83 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
		
		
			
		
	
	
			83 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
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								/*
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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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								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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								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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								#include "btUnionFind.h"
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								btUnionFind::~btUnionFind()
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								{
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									Free();
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								}
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								btUnionFind::btUnionFind()
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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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								void	btUnionFind::reset(int N)
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								{
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									allocate(N);
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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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								class btUnionFindElementSortPredicate
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								{
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									public:
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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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								///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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									//first store the original body index, and islandId
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									int numElements = m_elements.size();
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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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									 // 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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