CGAL 4.12 - Bounding Volumes
Min_annulus_d/min_annulus_d.cpp
// computes the smallest enclosing annulus of two point
// sets on nested squares in R^2, using double
// as input type and some internal EXACT floating point type
#include <CGAL/Min_annulus_d.h>
#include <CGAL/Min_sphere_annulus_d_traits_2.h>
#include <CGAL/Homogeneous.h>
#include <iostream>
#include <cassert>
#ifdef CGAL_USE_GMP
#include <CGAL/Gmpzf.h>
typedef CGAL::Gmpzf ET;
#else
#include <CGAL/MP_Float.h>
typedef CGAL::MP_Float ET;
#endif
// use an EXACT kernel...
typedef K::Point_2 Point;
// ...and the traits class based on the exact kernel
typedef CGAL::Min_annulus_d<Traits> Min_annulus;
int main()
{
// points on the squares [-1,1]^2 and [-2,2]^2
Point P[8] = { Point(-1,-1), Point(-1,1), Point(1,-1), Point(1,1),
Point(-2,-2), Point(-2,2), Point(2,-2), Point(2,2)};
Min_annulus ma(P, P+8);
assert (ma.is_valid());
// get center of annulus
Min_annulus::Coordinate_iterator coord_it;
std::cout << "center:"; // homogeneous point, (0,0,1)
for (coord_it = ma.center_coordinates_begin();
coord_it != ma.center_coordinates_end();
++coord_it)
std::cout << " " << *coord_it;
std::cout << std::endl;
// get inner squared radius, 1^2+1^2 = 2
std::cout << "Inner squared radius: " <<