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. P is initialized to the union of all generalized polygons in PL . This test is partial. P translated by vector v .