Reference Manual - 0.9.25
IDirectFBSurface   DrawGlyph

Draw a single glyph specified by its Unicode index at the specified position with the given color following the specified flags.

DrawGlyph (
  IDirectFBSurface   * thiz,
  unsigned int   index,
  int   x,
  int   y,
  DFBSurfaceTextFlags   flags
);

If font was loaded with the DFFA_NOCHARMAP flag, index specifies the raw glyph index in the font.

You need to set a font using the SetFont() method before calling this function.