/* 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 Saclay (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 .
*/
#ifndef SRC_BOTTLENECK_INCLUDE_GUDHI_PLANAR_NEIGHBORS_FINDER_H_
#define SRC_BOTTLENECK_INCLUDE_GUDHI_PLANAR_NEIGHBORS_FINDER_H_
#include
#include
#include
#include "Persistence_diagrams_graph.h"
namespace Gudhi {
namespace bottleneck {
// Planar_neighbors_finder is a data structure used to find if a query point from U has planar neighbors in V with the
// planar distance.
// V's points have to be added manually using their index. A neighbor returned is automatically removed but we can also
// remove points manually using their index.
class Abstract_planar_neighbors_finder {
public:
Abstract_planar_neighbors_finder(const Persistence_diagrams_graph& g, double r);
virtual ~Abstract_planar_neighbors_finder() = 0;
virtual void add(int v_point_index) = 0;
virtual void remove(int v_point_index) = 0;
virtual bool contains(int v_point_index) const = 0;
virtual int pull_near(int u_point_index) = 0;
virtual std::list* pull_all_near(int u_point_index);
protected:
const Persistence_diagrams_graph& g;
const double r;
};
// Naive_pnf is a nave implementation of Abstract_planar_neighbors_finder
class Naive_pnf : public Abstract_planar_neighbors_finder {
public:
Naive_pnf(const Persistence_diagrams_graph& g, double r);
void add(int v_point_index);
void remove(int v_point_index);
bool contains(int v_point_index) const;
int pull_near(int u_point_index);
private:
std::set candidates;
};
// Planar_neighbors_finder is the used Abstract_planar_neighbors_finder's implementation
typedef Naive_pnf Planar_neighbors_finder;
Abstract_planar_neighbors_finder::Abstract_planar_neighbors_finder(const Persistence_diagrams_graph& g, double r) :
g(g), r(r) { }
inline Abstract_planar_neighbors_finder::~Abstract_planar_neighbors_finder() { }
inline std::list* Abstract_planar_neighbors_finder::pull_all_near(int u_point_index) {
std::list* all_pull = new std::list();
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;
}
Naive_pnf::Naive_pnf(const Persistence_diagrams_graph& g, double r) :
Abstract_planar_neighbors_finder(g, r), candidates() { }
inline void Naive_pnf::add(int v_point_index) {
candidates.emplace(v_point_index);
}
inline void Naive_pnf::remove(int v_point_index) {
candidates.erase(v_point_index);
}
inline bool Naive_pnf::contains(int v_point_index) const {
return (candidates.count(v_point_index) > 0);
}
inline int Naive_pnf::pull_near(int u_point_index) {
for (auto it = candidates.begin(); it != candidates.end(); ++it)
if (g.distance(u_point_index, *it) <= r) {
int tmp = *it;
candidates.erase(it);
return tmp;
}
return null_point_index();
}
} // namespace bottleneck
} // namespace Gudhi
#endif // SRC_BOTTLENECK_INCLUDE_GUDHI_PLANAR_NEIGHBORS_FINDER_H_