| /* |
| Bullet Continuous Collision Detection and Physics Library |
| Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/ |
| |
| This software is provided 'as-is', without any express or implied warranty. |
| In no event will the authors be held liable for any damages arising from the use of this software. |
| Permission is granted to anyone to use this software for any purpose, |
| including commercial applications, and to alter it and redistribute it freely, |
| subject to the following restrictions: |
| |
| 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. |
| 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. |
| 3. This notice may not be removed or altered from any source distribution. |
| */ |
| |
| #include "BulletCollision/CollisionDispatch/btUnionFind.h" |
| |
| |
| |
| btUnionFind::~btUnionFind() |
| { |
| Free(); |
| |
| } |
| |
| btUnionFind::btUnionFind() |
| { |
| |
| } |
| |
| void btUnionFind::allocate(int N) |
| { |
| m_elements.resize(N); |
| } |
| void btUnionFind::Free() |
| { |
| m_elements.clear(); |
| } |
| |
| |
| void btUnionFind::reset(int N) |
| { |
| allocate(N); |
| |
| for (int i = 0; i < N; i++) |
| { |
| m_elements[i].m_id = i; m_elements[i].m_sz = 1; |
| } |
| } |
| |
| |
| class btUnionFindElementSortPredicate |
| { |
| public: |
| |
| bool operator() ( const btElement& lhs, const btElement& rhs ) |
| { |
| return lhs.m_id < rhs.m_id; |
| } |
| }; |
| |
| ///this is a special operation, destroying the content of btUnionFind. |
| ///it sorts the elements, based on island id, in order to make it easy to iterate over islands |
| void btUnionFind::sortIslands() |
| { |
| |
| //first store the original body index, and islandId |
| int numElements = m_elements.size(); |
| |
| for (int i=0;i<numElements;i++) |
| { |
| m_elements[i].m_id = find(i); |
| m_elements[i].m_sz = i; |
| } |
| |
| // Sort the vector using predicate and std::sort |
| //std::sort(m_elements.begin(), m_elements.end(), btUnionFindElementSortPredicate); |
| m_elements.quickSort(btUnionFindElementSortPredicate()); |
| |
| } |
| |