FGAPI void FGAPIENTRY glutMultiEntryFunc( void (* callback)( int, int ) );
FGAPI void FGAPIENTRY glutMultiButtonFunc( void (* callback)( int, int, int, int, int ) );
FGAPI void FGAPIENTRY glutMultiMotionFunc( void (* callback)( int, int, int ) );
FGAPI void FGAPIENTRY glutMultiEntryFunc( void (* callback)( int, int ) );
FGAPI void FGAPIENTRY glutMultiButtonFunc( void (* callback)( int, int, int, int, int ) );
FGAPI void FGAPIENTRY glutMultiMotionFunc( void (* callback)( int, int, int ) );