayoutResult.LangSysNotFound;
* }
*
* if (!GsubLangSys.IsNull)
* {
* GsubFeatureCount = GsubLangSys.FeatureCount(GsubTable);
* }
* else
* {
* GsubFeatureCount = 0;
* }
*
* if (!GposLangSys.IsNull)
* {
* GposFeatureCount = GposLangSys.FeatureCount(GposTable);
* }
* else
* {
* GposFeatureCount = 0;
* }
*
* Features = new TagInfo[GsubFeatureCount];
* int CurrentFeatureIndex = 0;
*
* for(i=0; i<GsubFeatureCount; i++)
* {
* ushort FeatureIndex = GsubLangSys.GetFeatureIndex(GsubTable,i);
* Features[CurrentFeatureIndex].Tag = GsubFeatureList.FeatureTag(GsubTable,FeatureIndex);
* Features[CurrentFeatureIndex].TagFlags = TagInfoFlags.Substitution;
++CurrentFeatureIndex;
* }
*
* Debug.Assert(CurrentFeatureIndex==Features.Length);
*
* //Check GPOS for tags that is not in GSUB
* GposNewTags=0;
* if (!GposLangSys.IsNull)
* {
* for(i=0;i<GposFeatureCount;i++)
* {
* ushort FeatureIndex = GposLangSys.GetFeatureIndex(GposTable,i);
* uint GposTag = GposFeatureList.FeatureTag(GposTable,FeatureIndex);
* if (TagInfo.IsNewTag(Features,GposTag))
* {
++GposNewTags;
* }
* }
* }
*
* //append new tags to ScriptTags if any exists
* if (GposNewTags>0)
* {
* //Allocate new array to fit all tags
* TagInfo[] tmp = Features;
* Features = new TagInfo[GsubFeatureCount+GposNewTags];
* Array.Copy(tmp,0,Features,0,tmp.Length);
*
* for(i=0;i<GposFeatureCount;i++)
* {
* ushort FeatureIndex = GposLangSys.GetFeatureIndex(GposTable,i);
* uint GposTag = GposFeatureList.FeatureTag(GposTable,FeatureIndex);
*
* if (TagInfo.IsNewTag(Features,GposTag))
* {
* Features[CurrentFeatureIndex].Tag = GposTag;
* Features[CurrentFeatureIndex].TagFlags = TagInfoFlags.Positioning;
++CurrentFeatureIndex;
* }
* else
* {
* int Index = TagInfo.GetTagIndex(Features,GposTag);
* Features[Index].TagFlags |= TagInfoFlags.Positioning;
* }
* }
*
* Debug.Assert(CurrentFeatureIndex==Features.Length);
* }
*
*
* }
* catch (FileFormatException)
* {
* return OpenTypeLayoutResult.BadFontTable;
* }
*
* return OpenTypeLayoutResult.Success;
* }
*/
/// <summary>
/// Substitutes glyphs according to features defined in the font.
/// </summary>
/// <param name="Font">In: Font access interface</param>
/// <param name="workspace">In: Workspace for layout engine</param>
/// <param name="ScriptTag">In: Script tag</param>
/// <param name="LangSysTag">In: LangSys tag</param>
/// <param name="FeatureSet">In: List of features to apply</param>
/// <param name="featureCount">In: Actual number of features in <paramref name="FeatureSet"/></param>
/// <param name="featureSetOffset">In: offset of input characters inside FeatureSet</param>
/// <param name="CharCount">In: Characters count (i.e. <paramref name="Charmap"/>.Length);</param>
/// <param name="Charmap">In/out: Char to glyph mapping</param>
/// <param name="Glyphs">In/out: List of GlyphInfo structs</param>
/// <returns>Substitution result</returns>
internal static OpenTypeLayoutResult SubstituteGlyphs(
IOpenTypeFont Font, // In: Font access interface
OpenTypeLayoutWorkspace workspace, // In: Workspace for layout engine
uint ScriptTag, // In: Script tag
uint LangSysTag, // In: LangSys tag
Feature[] FeatureSet, // In: List of features to apply
int featureCount, // In: Actual number of features in FeatureSet
int featureSetOffset,
int CharCount, // In: Characters count (i.e. Charmap.Length);
UshortList Charmap, // In/out: Char to glyph mapping
GlyphInfoList Glyphs // In/out: List of GlyphInfo structs
)
{
try
{
FontTable GsubTable = Font.GetFontTable(OpenTypeTags.GSUB);
if (!GsubTable.IsPresent)
{
return(OpenTypeLayoutResult.ScriptNotFound);
}
GSUBHeader GsubHeader = new GSUBHeader(0);
ScriptList ScriptList = GsubHeader.GetScriptList(GsubTable);
ScriptTable Script = ScriptList.FindScript(GsubTable, ScriptTag);
if (Script.IsNull)
{
return(OpenTypeLayoutResult.ScriptNotFound);
}
LangSysTable LangSys = Script.FindLangSys(GsubTable, LangSysTag);
if (LangSys.IsNull)
{
return(OpenTypeLayoutResult.LangSysNotFound);
}
FeatureList FeatureList = GsubHeader.GetFeatureList(GsubTable);
LookupList LookupList = GsubHeader.GetLookupList(GsubTable);
LayoutEngine.ApplyFeatures(
Font,
workspace,
OpenTypeTags.GSUB,
GsubTable,
new LayoutMetrics(), //it is not needed for substitution
LangSys,
FeatureList,
LookupList,
FeatureSet,
featureCount,
featureSetOffset,
CharCount,
Charmap,
Glyphs,
null,
null
);
}
catch (FileFormatException)
{
return(OpenTypeLayoutResult.BadFontTable);
}
return(OpenTypeLayoutResult.Success);
}
public ushort LigatureCount(FontTable Table)
{
return(Table.GetUShort(offset + offsetLigatureCount));
}
private ushort LigatureSetCount(FontTable Table)
{
return Table.GetUShort(offset + offsetLigatureSetCount);
}
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
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
)
{
Invariant.Assert(Format(Table)==2);
NextGlyph = FirstGlyph + 1; //in case we don't match
int glyphCount = GlyphInfo.Length;
int glyphIndex = FirstGlyph;
ushort glyphId = GlyphInfo.Glyphs[glyphIndex];
if (Coverage(Table).GetGlyphIndex(Table,glyphId) < 0) return false;
ClassDefTable inputClassDef = InputClassDef(Table),
backtrackClassDef = BacktrackClassDef(Table),
lookaheadClassDef = LookaheadClassDef(Table);
ushort GlyphClass = inputClassDef.GetClass(Table,glyphId);
if (GlyphClass >= ClassSetCount(Table)) return false; //!!! Bad font table
SubClassSet subClassSet = ClassSet(Table,GlyphClass);
if (subClassSet.IsNull) return false; // There are no rules for this class
ushort ruleCount = subClassSet.RuleCount(Table);
bool match = false;
for(ushort i=0; !match && i<ruleCount; i++)
{
match = subClassSet.Rule(Table,i).Apply(Font, TableTag, Table, Metrics,
inputClassDef,backtrackClassDef,lookaheadClassDef,
CharCount, Charmap,
GlyphInfo, Advances, Offsets,
LookupFlags, FirstGlyph, AfterLastGlyph,
Parameter,
nestingLevel,
out NextGlyph
);
}
return match;
}
public ushort LigatureCount(FontTable Table)
{
return Table.GetUShort(offset + offsetLigatureCount);
}
public bool IsLookupCovered(
FontTable table,
uint[] glyphBits,
ushort minGlyphId,
ushort maxGlyphId)
{
return true;
}
public ushort LigatureGlyph(FontTable Table)
{
return Table.GetUShort(offset + offsetLigatureGlyph);
}
public CoverageTable BacktrackCoverage(FontTable Table, ushort Index)
{
return new CoverageTable(offset +
Table.GetUShort(offset+
offsetBacktrackGlyphCount +
sizeGlyphCount +
Index*sizeCoverageOffset)
);
}
public ushort Component(FontTable Table, ushort Index)
{
//LigaTable includes comps from 1 to N. So, (Index-1)
return Table.GetUShort(offset + offsetComponentArray +
(Index-1) * sizeComponent);
}
public CoverageTable LookaheadCoverage(FontTable Table, ushort Index)
{
return new CoverageTable(offset +
Table.GetUShort(offset+
offsetLookaheadGlyphCount +
sizeGlyphCount +
Index*sizeCoverageOffset)
);
}
public bool IsLookupCovered(
FontTable table,
uint[] glyphBits,
ushort minGlyphId,
ushort maxGlyphId)
{
if (!Coverage(table).IsAnyGlyphCovered(table,
glyphBits,
minGlyphId,
maxGlyphId
)
) return false;
ushort ligatureSetCount = LigatureSetCount(table);
for(ushort setIndex = 0; setIndex < ligatureSetCount; setIndex++)
{
LigatureSetTable ligatureSet = LigatureSet(table, setIndex);
ushort ligaCount = ligatureSet.LigatureCount(table);
for (ushort liga = 0; liga < ligaCount; liga++)
{
LigatureTable ligature = ligatureSet.Ligature(table, liga);
ushort compCount = ligature.ComponentCount(table);
bool ligatureIsComplex = true;
for(ushort compIndex = 1; compIndex < compCount; compIndex++)
{
ushort glyphId = ligature.Component(table,compIndex);
if (glyphId > maxGlyphId ||
glyphId < minGlyphId ||
(glyphBits[glyphId >> 5] & (1 << (glyphId % 32))) == 0
)
{
ligatureIsComplex = false;
break;
}
}
if (ligatureIsComplex) return true;
}
}
return false;
}
public ContextualLookupRecords ContextualLookups(FontTable Table)
{
int recordCountOffset = offset + offsetLookaheadGlyphCount + sizeGlyphCount +
LookaheadGlyphCount(Table) * sizeCoverageOffset;
return new ContextualLookupRecords(recordCountOffset+sizeGlyphCount,
Table.GetUShort(recordCountOffset));
}
private short Format1DeltaGlyphId(FontTable Table)
{
Invariant.Assert(Format(Table)==1);
return Table.GetShort(offset + offsetFormat1DeltaGlyphId);
}
public CoverageChainingSubtable(FontTable Table, int Offset)
{
offset = Offset;
offsetInputGlyphCount = offsetBacktrackGlyphCount + sizeGlyphCount +
Table.GetUShort(offset+offsetBacktrackGlyphCount) *
sizeCoverageOffset;
offsetLookaheadGlyphCount = offsetInputGlyphCount + sizeGlyphCount +
Table.GetUShort(offset+offsetInputGlyphCount) *
sizeCoverageOffset;
}
public unsafe bool Apply(
IOpenTypeFont Font,
FontTable Table,
int CharCount,
UshortList Charmap, // Character to glyph map
GlyphInfoList GlyphInfo, // List of GlyphInfo
ushort LookupFlags, // Lookup flags for glyph lookups
int FirstGlyph, // where to apply it
int AfterLastGlyph, // how long is a context we can use
out int NextGlyph // Next glyph to process
)
{
NextGlyph = FirstGlyph + 1; // in case we don't match
if (Format(Table) != 1) return false; //unknown format
int oldGlyphCount=GlyphInfo.Length;
ushort glyphId = GlyphInfo.Glyphs[FirstGlyph];
int coverageIndex = Coverage(Table).GetGlyphIndex(Table,glyphId);
if (coverageIndex==-1) return false;
MultipleSubstitutionSequenceTable sequence = Sequence(Table,coverageIndex);
ushort sequenceLength = sequence.GlyphCount(Table);
int lengthDelta = sequenceLength - 1;
if (sequenceLength==0)
{
// This is illegal, because mapping will be broken -
// corresponding char will be lost. Just leave it as it is.
// (char will be attached to the following glyph).
GlyphInfo.Remove(FirstGlyph,1);
}
else
{
ushort firstChar = GlyphInfo.FirstChars[FirstGlyph];
ushort ligatureCount = GlyphInfo.LigatureCounts[FirstGlyph];
if (lengthDelta > 0)
{
GlyphInfo.Insert(FirstGlyph,lengthDelta);
}
//put glyphs in place
for(ushort gl=0; gl<sequenceLength; gl++)
{
GlyphInfo.Glyphs[FirstGlyph + gl] = sequence.Glyph(Table,gl);
GlyphInfo.GlyphFlags[FirstGlyph + gl] =
(ushort)(GlyphFlags.Unresolved | GlyphFlags.Substituted);
GlyphInfo.FirstChars[FirstGlyph + gl] = firstChar;
GlyphInfo.LigatureCounts[FirstGlyph + gl] = ligatureCount;
}
}
//Fix char mapping - very simple for now.
// Works only for arabic base+mark -> base and marks decomposition
//
for(int ch=0;ch<CharCount;ch++)
{
if (Charmap[ch]>FirstGlyph) Charmap[ch] = (ushort)(Charmap[ch]+lengthDelta);
}
NextGlyph = FirstGlyph + lengthDelta + 1;
return true;
}
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
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
)
{
Invariant.Assert(Format(Table)==3);
NextGlyph = FirstGlyph + 1; //in case we don't match
int glyphCount = GlyphInfo.Length;
int glyphIndex;
ushort backtrackGlyphCount = BacktrackGlyphCount(Table);
ushort inputGlyphCount = InputGlyphCount(Table);
ushort lookaheadGlyphCount = LookaheadGlyphCount(Table);
if (FirstGlyph < backtrackGlyphCount ||
(FirstGlyph + inputGlyphCount) > AfterLastGlyph)
{
return false;
}
bool match = true;
//Check backtrack sequence
glyphIndex = FirstGlyph;
for(ushort backtrackIndex = 0;
backtrackIndex < backtrackGlyphCount && match;
backtrackIndex++)
{
glyphIndex = LayoutEngine.GetNextGlyphInLookup(Font, GlyphInfo,
glyphIndex-1,
LookupFlags,
LayoutEngine.LookBackward
);
if (glyphIndex<0 ||
BacktrackCoverage(Table,backtrackIndex)
.GetGlyphIndex(Table,GlyphInfo.Glyphs[glyphIndex])<0)
{
match=false;
}
}
if (!match) return false;
glyphIndex = FirstGlyph;
for(ushort inputIndex = 0;
inputIndex < inputGlyphCount && match;
inputIndex++)
{
if (glyphIndex>=AfterLastGlyph ||
InputCoverage(Table,inputIndex)
.GetGlyphIndex(Table,GlyphInfo.Glyphs[glyphIndex])<0)
{
match=false;
}
else
{
glyphIndex = LayoutEngine.GetNextGlyphInLookup(Font, GlyphInfo,
glyphIndex + 1,
LookupFlags,
LayoutEngine.LookForward
);
}
}
if (!match) return false;
int afterInputGlyph = glyphIndex; // remember where we were after input seqence
for(ushort lookaheadIndex = 0;
lookaheadIndex < lookaheadGlyphCount && match;
lookaheadIndex++)
{
if (glyphIndex>=GlyphInfo.Length ||
LookaheadCoverage(Table,lookaheadIndex)
.GetGlyphIndex(Table,GlyphInfo.Glyphs[glyphIndex])<0)
{
match=false;
}
else
{
glyphIndex = LayoutEngine.
GetNextGlyphInLookup(Font, GlyphInfo,
glyphIndex + 1,
LookupFlags,
LayoutEngine.LookForward);
}
}
if (match)
{
ContextualLookups(Table).ApplyContextualLookups(
Font,
TableTag,
Table,
Metrics,
CharCount,
Charmap,
GlyphInfo,
Advances,
Offsets,
LookupFlags,
FirstGlyph,
afterInputGlyph, //As AfterLastGlyph
Parameter,
nestingLevel,
out NextGlyph
);
}
return match;
}
private CoverageTable Coverage(FontTable Table)
{
return new CoverageTable(offset + Table.GetUShort(offset + offsetCoverage));
}
private LigatureSetTable LigatureSet(FontTable Table, ushort Index)
{
return(new LigatureSetTable(offset + Table.GetUShort(offset +
offsetLigatureSetArray +
Index * sizeLigatureSet)));
}
// Not used. This value should be equal to glyph count in Coverage.
// Keeping it for future reference
//private ushort AlternateSetCount(FontTable Table)
//{
// return Table.GetUShort(offset + offsetAlternateSetCount);
//}
private AlternateSetTable AlternateSet(FontTable Table, int index)
{
return new AlternateSetTable(offset +
Table.GetUShort(offset +
offsetAlternateSets +
index * sizeAlternateSetOffset)
);
}
private static void ComputeTableCache(
IOpenTypeFont font,
OpenTypeTags tableTag,
int maxCacheSize,
ref int cacheSize,
ref GlyphLookupRecord[] records,
ref int recordCount,
ref int glyphCount,
ref int lastLookupAdded
)
{
FontTable table = font.GetFontTable(tableTag);
if (!table.IsPresent)
{
return;
}
FeatureList featureList;
LookupList lookupList;
Debug.Assert(tableTag == OpenTypeTags.GSUB || tableTag == OpenTypeTags.GPOS);
switch (tableTag)
{
case OpenTypeTags.GSUB:
{
GSUBHeader header = new GSUBHeader();
featureList = header.GetFeatureList(table);
lookupList = header.GetLookupList(table);
break;
}
case OpenTypeTags.GPOS:
{
GPOSHeader header = new GPOSHeader();
featureList = header.GetFeatureList(table);
lookupList = header.GetLookupList(table);
break;
}
default:
{
Debug.Assert(false);
featureList = new FeatureList(0);
lookupList = new LookupList(0);
break;
}
}
// Estimate number of records that can fit into cache using ratio of approximately
// 4 bytes of cache per actual record. Most of fonts will fit into this value, except
// some tiny caches and big EA font that can have ratio of around 5 (theoretical maximum is 8).
//
// If actual ratio for particluar font will be larger than 4, we will remove records
// from the end to fit into cache.
//
// If ratio is less than 4 we actually can fit more lookups, but for the speed and because most fonts
// will fit into cache completely anyway we do not do anything about this here.
int maxRecordCount = maxCacheSize / 4;
// For now, we will just allocate array of maximum size.
// Given heuristics above, it wont be greater than max cache size.
//
records = new GlyphLookupRecord[maxRecordCount];
//
// Now iterate through lookups and subtables, filling in lookup-glyph pairs list
//
int lookupCount = lookupList.LookupCount(table);
int recordCountAfterLastLookup = 0;
//
// Not all lookups can be invoked from feature directly,
// they are actions from contextual lookups.
// We are not interested in those, because they will
// never work from high level, so do not bother adding them to the cache.
//
// Filling array of lookup usage bits, to skip those not mapped to any lookup
//
BitArray lookupUsage = new BitArray(lookupCount);
for (ushort feature = 0; feature < featureList.FeatureCount(table); feature++)
{
FeatureTable featureTable = featureList.FeatureTable(table, feature);
for (ushort lookup = 0; lookup < featureTable.LookupCount(table); lookup++)
{
ushort lookupIndex = featureTable.LookupIndex(table, lookup);
if (lookupIndex >= lookupCount)
{
// This must be an invalid font. Just igonoring this lookup here.
continue;
}
lookupUsage[lookupIndex] = true;
}
}
// Done with lookup usage bits
for (ushort lookupIndex = 0; lookupIndex < lookupCount; lookupIndex++)
{
if (!lookupUsage[lookupIndex])
{
continue;
}
int firstLookupRecord = recordCount;
int maxLookupGlyph = -1;
bool cacheIsFull = false;
LookupTable lookup = lookupList.Lookup(table, lookupIndex);
ushort lookupType = lookup.LookupType();
ushort subtableCount = lookup.SubTableCount();
for (ushort subtableIndex = 0; subtableIndex < subtableCount; subtableIndex++)
{
int subtableOffset = lookup.SubtableOffset(table, subtableIndex);
CoverageTable coverage = GetSubtablePrincipalCoverage(table, tableTag, lookupType, subtableOffset);
if (coverage.IsInvalid)
{
continue;
}
cacheIsFull = !AppendCoverageGlyphRecords(table, lookupIndex, coverage, records, ref recordCount, ref maxLookupGlyph);
if (cacheIsFull)
{
break;
}
}
if (cacheIsFull)
{
break;
}
lastLookupAdded = lookupIndex;
recordCountAfterLastLookup = recordCount;
}
// We may hit storage overflow in the middle of lookup. Throw this partial lookup away
recordCount = recordCountAfterLastLookup;
if (lastLookupAdded == -1)
{
// We did not succeed adding even single lookup.
return;
}
// We now have glyph records for (may be not all) lookups in the table.
// Cache structures should be sorted by glyph, then by lookup index.
Array.Sort(records, 0, recordCount);
cacheSize = -1;
glyphCount = -1;
// It may happen, that records do not fit into cache, even using our heuristics.
// We will remove lookups one by one from the end until it fits.
while (recordCount > 0)
{
CalculateCacheSize(records, recordCount, out cacheSize, out glyphCount);
if (cacheSize <= maxCacheSize)
{
// Fine, we now fit into max cache size
break;
}
else
{
// Find last lookup index
int lastLookup = -1;
for (int i = 0; i < recordCount; i++)
{
int lookup = records[i].Lookup;
if (lastLookup < lookup)
{
lastLookup = lookup;
}
}
Debug.Assert(lastLookup >= 0); // There are lookups, so there was an index
// Remove it
int currentRecord = 0;
for (int i = 0; i < recordCount; i++)
{
if (records[i].Lookup == lastLookup)
{
continue;
}
if (currentRecord == i)
{
continue;
}
records[currentRecord] = records[i];
currentRecord++;
}
recordCount = currentRecord;
// Do not forget update lastLookupAdded variable
lastLookupAdded = lastLookup - 1;
}
}
if (recordCount == 0)
{
// We can't fit even single lookup into the cache
return;
}
Debug.Assert(cacheSize > 0); // We've calcucalted them at least ones, and
Debug.Assert(glyphCount > 0); // if there is no records, we already should've exited
}
public ushort Alternate(FontTable Table, uint FeatureParam)
{
Invariant.Assert(FeatureParam > 0); // Parameter 0 means feautre is disabled.
//Should be filtered out in GetNextEnabledGlyphRange
// Off by one - alternate number 1 is stored under index 0
uint index = FeatureParam - 1;
if (index >= GlyphCount(Table))
{
return AlternateSubstitutionSubtable.InvalidAlternateGlyph;
}
return Table.GetUShort(offset + offsetGlyphs + (ushort)index*sizeGlyph);
}
private static CoverageTable GetSubtablePrincipalCoverage(
FontTable table,
OpenTypeTags tableTag,
ushort lookupType,
int subtableOffset
)
{
Debug.Assert(tableTag == OpenTypeTags.GSUB || tableTag == OpenTypeTags.GPOS);
CoverageTable coverage = CoverageTable.InvalidCoverage;
switch (tableTag)
{
case OpenTypeTags.GSUB:
if (lookupType == 7)
{
ExtensionLookupTable extension =
new ExtensionLookupTable(subtableOffset);
lookupType = extension.LookupType(table);
subtableOffset = extension.LookupSubtableOffset(table);
}
switch (lookupType)
{
case 1: //SingleSubst
SingleSubstitutionSubtable singleSubst =
new SingleSubstitutionSubtable(subtableOffset);
return(singleSubst.GetPrimaryCoverage(table));
case 2: //MultipleSubst
MultipleSubstitutionSubtable multipleSub =
new MultipleSubstitutionSubtable(subtableOffset);
return(multipleSub.GetPrimaryCoverage(table));
case 3: //AlternateSubst
AlternateSubstitutionSubtable alternateSub =
new AlternateSubstitutionSubtable(subtableOffset);
return(alternateSub.GetPrimaryCoverage(table));
case 4: //Ligature subst
LigatureSubstitutionSubtable ligaSub =
new LigatureSubstitutionSubtable(subtableOffset);
return(ligaSub.GetPrimaryCoverage(table));
case 5: //ContextualSubst
ContextSubtable contextSub =
new ContextSubtable(subtableOffset);
return(contextSub.GetPrimaryCoverage(table));
case 6: //ChainingSubst
ChainingSubtable chainingSub =
new ChainingSubtable(subtableOffset);
return(chainingSub.GetPrimaryCoverage(table));
case 7: //Extension lookup
// Ext.Lookup processed earlier. It can't contain another ext.lookups in it
break;
case 8: //ReverseCahiningSubst
ReverseChainingSubtable reverseChainingSub =
new ReverseChainingSubtable(subtableOffset);
return(reverseChainingSub.GetPrimaryCoverage(table));
}
break;
case OpenTypeTags.GPOS:
if (lookupType == 9)
{
ExtensionLookupTable extension =
new ExtensionLookupTable(subtableOffset);
lookupType = extension.LookupType(table);
subtableOffset = extension.LookupSubtableOffset(table);
}
switch (lookupType)
{
case 1: //SinglePos
SinglePositioningSubtable singlePos =
new SinglePositioningSubtable(subtableOffset);
return(singlePos.GetPrimaryCoverage(table));
case 2: //PairPos
PairPositioningSubtable pairPos =
new PairPositioningSubtable(subtableOffset);
return(pairPos.GetPrimaryCoverage(table));
case 3: // CursivePos
CursivePositioningSubtable cursivePos =
new CursivePositioningSubtable(subtableOffset);
return(cursivePos.GetPrimaryCoverage(table));
case 4: //MarkToBasePos
MarkToBasePositioningSubtable markToBasePos =
new MarkToBasePositioningSubtable(subtableOffset);
return(markToBasePos.GetPrimaryCoverage(table));
case 5: //MarkToLigaturePos
// Under construction
MarkToLigaturePositioningSubtable markToLigaPos =
new MarkToLigaturePositioningSubtable(subtableOffset);
return(markToLigaPos.GetPrimaryCoverage(table));
case 6: //MarkToMarkPos
MarkToMarkPositioningSubtable markToMarkPos =
new MarkToMarkPositioningSubtable(subtableOffset);
return(markToMarkPos.GetPrimaryCoverage(table));
case 7: // Contextual
ContextSubtable contextPos =
new ContextSubtable(subtableOffset);
return(contextPos.GetPrimaryCoverage(table));
case 8: // Chaining
ChainingSubtable chainingPos =
new ChainingSubtable(subtableOffset);
return(chainingPos.GetPrimaryCoverage(table));
case 9: //Extension lookup
// Ext.Lookup processed earlier. It can't contain another ext.lookups in it
break;
}
break;
}
return(CoverageTable.InvalidCoverage);
}
private ushort LigatureSetCount(FontTable Table)
{
return(Table.GetUShort(offset + offsetLigatureSetCount));
}
///<summary>
/// Internal method to test layout tables if they are uitable for fast path.
/// Returns list of script-langauge pairs that are not optimizable.
///</summary>
internal static OpenTypeLayoutResult GetComplexLanguageList(
IOpenTypeFont Font, //In: Font access interface
uint[] featureList, //In: Feature to look in
uint[] glyphBits,
ushort minGlyphId,
ushort maxGlyphId,
out WritingSystem[] complexLanguages
// Out: List of script/langauge pair
// that are not optimizable
)
{
try
{
WritingSystem[] gsubComplexLanguages = null;
WritingSystem[] gposComplexLanguages = null;
int gsubComplexLanguagesCount = 0;
int gposComplexLanguagesCount = 0;
FontTable GsubTable = Font.GetFontTable(OpenTypeTags.GSUB);
FontTable GposTable = Font.GetFontTable(OpenTypeTags.GPOS);
if (GsubTable.IsPresent)
{
LayoutEngine.GetComplexLanguageList(
OpenTypeTags.GSUB,
GsubTable,
featureList,
glyphBits,
minGlyphId,
maxGlyphId,
out gsubComplexLanguages,
out gsubComplexLanguagesCount
);
}
if (GposTable.IsPresent)
{
LayoutEngine.GetComplexLanguageList(
OpenTypeTags.GPOS,
GposTable,
featureList,
glyphBits,
minGlyphId,
maxGlyphId,
out gposComplexLanguages,
out gposComplexLanguagesCount
);
}
if (gsubComplexLanguages == null && gposComplexLanguages == null)
{
complexLanguages = null;
return(OpenTypeLayoutResult.Success);
}
// Both tables have complex scrips, merge results
// Count gpos unique Languages
// and pack them at the same time
// so we do not research them again.
int gposNewLanguages = 0, i, j;
for (i = 0; i < gposComplexLanguagesCount; i++)
{
bool foundInGsub = false;
for (j = 0; j < gsubComplexLanguagesCount; j++)
{
if (gsubComplexLanguages[j].scriptTag == gposComplexLanguages[i].scriptTag &&
gsubComplexLanguages[j].langSysTag == gposComplexLanguages[i].langSysTag
)
{
foundInGsub = true;
break;
}
;
}
if (!foundInGsub)
{
if (gposNewLanguages < i)
{
gposComplexLanguages[gposNewLanguages] = gposComplexLanguages[i];
}
gposNewLanguages++;
}
}
//realloc array for merged results, merge both arrays
complexLanguages = new WritingSystem[gsubComplexLanguagesCount + gposNewLanguages];
for (i = 0; i < gsubComplexLanguagesCount; i++)
{
complexLanguages[i] = gsubComplexLanguages[i];
}
for (i = 0; i < gposNewLanguages; i++)
{
complexLanguages[gsubComplexLanguagesCount + i] = gposComplexLanguages[i];
}
return(OpenTypeLayoutResult.Success);
}
catch (FileFormatException)
{
complexLanguages = null;
return(OpenTypeLayoutResult.BadFontTable);
}
}
public CoverageTable GetPrimaryCoverage(FontTable table)
{
return Coverage(table);
}
public ushort Component(FontTable Table, ushort Index)
{
//LigaTable includes comps from 1 to N. So, (Index-1)
return(Table.GetUShort(offset + offsetComponentArray +
(Index - 1) * sizeComponent));
}