extern void drawLineComponent(poly *, int);
extern void drawOpaquePolygon(poly *, GC, GC, int);
extern poly * copyPolygons(poly *);
extern void minMaxPolygons(poly *);
extern int polyCompare(poly *, poly *);
extern void calcEyePoint(void);
extern void drawRenderedPolygon(poly *, int);
extern void freePointResevoir(void);
extern void freeListOfPolygons(poly *);
extern void drawPolygons(int);
extern int lessThan(float, float);
extern int greaterThan(float, float);
extern int isNaN(float);
extern int isNaNPoint(float, float, float);
extern int equal(float, float);
