diff options
Diffstat (limited to 'src/Simplex_tree/include/gudhi/Simplex_tree/Simplex_tree_iterators.h')
| -rw-r--r-- | src/Simplex_tree/include/gudhi/Simplex_tree/Simplex_tree_iterators.h | 136 |
1 files changed, 127 insertions, 9 deletions
diff --git a/src/Simplex_tree/include/gudhi/Simplex_tree/Simplex_tree_iterators.h b/src/Simplex_tree/include/gudhi/Simplex_tree/Simplex_tree_iterators.h index 9007b6bd..b63a5595 100644 --- a/src/Simplex_tree/include/gudhi/Simplex_tree/Simplex_tree_iterators.h +++ b/src/Simplex_tree/include/gudhi/Simplex_tree/Simplex_tree_iterators.h @@ -5,6 +5,7 @@ * Copyright (C) 2014 Inria * * Modification(s): + * - 2022/04 Vincent Rouvreau: Add Simplex_tree_boundary_opposite_vertex_simplex_iterator for alpha and cech purpose * - YYYY/MM Author: Description of the modification */ @@ -14,19 +15,19 @@ #include <gudhi/Debug_utils.h> #include <boost/iterator/iterator_facade.hpp> -#include <boost/version.hpp> #include <boost/container/static_vector.hpp> #include <vector> +#include <utility> // for std::pair namespace Gudhi { -/* \addtogroup simplex_tree +/** \addtogroup simplex_tree * Iterators and range types for the Simplex_tree. - * @{ + * @{ */ -/* \brief Iterator over the vertices of a simplex +/** \brief Iterator over the vertices of a simplex * in a SimplexTree. * * Forward iterator, 'value_type' is SimplexTree::Vertex_handle.*/ @@ -72,7 +73,7 @@ class Simplex_tree_simplex_vertex_iterator : public boost::iterator_facade< }; /*---------------------------------------------------------------------------*/ -/* \brief Iterator over the simplices of the boundary of a +/** \brief Iterator over the simplices of the boundary of a * simplex. * * Forward iterator, value_type is SimplexTree::Simplex_handle.*/ @@ -85,6 +86,12 @@ class Simplex_tree_boundary_simplex_iterator : public boost::iterator_facade< typedef typename SimplexTree::Vertex_handle Vertex_handle; typedef typename SimplexTree::Siblings Siblings; + // For cython purpose only. The object it initializes should be overwritten ASAP and never used before it is overwritten. + Simplex_tree_boundary_simplex_iterator() + : sib_(nullptr), + st_(nullptr) { + } + // any end() iterator explicit Simplex_tree_boundary_simplex_iterator(SimplexTree * st) : last_(st->null_vertex()), @@ -118,7 +125,7 @@ class Simplex_tree_boundary_simplex_iterator : public boost::iterator_facade< private: friend class boost::iterator_core_access; -// valid when iterating along the SAME boundary. + // valid when iterating along the SAME boundary. bool equal(Simplex_tree_boundary_simplex_iterator const& other) const { return sh_ == other.sh_; } @@ -173,8 +180,118 @@ class Simplex_tree_boundary_simplex_iterator : public boost::iterator_facade< Simplex_handle sh_; // current Simplex_handle in the boundary SimplexTree * st_; // simplex containing the simplicial complex }; + +/** \brief Iterator over the simplices of the boundary of a simplex and their opposite vertices. + * + * Forward iterator, value_type is std::pair<SimplexTree::Simplex_handle, SimplexTree::Vertex_handle>.*/ +template<class SimplexTree> +class Simplex_tree_boundary_opposite_vertex_simplex_iterator : public boost::iterator_facade< + Simplex_tree_boundary_opposite_vertex_simplex_iterator<SimplexTree>, + std::pair<typename SimplexTree::Simplex_handle, typename SimplexTree::Vertex_handle> const, boost::forward_traversal_tag> { + public: + using Simplex_handle = typename SimplexTree::Simplex_handle; + using Vertex_handle = typename SimplexTree::Vertex_handle; + using Siblings = typename SimplexTree::Siblings; + + // For cython purpose only. The object it initializes should be overwritten ASAP and never used before it is + // overwritten. + Simplex_tree_boundary_opposite_vertex_simplex_iterator() + : sib_(nullptr), + st_(nullptr) { + } + + // any end() iterator + explicit Simplex_tree_boundary_opposite_vertex_simplex_iterator(SimplexTree * st) + : last_(st->null_vertex()), + next_(st->null_vertex()), + sib_(nullptr), + baov_(st->null_simplex(), st->null_vertex()), + st_(st) { + } + + template<class SimplexHandle> + Simplex_tree_boundary_opposite_vertex_simplex_iterator(SimplexTree * st, SimplexHandle sh) + : last_(sh->first), + next_(st->null_vertex()), + sib_(nullptr), + baov_(st->null_simplex(), sh->first), + st_(st) { + // Only check once at the beginning instead of for every increment, as this is expensive. + if (SimplexTree::Options::contiguous_vertices) + GUDHI_CHECK(st_->contiguous_vertices(), "The set of vertices is not { 0, ..., n } without holes"); + Siblings * sib = st->self_siblings(sh); + next_ = sib->parent(); + sib_ = sib->oncles(); + if (sib_ != nullptr) { + if (SimplexTree::Options::contiguous_vertices && sib_->oncles() == nullptr) + // Only relevant for edges + baov_.first = sib_->members_.begin()+next_; + else + baov_.first = sib_->find(next_); + } + } + + private: + friend class boost::iterator_core_access; + + // valid when iterating along the SAME boundary. + bool equal(Simplex_tree_boundary_opposite_vertex_simplex_iterator const& other) const { + return (baov_.first == other.baov_.first); + } + + std::pair<Simplex_handle, Vertex_handle> const& dereference() const { + return baov_; + } + + void increment() { + if (sib_ == nullptr) { + baov_.first = 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) { + // We reached the root, use a short-cut to find a vertex. + if (rit == suffix_.rend()) { + baov_.second = baov_.first->first; + // Segment, this vertex is the last boundary simplex + baov_.first = for_sib->members_.begin()+last_; + sib_ = nullptr; + return; + } else { + // Dim >= 2, initial step of the descent + baov_.first = for_sib->members_.begin()+*rit; + for_sib = baov_.first->second.children(); + ++rit; + } + } + for (; rit != suffix_.rend(); ++rit) { + baov_.first = for_sib->find(*rit); + for_sib = baov_.first->second.children(); + } + baov_.first = for_sib->find(last_); // baov_.first points to the right simplex now + suffix_.push_back(next_); + next_ = sib_->parent(); + sib_ = new_sib; + baov_.second = suffix_.back(); + } + + // 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_ + // 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. + Siblings * sib_; // where the next search will start from + std::pair<Simplex_handle, Vertex_handle> baov_; // a pair containing the current Simplex_handle in the boundary and its opposite vertex + SimplexTree * st_; // simplex containing the simplicial complex +}; + /*---------------------------------------------------------------------------*/ -/* \brief Iterator over the simplices of a simplicial complex. +/** \brief Iterator over the simplices of a simplicial complex. * * Forward iterator, value_type is SimplexTree::Simplex_handle.*/ template<class SimplexTree> @@ -247,7 +364,7 @@ class Simplex_tree_complex_simplex_iterator : public boost::iterator_facade< SimplexTree * st_; }; -/* \brief Iterator over the simplices of the skeleton of a given +/** \brief Iterator over the simplices of the skeleton of a given * dimension of the simplicial complex. * * Forward iterator, value_type is SimplexTree::Simplex_handle.*/ @@ -330,7 +447,8 @@ class Simplex_tree_skeleton_simplex_iterator : public boost::iterator_facade< int curr_dim_; }; -/* @} */ // end addtogroup simplex_tree +/** @}*/ // end addtogroup simplex_tree + } // namespace Gudhi #endif // SIMPLEX_TREE_SIMPLEX_TREE_ITERATORS_H_ |