CGAL 6.2 - CGAL and the Boost Graph Library

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BGL_arrangement_2/primal.cpp
// Adapting an arrangement to a BGL graph.
#include "arr_rational_nt.h"
#include <CGAL/Cartesian.h>
#include <CGAL/Arr_segment_traits_2.h>
#include <CGAL/Arrangement_2.h>
#include <CGAL/graph_traits_Arrangement_2.h>
#include <CGAL/Arr_vertex_index_map.h>
#include <boost/graph/dijkstra_shortest_paths.hpp>
#include <CGAL/property_map.h>
typedef CGAL::Cartesian<Number_type> Kernel;
typedef CGAL::Arr_segment_traits_2<Kernel> Traits_2;
typedef Traits_2::Point_2 Point_2;
typedef Traits_2::X_monotone_curve_2 Segment_2;
typedef CGAL::Arrangement_2<Traits_2> Arrangement_2;
// A functor used to compute the length of an edge.
class Edge_length_func
{
public:
// Boost property type definitions:
typedef boost::readable_property_map_tag category;
typedef double value_type;
typedef value_type reference;
typedef Arrangement_2::Halfedge_handle key_type;
double operator()(Arrangement_2::Halfedge_handle e) const
{
const double x1 = CGAL::to_double (e->source()->point().x());
const double y1 = CGAL::to_double (e->source()->point().y());
const double x2 = CGAL::to_double (e->target()->point().x());
const double y2 = CGAL::to_double (e->target()->point().y());
const double diff_x = x2 - x1;
const double diff_y = y2 - y1;
return std::sqrt(diff_x*diff_x + diff_y*diff_y);
}
};
double get(const Edge_length_func& edge_length, Arrangement_2::Halfedge_handle e)
{
return edge_length(e);
}
int main()
{
Arrangement_2 arr;
// Construct an arrangement of seven intersecting line segments.
// We keep a handle for the vertex v_0 that corresponds to the point (1,1).
Arrangement_2::Halfedge_handle e =
insert_non_intersecting_curve (arr, Segment_2 (Point_2 (1, 1),
Point_2 (7, 1)));
Arrangement_2::Vertex_handle v0 = e->source();
insert (arr, Segment_2 (Point_2 (1, 1), Point_2 (3, 7)));
insert (arr, Segment_2 (Point_2 (1, 4), Point_2 (7, 1)));
insert (arr, Segment_2 (Point_2 (2, 2), Point_2 (9, 3)));
insert (arr, Segment_2 (Point_2 (2, 2), Point_2 (4, 4)));
insert (arr, Segment_2 (Point_2 (7, 1), Point_2 (9, 3)));
insert (arr, Segment_2 (Point_2 (3, 7), Point_2 (9, 3)));
// Create a mapping of the arrangement vertices to indices.
CGAL::Arr_vertex_index_map<Arrangement_2> index_map(arr);
// Perform Dijkstra's algorithm from the vertex v0.
Edge_length_func edge_length;
boost::vector_property_map<double, CGAL::Arr_vertex_index_map<Arrangement_2> > dist_map(static_cast<unsigned int>(arr.number_of_vertices()), index_map);
boost::dijkstra_shortest_paths(arr, v0,
boost::vertex_index_map(index_map).
weight_map(edge_length).
distance_map(dist_map));
// Print the results:
Arrangement_2::Vertex_iterator vit;
std::cout << "The distances of the arrangement vertices from ("
<< v0->point() << ") :" << std::endl;
for (vit = arr.vertices_begin(); vit != arr.vertices_end(); ++vit)
std::cout << "(" << vit->point() << ") at distance "
<< dist_map[vit] << std::endl;
return 0;
}
CGAL::Arr_segment_traits_2
CGAL::Arr_vertex_index_map
CGAL::Arrangement_2
CGAL::Polygon_mesh_processing::edge_length
FT edge_length(typename boost::graph_traits< PolygonMesh >::halfedge_descriptor h, const PolygonMesh &pmesh, const NamedParameters &np=parameters::default_values())
CGAL::to_double
double to_double(const NT &x)
CGAL::insert_non_intersecting_curve
Arrangement_2< Traits, Dcel >::Halfedge_handle insert_non_intersecting_curve(Arrangement_2< Traits, Dcel > &arr, const typename Traits::X_monotone_curve_2 &xc, const PointLocation &pl=walk_pl)
CGAL::insert
Arrangement_on_surface_with_history_2< GeometryTraits, TopologyTraits >::Curve_handle insert(Arrangement_on_surface_with_history_2< GeometryTraits, TopologyTraits > &arr, const typename Traits::Curve_2 &c, const PointLocation &pl=walk_pl)
Kernel
CGAL::Cartesian