CGAL 5.6.1 - 2D Straight Skeleton and Polygon Offsetting
Straight_skeleton_2/Create_skeleton_and_offset_polygons_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 <vector>
#include <cassert>
typedef K::Point_2 Point ;
typedef CGAL::Polygon_2<K> Polygon_2 ;
typedef CGAL::Polygon_with_holes_2<K> PolygonWithHoles ;
typedef boost::shared_ptr<PolygonWithHoles> PolygonWithHolesPtr ;
typedef std::vector<PolygonWithHolesPtr> PolygonWithHolesPtrVector;
int main()
{
Polygon_2 outer ;
outer.push_back( Point( 0.0, 0.0) ) ;
outer.push_back( Point(10.0, 0.0) ) ;
outer.push_back( Point(10.0, 4.5) ) ;
outer.push_back( Point(12.0, 4.5) ) ;
outer.push_back( Point(12.0, 2.0) ) ;
outer.push_back( Point(16.0, 2.0) ) ;
outer.push_back( Point(16.0, 8.0) ) ;
outer.push_back( Point(12.0, 8.0) ) ;
outer.push_back( Point(12.0, 5.5) ) ;
outer.push_back( Point(10.0, 5.5) ) ;
outer.push_back( Point(10.0,10.0) ) ;
outer.push_back( Point( 0.0,10.0) ) ;
Polygon_2 hole ;
hole.push_back( Point(3.0,3.0) ) ;
hole.push_back( Point(3.0,7.0) ) ;
hole.push_back( Point(7.0,7.0) ) ;
hole.push_back( Point(7.0,3.0) ) ;
assert(outer.is_counterclockwise_oriented());
assert(hole.is_clockwise_oriented());
PolygonWithHoles poly( outer ) ;
poly.add_hole( hole ) ;
double lOffset = 1 ;
PolygonWithHolesPtrVector offset_poly_with_holes = CGAL::create_interior_skeleton_and_offset_polygons_with_holes_2(lOffset,poly);
CGAL::Straight_skeletons_2::IO::print_polygons_with_holes(offset_poly_with_holes);
return EXIT_SUCCESS;
}