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Diffstat (limited to 'include/gudhi/Simplex_tree/Simplex_tree_iterators.h')
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diff --git a/include/gudhi/Simplex_tree/Simplex_tree_iterators.h b/include/gudhi/Simplex_tree/Simplex_tree_iterators.h new file mode 100644 index 00000000..7e0a454d --- /dev/null +++ b/include/gudhi/Simplex_tree/Simplex_tree_iterators.h @@ -0,0 +1,338 @@ +/* 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): Clément Maria + * + * 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 <http://www.gnu.org/licenses/>. + */ + +#ifndef SIMPLEX_TREE_SIMPLEX_TREE_ITERATORS_H_ +#define SIMPLEX_TREE_SIMPLEX_TREE_ITERATORS_H_ + +#include <boost/iterator/iterator_facade.hpp> +#include <boost/version.hpp> +#if BOOST_VERSION >= 105600 +# include <boost/container/static_vector.hpp> +#endif + +#include <vector> + +namespace Gudhi { + +/* \addtogroup simplex_tree + * Iterators and range types for the Simplex_tree. + * @{ + */ + +/* \brief Iterator over the vertices of a simplex + * in a SimplexTree. + * + * Forward iterator, 'value_type' is SimplexTree::Vertex_handle.*/ +template<class SimplexTree> +class Simplex_tree_simplex_vertex_iterator : public boost::iterator_facade< + Simplex_tree_simplex_vertex_iterator<SimplexTree>, + typename SimplexTree::Vertex_handle const, boost::forward_traversal_tag, + typename SimplexTree::Vertex_handle const> { + public: + typedef typename SimplexTree::Simplex_handle Simplex_handle; + typedef typename SimplexTree::Siblings Siblings; + typedef typename SimplexTree::Vertex_handle Vertex_handle; + + explicit Simplex_tree_simplex_vertex_iterator(SimplexTree * st) + : // any end() iterator + sib_(nullptr), + v_(st->null_vertex()) { + } + + Simplex_tree_simplex_vertex_iterator(SimplexTree * st, Simplex_handle sh) + : sib_(st->self_siblings(sh)), + v_(sh->first) { + } + + private: + friend class boost::iterator_core_access; + + bool equal(Simplex_tree_simplex_vertex_iterator const &other) const { + return sib_ == other.sib_ && v_ == other.v_; + } + + Vertex_handle const& dereference() const { + return v_; + } + + void increment() { + v_ = sib_->parent(); + sib_ = sib_->oncles(); + } + + Siblings * sib_; + Vertex_handle v_; +}; + +/*---------------------------------------------------------------------------*/ +/* \brief Iterator over the simplices of the boundary of a + * simplex. + * + * Forward iterator, value_type is SimplexTree::Simplex_handle.*/ +template<class SimplexTree> +class Simplex_tree_boundary_simplex_iterator : public boost::iterator_facade< + Simplex_tree_boundary_simplex_iterator<SimplexTree>, + typename SimplexTree::Simplex_handle const, boost::forward_traversal_tag> { + public: + typedef typename SimplexTree::Simplex_handle Simplex_handle; + typedef typename SimplexTree::Vertex_handle Vertex_handle; + typedef typename SimplexTree::Siblings Siblings; + +// any end() iterator + explicit Simplex_tree_boundary_simplex_iterator(SimplexTree * st) + : sib_(nullptr), + sh_(st->null_simplex()), + st_(st) { + } + + template<class SimplexHandle> + Simplex_tree_boundary_simplex_iterator(SimplexTree * st, SimplexHandle sh) + : last_(sh->first), + sib_(nullptr), + st_(st) { + Siblings * sib = st->self_siblings(sh); + next_ = sib->parent(); + sib_ = sib->oncles(); + if (sib_ != nullptr) { + sh_ = sib_->find(next_); + } else { + sh_ = st->null_simplex(); + } // vertex: == end() + } + + private: + friend class boost::iterator_core_access; +// valid when iterating along the SAME boundary. + bool equal(Simplex_tree_boundary_simplex_iterator const& other) const { + return sh_ == other.sh_; + } + + Simplex_handle const& dereference() const { + assert(sh_ != st_->null_simplex()); + return sh_; + } + + void increment() { + if (sib_ == nullptr) { + sh_ = st_->null_simplex(); + return; + } + + Siblings * for_sib = sib_; + Siblings * new_sib = sib_->oncles(); + auto rit = suffix_.rbegin(); + if (SimplexTree::Options::contiguous_vertices && new_sib == nullptr && rit != suffix_.rend()) { + // We reached the root, use a short-cut to find a vertex. We could also + // optimize finding the second vertex of a segment, but people are + // expected to call endpoints(). + assert(st_->contiguous_vertices()); + sh_ = for_sib->members_.begin()+*rit; + for_sib = sh_->second.children(); + ++rit; + } + for (; rit != suffix_.rend(); ++rit) { + sh_ = for_sib->find(*rit); + for_sib = sh_->second.children(); + } + sh_ = for_sib->find(last_); // sh_ points to the right simplex now + suffix_.push_back(next_); + next_ = sib_->parent(); + sib_ = new_sib; + } + + // Most of the storage should be moved to the range, iterators should be light. + Vertex_handle last_; // last vertex of the simplex + Vertex_handle next_; // next vertex to push in suffix_ +#if BOOST_VERSION >= 105600 + // 40 seems a conservative bound on the dimension of a Simplex_tree for now, + // as it would not fit on the biggest hard-drive. + boost::container::static_vector<Vertex_handle, 40> suffix_; + // static_vector still has some overhead compared to a trivial hand-made + // version using std::aligned_storage, or compared to making suffix_ static. +#else + std::vector<Vertex_handle> suffix_; +#endif + Siblings * sib_; // where the next search will start from + Simplex_handle sh_; // current Simplex_handle in the boundary + SimplexTree * st_; // simplex containing the simplicial complex +}; +/*---------------------------------------------------------------------------*/ +/* \brief Iterator over the simplices of a simplicial complex. + * + * Forward iterator, value_type is SimplexTree::Simplex_handle.*/ +template<class SimplexTree> +class Simplex_tree_complex_simplex_iterator : public boost::iterator_facade< + Simplex_tree_complex_simplex_iterator<SimplexTree>, + typename SimplexTree::Simplex_handle const, boost::forward_traversal_tag> { + public: + typedef typename SimplexTree::Simplex_handle Simplex_handle; + typedef typename SimplexTree::Siblings Siblings; + typedef typename SimplexTree::Vertex_handle Vertex_handle; + +// any end() iterator + Simplex_tree_complex_simplex_iterator() + : sib_(nullptr), + st_(nullptr) { + } + + explicit Simplex_tree_complex_simplex_iterator(SimplexTree * st) + : sib_(nullptr), + st_(st) { + if (st == nullptr || st->root() == nullptr || st->root()->members().empty()) { + st_ = nullptr; + } else { + sh_ = st->root()->members().begin(); + sib_ = st->root(); + while (st->has_children(sh_)) { + sib_ = sh_->second.children(); + sh_ = sib_->members().begin(); + } + } + } + private: + friend class boost::iterator_core_access; + +// valid when iterating along the SAME boundary. + bool equal(Simplex_tree_complex_simplex_iterator const& other) const { + if (other.st_ == nullptr) { + return (st_ == nullptr); + } + if (st_ == nullptr) { + return false; + } + return (&(sh_->second) == &(other.sh_->second)); + } + + Simplex_handle const& dereference() const { + return sh_; + } + +// Depth first traversal. + void increment() { + ++sh_; + if (sh_ == sib_->members().end()) { + if (sib_->oncles() == nullptr) { + st_ = nullptr; + return; + } // reach the end + sh_ = sib_->oncles()->members().find(sib_->parent()); + sib_ = sib_->oncles(); + return; + } + while (st_->has_children(sh_)) { + sib_ = sh_->second.children(); + sh_ = sib_->members().begin(); + } + } + + Simplex_handle sh_; + Siblings * sib_; + SimplexTree * st_; +}; + +/* \brief Iterator over the simplices of the skeleton of a given + * dimension of the simplicial complex. + * + * Forward iterator, value_type is SimplexTree::Simplex_handle.*/ +template<class SimplexTree> +class Simplex_tree_skeleton_simplex_iterator : public boost::iterator_facade< + Simplex_tree_skeleton_simplex_iterator<SimplexTree>, + typename SimplexTree::Simplex_handle const, boost::forward_traversal_tag> { + public: + typedef typename SimplexTree::Simplex_handle Simplex_handle; + typedef typename SimplexTree::Siblings Siblings; + typedef typename SimplexTree::Vertex_handle Vertex_handle; + +// any end() iterator + Simplex_tree_skeleton_simplex_iterator() + : sib_(nullptr), + st_(nullptr), + dim_skel_(0), + curr_dim_(0) { + } + + Simplex_tree_skeleton_simplex_iterator(SimplexTree * st, int dim_skel) + : sib_(nullptr), + st_(st), + dim_skel_(dim_skel), + curr_dim_(0) { + if (st == nullptr || st->root() == nullptr || st->root()->members().empty()) { + st_ = nullptr; + } else { + sh_ = st->root()->members().begin(); + sib_ = st->root(); + while (st->has_children(sh_) && curr_dim_ < dim_skel_) { + sib_ = sh_->second.children(); + sh_ = sib_->members().begin(); + ++curr_dim_; + } + } + } + private: + friend class boost::iterator_core_access; + +// valid when iterating along the SAME boundary. + bool equal(Simplex_tree_skeleton_simplex_iterator const& other) const { + if (other.st_ == nullptr) { + return (st_ == nullptr); + } + if (st_ == nullptr) { + return false; + } + return (&(sh_->second) == &(other.sh_->second)); + } + + Simplex_handle const& dereference() const { + return sh_; + } + +// Depth first traversal of the skeleton. + void increment() { + ++sh_; + if (sh_ == sib_->members().end()) { + if (sib_->oncles() == nullptr) { + st_ = nullptr; + return; + } // reach the end + sh_ = sib_->oncles()->members().find(sib_->parent()); + sib_ = sib_->oncles(); + --curr_dim_; + return; + } + while (st_->has_children(sh_) && curr_dim_ < dim_skel_) { + sib_ = sh_->second.children(); + sh_ = sib_->members().begin(); + ++curr_dim_; + } + } + + Simplex_handle sh_; + Siblings * sib_; + SimplexTree * st_; + int dim_skel_; + int curr_dim_; +}; + +/* @} */ // end addtogroup simplex_tree +} // namespace Gudhi + +#endif // SIMPLEX_TREE_SIMPLEX_TREE_ITERATORS_H_ |