-/* clip.c */
-int inside_obj(const OBJECT *obj, double x, double y, const int coord_type);
-int clipsegment(double *x1, double *y1, double *x2, double *y2, const double u, const double v);
-int clipsector(double *x1, double *y1, double *x2, double *y2, const double u, const double v);
-int clipcircle(double *x1, double *y1, double *x2, double *y2, const double cx, const double cy, const double radius, double t1, double t2);
-int cliptriangle(double *x1, double *y1, double *x2, double *y2, const double u, const double v, const int clip_xaxis);