CGAL 5.0 - 2D Polygons
Polygon/Example.cpp
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Polygon_2.h>
#include <list>
typedef CGAL::Point_2<K> Point;
typedef CGAL::Polygon_2<K> Polygon_2;
typedef Polygon_2::Vertex_iterator VertexIterator;
typedef Polygon_2::Edge_const_iterator EdgeIterator;
int main()
{
// create a polygon and put some points in it
Polygon_2 p;
p.push_back(Point(0,0));
p.push_back(Point(4,0));
p.push_back(Point(4,4));
p.push_back(Point(2,2));
p.push_back(Point(0,4));
std::cout << "created the polygon p:" << std::endl;
std::cout << p << std::endl;
std::cout << std::endl;
// determine some properties of the polygon
bool IsSimple = p.is_simple();
bool IsConvex = p.is_convex();
bool IsClockwise = (p.orientation() == CGAL::CLOCKWISE);
double Area = p.area();
std::cout << "polygon p is";
if (!IsSimple) std::cout << " not";
std::cout << " simple." << std::endl;
std::cout << "polygon p is";
if (!IsConvex) std::cout << " not";
std::cout << " convex." << std::endl;
std::cout << "polygon p is";
if (!IsClockwise) std::cout << " not";
std::cout << " clockwise oriented." << std::endl;
std::cout << "the area of polygon p is " << Area << std::endl;
std::cout << std::endl;
// apply some algorithms
Point q(1,1);
std::cout << "created point q = " << q << std::endl;
std::cout << std::endl;
bool IsInside = (p.bounded_side(q) == CGAL::ON_BOUNDED_SIDE);
std::cout << "point q is";
if (!IsInside) std::cout << " not";
std::cout << " inside polygon p." << std::endl;
std::cout << std::endl;
// traverse the vertices and the edges
int n=0;
for (VertexIterator vi = p.vertices_begin(); vi != p.vertices_end(); ++vi)
std::cout << "vertex " << n++ << " = " << *vi << std::endl;
std::cout << std::endl;
n=0;
for (EdgeIterator ei = p.edges_begin(); ei != p.edges_end(); ++ei)
std::cout << "edge " << n++ << " = " << *ei << std::endl;
return 0;
}