/// <summary>
/// Gets the character to glyph ID mapping.
/// </summary>
/// <param name="typeface">The typeface.</param>
/// <returns>Dictionary with pairs character - glyphId.</returns>
public IDictionary <char, ushort> GetCharacterToGlyphIdMapping(GlyphTypeface typeface)
{
/* Generate sequence of all characters representable in .Net and feed it into WPF conversion function
* - it will process the characters through its internal representation of CMAP and return glyph IDs. */
var conversionChars = Enumerable.Range(0, ushort.MaxValue).Select(p => (char)p).ToArray();
var characterBuffer = new CharacterBufferRange(conversionChars, 0, conversionChars.Length);
dynamic typefaceDynamic = new AccessPrivateWrapper(typeface);
var glyphIdArray = new ushort[conversionChars.Length];
typefaceDynamic.GetGlyphIndicesOptimized(characterBuffer, glyphIdArray);
return(conversionChars
.Zip(glyphIdArray, (charId, glyphId) => new { charId, glyphId })
.Where(p => p.glyphId != 0)
.ToDictionary(p => p.charId, p => p.glyphId));
}