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