public unsafe void ApplyContextualLookups(
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
)
{
// Limit nesting level for contextual lookups to
// prevent infinite loops from corrupt fonts
if (nestingLevel >= MaximumContextualLookupNestingLevel)
{
nextGlyph = AfterLastGlyph;
return;
}
LookupList lookupList;
if (TableTag == OpenTypeTags.GSUB)
{
lookupList = (new GSUBHeader(0)).GetLookupList(Table);
}
else
{
lookupList = (new GPOSHeader(0)).GetLookupList(Table);
}
int prevLookupIndex = -1;
int prevSequenceIndex = -1;
while (true)
{
ushort lookupIndex = ushort.MaxValue;
ushort sequenceIndex = ushort.MaxValue;
for(ushort i = 0; i < recordCount; i++)
{
ushort recordLookupIndex = LookupIndex(Table,i);
ushort recordSequenceIndex = SequenceIndex(Table,i);
if (recordLookupIndex < prevLookupIndex ||
(recordLookupIndex == prevLookupIndex &&
recordSequenceIndex <= prevSequenceIndex
)
)
{
// This record we already should have been processed
continue;
}
// Among not proccessed record, find next one
if ( recordLookupIndex < lookupIndex ||
(recordLookupIndex == lookupIndex &&
recordSequenceIndex < sequenceIndex
)
)
{
lookupIndex = recordLookupIndex;
sequenceIndex = recordSequenceIndex;
}
}
if (lookupIndex == ushort.MaxValue)
{
// All records processed (or we had duplicate records, which we skipped automatically)
break;
}
//remember for the next iteration
prevLookupIndex = lookupIndex;
prevSequenceIndex = sequenceIndex;
// Now find actual glyph where to apply lookup (may depend on lookup flags)
int recordFirstGlyph = FirstGlyph;
for (int i = 0; i < sequenceIndex && recordFirstGlyph < AfterLastGlyph; i++)
{
recordFirstGlyph = LayoutEngine.GetNextGlyphInLookup(Font, GlyphInfo,
recordFirstGlyph + 1,
LookupFlags,
LayoutEngine.LookForward
);
}
if (recordFirstGlyph >= AfterLastGlyph)
{
// Requested position is outside of input sequence, do nothing.
continue;
}
// And finally apply lookup
int prevLength = GlyphInfo.Length;
int dummyNextGlyph;
LayoutEngine.ApplyLookup(
Font,
TableTag,
Table,
Metrics,
lookupList.Lookup(Table, lookupIndex),
CharCount,
Charmap,
GlyphInfo,
Advances,
Offsets,
recordFirstGlyph,
AfterLastGlyph,
Parameter,
nestingLevel + 1,
out dummyNextGlyph // we don't need it here
);
//We need to adjust afterLastGlyph, in case non-single substitution happened
AfterLastGlyph += GlyphInfo.Length - prevLength;
}
nextGlyph = AfterLastGlyph;
}
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
out int NextGlyph // out: next glyph index
)
{
//This will be the next glyph, does not matter sequence matched or not
NextGlyph = AfterLastGlyph-1;
if (Format(Table)!=1) return false; //Unknown
bool match = true;
int inputGlyphIndex = AfterLastGlyph - 1;
int glyphIndex;
//Check input glyph
int coverageIndex = InputCoverage(Table).GetGlyphIndex(Table,GlyphInfo.Glyphs[inputGlyphIndex]);
if (coverageIndex<0) return false;
//we reading data sequenctially from table, moving pointer through it
int curOffset = offset + offsetBacktrackGlyphCount;
//
// Check backtrack sequence
//
ushort backtrackGlyphCount = GlyphCount(Table,curOffset);
curOffset += sizeCount;
glyphIndex = inputGlyphIndex;
for(ushort backtrackIndex = 0;
backtrackIndex < backtrackGlyphCount && match;
backtrackIndex++)
{
glyphIndex = LayoutEngine.GetNextGlyphInLookup(Font, GlyphInfo,
glyphIndex-1,
LookupFlags,
LayoutEngine.LookBackward
);
if (glyphIndex<0)
{
match = false;
}
else
{
match = (Coverage(Table,curOffset).GetGlyphIndex(Table,GlyphInfo.Glyphs[glyphIndex]) >= 0);
curOffset += sizeOffset;
}
}
ushort lookaheadGlyphCount = GlyphCount(Table,curOffset);
curOffset += sizeCount;
glyphIndex = inputGlyphIndex;
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
{
match = (Coverage(Table,curOffset).GetGlyphIndex(Table,GlyphInfo.Glyphs[glyphIndex]) >= 0);
curOffset += sizeOffset;
}
}
if (match)
{
curOffset += sizeCount + sizeGlyphId*coverageIndex;
GlyphInfo.Glyphs[inputGlyphIndex] = Glyph(Table,curOffset);
GlyphInfo.GlyphFlags[inputGlyphIndex] = (ushort)(GlyphFlags.Unresolved | GlyphFlags.Substituted);
}
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
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)==1);
NextGlyph = FirstGlyph + 1; //in case we don't match
int glyphCount = GlyphInfo.Length;
int glyphIndex = FirstGlyph;
ushort glyphId = GlyphInfo.Glyphs[glyphIndex];
int coverageIndex = Coverage(Table).GetGlyphIndex(Table,glyphId);
if (coverageIndex < 0) return false;
SubRuleSet subRuleSet= RuleSet(Table, coverageIndex);
ushort ruleCount = subRuleSet.RuleCount(Table);
bool match = false;
for(ushort i=0; !match && i<ruleCount; i++)
{
match = subRuleSet.Rule(Table,i).Apply(Font, TableTag, Table, Metrics,
CharCount, Charmap,
GlyphInfo, Advances, Offsets,
LookupFlags, FirstGlyph, 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;
}
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
)
{
switch (Format(Table))
{
case 1:
GlyphContextSubtable glyphContextSubtable =
new GlyphContextSubtable(offset);
return glyphContextSubtable.Apply(
Font, TableTag, Table, Metrics,
CharCount, Charmap,
GlyphInfo, Advances, Offsets,
LookupFlags, FirstGlyph, AfterLastGlyph,
Parameter,
nestingLevel,
out NextGlyph
);
case 2:
ClassContextSubtable classContextSubtable =
new ClassContextSubtable(offset);
return classContextSubtable.Apply(
Font, TableTag, Table, Metrics,
CharCount, Charmap,
GlyphInfo, Advances, Offsets,
LookupFlags, FirstGlyph, AfterLastGlyph,
Parameter,
nestingLevel,
out NextGlyph
);
case 3:
CoverageContextSubtable coverageContextSubtable =
new CoverageContextSubtable(offset);
return coverageContextSubtable.Apply(
Font, TableTag, Table, Metrics,
CharCount, Charmap,
GlyphInfo, Advances, Offsets,
LookupFlags, FirstGlyph, AfterLastGlyph,
Parameter,
nestingLevel,
out NextGlyph
);
default:
//Unknown format
NextGlyph = FirstGlyph+1; //don't match
return false;
}
}
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;
}
internal static bool ApplyLookup(
IOpenTypeFont Font, // Font access interface
OpenTypeTags TableTag, // Layout table tag (GSUB or GPOS)
FontTable Table, // Layout table (GSUB or GPOS)
LayoutMetrics Metrics, // LayoutMetrics
LookupTable Lookup, // List definition structure
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
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
)
{
Debug.Assert(TableTag==OpenTypeTags.GSUB || TableTag==OpenTypeTags.GPOS);
Debug.Assert(FirstGlyph<AfterLastGlyph);
Debug.Assert(AfterLastGlyph<=GlyphInfo.Length);
ushort lookupType = Lookup.LookupType();
ushort lookupFlags = Lookup.LookupFlags();
ushort subtableCount = Lookup.SubTableCount();
bool match=false;
NextGlyph=FirstGlyph+1; //Just to avoid compiler error
// Find first glyph
if (!IsLookupReversal(TableTag,lookupType))
{
FirstGlyph=LayoutEngine.GetNextGlyphInLookup(Font,GlyphInfo,FirstGlyph,
lookupFlags,LayoutEngine.LookForward);
}
else
{
AfterLastGlyph = LayoutEngine.GetNextGlyphInLookup(Font,GlyphInfo,AfterLastGlyph-1,
lookupFlags,LayoutEngine.LookBackward) + 1;
}
if (FirstGlyph>=AfterLastGlyph) return match;
ushort originalLookupType = lookupType; // We need it to recover, if extension lookup updated lookupFormat
for(ushort subtableIndex=0; !match && subtableIndex < subtableCount; subtableIndex++)
{
lookupType = originalLookupType;
int subtableOffset = Lookup.SubtableOffset(Table, subtableIndex);
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 singleSub =
new SingleSubstitutionSubtable(subtableOffset);
match = singleSub.Apply( Table,
GlyphInfo,
FirstGlyph,
out NextGlyph
);
break;
case 2: //MultipleSubst
MultipleSubstitutionSubtable multipleSub =
new MultipleSubstitutionSubtable(subtableOffset);
match = multipleSub.Apply( Font,
Table,
CharCount,
Charmap,
GlyphInfo,
lookupFlags,
FirstGlyph,
AfterLastGlyph,
out NextGlyph
);
break;
case 3: //AlternateSubst
AlternateSubstitutionSubtable alternateSub =
new AlternateSubstitutionSubtable(subtableOffset);
match = alternateSub.Apply( Table,
GlyphInfo,
Parameter,
FirstGlyph,
out NextGlyph
);
break;
case 4: //Ligature subst
LigatureSubstitutionSubtable ligaSub =
new LigatureSubstitutionSubtable(subtableOffset);
match = ligaSub.Apply( Font,
Table,
CharCount,
Charmap,
GlyphInfo,
lookupFlags,
FirstGlyph,
AfterLastGlyph,
out NextGlyph
);
break;
case 5: //ContextualSubst
ContextSubtable contextSub =
new ContextSubtable(subtableOffset);
match = contextSub.Apply( Font,
TableTag,
Table,
Metrics,
CharCount,
Charmap,
GlyphInfo,
Advances,
Offsets,
lookupFlags,
FirstGlyph,
AfterLastGlyph,
Parameter,
nestingLevel,
out NextGlyph
);
break;
case 6: //ChainingSubst
ChainingSubtable chainingSub =
new ChainingSubtable(subtableOffset);
match = chainingSub.Apply( Font,
TableTag,
Table,
Metrics,
CharCount,
Charmap,
GlyphInfo,
Advances,
Offsets,
lookupFlags,
FirstGlyph,
AfterLastGlyph,
Parameter,
nestingLevel,
out NextGlyph
);
break;
case 7: //Extension lookup
// Ext.Lookup processed earlier. It can't contain another ext.lookups in it.
// Just skip it (do nothing);
NextGlyph = FirstGlyph + 1;
break;
case 8: //ReverseCahiningSubst
ReverseChainingSubtable reverseChainingSub =
new ReverseChainingSubtable(subtableOffset);
match = reverseChainingSub.Apply(
Font,
TableTag,
Table,
Metrics,
CharCount,
Charmap,
GlyphInfo,
Advances,
Offsets,
lookupFlags,
FirstGlyph,
AfterLastGlyph,
Parameter,
out NextGlyph
);
break;
default:
// Unknown format
NextGlyph = FirstGlyph+1;
break;
}
if (match)
{
if (!IsLookupReversal(TableTag,lookupType))
{
UpdateGlyphFlags(Font,GlyphInfo,FirstGlyph,NextGlyph,true,GlyphFlags.Substituted);
}
else
{
UpdateGlyphFlags(Font,GlyphInfo,NextGlyph,AfterLastGlyph,true,GlyphFlags.Substituted);
}
}
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);
match = singlePos.Apply(Table,
Metrics,
GlyphInfo,
Advances,
Offsets,
FirstGlyph,
AfterLastGlyph,
out NextGlyph
);
break;
case 2: //PairPos
PairPositioningSubtable pairPos =
new PairPositioningSubtable(subtableOffset);
match = pairPos.Apply( Font,
Table,
Metrics, // LayoutMetrics
GlyphInfo, // List of GlyphInfo structs
lookupFlags, // Lookup flags for glyph lookups
Advances, // Glyph adv.widths
Offsets, // Glyph offsets
FirstGlyph, // where to apply lookup
AfterLastGlyph, // how long is a context we can use
out NextGlyph // Next glyph to process
);
break;
case 3: // CursivePos
// Under construction
CursivePositioningSubtable cursivePositioningSubtable =
new CursivePositioningSubtable(subtableOffset);
cursivePositioningSubtable.Apply( Font,
Table,
Metrics, // LayoutMetrics
GlyphInfo, // List of GlyphInfo structs
lookupFlags, // Lookup flags for glyph lookups
Advances, // Glyph adv.widths
Offsets, // Glyph offsets
FirstGlyph, // where to apply lookup
AfterLastGlyph, // how long is a context we can use
out NextGlyph // Next glyph to process
);
break;
case 4: //MarkToBasePos
MarkToBasePositioningSubtable markToBasePos =
new MarkToBasePositioningSubtable(subtableOffset);
match = markToBasePos.Apply(Font,
Table,
Metrics, // LayoutMetrics
GlyphInfo, // List of GlyphInfo structs
lookupFlags, // Lookup flags for glyph lookups
Advances, // Glyph adv.widths
Offsets, // Glyph offsets
FirstGlyph, // where to apply lookup
AfterLastGlyph, // how long is a context we can use
out NextGlyph // Next glyph to process
);
break;
case 5: //MarkToLigaturePos
// Under construction
MarkToLigaturePositioningSubtable markToLigaPos =
new MarkToLigaturePositioningSubtable(subtableOffset);
match = markToLigaPos.Apply(
Font,
Table,
Metrics, // LayoutMetrics
GlyphInfo, // List of GlyphInfo structs
lookupFlags, // Lookup flags for glyph lookups
CharCount, // Characters count (i.e. Charmap.Length);
Charmap, // Char to glyph mapping
Advances, // Glyph adv.widths
Offsets, // Glyph offsets
FirstGlyph, // where to apply lookup
AfterLastGlyph, // how long is a context we can use
out NextGlyph // Next glyph to process
);
break;
case 6: //MarkToMarkPos
MarkToMarkPositioningSubtable markToMarkPos =
new MarkToMarkPositioningSubtable(subtableOffset);
match = markToMarkPos.Apply(
Font,
Table,
Metrics, // LayoutMetrics
GlyphInfo, // List of GlyphInfo structs
lookupFlags, // Lookup flags for glyph lookups
Advances, // Glyph adv.widths
Offsets, // Glyph offsets
FirstGlyph, // where to apply lookup
AfterLastGlyph, // how long is a context we can use
out NextGlyph // Next glyph to process
);
break;
case 7: // Contextual
ContextSubtable contextSub =
new ContextSubtable(subtableOffset);
match = contextSub.Apply( Font,
TableTag,
Table,
Metrics,
CharCount,
Charmap,
GlyphInfo,
Advances,
Offsets,
lookupFlags,
FirstGlyph,
AfterLastGlyph,
Parameter,
nestingLevel,
out NextGlyph
);
break;
case 8: // Chaining
ChainingSubtable chainingSub =
new ChainingSubtable(subtableOffset);
match = chainingSub.Apply( Font,
TableTag,
Table,
Metrics,
CharCount,
Charmap,
GlyphInfo,
Advances,
Offsets,
lookupFlags,
FirstGlyph,
AfterLastGlyph,
Parameter,
nestingLevel,
out NextGlyph
);
break;
case 9: //Extension lookup
// Ext.Lookup processed earlier. It can't contain another ext.lookups in it.
// Just skip it (do nothing);
NextGlyph = FirstGlyph + 1;
break;
default:
// Unknown format
NextGlyph = FirstGlyph + 1;
break;
}
if (match)
{
UpdateGlyphFlags(Font,GlyphInfo,FirstGlyph,NextGlyph,false,GlyphFlags.Positioned);
}
break;
}
default:
Debug.Assert(false,"Unknown OpenType layout table!");
break;
}
}
return match;
}
public LayoutOffset AnchorCoordinates(
FontTable Table,
LayoutMetrics Metrics,
LayoutOffset ContourPoint
)
{
LayoutOffset Point = new LayoutOffset();
switch (format)
{
case 1: //Simple coordinates
Point.dx = Positioning.DesignToPixels(Metrics.DesignEmHeight,Metrics.PixelsEmWidth,XCoordinate(Table));
Point.dy = Positioning.DesignToPixels(Metrics.DesignEmHeight,Metrics.PixelsEmHeight,YCoordinate(Table));
break;
case 2: //Coordinates + anchor point
if (ContourPoint.dx==int.MinValue)
{
Point.dx = Positioning.DesignToPixels(Metrics.DesignEmHeight,Metrics.PixelsEmWidth,XCoordinate(Table));
Point.dy = Positioning.DesignToPixels(Metrics.DesignEmHeight,Metrics.PixelsEmHeight,YCoordinate(Table));
}
else
{
Point.dx = Positioning.DesignToPixels(Metrics.DesignEmHeight,Metrics.PixelsEmWidth,ContourPoint.dx);
Point.dy = Positioning.DesignToPixels(Metrics.DesignEmHeight,Metrics.PixelsEmWidth,ContourPoint.dy);
}
break;
case 3: //Coordinates + Device table
Point.dx = Positioning.DesignToPixels(Metrics.DesignEmHeight,Metrics.PixelsEmWidth,XCoordinate(Table))+
Format3XDeviceTable(Table).Value(Table,Metrics.PixelsEmWidth);
Point.dy = Positioning.DesignToPixels(Metrics.DesignEmHeight,Metrics.PixelsEmHeight,YCoordinate(Table))+
Format3YDeviceTable(Table).Value(Table,Metrics.PixelsEmHeight);
break;
default: //Unknown format
Point.dx = 0;
Point.dx = 0;
break;
}
return Point;
}
public unsafe bool Apply(
FontTable Table,
LayoutMetrics Metrics, // LayoutMetrics
GlyphInfoList GlyphInfo, // List of GlyphInfo structs
int* Advances, // Glyph adv.widths
LayoutOffset* Offsets, // Glyph offsets
int FirstGlyph, // where to apply lookup
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;
int glyphCount=GlyphInfo.Length;
ushort glyphId = GlyphInfo.Glyphs[FirstGlyph];
int coverageIndex = Coverage(Table).GetGlyphIndex(Table,glyphId);
if (coverageIndex == -1) return false;
ValueRecordTable valueRecord;
switch (Format(Table))
{
case 1:
valueRecord = Format1ValueRecord(Table);
break;
case 2:
valueRecord = Format2ValueRecord(Table,(ushort)coverageIndex);
break;
default:
return false;
}
valueRecord.AdjustPos(Table, Metrics, ref Offsets[FirstGlyph], ref Advances[FirstGlyph]);
return true;
}
public unsafe bool Apply(
IOpenTypeFont Font,
FontTable Table,
LayoutMetrics Metrics, // LayoutMetrics
GlyphInfoList GlyphInfo, // List of GlyphInfo structs
ushort LookupFlags, // Lookup flags for glyph lookups
int CharCount, // Characters count (i.e. Charmap.Length);
UshortList Charmap, // Char to glyph mapping
int* Advances, // Glyph adv.widths
LayoutOffset* Offsets, // Glyph offsets
int FirstGlyph, // where to apply lookup
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; //Always move to the next glyph, whether matched or not
if (Format(Table) != 1) return false; //unknown format
int glyphCount=GlyphInfo.Length;
int markGlyph=FirstGlyph;
//Lookup works with marks only
if ((GlyphInfo.GlyphFlags[markGlyph]&(ushort)GlyphFlags.GlyphTypeMask)!=(ushort)GlyphFlags.Mark) return false;
int markCoverageIndex = MarkCoverage(Table).GetGlyphIndex(Table,GlyphInfo.Glyphs[markGlyph]);
if (markCoverageIndex==-1) return false;
int baseGlyph;
ushort component;
FindBaseLigature(CharCount, Charmap,GlyphInfo,markGlyph,
out component, out baseGlyph);
if (baseGlyph<0) return false;
int baseCoverageIndex = LigatureCoverage(Table).
GetGlyphIndex(Table,GlyphInfo.Glyphs[baseGlyph]);
if (baseCoverageIndex == -1) return false;
ushort classCount = ClassCount(Table);
MarkArray marks = Marks(Table);
ushort markClass = marks.Class(Table,(ushort)markCoverageIndex);
if (markClass>=classCount) return false; //Invalid mark class
AnchorTable baseAnchor = Ligatures(Table,baseCoverageIndex, classCount).
LigatureAnchor(Table,component,markClass);
if (baseAnchor.IsNull())
{
return false;
}
AnchorTable markAnchor = marks.MarkAnchor(Table,(ushort)markCoverageIndex);
if (markAnchor.IsNull())
{
return false;
}
Positioning.AlignAnchors(Font,Table,Metrics,GlyphInfo,Advances,Offsets,
baseGlyph,markGlyph,baseAnchor,markAnchor,false);
return true;
}
public void AdjustPos( FontTable Table,
LayoutMetrics Metrics,
ref LayoutOffset GlyphOffset,
ref int GlyphAdvance
)
{
int curOffset=offset;
if ((format&XPlacmentFlag)!=0)
{
GlyphOffset.dx += Positioning.DesignToPixels(Metrics.DesignEmHeight,Metrics.PixelsEmWidth,
Table.GetShort(curOffset));
curOffset+=2;
}
if ((format&YPlacmentFlag)!=0)
{
GlyphOffset.dy += Positioning.DesignToPixels(Metrics.DesignEmHeight,Metrics.PixelsEmHeight,
Table.GetShort(curOffset));
curOffset+=2;
}
if ((format&XAdvanceFlag)!=0)
{
GlyphAdvance += Positioning.DesignToPixels(Metrics.DesignEmHeight,Metrics.PixelsEmWidth,
Table.GetShort(curOffset));
curOffset+=2;
}
if ((format&YAdvanceFlag)!=0)
{
GlyphAdvance += Positioning.DesignToPixels(Metrics.DesignEmHeight,Metrics.PixelsEmHeight,
Table.GetShort(curOffset));
curOffset+=2;
}
if ((format&XPlacementDeviceFlag)!=0)
{
int deviceTableOffset = Table.GetOffset(curOffset);
if (deviceTableOffset != FontTable.NullOffset)
{
DeviceTable deviceTable = new DeviceTable(baseTableOffset+deviceTableOffset);
GlyphOffset.dx += deviceTable.Value(Table,Metrics.PixelsEmWidth);
}
curOffset+=2;
}
if ((format&YPlacementDeviceFlag)!=0)
{
int deviceTableOffset = Table.GetOffset(curOffset);
if (deviceTableOffset != FontTable.NullOffset)
{
DeviceTable deviceTable = new DeviceTable(baseTableOffset+deviceTableOffset);
GlyphOffset.dy += deviceTable.Value(Table,Metrics.PixelsEmHeight);
}
curOffset+=2;
}
if ((format&XAdvanceDeviceFlag)!=0)
{
if (Metrics.Direction==TextFlowDirection.LTR || Metrics.Direction==TextFlowDirection.RTL)
{
int deviceTableOffset = Table.GetOffset(curOffset);
if (deviceTableOffset != FontTable.NullOffset)
{
DeviceTable deviceTable = new DeviceTable(baseTableOffset+deviceTableOffset);
GlyphAdvance += deviceTable.Value(Table,Metrics.PixelsEmWidth);
}
}
curOffset+=2;
}
if ((format&YAdvanceDeviceFlag)!=0)
{
if (Metrics.Direction==TextFlowDirection.TTB || Metrics.Direction==TextFlowDirection.BTT)
{
int deviceTableOffset = Table.GetOffset(curOffset);
if (deviceTableOffset != FontTable.NullOffset)
{
DeviceTable deviceTable = new DeviceTable(baseTableOffset+deviceTableOffset);
GlyphAdvance += deviceTable.Value(Table,Metrics.PixelsEmHeight);
}
}
curOffset+=2;
}
}
public unsafe bool Apply(
IOpenTypeFont Font,
FontTable Table,
LayoutMetrics Metrics, // LayoutMetrics
GlyphInfoList GlyphInfo, // List of GlyphInfo structs
ushort LookupFlags, // Lookup flags for glyph lookups
int* Advances, // Glyph adv.widths
LayoutOffset* Offsets, // Glyph offsets
int FirstGlyph, // where to apply lookup
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;
if (Format(Table) != 1) return false; // Unknown format
bool RTL = (LookupFlags & LayoutEngine.LookupFlagRightToLeft) != 0;
ushort cursiveBit = (ushort)GlyphFlags.CursiveConnected;
//
int glyphIndex, prevGlyphIndex,
coverageIndex, prevCoverageIndex;
glyphIndex = LayoutEngine.GetNextGlyphInLookup(Font,GlyphInfo,
FirstGlyph,LookupFlags,
LayoutEngine.LookForward
);
//clear "CursiveConected" bit,
//we will set it only if there is a connection to previous glyph
if (RTL)
{
GlyphInfo.GlyphFlags[glyphIndex] &= (ushort)~cursiveBit;
}
if ( glyphIndex >= AfterLastGlyph )
{
return false;
}
prevGlyphIndex = LayoutEngine.GetNextGlyphInLookup(Font,GlyphInfo,
FirstGlyph-1,LookupFlags,
LayoutEngine.LookBackward
);
if ( prevGlyphIndex < 0 )
{
return false;
}
CoverageTable coverage = Coverage(Table);
coverageIndex = coverage.GetGlyphIndex(Table,GlyphInfo.Glyphs[glyphIndex]);
if (coverageIndex == -1)
{
return false;
}
prevCoverageIndex = coverage.
GetGlyphIndex(Table,GlyphInfo.Glyphs[prevGlyphIndex]);
if (prevCoverageIndex == -1)
{
return false;
}
AnchorTable prevExitAnchor, entryAnchor;
prevExitAnchor = ExitAnchor(Table, prevCoverageIndex);
if (prevExitAnchor.IsNull())
{
return false;
}
entryAnchor = EntryAnchor(Table,coverageIndex);
if (entryAnchor.IsNull())
{
return false;
}
Positioning.AlignAnchors(Font, Table, Metrics,
GlyphInfo, Advances, Offsets,
prevGlyphIndex, glyphIndex,
prevExitAnchor, entryAnchor, true);
if (RTL)
{
UshortList glyphFlags = GlyphInfo.GlyphFlags;
int index;
//set "cursive" bit for everything up to prevGlyphIndex
for(index = glyphIndex; index>prevGlyphIndex; index--)
{
glyphFlags[index] |= cursiveBit;
}
//fix cursive dependencies
int yCorrection = Offsets[glyphIndex].dy;
for(index = glyphIndex;
(glyphFlags[index] & cursiveBit) != 0 ;
index--
)
{
Offsets[index].dy -= yCorrection;
}
Invariant.Assert(glyphIndex>=0); //First glyph should not have bit set
Offsets[index].dy -= yCorrection;
}
return true;
}
public unsafe bool Apply(
IOpenTypeFont Font,
FontTable Table,
LayoutMetrics Metrics, // LayoutMetrics
GlyphInfoList GlyphInfo, // List of GlyphInfo structs
ushort LookupFlags, // Lookup flags for glyph lookups
int* Advances, // Glyph adv.widths
LayoutOffset* Offsets, // Glyph offsets
int FirstGlyph, // where to apply lookup
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; //Always move to the next glyph, whether matched or not
if (Format(Table) != 1) return false; //unknown format
int glyphCount=GlyphInfo.Length;
int mark1Glyph=FirstGlyph;
//Lookup works with marks only
if ((GlyphInfo.GlyphFlags[mark1Glyph]&(ushort)GlyphFlags.GlyphTypeMask)!=(ushort)GlyphFlags.Mark) return false;
int mark1CoverageIndex = Mark1Coverage(Table).GetGlyphIndex(Table,GlyphInfo.Glyphs[mark1Glyph]);
if (mark1CoverageIndex==-1) return false;
//Find preceeding mark according mark from specified class
int mark2Glyph = LayoutEngine.GetNextGlyphInLookup(Font,
GlyphInfo,
FirstGlyph-1,
(ushort)(LookupFlags & 0xFF00), //Clear Ignore... flags
LayoutEngine.LookBackward);
if (mark2Glyph<0) return false;
int mark2CoverageIndex = Mark2Coverage(Table).GetGlyphIndex(Table,GlyphInfo.Glyphs[mark2Glyph]);
if (mark2CoverageIndex==-1) return false;
ushort classCount = Mark1ClassCount(Table);
MarkArray mark1Array = Mark1Array(Table);
ushort mark1Class = mark1Array.Class(Table,(ushort)mark1CoverageIndex);
if (mark1Class>=classCount) return false; //Invalid mark class
AnchorTable mark1Anchor = mark1Array.MarkAnchor(Table,(ushort)mark1CoverageIndex);
if (mark1Anchor.IsNull())
{
return false;
}
AnchorTable mark2Anchor = Marks2(Table).Anchor(Table,(ushort)mark2CoverageIndex,classCount,mark1Class);
if (mark2Anchor.IsNull())
{
return false;
}
Positioning.AlignAnchors(Font,Table,Metrics,GlyphInfo,Advances,Offsets,
mark2Glyph,mark1Glyph,mark2Anchor,mark1Anchor,false);
return true;
}
public static void ApplyFeatures(
IOpenTypeFont Font,
OpenTypeLayoutWorkspace workspace,
OpenTypeTags TableTag,
FontTable Table,
LayoutMetrics Metrics,
LangSysTable LangSys,
FeatureList Features,
LookupList Lookups,
Feature[] FeatureSet,
int featureCount,
int featureSetOffset,
int CharCount,
UshortList Charmap,
GlyphInfoList GlyphInfo,
int* Advances,
LayoutOffset* Offsets
)
{
UpdateGlyphFlags(Font, GlyphInfo, 0, GlyphInfo.Length, false, GlyphFlags.NotChanged);
// if client did not supply us with workspace
// we will create our own (temporarily)
if (workspace == null)
{
workspace = new OpenTypeLayoutWorkspace();
}
ushort lookupCount=Lookups.LookupCount(Table);
//Compile feature set
CompileFeatureSet(
FeatureSet,
featureCount,
featureSetOffset,
CharCount,
Table,
LangSys,
Features,
lookupCount,
workspace
);
OpenTypeLayoutCache.InitCache(Font, TableTag, GlyphInfo, workspace);
for(ushort lookupIndex = 0; lookupIndex < lookupCount; lookupIndex++)
{
if (!workspace.IsAggregatedFlagSet(lookupIndex))
{
continue;
}
int firstChar=0,
afterLastChar=0,
firstGlyph=0,
afterLastGlyph=0;
OpenTypeLayoutCache.FindNextLookup(workspace,
GlyphInfo,
lookupIndex,
out lookupIndex,
out firstGlyph);
// We need to check this again, because FindNextLookup will change lookupIndex
if (lookupIndex >= lookupCount)
{
break;
}
if (!workspace.IsAggregatedFlagSet(lookupIndex))
{
continue;
}
LookupTable lookup = Lookups.Lookup(Table, lookupIndex);
uint parameter=0;
bool isLookupReversal = IsLookupReversal(TableTag, lookup.LookupType());
while(firstGlyph < GlyphInfo.Length) // While we have ranges to work on
{
if (!OpenTypeLayoutCache.FindNextGlyphInLookup(workspace, lookupIndex, isLookupReversal, ref firstGlyph, ref afterLastGlyph))
{
firstGlyph = afterLastGlyph;
}
if (firstGlyph < afterLastGlyph) // Apply lookup while in one range
{
int nextGlyph;
int oldLength = GlyphInfo.Length;
int glyphsAfterLastChar = oldLength - afterLastGlyph;
bool match = ApplyLookup(
Font, // In: Font access interface
TableTag, // Layout table tag (GSUB or GPOS)
Table, // Layout table (GSUB or GPOS)
Metrics, // In: LayoutMetrics
lookup, // Lookup definition structure
CharCount,
Charmap, // In: Char to glyph mapping
GlyphInfo, // In/out: List of GlyphInfo structs
Advances, // In/out: Glyph adv.widths
Offsets, // In/out: Glyph offsets
firstGlyph, // where to apply it
afterLastGlyph, // how long is a context we can use
parameter, // lookup parameter
0, // Nesting level for contextual lookups
out nextGlyph // out: next glyph index
// !!!: for reversal lookup, should
// return new afterLastGlyph
);
if (match)
{
//Adjust range end if length changed,
// for reversal changes happens beyond afterLast, no change needed
if (!isLookupReversal)
{
OpenTypeLayoutCache.OnGlyphsChanged(workspace, GlyphInfo, oldLength, firstGlyph, nextGlyph);
afterLastGlyph = GlyphInfo.Length - glyphsAfterLastChar;
firstGlyph = nextGlyph;
}
else
{
OpenTypeLayoutCache.OnGlyphsChanged(workspace, GlyphInfo, oldLength, nextGlyph, afterLastGlyph);
afterLastGlyph = nextGlyph;
}
}
else
{
if (isLookupReversal)
afterLastGlyph = nextGlyph;
else
firstGlyph = nextGlyph;
}
}
else // End of range. Get next
{
GetNextEnabledGlyphRange(
FeatureSet,
featureCount,
featureSetOffset,
Table,
workspace,
LangSys,
Features,
lookupIndex,
CharCount,
Charmap,
afterLastChar,
afterLastGlyph,
GlyphInfo.Length,
out firstChar,
out afterLastChar,
out firstGlyph,
out afterLastGlyph,
out parameter);
}
}
}
}
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;
}
/// <summary>
/// Align to anchors between two glyphs (e.g. mark and base)
/// by changing adv.width and offsets for both of them
/// </summary>
/// <param name="Font"></param>
/// <param name="Table"></param>
/// <param name="Metrics"></param>
/// <param name="GlyphInfo"></param>
/// <param name="Advances"></param>
/// <param name="Offsets"></param>
/// <param name="StaticGlyph"></param>
/// <param name="MobileGlyph"></param>
/// <param name="StaticAnchor"></param>
/// <param name="MobileAnchor"></param>
/// <param name="UseAdvances"></param>
/// <returns></returns>
public static unsafe void AlignAnchors(
IOpenTypeFont Font,
FontTable Table,
LayoutMetrics Metrics,
GlyphInfoList GlyphInfo,
int* Advances,
LayoutOffset* Offsets,
int StaticGlyph,
int MobileGlyph,
AnchorTable StaticAnchor,
AnchorTable MobileAnchor,
bool UseAdvances
)
{
Invariant.Assert(StaticGlyph>=0 && StaticGlyph<GlyphInfo.Length);
Invariant.Assert(MobileGlyph>=0 && MobileGlyph<GlyphInfo.Length);
Invariant.Assert(!StaticAnchor.IsNull());
Invariant.Assert(!MobileAnchor.IsNull());
LayoutOffset ContourPoint = new LayoutOffset();
if (StaticAnchor.NeedContourPoint(Table))
{
ContourPoint = Font.GetGlyphPointCoord(GlyphInfo.Glyphs[MobileGlyph],
StaticAnchor.ContourPointIndex(Table));
}
LayoutOffset StaticAnchorPoint = StaticAnchor.AnchorCoordinates(Table,Metrics,ContourPoint);
if (MobileAnchor.NeedContourPoint(Table))
{
ContourPoint = Font.GetGlyphPointCoord(GlyphInfo.Glyphs[MobileGlyph],
MobileAnchor.ContourPointIndex(Table));
}
LayoutOffset MobileAnchorPoint = MobileAnchor.AnchorCoordinates(Table,Metrics,ContourPoint);
int AdvanceInBetween=0;
if (StaticGlyph<MobileGlyph)
for(int i=StaticGlyph+1;i<MobileGlyph;i++) AdvanceInBetween+=Advances[i];
else
for(int i=MobileGlyph+1;i<StaticGlyph;i++) AdvanceInBetween+=Advances[i];
if (Metrics.Direction==TextFlowDirection.LTR ||
Metrics.Direction==TextFlowDirection.RTL)
{
Offsets[MobileGlyph].dy = Offsets[StaticGlyph].dy + StaticAnchorPoint.dy
- MobileAnchorPoint.dy;
if ((Metrics.Direction==TextFlowDirection.LTR)==(StaticGlyph<MobileGlyph))
{
// static glyph is on the left(phisically, not logically) to the mobile glyph
int dx = Offsets[StaticGlyph].dx - Advances[StaticGlyph] + StaticAnchorPoint.dx
- AdvanceInBetween - MobileAnchorPoint.dx;
if (UseAdvances)
{
Advances[StaticGlyph] += dx;
}
else
{
Offsets[MobileGlyph].dx = dx;
}
}
else
{
// static glyph is on the right(phisically, not logically) to the mobile glyph
int dx = Offsets[StaticGlyph].dx + Advances[MobileGlyph] + StaticAnchorPoint.dx
+ AdvanceInBetween - MobileAnchorPoint.dx;
if (UseAdvances)
{
Advances[MobileGlyph] -= dx;
}
else
{
Offsets[MobileGlyph].dx = dx;
}
}
}
else
{
//TTB, BTT: //Under construction
}
}
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 unsafe bool Apply(
IOpenTypeFont Font,
FontTable Table,
LayoutMetrics Metrics, // LayoutMetrics
GlyphInfoList GlyphInfo, // List of GlyphInfo structs
ushort LookupFlags, // Lookup flags for glyph lookups
int* Advances, // Glyph adv.widths
LayoutOffset* Offsets, // Glyph offsets
int FirstGlyph, // where to apply lookup
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; //Always move to the next glyph, whether matched or not
int glyphCount=GlyphInfo.Length;
ushort firstGlyphId = GlyphInfo.Glyphs[FirstGlyph];
int secondGlyph = LayoutEngine.GetNextGlyphInLookup(Font,GlyphInfo,FirstGlyph+1,LookupFlags,LayoutEngine.LookForward);
if (secondGlyph>=AfterLastGlyph) return false;
ushort secondGlyphId = GlyphInfo.Glyphs[secondGlyph];
ValueRecordTable firstValueRecord, secondValueRecord;
switch (Format(Table))
{
case 1:
{
int coverageIndex = Coverage(Table).GetGlyphIndex(Table,firstGlyphId);
if (coverageIndex==-1) return false;
PairSetTable pairSet = Format1PairSet(Table,(ushort)coverageIndex);
int pairValueIndex = pairSet.FindPairValue(Table, secondGlyphId);
if (pairValueIndex == -1) return false;
firstValueRecord = pairSet.FirstValueRecord(Table,(ushort)pairValueIndex,FirstValueFormat(Table));
secondValueRecord = pairSet.SecondValueRecord(Table,(ushort)pairValueIndex,SecondValueFormat(Table));
break;
}
case 2:
{
int coverageIndex = Coverage(Table).GetGlyphIndex(Table,firstGlyphId);
if (coverageIndex == -1) return false;
ushort firstClassIndex = Format2Class1Table(Table).GetClass(Table,firstGlyphId);
if (firstClassIndex >= Format2Class1Count(Table)) return false; //this is invalid font;
ushort secondClassIndex = Format2Class2Table(Table).GetClass(Table,secondGlyphId);
if (secondClassIndex >= Format2Class2Count(Table)) return false; //this is invalid font;
ushort class2Count = Format2Class2Count(Table);
firstValueRecord = Format2FirstValueRecord(Table,
class2Count,
firstClassIndex,
secondClassIndex
);
secondValueRecord = Format2SecondValueRecord(Table,
class2Count,
firstClassIndex,
secondClassIndex
);
break;
}
default:
return false;
}
//Now adjust positions
firstValueRecord.AdjustPos (Table, Metrics, ref Offsets[FirstGlyph], ref Advances[FirstGlyph]);
secondValueRecord.AdjustPos(Table, Metrics, ref Offsets[secondGlyph], ref Advances[secondGlyph]);
return true;
}
/// <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);
}
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;
}