Bullet Collision Detection & Physics Library
btUnionFind.cpp
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1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
4 
5 This software is provided 'as-is', without any express or implied warranty.
6 In no event will the authors be held liable for any damages arising from the use of this software.
7 Permission is granted to anyone to use this software for any purpose,
8 including commercial applications, and to alter it and redistribute it freely,
9 subject to the following restrictions:
10 
11 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
12 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
13 3. This notice may not be removed or altered from any source distribution.
14 */
15 
16 #include "btUnionFind.h"
17 
18 
19 
21 {
22  Free();
23 
24 }
25 
27 {
28 
29 }
30 
32 {
33  m_elements.resize(N);
34 }
36 {
37  m_elements.clear();
38 }
39 
40 
41 void btUnionFind::reset(int N)
42 {
43  allocate(N);
44 
45  for (int i = 0; i < N; i++)
46  {
47  m_elements[i].m_id = i; m_elements[i].m_sz = 1;
48  }
49 }
50 
51 
53 {
54  public:
55 
56  bool operator() ( const btElement& lhs, const btElement& rhs ) const
57  {
58  return lhs.m_id < rhs.m_id;
59  }
60 };
61 
65 {
66 
67  //first store the original body index, and islandId
68  int numElements = m_elements.size();
69 
70  for (int i=0;i<numElements;i++)
71  {
72  m_elements[i].m_id = find(i);
73 #ifndef STATIC_SIMULATION_ISLAND_OPTIMIZATION
74  m_elements[i].m_sz = i;
75 #endif //STATIC_SIMULATION_ISLAND_OPTIMIZATION
76  }
77 
78  // Sort the vector using predicate and std::sort
79  //std::sort(m_elements.begin(), m_elements.end(), btUnionFindElementSortPredicate);
81 
82 }
void sortIslands()
this is a special operation, destroying the content of btUnionFind.
Definition: btUnionFind.cpp:64
int find(int p, int q)
Definition: btUnionFind.h:76
void reset(int N)
Definition: btUnionFind.cpp:41
void clear()
clear the array, deallocated memory. Generally it is better to use array.resize(0), to reduce performance overhead of run-time memory (de)allocations.
int size() const
return the number of elements in the array
void resize(int newsize, const T &fillData=T())
btAlignedObjectArray< btElement > m_elements
Definition: btUnionFind.h:38
void quickSort(const L &CompareFunc)
void allocate(int N)
Definition: btUnionFind.cpp:31