K_nearest_builder.h
1/* This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
2 * See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
3 * Author(s): David Salinas
4 *
5 * Copyright (C) 2014 Inria
6 *
7 * Modification(s):
8 * - YYYY/MM Author: Description of the modification
9 */
10
11#ifndef UTILS_K_NEAREST_BUILDER_H_
12#define UTILS_K_NEAREST_BUILDER_H_
13
14#include <CGAL/Euclidean_distance.h>
15#include <CGAL/Orthogonal_k_neighbor_search.h>
16#include <CGAL/Search_traits_d.h>
17#include <CGAL/Search_traits_adapter.h>
18#include <CGAL/property_map.h>
19
20#include <unordered_map>
21#include <list>
22#include <utility>
23
24#include "utils/UI_utils.h"
25#include "model/Complex_typedefs.h"
26
27template<typename SkBlComplex> class K_nearest_builder {
28 private:
29 typedef Geometry_trait Kernel;
30 typedef Point Point_d;
31 typedef std::pair<Point_d, unsigned> Point_d_with_id;
32 typedef CGAL::Search_traits_d<Kernel> Traits_base;
33 typedef CGAL::Search_traits_adapter<Point_d_with_id, CGAL::First_of_pair_property_map<Point_d_with_id>,
34 Traits_base> Traits;
35 typedef CGAL::Orthogonal_k_neighbor_search<Traits> Neighbor_search;
36 typedef Neighbor_search::Tree Tree;
37 typedef Neighbor_search::Distance Distance;
38
39 SkBlComplex& complex_;
40
41 public:
46 K_nearest_builder(SkBlComplex& complex, unsigned k) : complex_(complex) {
47 complex.keep_only_vertices();
48 compute_edges(k);
49 }
50
51 private:
52 double squared_eucl_distance(const Point& p1, const Point& p2) const {
53 return Geometry_trait::Squared_distance_d()(p1, p2);
54 }
55
56 void compute_edges(unsigned k) {
57 std::list<Point_d_with_id> points_with_id;
58 for (auto v : complex_.vertex_range()) {
59 Point_d_with_id point_v(complex_.point(v), v.vertex);
60 points_with_id.push_back(point_v);
61 }
62
63 Tree tree(points_with_id.begin(), points_with_id.end());
64
65 typedef typename SkBlComplex::Vertex_handle Vertex_handle;
66 for (auto p : complex_.vertex_range()) {
67 Neighbor_search search(tree, complex_.point(p), k + 1);
68 for (auto it = ++search.begin(); it != search.end(); ++it) {
69 Vertex_handle q(std::get<1>(it->first));
70 if (p != q && complex_.contains_vertex(p) && complex_.contains_vertex(q))
71 complex_.add_edge_without_blockers(p, q);
72 }
73 }
74 }
75};
76
77#endif // UTILS_K_NEAREST_BUILDER_H_
Handle type for the vertices of a cell complex.
Definition: VertexHandle.h:15
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