/// <summary>
/// Populates text measures. If you use a shared textShaper, call this before GetSpans, or GetLines.
/// </summary>
public void LoadMeasures(TextShaper textShaper = null)
{
if (textShaper == null)
{
textShaper = new TextShaper(false);
}
if (GlyphSpan == null)
{
GlyphSpan = textShaper.GetGlyphSpan(Font, Text);
var fontMetrics = GlyphSpan.Paints[0].FontMetrics;
FontHeight = fontMetrics.CapHeight;
if (Font.LineHeight.HasValue)
{
LineHeight = Font.LineHeight.Value;
}
else
{
LineHeight = (fontMetrics.Descent - fontMetrics.Ascent + fontMetrics.Leading) * LineSpacing;
}
MarginY = (LineHeight - FontHeight) / 2;
}
if (LineBreakMode == LineBreakMode.MiddleTruncation)
{
if (EllipsisGlyphSpan == null)
{
EllipsisGlyphSpan = textShaper.GetGlyphSpan(Font, " … ");
}
}
}
/// <summary>
/// Draw a measuredspan (ie a substring) of the glyphspan
/// </summary>
/// <param name="x">Left coordinate</param>
/// <param name="y">Bottom coordinate of the text baseline</param>
/// <param name="measuredSpan"></param>
public static void DrawGlyphSpan(this SKCanvas canvas, GlyphSpan glyphSpan, float x, float y, SKColor color, MeasuredSpan measuredSpan, GlyphAnimation glyphAnimation = null)
{
if (canvas == null)
{
return;
}
if (color.Alpha == 0)
{
return;
}
if (measuredSpan.glyphstart < 0)
{
return;
}
if (measuredSpan.glyphend < 0)
{
return;
}
// paint the "substring" blocks
if (glyphAnimation == null)
{
glyphSpan.PaintBlocks(canvas, measuredSpan.glyphstart, measuredSpan.glyphend, x, y, color);
}
else
{
glyphSpan.PaintBlocks(canvas, measuredSpan.glyphstart, measuredSpan.glyphend, x, y, color, glyphAnimation);
}
}