A region is polygonal if its boundary consists of a finite number of line segments. There are two regions whose boundary is empty, namely the empty region and the full region. The full region encompasses the entire plane. Only the former guarantee correct results. A detailed discussion of polygons and generalized polygons can be found in the LEDA book.
P is initialized to the polygonal region with boundary p .
Precondition p must be a weakly simple polygon. If check is set appropriately this is checked. P is initialized to the polygon with vertex sequence pl . P is initialized to the polygon with boundary representation PL . Precondition PL must be a boundary representation.