internal Rect Draw(
DrawingContext drawingContext,
double x,
double y,
bool visiCodePath
)
{
if (Length <= 0 || this.Ghost)
{
return Rect.Empty; // nothing to draw
}
Brush foregroundBrush = TextRun.Properties.ForegroundBrush;
if(visiCodePath && foregroundBrush is SolidColorBrush)
{
Color color = ((SolidColorBrush)foregroundBrush).Color;
foregroundBrush = new SolidColorBrush(Color.FromArgb(
(byte)(color.A>>2), // * 0.25
color.R,
color.G,
color.B
));
}
Rect inkBoundingBox;
IList<double> displayGlyphAdvances;
if (_textFormatterImp.TextFormattingMode == TextFormattingMode.Ideal)
{
displayGlyphAdvances = new ThousandthOfEmRealDoubles(EmSize, NominalAdvances.Length);
for (int i = 0; i < displayGlyphAdvances.Count; i++)
{
// convert ideal glyph advance width to real width for displaying.
displayGlyphAdvances[i] = _textFormatterImp.IdealToReal(NominalAdvances[i]);
}
}
else
{
displayGlyphAdvances = new List<double>(NominalAdvances.Length);
for (int i = 0; i < NominalAdvances.Length; i++)
{
// convert ideal glyph advance width to real width for displaying.
displayGlyphAdvances.Add(_textFormatterImp.IdealToReal(NominalAdvances[i]));
}
}
CharacterBufferRange charBufferRange = new CharacterBufferRange(CharBufferReference, Length);
GlyphTypeface glyphTypeface = Typeface.TryGetGlyphTypeface();
Invariant.Assert(glyphTypeface != null);
GlyphRun glyphRun = glyphTypeface.ComputeUnshapedGlyphRun(
new Point(x, y),
charBufferRange,
displayGlyphAdvances,
EmSize,
TextRun.Properties.FontHintingEmSize,
Typeface.NullFont,
CultureMapper.GetSpecificCulture(TextRun.Properties.CultureInfo),
null, // device font name
_textFormatterImp.TextFormattingMode
);
if (glyphRun != null)
{
inkBoundingBox = glyphRun.ComputeInkBoundingBox();
}
else
{
inkBoundingBox = Rect.Empty;
}
if (!inkBoundingBox.IsEmpty)
{
// glyph run's ink bounding box is relative to its origin
inkBoundingBox.X += glyphRun.BaselineOrigin.X;
inkBoundingBox.Y += glyphRun.BaselineOrigin.Y;
}
if (drawingContext != null)
{
if (glyphRun != null)
{
glyphRun.EmitBackground(drawingContext, TextRun.Properties.BackgroundBrush);
drawingContext.DrawGlyphRun(foregroundBrush, glyphRun);
}
// draw underline here
if (Underline != null)
{
// Determine number of characters to underline. We don't underline trailing spaces
// if the TrimTrailingUnderline flag is set.
int underlineLength = Length;
if (TrimTrailingUnderline)
{
while (underlineLength > 0 && IsSpace(charBufferRange[underlineLength - 1]))
{
--underlineLength;
}
}
// Determine the width of the underline.
double dxUnderline = 0;
for (int i = 0; i < underlineLength; ++i)
{
dxUnderline += _textFormatterImp.IdealToReal(NominalAdvances[i]);
}
// We know only TextDecoration.Underline will be handled in Simple Path.
double offset = -Typeface.UnderlinePosition * EmSize;
double penThickness = Typeface.UnderlineThickness * EmSize;
Point lineOrigin = new Point(x, y + offset);
Rect underlineRect = new Rect(
lineOrigin.X,
lineOrigin.Y - penThickness * 0.5,
dxUnderline,
penThickness
);
// Apply the pair of guidelines: one for baseline and another
// for top edge of undelining line. Both will be snapped to pixel grid.
// Guideline pairing algorithm detects the case when these two
// guidelines happen to be close to one another and provides
// synchronous snapping, so that the gap between baseline and
// undelining line does not depend on the position of text line.
drawingContext.PushGuidelineY2(y, lineOrigin.Y - penThickness * 0.5 - y);
try
{
drawingContext.DrawRectangle(
foregroundBrush,
null, // pen
underlineRect
);
}
finally
{
drawingContext.Pop();
}
// underline pen thickness is always positive in fast path
inkBoundingBox.Union(
underlineRect
);
}
}
return inkBoundingBox;
}
