Polygon/Example.cpp

#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Polygon_2.h>

#include <list>

typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
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));

  CGAL::set_pretty_mode(std::cout);
  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;
}