Meziantou.Framework

Getting started

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Install the package

Add the Meziantou.Framework.Fonts package to a project:

dotnet package add Meziantou.Framework.Fonts

The examples of this documentation omit the using directives: they need using Meziantou.Framework.Fonts;, and using Meziantou.Framework; for the Unicode types (UnicodeScript).

Load a font and read it

FontLoader.Load reads a font file and gives its faces. A PooledFontEnvironment gives the limits of the font code and the storage of its temporary buffers:

static string DescribeFont(string path)
{
    // The limits that protect the application from hostile fonts, and the storage of the temporary buffers
    var environment = new PooledFontEnvironment(FontResourceLimits.Default, maxLiveAllocationBytes: 64 * 1024 * 1024);

    // One face per font of the file: a font collection has several
    using var stream = File.OpenRead(path);
    var face = FontLoader.Load(stream, environment)[0];

    var glyph = face.MapCodePoint('A'); // 0 when the font does not have the character
    return string.Create(
        CultureInfo.InvariantCulture,
        $"{face.FamilyName} {face.SubfamilyName}: {face.UnitsPerEm} units per em, 'A' is glyph {glyph}, {face.GetAdvanceWidth(glyph)} units wide");
}

With the regular face of Noto Sans, the result is Noto Sans Regular: 1000 units per em, 'A' is glyph 34, 639 units wide.

  • A font file gives one face, and a font collection (.ttc, .otc) one face per font. The format is detected from the content, never from the file name; WOFF and WOFF2 files are expanded in memory.
  • The values of a font are in font units: divide them by UnitsPerEm and multiply them by the size of the text to get pixels or points.
  • MapCodePoint gives the glyph of a character, or 0, the missing glyph, when the font does not have it.
  • Load a font once and reuse it: a FontFace is immutable and can be used by several threads at the same time.

Next steps

  • Loading fonts: environments, limits and errors.
  • Glyphs: metrics, outlines and color glyphs.
  • Shaping: turn a text into positioned glyphs.