func ParseFont(data []byte, readFile func(relFilename string) ([]byte, error)) (font.Face, error)
ParseFont parses a Plan 9 font file. data is the contents of that font file, which gives relative filenames for subfont files. readFile returns the contents of those subfont files. It is similar to io/ioutil's ReadFile function, except that it takes a relative filename instead of an absolute one.
▹ Example
func ParseSubfont(data []byte, firstRune rune) (font.Face, error)
ParseSubfont parses a Plan 9 subfont file.
firstRune is the first rune in the subfont file. For example, the Phonetic.6.0 subfont, containing glyphs in the range U+0250 to U+02E9, would set firstRune to '\u0250'.