/*
* Garland_heckbert.h
* Created on: Feb 10, 2015
* 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): David Salinas
*
* Copyright (C) 2014 INRIA Sophia Antipolis-Méditerranée (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 GARLAND_HECKBERT_H_
#define GARLAND_HECKBERT_H_
#include
#include
#include "gudhi/Point.h"
#include "gudhi/Edge_contraction.h"
#include "gudhi/Skeleton_blocker.h"
#include "gudhi/Off_reader.h"
#include "Garland_heckbert/Error_quadric.h"
using namespace std;
using namespace Gudhi;
using namespace skbl;
using namespace contraction;
struct Geometry_trait{
typedef Point_d Point;
};
/**
* The vertex stored in the complex contains a quadric.
*/
struct Garland_heckbert_traits : public Skeleton_blocker_simple_geometric_traits {
public:
struct Garland_heckbert_vertex : public Simple_geometric_vertex{
Error_quadric quadric;
};
typedef Garland_heckbert_vertex Graph_vertex;
};
typedef Skeleton_blocker_geometric_complex< Garland_heckbert_traits > Complex;
typedef Edge_profile EdgeProfile;
typedef Skeleton_blocker_contractor Complex_contractor;
/**
* How the new vertex is placed after an edge collapse : here it is placed at
* the point minimizing the cost of the quadric.
*/
class GH_placement : public Gudhi::contraction::Placement_policy{
Complex& complex_;
public:
typedef typename Gudhi::contraction::Placement_policy::Placement_type Placement_type;
GH_placement(Complex& complex):complex_(complex){}
Placement_type operator()(const EdgeProfile& profile) const override{
auto sum_quad(profile.v0().quadric);
sum_quad += profile.v1().quadric;
boost::optional min_quadric_pt(sum_quad.min_cost());
if (min_quadric_pt)
return Placement_type(*min_quadric_pt);
else
return profile.p0();
}
};
/**
* How much cost an edge collapse : here the costs is given by a quadric
* which expresses a squared distances with triangles planes.
*/
class GH_cost : public Gudhi::contraction::Cost_policy{
Complex& complex_;
public:
typedef typename Gudhi::contraction::Cost_policy::Cost_type Cost_type;
GH_cost(Complex& complex):complex_(complex){}
Cost_type operator()( EdgeProfile const& profile, boost::optional const& new_point ) const override {
Cost_type res;
if (new_point){
auto sum_quad(profile.v0().quadric);
sum_quad += profile.v1().quadric;
res = sum_quad.cost(*new_point);
}
return res;
}
};
/**
* Visitor that is called at several moment.
* Here we initializes the quadrics of every vertex at the on_started call back
* and we update them when contracting an edge (the quadric become the sum of both quadrics).
*/
class GH_visitor: public Gudhi::contraction::Contraction_visitor {
Complex& complex_;
public:
GH_visitor(Complex& complex):complex_(complex){}
//Compute quadrics for every vertex v
//The quadric of v consists in the sum of quadric
//of every triangles passing through v weighted by its area
void on_started(Complex & complex) override{
for(auto v : complex.vertex_range()){
auto & quadric_v(complex[v].quadric);
for(auto t : complex.triangle_range(v)){
auto t_it = t.begin();
const auto& p0(complex.point(*t_it++));
const auto& p1(complex.point(*t_it++));
const auto& p2(complex.point(*t_it++));
quadric_v+=Error_quadric(p0,p1,p2);
}
}
}
/**
* @brief Called when an edge is about to be contracted and replaced by a vertex whose position is *placement.
*/
void on_contracting(EdgeProfile const &profile, boost::optional< Point > placement)
override{
profile.v0().quadric += profile.v1().quadric;
}
};
int main(int argc, char *argv[]){
if (argc!=4){
std::cerr << "Usage "< off_reader(argv[1],complex);
if(!off_reader.is_valid()){
std::cerr << "Unable to read file:"<(),
new GH_visitor(complex)
);
std::cout<<"Contract "< off_writer(argv[2],complex);
return EXIT_SUCCESS;
}
#endif /* GARLAND_HECKBERT_H_ */