CGAL 5.4 - 2D Apollonius Graphs (Delaunay Graphs of Disks)
#include <CGAL/config.h>
// standard includes
#include <iostream>
#include <fstream>
#include <cassert>
#if defined(CGAL_USE_CORE) || defined(CGAL_USE_LEDA)
# include <CGAL/Exact_algebraic.h>
// *** WARNING ***
// The use of a kernel based on an exact number type is highly inefficient.
// It is used in this example primarily for illustration purposes.
// In an efficiency critical context, and/or for the purposes of
// benchmarking the Apollonius_graph_filtered_traits_2<> class should
// be used.
#if defined(CGAL_USE_CORE) || defined(CGAL_USE_LEDA)
// If LEDA is present use leda_real as the exact number type
// Otherwise if CORE is present use CORE's Expr as the exact number type
typedef CGAL::Exact_algebraic NT;
// Otherwise just use double. This may cause numerical errors but it
// is still worth doing it to show how to define correctly the traits
// class
typedef double NT;
#include <CGAL/Simple_cartesian.h>
// typedefs for the traits and the algorithm
#include <CGAL/Apollonius_graph_2.h>
#include <CGAL/Apollonius_graph_traits_2.h>
// the traits class is now going to assume that the operations
// +,-,*,/ and sqrt are supported exactly
typedef CGAL::Apollonius_graph_2<Traits> Apollonius_graph;
int main()
std::ifstream ifs("data/sites.cin");
assert( ifs );
Apollonius_graph ag;
Apollonius_graph::Site_2 site;
// read the sites and insert them in the Apollonius graph
while ( ifs >> site ) {
// validate the Apollonius graph
assert( ag.is_valid(true, 1) );
std::cout << std::endl;
return 0;