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/* This file is part of the Gudhi Library. The Gudhi library
* (Geometric Understanding in Higher Dimensions) is a generic C++
* library for computational topology.
*
* Author(s): Francois Godi
*
* Copyright (C) 2015 INRIA Sophia-Antipolis (France)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef SRC_BOTTLENECK_INCLUDE_GUDHI_PLANAR_NEIGHBORS_FINDER_H_
#define SRC_BOTTLENECK_INCLUDE_GUDHI_PLANAR_NEIGHBORS_FINDER_H_
#include <list>
#include <map>
#include <CGAL/Search_traits.h>
#include <CGAL/Orthogonal_incremental_neighbor_search.h>
#include <CGAL/Weighted_Minkowski_distance.h>
#include <CGAL/Miscellaneous.h>
#include <gudhi/Persistence_diagrams_graph.h>
namespace Gudhi {
namespace Bottleneck_distance {
/** \internal \brief Structure used to find any point in V near (according to the planar distance) to a query point from U.
*
* V points have to be added manually using their index and before the first remove/pull. A neighbor pulled is automatically removed. but we can also
* remove points manually using their index.
*
* \ingroup bottleneck_distance
*/
class Naive_pnf {
public:
/** \internal \brief Constructor taking the near distance definition as parameter. */
Naive_pnf(double r_);
/** \internal \brief A point added will be possibly pulled. */
void add(int v_point_index);
/** \internal \brief A point manually removed will no longer be possibly pulled. */
void remove(int v_point_index);
/** \internal \brief Can the point given as parameter be returned ? */
bool contains(int v_point_index) const;
/** \internal \brief Provide and remove a V point near to the U point given as parameter, null_point_index() if there isn't such a point. */
int pull_near(int u_point_index);
/** \internal \brief Provide and remove all the V points near to the U point given as parameter. */
virtual std::shared_ptr< std::list<int> > pull_all_near(int u_point_index);
private:
double r;
std::pair<int,int> get_v_key(int v_point_index) const;
std::multimap<std::pair<int,int>,int> grid;
};
class Cgal_pnf {
typedef CGAL::Dimension_tag<2> D;
typedef CGAL::Search_traits<double, Internal_point, const double*, CGAL::Construct_coord_iterator, D> Traits;
typedef CGAL::Weighted_Minkowski_distance<Traits> Distance;
typedef CGAL::Orthogonal_incremental_neighbor_search<Traits, Distance> K_neighbor_search;
typedef K_neighbor_search::Tree Kd_tree;
public:
/** \internal \brief Constructor taking the near distance definition as parameter. */
Cgal_pnf(double r_);
/** \internal \brief A point added will be possibly pulled. */
void add(int v_point_index);
/** \internal \brief A point manually removed will no longer be possibly pulled. */
void remove(int v_point_index);
/** \internal \brief Can the point given as parameter be returned ? */
bool contains(int v_point_index) const;
/** \internal \brief Provide a V point near to the U point given as parameter, null_point_index() if there isn't such a point. */
int pull_near(int u_point_index);
/** \internal \brief Provide and remove all the V points near to the U point given as parameter. */
virtual std::shared_ptr< std::list<int> > pull_all_near(int u_point_index);
private:
double r;
std::set<int> contents;
Kd_tree kd_t;
};
/** \internal \typedef \brief Planar_neighbors_finder is the used implementation. */
typedef Cgal_pnf Planar_neighbors_finder;
inline Naive_pnf::Naive_pnf(double r_) :
r(r_), grid() { }
inline std::pair<int,int> Naive_pnf::get_v_key(int v_point_index) const{
Internal_point v_point = G::get_v_point(v_point_index);
return std::make_pair(static_cast<int>(v_point.x()/r), static_cast<int>(v_point.y()/r));
}
inline void Naive_pnf::add(int v_point_index) {
grid.emplace(get_v_key(v_point_index),v_point_index);
}
inline void Naive_pnf::remove(int v_point_index) {
if(v_point_index != null_point_index())
for(auto it = grid.find(get_v_key(v_point_index)); it!=grid.end(); it++)
if(it->second==v_point_index){
grid.erase(it);
return;
}
}
inline bool Naive_pnf::contains(int v_point_index) const {
if(v_point_index == null_point_index())
return false;
for(auto it = grid.find(get_v_key(v_point_index)); it!=grid.end(); it++)
if(it->second==v_point_index)
return true;
return false;
}
inline int Naive_pnf::pull_near(int u_point_index) {
Internal_point u_point = G::get_u_point(u_point_index);
int i0 = static_cast<int>(u_point.x()/r);
int j0 = static_cast<int>(u_point.y()/r);
for(int i = 1; i<= 3; i++)
for(int j = 1; j<= 3; j++)
for(auto it = grid.find(std::make_pair(i0 +(i%3)-1, j0+(j%3)-1)); it!=grid.end(); it++)
if (G::distance(u_point_index, it->second) <= r) {
int tmp = it->second;
grid.erase(it);
return tmp;
}
return null_point_index();
}
inline std::shared_ptr< std::list<int> > Naive_pnf::pull_all_near(int u_point_index) {
std::shared_ptr< std::list<int> > all_pull(new std::list<int>);
Internal_point u_point = G::get_u_point(u_point_index);
int i0 = static_cast<int>(u_point.x()/r);
int j0 = static_cast<int>(u_point.y()/r);
for(int i = 1; i<= 3; i++)
for(int j = 1; j<= 3; j++)
for(auto it = grid.find(std::make_pair(i0 +(i%3)-1, j0+(j%3)-1)); it!=grid.end();)
if (G::distance(u_point_index, it->second) <= r) {
all_pull->emplace_back(it->second);
it = grid.erase(it);
}
else it++;
return all_pull;
}
/** \internal \brief Constructor taking the near distance definition as parameter. */
inline Cgal_pnf::Cgal_pnf(double r_)
: r(r_), contents(), kd_t() {}
/** \internal \brief A point added will be possibly pulled. */
inline void Cgal_pnf::add(int v_point_index){
if(v_point_index == null_point_index())
return;
contents.insert(v_point_index);
kd_t.insert(G::get_v_point(v_point_index));
}
/** \internal \brief A point manually removed will no longer be possibly pulled. */
inline void Cgal_pnf::remove(int v_point_index){
if(contains(v_point_index)){
contents.erase(v_point_index);
kd_t.remove(G::get_v_point(v_point_index));
}
}
/** \internal \brief Can the point given as parameter be returned ? */
inline bool Cgal_pnf::contains(int v_point_index) const{
if(v_point_index == null_point_index())
return false;
return contents.count(v_point_index)>0;
}
/** \internal \brief Provide and remove a V point near to the U point given as parameter, null_point_index() if there isn't such a point. */
inline int Cgal_pnf::pull_near(int u_point_index){
Internal_point u_point = G::get_u_point(u_point_index);
std::vector<double> w = {1., 1.};
K_neighbor_search search(kd_t, u_point, 0., true, Distance(0, 2, w));
auto it = search.begin();
if(it==search.end() || G::distance(u_point_index, it->first.point_index) > r)
return null_point_index();
int tmp = it->first.point_index;
remove(tmp);
return tmp;
}
inline std::shared_ptr< std::list<int> > Cgal_pnf::pull_all_near(int u_point_index) {
std::shared_ptr< std::list<int> > all_pull(new std::list<int>);
int last_pull = pull_near(u_point_index);
while (last_pull != null_point_index()) {
all_pull->emplace_back(last_pull);
last_pull = pull_near(u_point_index);
}
return all_pull;
}
} // namespace Bottleneck_distance
} // namespace Gudhi
#endif // SRC_BOTTLENECK_INCLUDE_GUDHI_PLANAR_NEIGHBORS_FINDER_H_
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