FcFreeTypeCharSetAndSpacing - compute Unicode coverage and spacing type
#include <fontconfig.h>
#include <fcfreetype.h>
FcCharSet * FcFreeTypeCharSetAndSpacing (FT_Face face, FcBlanks *blanks, int *spacing);
Scans a FreeType face and returns the set of encoded Unicode chars. FcBlanks is
deprecated, blanks is ignored and accepted only for compatibility with
older code. spacing receives the computed spacing type of the font, one
of FC_MONO for a font where all glyphs have the same width, FC_DUAL, where the
font has glyphs in precisely two widths, one twice as wide as the other, or
FC_PROPORTIONAL where the font has glyphs of many widths.