double calc_objsum(const OBJECT *obj, const double x1, const double y1, const double x2, const double y2);
int clipobj(const OBJECT *obj, double *x1, double *y1, double *x2, double *y2);
/* rayio.c */
double calc_objsum(const OBJECT *obj, const double x1, const double y1, const double x2, const double y2);
int clipobj(const OBJECT *obj, double *x1, double *y1, double *x2, double *y2);
/* rayio.c */