void Layout(GlyphIndexList glyphs)
{
if (_needPlanUpdate)
{
UpdateLayoutPlan();
}
//[C]
//----------------------------------------------
//glyph substitution
if (_gsub != null && glyphs.Count > 0)
{
//TODO: review perf here
_gsub.EnableLigation = this.EnableLigature;
_gsub.EnableComposition = this.EnableComposition;
_gsub.DoSubstitution(glyphs);
}
//----------------------------------------------
//after glyph substitution,
//number of input glyph MAY changed (increase or decrease).***
//so count again.
int finalGlyphCount = glyphs.Count;
//----------------------------------------------
//[D]
//glyph position
_glyphPositions.Clear();
_glyphPositions.Typeface = _typeface;
for (int i = 0; i < finalGlyphCount; ++i)
{
//at this stage _inputGlyphs and _glyphPositions
//has member 1:1
ushort glyIndex, input_codepointOffset, input_mapLen;
glyphs.GetGlyphIndexAndMap(i, out glyIndex, out input_codepointOffset, out input_mapLen);
//
Glyph orgGlyph = _typeface.GetGlyphByIndex(glyIndex);
//this is original value WITHOUT fit-to-grid adjust
_glyphPositions.AddGlyph(input_codepointOffset, glyIndex, orgGlyph);
}
PositionTechnique posTech = this.PositionTechnique;
if (_gpos != null && glyphs.Count > 1 && posTech == PositionTechnique.OpenFont)
{
_gpos.DoGlyphPosition(_glyphPositions);
}
//----------------------------------------------
//at this point, all positions are layouted at its original scale ***
//then we will scale it to target scale later
//----------------------------------------------
}
/// <summary>
/// do glyph shaping and glyph out
/// </summary>
/// <param name="str"></param>
/// <param name="startAt"></param>
/// <param name="len"></param>
public void Layout(
char[] str,
int startAt,
int len)
{
if (_needPlanUpdate)
{
UpdateLayoutPlan();
}
//[A]
// this is important!
// -----------------------
// from @samhocevar's PR: (https://github.com/LayoutFarm/Typography/pull/56/commits/b71c7cf863531ebf5caa478354d3249bde40b96e)
// In many places, "char" is not a valid type to handle characters, because it
// only supports 16 bits.In order to handle the full range of Unicode characters,
// we need to use "int".
// This allows characters such as 🙌 or 𐐷 or to be treated as single codepoints even
// though they are encoded as two "char"s in a C# string.
_reusableCodePointFromUserCharList.Clear();
for (int i = 0; i < len; ++i)
{
char ch = str[startAt + i];
int codepoint = ch;
if (ch >= 0xd800 && ch <= 0xdbff && i + 1 < len)
{
char nextCh = str[startAt + i + 1];
if (nextCh >= 0xdc00 && nextCh <= 0xdfff)
{
//please note:
//num of codepoint may be less than original user input char
++i;
codepoint = char.ConvertToUtf32(ch, nextCh);
}
}
_reusableCodePointFromUserCharList.Add(new CodePointFromUserChar((ushort)i, codepoint));
}
//
//[B]
// convert codepoint-list to input glyph-list
// clear before use
_inputGlyphs.Clear();
int codePointCount = _reusableCodePointFromUserCharList.Count;
for (int i = 0; i < codePointCount; ++i)
{
CodePointFromUserChar cp = _reusableCodePointFromUserCharList[i];
ushort glyphIndex = _typeface.LookupIndex(cp.codePoint);
if (i + 1 < codePointCount)
{
// Maybe this is a UVS sequence; in that case,
//***SKIP*** the second codepoint
CodePointFromUserChar nextCp = _reusableCodePointFromUserCharList[i + 1];
ushort variationGlyphIndex = _typeface.LookupIndex(cp.codePoint, nextCp.codePoint);
if (variationGlyphIndex > 0)
{
//user glyph index from next codepoint
glyphIndex = variationGlyphIndex;
//but record as current code point i
_inputGlyphs.AddGlyph(i, glyphIndex);
++i; //skip
continue; //***
}
}
_inputGlyphs.AddGlyph(i, glyphIndex);
}
//[C]
//----------------------------------------------
//glyph substitution
if (_gsub != null & len > 0)
{
//TODO: review perf here
_gsub.EnableLigation = this.EnableLigature;
_gsub.EnableComposition = this.EnableComposition;
_gsub.DoSubstitution(_inputGlyphs);
}
//----------------------------------------------
//after glyph substitution,
//number of input glyph MAY changed (increase or decrease).***
//so count again.
int finalGlyphCount = _inputGlyphs.Count;
//----------------------------------------------
//[D]
//glyph position
_glyphPositions.Clear();
_glyphPositions.Typeface = _typeface;
for (int i = 0; i < finalGlyphCount; ++i)
{
//at this stage _inputGlyphs and _glyphPositions
//has member 1:1
ushort glyIndex, input_codepointOffset, input_mapLen;
_inputGlyphs.GetGlyphIndexAndMap(i, out glyIndex, out input_codepointOffset, out input_mapLen);
//
Glyph orgGlyph = _typeface.GetGlyphByIndex(glyIndex);
//this is original value WITHOUT fit-to-grid adjust
_glyphPositions.AddGlyph((short)input_codepointOffset, glyIndex, orgGlyph);
}
PositionTechnique posTech = this.PositionTechnique;
if (_gpos != null && len > 1 && posTech == PositionTechnique.OpenFont)
{
_gpos.DoGlyphPosition(_glyphPositions);
}
//----------------------------------------------
//at this point, all positions are layouted at its original scale ***
//then we will scale it to target scale later
//----------------------------------------------
}
List <int> _codepoints = new List <int>();//not thread-safe***
/// <summary>
/// do glyph shaping and glyph out
/// </summary>
/// <param name="str"></param>
/// <param name="startAt"></param>
/// <param name="len"></param>
public void Layout(
char[] str,
int startAt,
int len)
{
if (_needPlanUpdate)
{
UpdateLayoutPlan();
}
// this is important!
// -----------------------
// from @samhocevar's PR: (https://github.com/LayoutFarm/Typography/pull/56/commits/b71c7cf863531ebf5caa478354d3249bde40b96e)
// In many places, "char" is not a valid type to handle characters, because it
// only supports 16 bits.In order to handle the full range of Unicode characters,
// we need to use "int".
// This allows characters such as 🙌 or 𐐷 or to be treated as single codepoints even
// though they are encoded as two "char"s in a C# string.
_codepoints.Clear();
for (int i = 0; i < len; ++i)
{
char ch = str[startAt + i];
int codepoint = ch;
if (Char.IsHighSurrogate(ch) && i + 1 < len)
{
char nextCh = str[startAt + i + 1];
if (Char.IsLowSurrogate(nextCh))
{
++i;
codepoint = char.ConvertToUtf32(ch, nextCh);
}
}
_codepoints.Add(codepoint);
}
// clear before use
_inputGlyphs.Clear();
// convert codepoints to input glyphs
for (int i = 0; i < _codepoints.Count; ++i)
{
int codepoint = _codepoints[i];
ushort glyphIndex = _typeface.LookupIndex(codepoint);
if (i + 1 < _codepoints.Count)
{
// Maybe this is a UVS sequence; in that case, skip the second codepoint
int nextCodepoint = _codepoints[i + 1];
ushort variationGlyphIndex = _typeface.LookupIndex(codepoint, nextCodepoint);
if (variationGlyphIndex > 0)
{
++i;
glyphIndex = variationGlyphIndex;
}
}
_inputGlyphs.AddGlyph(codepoint, glyphIndex);
}
//----------------------------------------------
//glyph substitution
if (_gsub != null & len > 0)
{
//TODO: review perf here
_gsub.EnableLigation = this.EnableLigature;
_gsub.EnableComposition = this.EnableComposition;
_gsub.DoSubstitution(_inputGlyphs);
//
_inputGlyphs.CreateMapFromUserCharToGlyphIndices();
}
//----------------------------------------------
//after glyph substitution,
//number of input glyph MAY changed (increase or decrease).***
//so count again.
int finalGlyphCount = _inputGlyphs.Count;
//----------------------------------------------
//glyph position
_glyphPositions.Clear();
_glyphPositions.Typeface = _typeface;
for (int i = 0; i < finalGlyphCount; ++i)
{
//at this stage _inputGlyphs and _glyphPositions
//has member 1:1
ushort glyIndex = _inputGlyphs[i];
//
TtfGlyph orgGlyph = _typeface.GetGlyphByIndex(glyIndex);
//this is original value WITHOUT fit-to-grid adjust
_glyphPositions.AddGlyph(glyIndex, orgGlyph);
}
PositionTechnique posTech = this.PositionTechnique;
if (_gpos != null && len > 1 && posTech == PositionTechnique.OpenFont)
{
_gpos.DoGlyphPosition(_glyphPositions);
}
//----------------------------------------------
//at this point, all position is layout at original scale ***
//then we will scale it to target scale later
//----------------------------------------------
}