cairo_user_scaled_font_unicode_to_glyph_func_t
for details of how the callback
works.cairoUserFontFaceSetUnicodeToGlyphFunc(font.face, unicode.to.glyph.func)
font.face
CairoFontFace
] A user font faceunicode.to.glyph.func
NULL
CAIRO_STATUS_USER_FONT_IMMUTABLE
error will occur. A user font-face is immutable as soon as a scaled-font
is created from it.
Since 1.8