File indexing completed on 2025-08-03 03:49:55

 /*
 * Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com
 *
 * 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 <Box2D/Collision/b2BroadPhase.h>
 #include <cstring>
 using namespace std;
 
 b2BroadPhase::b2BroadPhase()
 {
     m_proxyCount = 0;
 
     m_pairCapacity = 16;
     m_pairCount = 0;
     m_pairBuffer = (b2Pair*)b2Alloc(m_pairCapacity * sizeof(b2Pair));
 
     m_moveCapacity = 16;
     m_moveCount = 0;
     m_moveBuffer = (int32*)b2Alloc(m_moveCapacity * sizeof(int32));
 }
 
 b2BroadPhase::~b2BroadPhase()
 {
     b2Free(m_moveBuffer);
     b2Free(m_pairBuffer);
 }
 
 int32 b2BroadPhase::CreateProxy(const b2AABB& aabb, void* userData)
 {
     int32 proxyId = m_tree.CreateProxy(aabb, userData);
     ++m_proxyCount;
     BufferMove(proxyId);
     return proxyId;
 }
 
 void b2BroadPhase::DestroyProxy(int32 proxyId)
 {
     UnBufferMove(proxyId);
     --m_proxyCount;
     m_tree.DestroyProxy(proxyId);
 }
 
 void b2BroadPhase::MoveProxy(int32 proxyId, const b2AABB& aabb, const b2Vec2& displacement)
 {
     bool buffer = m_tree.MoveProxy(proxyId, aabb, displacement);
     if (buffer)
     {
         BufferMove(proxyId);
     }
 }
 
 void b2BroadPhase::BufferMove(int32 proxyId)
 {
     if (m_moveCount == m_moveCapacity)
     {
         int32* oldBuffer = m_moveBuffer;
         m_moveCapacity *= 2;
         m_moveBuffer = (int32*)b2Alloc(m_moveCapacity * sizeof(int32));
         memcpy(m_moveBuffer, oldBuffer, m_moveCount * sizeof(int32));
         b2Free(oldBuffer);
     }
 
     m_moveBuffer[m_moveCount] = proxyId;
     ++m_moveCount;
 }
 
 void b2BroadPhase::UnBufferMove(int32 proxyId)
 {
     for (int32 i = 0; i < m_moveCount; ++i)
     {
         if (m_moveBuffer[i] == proxyId)
         {
             m_moveBuffer[i] = e_nullProxy;
             return;
         }
     }
 }
 
 // This is called from b2DynamicTree::Query when we are gathering pairs.
 bool b2BroadPhase::QueryCallback(int32 proxyId)
 {
     // A proxy cannot form a pair with itself.
     if (proxyId == m_queryProxyId)
     {
         return true;
     }
 
     // Grow the pair buffer as needed.
     if (m_pairCount == m_pairCapacity)
     {
         b2Pair* oldBuffer = m_pairBuffer;
         m_pairCapacity *= 2;
         m_pairBuffer = (b2Pair*)b2Alloc(m_pairCapacity * sizeof(b2Pair));
         memcpy(m_pairBuffer, oldBuffer, m_pairCount * sizeof(b2Pair));
         b2Free(oldBuffer);
     }
 
     m_pairBuffer[m_pairCount].proxyIdA = b2Min(proxyId, m_queryProxyId);
     m_pairBuffer[m_pairCount].proxyIdB = b2Max(proxyId, m_queryProxyId);
     ++m_pairCount;
 
     return true;
 }