/// <summary>
/// Paint this font run
/// </summary>
/// <param name="ctx"></param>
internal void Paint(PaintTextContext ctx)
{
// Paint selection?
if (ctx.PaintSelectionBackground != null)
{
float selStartXCoord;
if (ctx.SelectionStart < Start)
{
selStartXCoord = Direction == TextDirection.LTR ? 0 : Width;
}
else if (ctx.SelectionStart >= End)
{
selStartXCoord = Direction == TextDirection.LTR ? Width : 0;
}
else
{
selStartXCoord = RelativeCodePointXCoords[ctx.SelectionStart - this.Start];
}
float selEndXCoord;
if (ctx.SelectionEnd < Start)
{
selEndXCoord = Direction == TextDirection.LTR ? 0 : Width;
}
else if (ctx.SelectionEnd >= End)
{
selEndXCoord = Direction == TextDirection.LTR ? Width : 0;
}
else
{
selEndXCoord = RelativeCodePointXCoords[ctx.SelectionEnd - this.Start];
}
if (selStartXCoord != selEndXCoord)
{
var rect = new SKRect(this.XCoord + selStartXCoord, Line.YCoord,
this.XCoord + selEndXCoord, Line.YCoord + Line.Height);
ctx.Canvas.DrawRect(rect, ctx.PaintSelectionBackground);
}
}
// Don't paint trailing whitespace runs
if (RunKind == FontRunKind.TrailingWhitespace)
{
return;
}
// Text
using (var paint = new SKPaint())
{
// Work out font variant adjustments
float glyphScale = 1;
float glyphVOffset = 0;
if (Style.FontVariant == FontVariant.SuperScript)
{
glyphScale = 0.65f;
glyphVOffset = -Style.FontSize * 0.35f;
}
if (Style.FontVariant == FontVariant.SubScript)
{
glyphScale = 0.65f;
glyphVOffset = Style.FontSize * 0.1f;
}
// Setup SKPaint
paint.Color = Style.TextColor;
paint.TextEncoding = SKTextEncoding.GlyphId;
paint.Typeface = Typeface;
paint.TextSize = Style.FontSize * glyphScale;
paint.SubpixelText = true;
paint.IsAntialias = ctx.Options.IsAntialias;
paint.LcdRenderText = ctx.Options.LcdRenderText;
unsafe
{
fixed(ushort *pGlyphs = Glyphs.Underlying)
{
// Get glyph positions
var glyphPositions = GlyphPositions.ToArray();
// Paint underline
if (Style.Underline != UnderlineStyle.None && RunKind == FontRunKind.Normal)
{
// Work out underline metrics
paint.TextSize = Style.FontSize;
float underlineYPos = Line.YCoord + Line.BaseLine + (paint.FontMetrics.UnderlinePosition ?? 0);
paint.StrokeWidth = paint.FontMetrics.UnderlineThickness ?? 0;
paint.TextSize = Style.FontSize * glyphScale;
if (Style.Underline == UnderlineStyle.Gapped)
{
// Get intercept positions
var interceptPositions = paint.GetPositionedTextIntercepts(
(IntPtr)(pGlyphs + Glyphs.Start),
Glyphs.Length * sizeof(ushort),
glyphPositions, underlineYPos - paint.StrokeWidth / 2, underlineYPos + paint.StrokeWidth);
// Paint gapped underlinline
float x = XCoord;
for (int i = 0; i < interceptPositions.Length; i += 2)
{
float b = interceptPositions[i] - paint.StrokeWidth;
if (x < b)
{
ctx.Canvas.DrawLine(new SKPoint(x, underlineYPos), new SKPoint(b, underlineYPos), paint);
}
x = interceptPositions[i + 1] + paint.StrokeWidth;
}
if (x < XCoord + Width)
{
ctx.Canvas.DrawLine(new SKPoint(x, underlineYPos), new SKPoint(XCoord + Width, underlineYPos), paint);
}
}
else
{
// Paint solid underline
ctx.Canvas.DrawLine(new SKPoint(XCoord, underlineYPos), new SKPoint(XCoord + Width, underlineYPos), paint);
}
}
// Draw the text
ctx.Canvas.DrawPositionedText((IntPtr)(pGlyphs + Glyphs.Start), Glyphs.Length * sizeof(ushort), glyphPositions, paint);
}
}
// Paint strikethrough
if (Style.StrikeThrough != StrikeThroughStyle.None && RunKind == FontRunKind.Normal)
{
paint.StrokeWidth = paint.FontMetrics.StrikeoutThickness ?? 0;
float strikeYPos = Line.YCoord + Line.BaseLine + (paint.FontMetrics.StrikeoutPosition ?? 0) + glyphVOffset;
ctx.Canvas.DrawLine(new SKPoint(XCoord, strikeYPos), new SKPoint(XCoord + Width, strikeYPos), paint);
}
}
}
