TwGraphAPI	 T_IV
TwBar*           T_PTRREF
TwType 		 T_UV
SDL_Event * 	 O_OBJECT

INPUT

O_OBJECT
    if( sv_isobject($arg) && (SvTYPE(SvRV($arg)) == SVt_PVMG) ) {
        void** pointers = (void**)INT2PTR(void *, SvIV((SV *)SvRV( $arg )));
        $var = ($type)(pointers[0]);
    } else if ($arg == 0) {
        XSRETURN(0);
    } else {
        XSRETURN_UNDEF;
    }
