userFontFaceCreate

Creates a new user font-face.

Use the setter functions to associate callbacks with the returned user font. The only mandatory callback is render_glyph.

After the font-face is created, the user can attach arbitrary data (the actual font data) to it using [cairo.font_face.FontFace.setUserData] and access it from the user-font callbacks by using [cairo.scaled_font.ScaledFont.getFontFace] followed by [cairo.font_face.FontFace.getUserData].