BoundingBoxTree.h

// Copyright (C) 2013 Anders Logg
//
// This file is part of DOLFINx (https://www.fenicsproject.org)
//
// SPDX-License-Identifier:    LGPL-3.0-or-later
 
#pragma once
 
#include <algorithm>
#include <array>
#include <cassert>
#include <cstdint>
#include <mpi.h>
#include <span>
#include <string>
#include <vector>
 
namespace dolfinx::mesh
{
class Mesh;
}
 
namespace dolfinx::geometry
{
 
class BoundingBoxTree
{
 
public:
  BoundingBoxTree(const mesh::Mesh& mesh, int tdim,
                  std::span<const std::int32_t> entities, double padding = 0);
 
  BoundingBoxTree(const mesh::Mesh& mesh, int tdim, double padding = 0);
 
  BoundingBoxTree(
      std::vector<std::pair<std::array<double, 3>, std::int32_t>> points);
 
  BoundingBoxTree(BoundingBoxTree&& tree) = default;
 
  BoundingBoxTree(const BoundingBoxTree& tree) = delete;
 
  BoundingBoxTree& operator=(BoundingBoxTree&& other) = default;
 
  BoundingBoxTree& operator=(const BoundingBoxTree& other) = default;
 
  ~BoundingBoxTree() = default;
 
  std::array<double, 6> get_bbox(std::size_t node) const
  {
    std::array<double, 6> x;
    std::copy_n(_bbox_coordinates.data() + 6 * node, 6, x.begin());
    return x;
  }
 
  BoundingBoxTree create_global_tree(MPI_Comm comm) const;
 
  std::int32_t num_bboxes() const;
 
  int tdim() const;
 
  std::string str() const;
 
  std::array<std::int32_t, 2> bbox(std::size_t node) const
  {
    assert(2 * node + 1 < _bboxes.size());
    return {_bboxes[2 * node], _bboxes[2 * node + 1]};
  }
 
private:
  // Constructor
  BoundingBoxTree(std::vector<std::int32_t>&& bboxes,
                  std::vector<double>&& bbox_coords);
 
  // Topological dimension of leaf entities
  int _tdim;
 
  // Print out recursively, for debugging
  void tree_print(std::stringstream& s, std::int32_t i) const;
 
  // List of bounding boxes (parent-child-entity relations)
  std::vector<std::int32_t> _bboxes;
 
  // List of bounding box coordinates
  std::vector<double> _bbox_coordinates;
};
} // namespace dolfinx::geometry