public TextLine FormatLine(TextSource textSource, int firstCharIndex, double paragraphWidth, TextParagraphProperties paragraphProperties, TextLineBreak previousLineBreak)
{
var runs = new List <Tuple <TextRun, GlyphRun, int, double> >();
int index = firstCharIndex;
double x = paragraphProperties.Indent, height = 0, baseline = 0;
double trailWhitespaceWidth = 0;
while (true)
{
var run = textSource.GetTextRun(index);
var textProps = run.Properties ?? paragraphProperties.DefaultTextRunProperties;
var fontSize = textProps.FontRenderingEmSize;
var len = run.Length;
if (textProps != null)
{
height = Math.Max(height, (int)(textProps.Typeface.FontFamily.LineSpacing * fontSize));
baseline = Math.Max(baseline, (int)(textProps.Typeface.FontFamily.Baseline * fontSize));
}
if (run is TextEndOfLine || run == null)
{
index += len;
runs.Add(Tuple.Create(run, (GlyphRun)null, 0, 0.0));
break;
}
else if (run is TextCharacters)
{
var chrs = (TextCharacters)run;
var charBuf = getCharBuf(chrs.CharacterBufferReference);
var charOffset = getCharOffset(chrs.CharacterBufferReference);
GlyphTypeface gl;
if (!textProps.Typeface.TryGetGlyphTypeface(out gl))
{
throw new Exception("GlyphTypeface does not exists for font '" + textProps.Typeface.FontFamily + "'.");
}
ushort[] glyphIndexes = new ushort[len];
double[] advanceWidths = new double[len];
double totalWidth = 0;
int trailWhitespace = 0;
trailWhitespaceWidth = 0;
for (int n = 0; n < len; n++)
{
var c = charBuf[charOffset + n];
ushort glyphIndex;
double width;
if (c == '\t')
{
glyphIndex = gl.CharacterToGlyphMap[' '];
width = paragraphProperties.DefaultIncrementalTab - x % paragraphProperties.DefaultIncrementalTab;
}
else
{
if (!gl.CharacterToGlyphMap.TryGetValue(c, out glyphIndex))
{
glyphIndex = gl.CharacterToGlyphMap['?'];
}
width = gl.AdvanceWidths[glyphIndex] * fontSize;
}
glyphIndexes[n] = glyphIndex;
advanceWidths[n] = width;
if (char.IsWhiteSpace(c))
{
trailWhitespace++;
trailWhitespaceWidth += width;
}
else
{
totalWidth += trailWhitespaceWidth + width;
trailWhitespaceWidth = 0;
trailWhitespace = 0;
}
}
var origin = new Point(x, 0);
var glyphRun = new GlyphRun(
gl, 0, false, fontSize, glyphIndexes, origin, advanceWidths,
null, null, null, null, null, null);
runs.Add(Tuple.Create(run, glyphRun, trailWhitespace, trailWhitespaceWidth));
x += totalWidth + trailWhitespaceWidth;
index += len;
}
else if (run is TextEmbeddedObject)
{
var obj = (TextEmbeddedObject)run;
var metrics = obj.Format(paragraphWidth - x);
runs.Add(Tuple.Create(run, (GlyphRun)null, 0, metrics.Width));
height = Math.Max(height, obj.Format(paragraphWidth - x).Height);
x += metrics.Width;
index += len;
}
}
return(new GlyphRunLine {
entries = runs.ToArray(),
baseline = baseline,
width = x - trailWhitespaceWidth,
height = height,
mode = mode
});
}