mirror of https://github.com/CGAL/cgal
60 lines
2.0 KiB
C++
60 lines
2.0 KiB
C++
// example with random points on a sphere
|
|
|
|
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
|
|
|
|
#include <CGAL/point_generators_3.h>
|
|
#include <CGAL/algorithm.h>
|
|
#include <CGAL/Origin.h>
|
|
|
|
#include <CGAL/surface_neighbor_coordinates_3.h>
|
|
|
|
#include <iostream>
|
|
#include <iterator>
|
|
#include <vector>
|
|
|
|
typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
|
|
typedef K::FT Coord_type;
|
|
typedef K::Point_3 Point_3;
|
|
typedef K::Vector_3 Vector_3;
|
|
typedef std::vector< std::pair< Point_3, K::FT > > Point_coordinate_vector;
|
|
|
|
int main()
|
|
{
|
|
int n = 100;
|
|
std::vector< Point_3> points;
|
|
points.reserve(n);
|
|
|
|
std::cout << "Generate " << n << " random points on a sphere." << std::endl;
|
|
CGAL::Random_points_on_sphere_3<Point_3> g(1);
|
|
std::copy_n(g, n, std::back_inserter(points));
|
|
|
|
Point_3 p(1, 0, 0);
|
|
Vector_3 normal(p - CGAL::ORIGIN);
|
|
std::cout << "Compute surface neighbor coordinates for " << p << std::endl;
|
|
Point_coordinate_vector coords;
|
|
CGAL::Triple<std::back_insert_iterator<Point_coordinate_vector>, K::FT, bool> result =
|
|
CGAL::surface_neighbor_coordinates_3(points.begin(), points.end(),
|
|
p, normal,
|
|
std::back_inserter(coords),
|
|
K());
|
|
if(!result.third)
|
|
{
|
|
//Undersampling:
|
|
std::cout << "The coordinate computation was not successful." << std::endl;
|
|
return 0;
|
|
}
|
|
|
|
K::FT norm = result.second;
|
|
|
|
std::cout << "Testing the barycentric property " << std::endl;
|
|
Point_3 b(0, 0, 0);
|
|
for(std::vector< std::pair< Point_3, Coord_type > >::const_iterator
|
|
it = coords.begin(); it!=coords.end(); ++it)
|
|
b = b + (it->second/norm) * (it->first - CGAL::ORIGIN);
|
|
|
|
std::cout << " weighted barycenter: " << b <<std::endl;
|
|
std::cout << " squared distance: " << CGAL::squared_distance(p,b) << std::endl;
|
|
|
|
return EXIT_SUCCESS;
|
|
}
|