public override SizeF MeasureText(string text, FontMeasure measure)
{
var rect = new SKRect();
var width = SKPaint.MeasureText(text, ref rect);
var height = SKFont.Size;
switch (measure)
{
case FontMeasure.Strict:
SKPaint.MeasureText("X", ref rect);
height = rect.Height;
break;
case FontMeasure.Extended:
height = SKFont.Size + SKFont.Metrics.Descent;
break;
}
return(new SizeF(width, height));
}
private Vector2 CalculateTargetPosition(Font font, string line, RectangleF target, TextAlign textAlign, FontMeasure fontMeasure, out SizeF size)
{
var skiaFont = (SkiaFont)font;
var skPaint = skiaFont.SKPaint;
skPaint.IsStroke = false;
size = font.MeasureText(line, fontMeasure);
float positionX = target.X;
switch (textAlign & (TextAlign.Left | TextAlign.Center | TextAlign.Right))
{
case TextAlign.Right:
positionX = target.Right - size.Width;
break;
case TextAlign.Center:
positionX = target.Center.X - size.Width / 2;
break;
}
float positionY = target.Top;
switch (textAlign & (TextAlign.Top | TextAlign.Middle | TextAlign.Bottom))
{
case TextAlign.Bottom:
positionY = target.Bottom - size.Height;
break;
case TextAlign.Middle:
positionY = target.Center.Y - size.Height / 2;
break;
}
var offsetY = size.Height;
if (fontMeasure == FontMeasure.Extended)
{
offsetY = skiaFont.SKFont.Size;
}
return(new Vector2(positionX, positionY + offsetY));
}
public override Vector2 DrawText(string line, Font font, RectangleF target, TextAlign textAlign, Color color, FontMeasure fontMeasure = FontMeasure.Extended)
{
if (font == null)
{
return(Vector2.Zero);
}
if (line == null)
{
return(Vector2.Zero);
}
var skiaFont = (SkiaFont)font;
var position = CalculateTargetPosition(font, line, target, textAlign, fontMeasure, out var size);
var skPaint = skiaFont.SKPaint;
PreparePaint(skPaint);
skPaint.IsStroke = false;
skPaint.IsAntialias = true;
skPaint.FilterQuality = SKFilterQuality.Low;
skPaint.Color = color.ToSkia();
skCanvas.DrawText(line, position.X, position.Y, skPaint);
return(size);
}
public abstract Vector2 DrawText(string text, Font font, RectangleF target, TextAlign align, Color color, FontMeasure fontMeasure = FontMeasure.Extended);
public abstract SizeF MeasureText(string text, FontMeasure measure);
