public TypefaceTextShaper(SKTypeface typeface)
{
Typeface = typeface ?? throw new ArgumentNullException(nameof(typeface));
int index;
using (var blob = Typeface.OpenStream(out index).ToHarfBuzzBlob())
using (var face = new Face(blob, index))
{
face.Index = index;
face.UnitsPerEm = Typeface.UnitsPerEm;
font = new HarfBuzzSharp.Font(face);
font.SetScale(FONT_SIZE_SCALE, FONT_SIZE_SCALE);
font.SetFunctionsOpenType();
}
}
/// <summary>
/// Constructs a new TextShaper
/// </summary>
/// <param name="typeface">The typeface of this shaper</param>
private TextShaper(SKTypeface typeface)
{
// Load the typeface stream to a HarfBuzz font
int index;
using (var blob = typeface.OpenStream(out index).ToHarfBuzzBlob())
using (var face = new Face(blob, (uint)index))
{
face.UnitsPerEm = (uint)typeface.UnitsPerEm;
_font = new HarfBuzzSharp.Font(face);
_font.SetScale(overScale, overScale);
_font.SetFunctionsOpenType();
}
// Get font metrics for this typeface
using (var paint = new SKPaint())
{
paint.Typeface = typeface;
paint.TextSize = overScale;
_fontMetrics = paint.FontMetrics;
}
}
/// <summary>
/// Constructs a new TextShaper
/// </summary>
/// <param name="typeface">The typeface of this shaper</param>
private TextShaper(SKTypeface typeface)
{
// Store typeface
_typeface = typeface;
// Load the typeface stream to a HarfBuzz font
int index;
using (var blob = GetHarfBuzzBlob(typeface.OpenStream(out index)))
using (var face = new Face(blob, (uint)index))
{
face.UnitsPerEm = typeface.UnitsPerEm;
_font = new HarfBuzzSharp.Font(face);
_font.SetScale(overScale, overScale);
_font.SetFunctionsOpenType();
}
// Get font metrics for this typeface
using (var paint = new SKPaint())
{
paint.Typeface = typeface;
paint.TextSize = overScale;
_fontMetrics = paint.FontMetrics;
// This is a temporary hack until SkiaSharp exposes
// a way to check if a font is fixed pitch. For now
// we just measure and `i` and a `w` and see if they're
// the same width.
float[] widths = paint.GetGlyphWidths("iw", out var rects);
_isFixedPitch = widths != null && widths.Length > 1 && widths[0] == widths[1];
if (_isFixedPitch)
{
_fixedCharacterWidth = widths[0];
}
}
}
