template<class Kernel, class Container>

typename Gps_circle_segment_traits_2<Kernel>::Polygon_with_holes_2


approximated_offset_2 ( Polygon_2<Kernel, Container> P, typename Kernel::FT r, double eps)

 
Provides a guaranteed approximation of the offset of the given polygon
P by a given radius r  namely, the function computes the
the Minkowski sum $$P B_{r}, where $$B_{r} is a disc of radius
r centered at the origin.
The function actually outputs a set $$S that contains the Minkowski sum,
such that the approximation error is bounded by eps.
Note that as the input polygon not be convex, its offset may not be a
simple polygon. The result is therefore represented as a polygon with
holes, whose edges are either line segments or circular arcs.
Precondition:  P is a simple polygon. 


template<class Kernel, class Container, class DecompositionStrategy>

typename Gps_circle_segment_traits_2<Kernel>::Polygon_with_holes_2



 
Provides a guaranteed approximation of the offset of the given polygon
P by a radius r, as described above.
If the input polygon P is not convex, the function
decomposes it into convex subpolygons $$P_{1}, ..., P_{k} and computes
the union of the suboffsets (namely $$ _{i}(P_{i} B_{r})).
The decomposition is performed using the given decomposition strategy
decomp, which must be an instance of a class that models the
concept PolygonConvexDecomposition.
Precondition:  P is a simple polygon. 
