GetFEM  5.4.3
bgeot_rtree.h
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30 ===========================================================================*/
31 
32 #ifndef BGEOT_RTREE_H
33 #define BGEOT_RTREE_H
34 
35 /** @file bgeot_rtree.h
36  @author Julien Pommier <Julien.Pommier@insa-toulouse.fr>
37  @date January 2004.
38  @brief region-tree for window/point search on a set of rectangles.
39 */
40 
41 #include <set>
42 #include "bgeot_small_vector.h"
43 #include "bgeot_node_tab.h"
44 
45 namespace bgeot {
46 
47  struct box_index {
48  size_type id;
49  const base_node *min, *max;
50  };
51 
52  struct box_index_id_compare {
53  bool operator()(const box_index *plhs, const box_index *prhs) const {
54  return plhs->id < prhs->id;
55  }
56  };
57 
58  struct box_index_topology_compare {
59  const scalar_type EPS;
60  bool is_less(const base_node &lhs, const base_node &rhs) const {
61  GMM_ASSERT2(lhs.size() == rhs.size(), "size mismatch");
62  for (size_type i = 0; i < lhs.size(); ++i)
63  if (gmm::abs(lhs[i] - rhs[i]) > EPS) {
64  return lhs[i] < rhs[i];
65  }
66  return false;
67  }
68 
69  box_index_topology_compare(scalar_type EPS_) : EPS{EPS_} {}
70 
71  bool operator()(const box_index &lhs, const box_index &rhs) const {
72  if (EPS == scalar_type(0))
73  return lhs.id < rhs.id;
74  else
75  return is_less(*lhs.min, *rhs.min) ||
76  (!is_less(*rhs.min, *lhs.min) && is_less(*lhs.max, *rhs.max));
77  }
78  };
79 
80  struct rtree_elt_base {
81  enum { RECTS_PER_LEAF=8 };
82  bool isleaf_;
83  bool isleaf() const { return isleaf_; }
84  base_node rmin, rmax;
85  rtree_elt_base(bool leaf, const base_node& rmin_, const base_node& rmax_)
86  : isleaf_(leaf), rmin(rmin_), rmax(rmax_) {}
87  virtual ~rtree_elt_base() {}
88  };
89 
90  /** Balanced tree of n-dimensional rectangles.
91  *
92  * This is not a dynamic structure. Once a query has been made on the
93  * tree, new boxes should not be added.
94  *
95  * CAUTION : For EPS > 0, nearly identically boxes are eliminated
96  * For EPS = 0 all boxes are stored.
97  */
98  class rtree {
99  public:
100  using box_cont = std::set<box_index,box_index_topology_compare> ;
101  using pbox_cont = std::vector<const box_index*>;
102  using pbox_set = std::set<const box_index *, box_index_id_compare>;
103 
104  rtree(scalar_type EPS = 0);
105  rtree(const rtree&) = delete;
106  rtree& operator = (const rtree&) = delete;
107 
108  size_type add_box(const base_node &min, const base_node &max,
109  size_type id=size_type(-1));
110  size_type nb_boxes() const { return boxes.size(); }
111  void clear();
112 
113  void find_intersecting_boxes(const base_node& bmin, const base_node& bmax,
114  pbox_set& boxlst) const;
115  void find_containing_boxes(const base_node& bmin, const base_node& bmax,
116  pbox_set& boxlst) const;
117  void find_contained_boxes(const base_node& bmin, const base_node& bmax,
118  pbox_set& boxlst) const;
119  void find_boxes_at_point(const base_node& P, pbox_set& boxlst) const;
120  void find_line_intersecting_boxes(const base_node& org,
121  const base_small_vector& dirv,
122  pbox_set& boxlst) const;
123  void find_line_intersecting_boxes(const base_node& org,
124  const base_small_vector& dirv,
125  const base_node& bmin,
126  const base_node& bmax,
127  pbox_set& boxlst) const;
128 
129  void find_intersecting_boxes(const base_node& bmin, const base_node& bmax,
130  std::vector<size_type>& idvec) {
131  pbox_set bs;
132  find_intersecting_boxes(bmin, bmax, bs);
133  pbox_set_to_idvec(bs, idvec);
134  }
135  void find_containing_boxes(const base_node& bmin, const base_node& bmax,
136  std::vector<size_type>& idvec) {
137  pbox_set bs;
138  find_containing_boxes(bmin, bmax, bs);
139  pbox_set_to_idvec(bs, idvec);
140  }
141  void find_contained_boxes(const base_node& bmin,
142  const base_node& bmax,
143  std::vector<size_type>& idvec) {
144  pbox_set bs;
145  find_contained_boxes(bmin, bmax, bs);
146  pbox_set_to_idvec(bs, idvec);
147  }
148  void find_boxes_at_point(const base_node& P,
149  std::vector<size_type>& idvec) const
150  { pbox_set bs; find_boxes_at_point(P, bs); pbox_set_to_idvec(bs, idvec); }
151  void find_line_intersecting_boxes(const base_node& org,
152  const base_small_vector& dirv,
153  std::vector<size_type>& idvec) {
154  pbox_set bs;
155  find_line_intersecting_boxes(org, dirv, bs);
156  pbox_set_to_idvec(bs, idvec);
157  }
158  void find_line_intersecting_boxes(const base_node& org,
159  const base_small_vector& dirv,
160  const base_node& bmin,
161  const base_node& bmax,
162  std::vector<size_type>& idvec) {
163  pbox_set bs;
164  find_line_intersecting_boxes(org, dirv, bmin, bmax, bs);
165  pbox_set_to_idvec(bs, idvec);
166  }
167 
168  void dump();
169  void build_tree();
170  private:
171  void pbox_set_to_idvec(pbox_set bs, std::vector<size_type>& idvec) const {
172  idvec.reserve(bs.size()); idvec.resize(0);
173  for (pbox_set::const_iterator it=bs.begin(); it != bs.end(); ++it)
174  idvec.push_back((*it)->id);
175  }
176 
177  const scalar_type EPS;
178  node_tab nodes;
179  box_cont boxes;
180  std::unique_ptr<rtree_elt_base> root;
181  bool tree_built;
182  getfem::lock_factory locks_;
183  };
184 
185 }
186 
187 #endif
bgeot_node_tab.h
Structure which dynamically collects points identifying points that are nearer than a certain very sm...
bgeot_small_vector.h
Small (dim < 8) vectors.
bgeot::node_tab
Store a set of points, identifying points that are nearer than a certain very small distance.
Definition: bgeot_node_tab.h:52
bgeot::rtree
Balanced tree of n-dimensional rectangles.
Definition: bgeot_rtree.h:98
bgeot::small_vector< scalar_type >
bgeot
Basic Geometric Tools.
Definition: bgeot_convex_ref.cc:27
bgeot::size_type
size_t size_type
used as the common size type in the library
Definition: bgeot_poly.h:49