public static void MeasureString(
this GlyphLayout glyphLayout,
char[] textBuffer,
int startAt,
int len, out MeasuredStringBox strBox, float scale = 1)
{
//TODO: consider extension method
List <GlyphPlan> outputGlyphPlans = glyphLayout._myGlyphPlans;
outputGlyphPlans.Clear();
glyphLayout.Layout(textBuffer, startAt, len, outputGlyphPlans);
//
int j = outputGlyphPlans.Count;
Typeface currentTypeface = glyphLayout.Typeface;
if (j == 0)
{
//not scale
strBox = new MeasuredStringBox(0,
currentTypeface.Ascender * scale,
currentTypeface.Descender * scale,
currentTypeface.LineGap * scale);
}
//get last one
GlyphPlan lastOne = outputGlyphPlans[j - 1];
strBox = new MeasuredStringBox((lastOne.x + lastOne.advX) * scale,
currentTypeface.Ascender * scale,
currentTypeface.Descender * scale,
currentTypeface.LineGap * scale);
}
public void DoLeft()
{
int count = _charBuffer.Count;
if (count == 0)
{
_caretCharIndex = 0;
return;
}
else if (_caretCharIndex > 0)
{
//this is on the end
_caretCharIndex--;
//check if the caret can rest on this glyph?
if (_caretCharIndex > 0)
{
//find its mapping to glyph index
UserCharToGlyphIndexMap userCharToGlyphMap = _userCharToGlyphMap[_caretCharIndex];
int mapToGlyphIndex = userCharToGlyphMap.glyphIndexListOffset_plus1;
//
if (mapToGlyphIndex == 0)
{
//no map
DoLeft(); //recursive ***
return;
}
//-------------------------
//we -1 ***
GlyphPlan glyphPlan = _glyphPlans[userCharToGlyphMap.glyphIndexListOffset_plus1 - 1];
if (!glyphPlan.AdvanceMoveForward)
{
//caret can't rest here
//so
DoLeft(); //recursive ***
return;
}
//---------------------
//
}
}
else
{
}
}
public void Append(GlyphPlan glyphPlan)
{
_glyphPlans.Add(glyphPlan);
_accumAdvanceX += glyphPlan.AdvanceX;
}
List <ushort> inputGlyphs = new List <ushort>(); //not thread safe***
public void Layout(Typeface typeface, float size, char[] str, List <GlyphPlan> glyphPlanBuffer)
{
//----------------------------------------------
//1. convert char[] to glyph[]
//2. send to shaping engine
//3. layout position of each glyph
//----------------------------------------------
//check if we have created a glyph cache for the typeface
GlyphsCache glyphCache;
if (!_glyphCaches.TryGetValue(typeface, out glyphCache))
{
//create new
glyphCache = new GlyphsCache(typeface);
_glyphCaches.Add(typeface, glyphCache);
}
//----------------------------------------------
int j = str.Length;
inputGlyphs.Clear();
for (int i = 0; i < j; ++i)
{
//1. convert char[] to glyphIndex[]
inputGlyphs.Add((ushort)typeface.LookupIndex(str[i]));
}
//----------------------------------------------
//glyph substitution
if (j > 1)
{
GlyphSubStitution glyphSubstitution = new GlyphSubStitution(typeface, this.ScriptLang.shortname);
glyphSubstitution.EnableLigation = this.EnableLigature;
glyphSubstitution.DoSubstitution(inputGlyphs);
}
//----------------------------------------------
//glyph position
j = inputGlyphs.Count;
List <GlyphPos> glyphPositions = new List <GlyphPos>(j);
for (int i = 0; i < j; ++i)
{
ushort glyIndex = inputGlyphs[i];
glyphPositions.Add(new GlyphPos(
glyIndex,
typeface.GetGlyphByIndex(glyIndex).GlyphClass,
typeface.GetHAdvanceWidthFromGlyphIndex(glyIndex))
);
}
PositionTecnhique posTech = this.PositionTechnique;
if (j > 1 && posTech == PositionTecnhique.OpenFont)
{
GlyphSetPosition glyphSetPos = new GlyphSetPosition(typeface, ScriptLang.shortname);
glyphSetPos.DoGlyphPosition(glyphPositions);
}
//--------------
float scale = typeface.CalculateFromPointToPixelScale(size);
float cx = 0;
float cy = 0;
j = inputGlyphs.Count;
for (int i = 0; i < j; ++i)
{
ushort glyIndex = inputGlyphs[i];
GlyphPlan glyphPlan = new GlyphPlan(glyIndex);
glyphPlanBuffer.Add(glyphPlan);
//this advWidth in font design unit
float advWidth = typeface.GetHAdvanceWidthFromGlyphIndex(glyIndex) * scale;
//----------------------------------
switch (posTech)
{
case PositionTecnhique.None:
{
glyphPlan.x = cx;
glyphPlan.y = cy;
glyphPlan.advX = advWidth;
}
break;
case PositionTecnhique.OpenFont:
{
GlyphPos gpos_offset = glyphPositions[i];
glyphPlan.x = cx + (scale * gpos_offset.xoffset);
glyphPlan.y = cy + (scale * gpos_offset.yoffset);
glyphPlan.advX = advWidth;
}
break;
case PositionTecnhique.Kerning:
{
glyphPlan.x = cx;
glyphPlan.y = cy;
glyphPlan.advX = advWidth;
if (i > 0)
{
advWidth += typeface.GetKernDistance(glyphPlanBuffer[i - 1].glyphIndex, glyphPlanBuffer[i].glyphIndex) * scale;
}
}
break;
}
cx += advWidth;
}
}
