The cpdf_set_font() function sets the current font face, font size and encoding. Currently only the standard postscript fonts are supported. Returns TRUE on success or FALSE on failure.
The last parameter encoding can take the following values: "MacRomanEncoding", "MacExpertEncoding", "WinAnsiEncoding", and "NULL". "NULL" stands for the font's built-in encoding.
See the ClibPDF Manual for more information, especially how to support Asian fonts.