Line data Source code
1 : /*
2 : * Copyright (c) 2010-2015: G-CSC, Goethe University Frankfurt
3 : * Author: Sebastian Reiter
4 : *
5 : * This file is part of UG4.
6 : *
7 : * UG4 is free software: you can redistribute it and/or modify it under the
8 : * terms of the GNU Lesser General Public License version 3 (as published by the
9 : * Free Software Foundation) with the following additional attribution
10 : * requirements (according to LGPL/GPL v3 §7):
11 : *
12 : * (1) The following notice must be displayed in the Appropriate Legal Notices
13 : * of covered and combined works: "Based on UG4 (www.ug4.org/license)".
14 : *
15 : * (2) The following notice must be displayed at a prominent place in the
16 : * terminal output of covered works: "Based on UG4 (www.ug4.org/license)".
17 : *
18 : * (3) The following bibliography is recommended for citation and must be
19 : * preserved in all covered files:
20 : * "Reiter, S., Vogel, A., Heppner, I., Rupp, M., and Wittum, G. A massively
21 : * parallel geometric multigrid solver on hierarchically distributed grids.
22 : * Computing and visualization in science 16, 4 (2013), 151-164"
23 : * "Vogel, A., Reiter, S., Rupp, M., Nägel, A., and Wittum, G. UG4 -- a novel
24 : * flexible software system for simulating pde based models on high performance
25 : * computers. Computing and visualization in science 16, 4 (2013), 165-179"
26 : *
27 : * This program is distributed in the hope that it will be useful,
28 : * but WITHOUT ANY WARRANTY; without even the implied warranty of
29 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
30 : * GNU Lesser General Public License for more details.
31 : */
32 :
33 : #ifndef __H__LIB_GRID__OCTREE_IMPL__
34 : #define __H__LIB_GRID__OCTREE_IMPL__
35 :
36 : #include <vector>
37 : #include "lib_grid/lg_base.h"
38 : #include "common/node_tree/octree.h"
39 :
40 : namespace ug
41 : {
42 :
43 : ////////////////////////////////////////////////////////////////////////
44 : // CreateOctree
45 : template <class TIterator>
46 : SPOctree
47 0 : CreateOctree(Grid& grid, TIterator elemsBegin, TIterator elemsEnd,
48 : int maxDepth, int elemThreshold, bool bLoose,
49 : APosition& aPos)
50 : {
51 : const char* logMsgPrefix = " CreateOctree: ";
52 :
53 0 : if(elemsBegin == elemsEnd)
54 : return node_tree::SPCollisionTreeRootNode(NULL);
55 :
56 : // access the position attachment of the grid.
57 0 : if(!grid.has_vertex_attachment(aPos)){
58 0 : UG_LOG(logMsgPrefix << "vertex-attachment missing: aPos\n");
59 : return node_tree::SPCollisionTreeRootNode(NULL);
60 : }
61 :
62 : Grid::VertexAttachmentAccessor<APosition> aaPos(grid, aPos);
63 :
64 : // we have to attach an int-attachment to the vertices of the grid.
65 : AInt aInt;
66 : grid.attach_to_vertices(aInt);
67 : Grid::VertexAttachmentAccessor<AInt> aaInt(grid, aInt);
68 :
69 : // all elements have to have the same amount of vertices
70 0 : const size_t numVertices = (*elemsBegin)->num_vertices();
71 :
72 : // initialise all entries of aInt to -1
73 : // since we want to allow to construct an OctTree even for small subsets
74 : // of a grid, we only want to touch vertices that are important.
75 0 : for(TIterator iter = elemsBegin; iter != elemsEnd; ++iter){
76 0 : for(size_t i = 0; i < numVertices; ++i)
77 0 : aaInt[(*iter)->vertex(i)] = -1;
78 : }
79 :
80 : // create the vElems and the vPoints arrays.
81 : std::vector<vector3> vPoints;
82 : std::vector<int> vElems;
83 : std::vector<node_tree::CollisionElementID> vElemIDs;
84 :
85 : /* If you want to match the indices that are referenced by the oct-trees
86 : * triangles with the order of the grids vertices, than you can uncomment
87 : * the following code. Please note, that this code is slower than the
88 : * original code, if only a tiny subset of the grid is sorted into the
89 : * tree.
90 : int tmpCounter = 0;
91 : for(VertexIterator iter = grid.vertices_begin(); iter != grid.vertices_end(); ++iter){
92 : aaInt[*iter] = tmpCounter++;
93 : vPoints.push_back(aaPos[*iter]);
94 : }
95 : */
96 :
97 0 : for(TIterator iter = elemsBegin; iter != elemsEnd; ++iter){
98 : typename TIterator::value_type elem = *iter;
99 :
100 : // insert the indices into vElems and build vPoints at the same time
101 0 : for(size_t i = 0; i < numVertices; ++i){
102 0 : Vertex* v = elem->vertex(i);
103 0 : if(aaInt[v] == -1){
104 0 : aaInt[v] = (int)vPoints.size();
105 0 : vPoints.push_back(aaPos[v]);
106 : }
107 :
108 0 : vElems.push_back(aaInt[v]);
109 : }
110 :
111 : // insert the element-id (the pointer to the associated grid element)
112 0 : vElemIDs.push_back(elem);
113 : }
114 :
115 : // arrays have been created. remove obsolete attachments
116 : grid.detach_from_vertices(aInt);
117 :
118 : // call the octree creation algorithm
119 : return node_tree::CreateOctree(&vPoints.front(), vPoints.size(),
120 : &vElems.front(), vElems.size(), numVertices,
121 0 : &vElemIDs.front(), maxDepth, elemThreshold, bLoose);
122 0 : }
123 :
124 : }// end of namespace
125 :
126 : #endif
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