typemap

TYPEMAP
char				T_CHAR
int				T_INT
int *				T_PTR
float * 			T_PTR
float				T_FLOAT
Entity *			O_OBJECT
Collision *		O_OBJECT
Point *		   O_OBJECT
Rect *		   O_OBJECT
Grid *		   O_OBJECT
Circle *		   O_OBJECT
OUTPUT

# The Perl object is blessed into 'CLASS', which should be a
# char* having the name of the package for the blessing.
O_OBJECT
   if ($var) {
      void** pointers = malloc(2 * sizeof(void*));
      pointers[0] = (void*)$var;
      pointers[1] = (void*)PERL_GET_CONTEXT;
      sv_setref_pv( $arg, CLASS, (void*)pointers );
   } else {
      XSRETURN_UNDEF;
   }

INPUT

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