grid_tools_cache.h

// ---------------------------------------------------------------------
//
// Copyright (C) 2017 - 2019 by the deal.II authors
//
// This file is part of the deal.II library.
//
// The deal.II library is free software; you can use it, redistribute
// it, and/or modify it under the terms of the GNU Lesser General
// Public License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// The full text of the license can be found in the file LICENSE.md at
// the top level directory of deal.II.
//
// ---------------------------------------------------------------------

#ifndef dealii_grid_grid_tools_cache_h
#define dealii_grid_grid_tools_cache_h


#include <deal.II/base/config.h>

#include <deal.II/base/exceptions.h>
#include <deal.II/base/point.h>
#include <deal.II/base/subscriptor.h>

#include <deal.II/fe/mapping_q1.h>

#include <deal.II/grid/grid_tools_cache_update_flags.h>
#include <deal.II/grid/tria.h>
#include <deal.II/grid/tria_accessor.h>
#include <deal.II/grid/tria_iterator.h>

#include <deal.II/numerics/kdtree.h>
#include <deal.II/numerics/rtree.h>

#include <boost/signals2.hpp>

#include <cmath>

DEAL_II_NAMESPACE_OPEN

namespace GridTools
{
  template <int dim, int spacedim = dim>
  class Cache : public Subscriptor
  {
  public:
    Cache(const Triangulation<dim, spacedim> &tria,
          const Mapping<dim, spacedim> &      mapping =
            StaticMappingQ1<dim, spacedim>::mapping);

    ~Cache() override;

    void
    mark_for_update(const CacheUpdateFlags &flags = update_all);


    const std::vector<
      std::set<typename Triangulation<dim, spacedim>::active_cell_iterator>> &
    get_vertex_to_cell_map() const;

    const std::vector<std::vector<Tensor<1, spacedim>>> &
    get_vertex_to_cell_centers_directions() const;

    const std::map<unsigned int, Point<spacedim>> &
    get_used_vertices() const;

    const RTree<std::pair<Point<spacedim>, unsigned int>> &
    get_used_vertices_rtree() const;

    const RTree<
      std::pair<BoundingBox<spacedim>,
                typename Triangulation<dim, spacedim>::active_cell_iterator>> &
    get_cell_bounding_boxes_rtree() const;

    const Triangulation<dim, spacedim> &
    get_triangulation() const;

    const Mapping<dim, spacedim> &
    get_mapping() const;


    const RTree<std::pair<BoundingBox<spacedim>, unsigned int>> &
    get_covering_rtree() const;

#ifdef DEAL_II_WITH_NANOFLANN

    const KDTree<spacedim> &
    get_vertex_kdtree() const;
#endif

  private:
    mutable CacheUpdateFlags update_flags;

    SmartPointer<const Triangulation<dim, spacedim>, Cache<dim, spacedim>> tria;

    SmartPointer<const Mapping<dim, spacedim>, Cache<dim, spacedim>> mapping;


    mutable std::vector<
      std::set<typename Triangulation<dim, spacedim>::active_cell_iterator>>
      vertex_to_cells;

    mutable std::vector<std::vector<Tensor<1, spacedim>>>
      vertex_to_cell_centers;

    mutable RTree<std::pair<BoundingBox<spacedim>, unsigned int>>
      covering_rtree;

#ifdef DEAL_II_WITH_NANOFLANN

    mutable KDTree<spacedim> vertex_kdtree;
#endif

    mutable std::map<unsigned int, Point<spacedim>> used_vertices;

    mutable RTree<std::pair<Point<spacedim>, unsigned int>> used_vertices_rtree;

    mutable RTree<
      std::pair<BoundingBox<spacedim>,
                typename Triangulation<dim, spacedim>::active_cell_iterator>>
      cell_bounding_boxes_rtree;

    boost::signals2::connection tria_signal;
  };



  // Inline functions
  template <int dim, int spacedim>
  inline const Triangulation<dim, spacedim> &
  Cache<dim, spacedim>::get_triangulation() const
  {
    return *tria;
  }



  template <int dim, int spacedim>
  inline const Mapping<dim, spacedim> &
  Cache<dim, spacedim>::get_mapping() const
  {
    return *mapping;
  }
} // namespace GridTools



DEAL_II_NAMESPACE_CLOSE

#endif