/* This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT. * See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details. * Author(s): David Salinas * * Copyright (C) 2014 Inria * * Modification(s): * - YYYY/MM Author: Description of the modification */ #ifndef UTILS_EDGE_CONTRACTOR_H_ #define UTILS_EDGE_CONTRACTOR_H_ #include #include #include #include /** * Iteratively puts every vertex at the center of its neighbors */ template class Edge_contractor { private: SkBlComplex& complex_; unsigned num_contractions_; /** * @brief return a cost corresponding to the squared length of the edge */ template< typename EdgeProfile> class Length_cost : public contraction::Cost_policy { public: typedef typename contraction::Cost_policy::Cost_type Cost_type; typedef typename EdgeProfile::Point Point; Cost_type operator()(const EdgeProfile& profile, const boost::optional& placement) const override { Cost_type res; if (!placement) return res; return Geometry_trait::Squared_distance_d()(profile.p0(), profile.p1()); // not working?? } }; /** * @brief return a cost corresponding to the squared length of the edge */ template< typename EdgeProfile> class Middle_placement : public contraction::Placement_policy { public: typedef typename contraction::Placement_policy::Placement_type Placement_type; typedef typename EdgeProfile::Point Point; Placement_type operator()(const EdgeProfile& profile) const override { std::vector mid_coords(profile.p0().dimension(), 0); for (int i = 0; i < profile.p0().dimension(); ++i) { mid_coords[i] = (profile.p0()[i] + profile.p1()[i]) / 2.; } return Point(profile.p0().dimension(), mid_coords.begin(), mid_coords.end()); } }; 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_contractor(SkBlComplex& complex, unsigned num_contractions) : complex_(complex), num_contractions_(num_contractions) { typedef typename contraction::Edge_profile Profile; num_contractions = (std::min)(static_cast(num_contractions), static_cast(complex_.num_vertices() - 1)); typedef typename contraction::Skeleton_blocker_contractor Contractor; Contractor contractor(complex_, new Length_cost> (), new Middle_placement> (), contraction::make_link_valid_contraction(), contraction::make_remove_popable_blockers_visitor()); contractor.contract_edges(num_contractions); } }; #endif // UTILS_EDGE_CONTRACTOR_H_