b2BroadPhase.cpp
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上传日期:2022-01-07
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- /*
- * 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>
- 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;
- }