blob: 9cf880e0dc3c4cbdd0ed8f3e63f6c18c1646b044 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
|
/*
* Collapsor.h
*
* Created on: Sep 25, 2014
* Author: dsalinas
*/
#ifndef COLLAPSOR_H_
#define COLLAPSOR_H_
#include <list>
#include "utils/Edge_contractor.h"
/**
* Iteratively puts every vertex at the center of its neighbors
*/
template<typename SkBlComplex> class Edge_collapsor{
private:
SkBlComplex& complex_;
unsigned num_collapses_;
public:
typedef typename SkBlComplex::Vertex_handle Vertex_handle;
typedef typename SkBlComplex::Edge_handle Edge_handle;
/**
* @brief Modify complex to be the expansion of the k-nearest neighbor
* symetric graph.
*/
Edge_collapsor(SkBlComplex& complex,unsigned num_collapses):
complex_(complex),num_collapses_(num_collapses)
{
std::list<Edge_handle> edges;
edges.insert(edges.begin(),complex_.edge_range().begin(),complex_.edge_range().end());
edges.sort(
[&](Edge_handle e1,Edge_handle e2){
return squared_edge_length(e1) < squared_edge_length(e2);
});
collapse_edges(edges);
}
private:
void collapse_edges(std::list<Edge_handle>& edges){
while(!edges.empty() && num_collapses_--){
Edge_handle current_edge = edges.front();
edges.pop_front();
if(is_link_reducible(current_edge))
complex_.remove_edge(current_edge);
}
}
bool is_link_reducible(Edge_handle e){
auto link = complex_.link(e);
if(link.empty()) return false;
if(link.is_cone()) return true;
if(link.num_connected_components()>1) return false;
Edge_contractor<Complex> contractor(link,link.num_vertices()-1);
return (link.num_vertices()==1);
}
double squared_edge_length(Edge_handle e) const{
return squared_eucl_distance(complex_.point(complex_.first_vertex(e)),complex_.point(complex_.second_vertex(e)));
}
double squared_eucl_distance(const Point& p1,const Point& p2) const{
return Geometry_trait::Squared_distance_d()(p1,p2);
}
};
#endif /* COLLAPSOR_H_ */
|