CGAL 5.3 - 2D Boolean Operations on Nef Polygons
Nef_2/nef_2_polylines.cpp
#include <CGAL/Simple_cartesian.h>
#include <CGAL/Bounded_kernel.h>
#include <CGAL/Nef_polyhedron_2.h>
typedef CGAL::Bounded_kernel<Kernel> Extended_kernel;
typedef Nef_polyhedron::Point Point;
typedef Nef_polyhedron::Explorer Explorer;
typedef Explorer::Face_const_iterator Face_const_iterator;
typedef Explorer::Hole_const_iterator Hole_const_iterator;
typedef Explorer::Halfedge_around_face_const_circulator Halfedge_around_face_const_circulator;
typedef Explorer::Vertex_const_handle Vertex_const_handle;
int main()
{
Point r1[3] = { Point(20,15), Point(25,5), Point(30,15) };
//Point s1[3] = { Point(40,15), Point(40,5) };
Point t1[3] = { Point(20,10), Point(30,10), Point(25, 15) };
std::list<std::pair<Point*,Point*> > polylines;
polylines.push_back(std::make_pair(r1+0, r1+3));
//polylines.push_back(std::make_pair(s1+0, s1+2));
polylines.push_back(std::make_pair(t1+0, t1+3));
Nef_polyhedron RST(polylines.begin(), polylines.end(), Nef_polyhedron::POLYLINES);
std::cout << RST << std::endl;
Explorer explorer = RST.explorer();
// The first face is the infinite one. It has no outer face cycle but only holes
Face_const_iterator fit = explorer.faces_begin();
std::cout << "explorer.mark(explorer.faces_begin()) " << ((explorer.mark(fit))? "is part of polygon" : "is not part of polygon") << std::endl;
for(Hole_const_iterator hit = explorer.holes_begin(fit); hit != explorer.holes_end(fit); hit++){
std::cout << " A hole" << std::endl;
Halfedge_around_face_const_circulator hafc(hit), done(hit);
do{
Vertex_const_handle vh = explorer.target(hafc);
std::cout << explorer.point(vh) << " [" << explorer.point(vh).x().exact() << " | " << explorer.point(vh).y().exact() << "], " ;
hafc++;
}while(hafc != done);
std::cout << std::endl;
}
// The other faces have outer face cycles, and they may have holes
for( fit++;
fit != explorer.faces_end();
fit++){
Halfedge_around_face_const_circulator hafc = explorer.face_cycle(fit), done(hafc);
std::cout << "face: " << ((explorer.mark(fit))? "is part of polygon" : "is not part of polygon") << std::endl;
do{
Vertex_const_handle vh = explorer.target(hafc);
std::cout << explorer.point(vh) << " [" << explorer.point(vh).x().exact() << " | " << explorer.point(vh).y().exact() << "], " ;
hafc++;
}while(hafc != done);
std::cout << std::endl;
for(Hole_const_iterator hit = explorer.holes_begin(fit); hit != explorer.holes_end(fit); hit++){
std::cout << " A hole" << std::endl;
Halfedge_around_face_const_circulator hafc(hit), done(hit);
do{
Vertex_const_handle vh = explorer.target(hafc);
std::cout << explorer.point(vh) << " [" << explorer.point(vh).x().exact() << " | " << explorer.point(vh).y().exact() << "], " ;
hafc++;
}while(hafc != done);
std::cout << std::endl;
}
}
return 0;
}