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 );