CGAL 5.5.2 - dD Spatial Searching
Spatial_searching/searching_with_point_with_info_inplace.cpp
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Search_traits_3.h>
#include <CGAL/Search_traits_adapter.h>
#include <CGAL/point_generators_3.h>
#include <CGAL/Orthogonal_k_neighbor_search.h>
#include <CGAL/boost/iterator/counting_iterator.hpp>
#include <utility>
typedef Kernel::Point_3 Point_3;
//definition of a non-mutable lvalue property map,
//with the get function as a friend function to give it
//access to the private member
class My_point_property_map
{
const std::vector<Point_3>& points;
public:
typedef Point_3 value_type;
typedef const value_type& reference;
typedef std::size_t key_type;
typedef boost::lvalue_property_map_tag category;
My_point_property_map(const std::vector<Point_3>& pts):points(pts){}
reference operator[](key_type k) const {return points[k];}
friend reference get(const My_point_property_map& ppmap,key_type i)
{return ppmap[i];}
};
typedef CGAL::Random_points_in_cube_3<Point_3> Random_points_iterator;
typedef CGAL::Search_traits_3<Kernel> Traits_base;
typedef K_neighbor_search::Tree Tree;
typedef Tree::Splitter Splitter;
typedef K_neighbor_search::Distance Distance;
int main()
{
const unsigned int K = 5;
// generator for random data points in the cube ( (-1,-1,-1), (1,1,1) )
Random_points_iterator rpit( 1.0);
std::vector<Point_3> points;
points.push_back(Point_3(*rpit++));
points.push_back(Point_3(*rpit++));
points.push_back(Point_3(*rpit++));
points.push_back(Point_3(*rpit++));
points.push_back(Point_3(*rpit++));
points.push_back(Point_3(*rpit++));
points.push_back(Point_3(*rpit++));
My_point_property_map ppmap(points);
// Insert number_of_data_points in the tree
Tree tree(boost::counting_iterator<std::size_t>(0),
boost::counting_iterator<std::size_t>(points.size()),
Traits(ppmap));
// search K nearest neighbours
Point_3 query(0.0, 0.0, 0.0);
Distance tr_dist(ppmap);
K_neighbor_search search(tree, query, K,0,true,tr_dist);
for(K_neighbor_search::iterator it = search.begin(); it != search.end(); it++){
std::cout << " d(q, nearest neighbor)= "
<< tr_dist.inverse_of_transformed_distance(it->second) << " "
<< points[it->first] << " " << it->first << std::endl;
}
return 0;
}