private void Canvas_Draw(CanvasControl sender, CanvasDrawEventArgs args)
{
EnsureLayout(sender);
if (ShowLayoutRectangles)
{
foreach (var layoutRectangle in layoutRectangles)
{
args.DrawingSession.DrawRectangle(layoutRectangle, Colors.Gray);
}
}
if (ShowSelectionBox)
{
args.DrawingSession.DrawRectangle(layoutBox, Colors.LightGray, 2.0f, dashedStroke);
}
var brush = new CanvasSolidColorBrush(sender, Colors.LightSkyBlue);
foreach (LayoutBox l in layoutBoxes)
{
if (l.GlyphRuns.Count > 0)
{
float layoutAdvance = 0;
foreach (var g in l.GlyphRuns)
{
layoutAdvance += g.GetAdvance();
}
float x = (float)l.Rectangle.Left;
if (CurrentTextDirection == TextDirection.RightToLeft)
{
x = (float)l.Rectangle.Right - layoutAdvance;
}
int[] bidiOrdering = l.ProduceBidiOrdering();
foreach (int glyphRunIndex in bidiOrdering)
{
GlyphRun g = l.GlyphRuns[glyphRunIndex];
//
// The Arabic test string contains control characters. A typical text renderer will just not draw these.
//
if (g.FormattingSpan.Script.Shape == CanvasScriptShape.NoVisual)
{
continue;
}
if (g.Glyphs.Count > 0)
{
float advance = g.GetAdvance();
Vector2 position;
position.X = x;
position.Y = (float)l.Rectangle.Bottom;
if (g.FormattingSpan.BidiLevel % 2 != 0)
{
position.X += advance;
}
args.DrawingSession.DrawGlyphRun(
position,
g.FormattingSpan.FontFace,
g.FormattingSpan.FontSize,
g.Glyphs.ToArray(),
false, // isSideways
g.FormattingSpan.BidiLevel,
brush);
x += advance;
}
}
}
}
}