CGAL 5.6.1 - 2D Straight Skeleton and Polygon Offsetting
Straight_skeleton_2/Create_saop_from_polygon_with_holes_2.cpp
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Polygon_with_holes_2.h>
#include <CGAL/create_offset_polygons_from_polygon_with_holes_2.h>
#include <CGAL/Straight_skeleton_2/IO/print.h>
#include <boost/shared_ptr.hpp>
#include <cassert>
#include <vector>
typedef K::Point_2 Point ;
typedef CGAL::Polygon_2<K> Polygon_2 ;
typedef CGAL::Polygon_with_holes_2<K> Polygon_with_holes ;
typedef boost::shared_ptr<Polygon_2> PolygonPtr ;
typedef boost::shared_ptr<Ss> SsPtr ;
typedef std::vector<PolygonPtr> PolygonPtrVector ;
int main()
{
Polygon_2 outer ;
outer.push_back( Point(-1,-1) ) ;
outer.push_back( Point(0,-12) ) ;
outer.push_back( Point(1,-1) ) ;
outer.push_back( Point(12,0) ) ;
outer.push_back( Point(1,1) ) ;
outer.push_back( Point(0,12) ) ;
outer.push_back( Point(-1,1) ) ;
outer.push_back( Point(-12,0) ) ;
Polygon_2 hole ;
hole.push_back( Point(-1,0) ) ;
hole.push_back( Point(0,1 ) ) ;
hole.push_back( Point(1,0 ) ) ;
hole.push_back( Point(0,-1) ) ;
assert(outer.is_counterclockwise_oriented());
assert(hole.is_clockwise_oriented());
Polygon_with_holes poly( outer ) ;
poly.add_hole( hole ) ;
double lOffset = 0.2 ;
PolygonPtrVector offset_polygons = CGAL::create_interior_skeleton_and_offset_polygons_2(lOffset,poly);
CGAL::Straight_skeletons_2::IO::print_polygons(offset_polygons);
return EXIT_SUCCESS;
}