public override bool TransformOne(GlyphLine line)
{
if (line.idx >= line.end)
{
return(false);
}
if (openReader.IsSkip(line.Get(line.idx).GetCode(), lookupFlag))
{
line.idx++;
return(false);
}
bool changed = false;
OpenTableLookup.GlyphIndexer gi = null;
foreach (GposLookupType4.MarkToBase mb in marksbases)
{
OtfMarkRecord omr = mb.marks.Get(line.Get(line.idx).GetCode());
if (omr == null)
{
continue;
}
if (gi == null)
{
gi = new OpenTableLookup.GlyphIndexer();
gi.idx = line.idx;
gi.line = line;
while (true)
{
gi.PreviousGlyph(openReader, lookupFlag);
if (gi.glyph == null)
{
break;
}
// not mark => base glyph
if (!mb.marks.ContainsKey(gi.glyph.GetCode()))
{
break;
}
}
if (gi.glyph == null)
{
break;
}
}
GposAnchor[] gpas = mb.bases.Get(gi.glyph.GetCode());
if (gpas == null)
{
continue;
}
int markClass = omr.markClass;
GposAnchor baseAnchor = gpas[markClass];
GposAnchor markAnchor = omr.anchor;
line.Set(line.idx, new Glyph(line.Get(line.idx), -markAnchor.XCoordinate + baseAnchor.XCoordinate, -markAnchor
.YCoordinate + baseAnchor.YCoordinate, 0, 0, gi.idx - line.idx));
changed = true;
break;
}
line.idx++;
return(changed);
}
public static GposAnchor[] ReadAnchorArray(OpenTypeFontTableReader tableReader, int[] locations, int left,
int right)
{
GposAnchor[] anchors = new GposAnchor[right - left];
for (int i = left; i < right; i++)
{
anchors[i - left] = ReadGposAnchor(tableReader, locations[i]);
}
return(anchors);
}
public static GposAnchor ReadGposAnchor(OpenTypeFontTableReader tableReader, int location)
{
if (location == 0)
{
return(null);
}
tableReader.rf.Seek(location);
int format = tableReader.rf.ReadUnsignedShort();
GposAnchor t = null;
switch (format)
{
default: {
t = new GposAnchor();
t.XCoordinate = tableReader.rf.ReadShort() * 1000 / tableReader.GetUnitsPerEm();
t.YCoordinate = tableReader.rf.ReadShort() * 1000 / tableReader.GetUnitsPerEm();
break;
}
}
return(t);
}
public override bool TransformOne(GlyphLine line)
{
// TODO it seems that for complex cases (symbol1, symbol2, mark, symbol3) and (symbol1, symbol2, symbol3) compose a ligature,
// mark should be placed in the corresponding anchor of that ligature (second component's anchor).
// But for now we do not store all the substitution info and therefore not able to follow that logic.
// Place the mark symbol in the first available place for now.
if (line.idx >= line.end)
{
return(false);
}
if (openReader.IsSkip(line.Get(line.idx).GetCode(), lookupFlag))
{
line.idx++;
return(false);
}
bool changed = false;
OpenTableLookup.GlyphIndexer gi = null;
foreach (GposLookupType5.MarkToLigature mb in marksligatures)
{
OtfMarkRecord omr = mb.marks.Get(line.Get(line.idx).GetCode());
if (omr == null)
{
continue;
}
if (gi == null)
{
gi = new OpenTableLookup.GlyphIndexer();
gi.idx = line.idx;
gi.line = line;
while (true)
{
gi.PreviousGlyph(openReader, lookupFlag);
if (gi.glyph == null)
{
break;
}
// not mark => ligature glyph
if (!mb.marks.ContainsKey(gi.glyph.GetCode()))
{
break;
}
}
if (gi.glyph == null)
{
break;
}
}
IList <GposAnchor[]> gpas = mb.ligatures.Get(gi.glyph.GetCode());
if (gpas == null)
{
continue;
}
int markClass = omr.markClass;
for (int component = 0; component < gpas.Count; component++)
{
if (gpas[component][markClass] != null)
{
GposAnchor baseAnchor = gpas[component][markClass];
GposAnchor markAnchor = omr.anchor;
line.Add(line.idx, new Glyph(line.Get(line.idx), markAnchor.XCoordinate - baseAnchor.XCoordinate, markAnchor
.YCoordinate - baseAnchor.YCoordinate, 0, 0, gi.idx - line.idx));
changed = true;
break;
}
}
break;
}
line.idx++;
return(changed);
}
public override bool TransformOne(GlyphLine line)
{
if (line.idx >= line.end)
{
return(false);
}
if (openReader.IsSkip(line.Get(line.idx).GetCode(), lookupFlag))
{
line.idx++;
return(false);
}
bool changed = false;
OpenTableLookup.GlyphIndexer gi = null;
foreach (GposLookupType6.MarkToBaseMark mb in marksbases)
{
OtfMarkRecord omr = mb.marks.Get(line.Get(line.idx).GetCode());
if (omr == null)
{
continue;
}
if (gi == null)
{
gi = new OpenTableLookup.GlyphIndexer();
gi.idx = line.idx;
gi.line = line;
while (true)
{
int prev = gi.idx;
// avoid attaching this mark glyph to another very distant mark glyph
bool foundBaseGlyph = false;
gi.PreviousGlyph(openReader, lookupFlag);
if (gi.idx != -1)
{
for (int i = gi.idx; i < prev; i++)
{
if (openReader.GetGlyphClass(line.Get(i).GetCode()) == OtfClass.GLYPH_BASE)
{
foundBaseGlyph = true;
break;
}
}
}
if (foundBaseGlyph)
{
gi.glyph = null;
break;
}
if (gi.glyph == null)
{
break;
}
if (mb.baseMarks.ContainsKey(gi.glyph.GetCode()))
{
break;
}
}
if (gi.glyph == null)
{
break;
}
}
GposAnchor[] gpas = mb.baseMarks.Get(gi.glyph.GetCode());
if (gpas == null)
{
continue;
}
int markClass = omr.markClass;
GposAnchor baseAnchor = gpas[markClass];
GposAnchor markAnchor = omr.anchor;
line.Set(line.idx, new Glyph(line.Get(line.idx), -markAnchor.XCoordinate + baseAnchor.XCoordinate, -markAnchor
.YCoordinate + baseAnchor.YCoordinate, 0, 0, gi.idx - line.idx));
changed = true;
break;
}
line.idx++;
return(changed);
}
public override bool TransformOne(GlyphLine line)
{
if (line.idx >= line.end)
{
return(false);
}
if (openReader.IsSkip(line.Get(line.idx).GetCode(), lookupFlag))
{
line.idx++;
return(false);
}
bool changed = false;
OpenTableLookup.GlyphIndexer ligatureGlyphIndexer = null;
foreach (GposLookupType5.MarkToLigature mb in marksligatures)
{
OtfMarkRecord omr = mb.marks.Get(line.Get(line.idx).GetCode());
if (omr == null)
{
continue;
}
if (ligatureGlyphIndexer == null)
{
ligatureGlyphIndexer = new OpenTableLookup.GlyphIndexer();
ligatureGlyphIndexer.idx = line.idx;
ligatureGlyphIndexer.line = line;
while (true)
{
ligatureGlyphIndexer.PreviousGlyph(openReader, lookupFlag);
if (ligatureGlyphIndexer.glyph == null)
{
break;
}
// not mark => ligature glyph
if (!mb.marks.ContainsKey(ligatureGlyphIndexer.glyph.GetCode()))
{
break;
}
}
if (ligatureGlyphIndexer.glyph == null)
{
break;
}
}
IList <GposAnchor[]> componentAnchors = mb.ligatures.Get(ligatureGlyphIndexer.glyph.GetCode());
if (componentAnchors == null)
{
continue;
}
int markClass = omr.markClass;
// TODO DEVSIX-3732 For complex cases like (glyph1, glyph2, mark, glyph3) and
// (glyph1, mark, glyph2, glyph3) when the base glyphs compose a ligature and the mark
// is attached to the ligature afterwards, mark should be placed in the corresponding anchor
// of that ligature (by finding the right component's anchor).
// Excerpt from Microsoft Docs: "For a given mark assigned to a particular class, the appropriate
// base attachment point is determined by which ligature component the mark is associated with.
// This is dependent on the original character string and subsequent character- or glyph-sequence
// processing, not the font data alone. While a text-layout client is performing any character-based
// preprocessing or any glyph-substitution operations using the GSUB table, the text-layout client
// must keep track of the associations of marks to particular ligature-glyph components."
// For now we do not store all the substitution info and therefore not able to follow that logic.
// We place the mark symbol in the last available place for now (seems to be better default than
// first available place).
for (int component = componentAnchors.Count - 1; component >= 0; component--)
{
if (componentAnchors[component][markClass] != null)
{
GposAnchor baseAnchor = componentAnchors[component][markClass];
GposAnchor markAnchor = omr.anchor;
line.Set(line.idx, new Glyph(line.Get(line.idx), baseAnchor.XCoordinate - markAnchor.XCoordinate, baseAnchor
.YCoordinate - markAnchor.YCoordinate, 0, 0, ligatureGlyphIndexer.idx - line.idx));
changed = true;
break;
}
}
break;
}
line.idx++;
return(changed);
}