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Diffstat (limited to 'src/3rdparty/Box2D/Collision/b2BroadPhase.h')
-rw-r--r-- | src/3rdparty/Box2D/Collision/b2BroadPhase.h | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/src/3rdparty/Box2D/Collision/b2BroadPhase.h b/src/3rdparty/Box2D/Collision/b2BroadPhase.h new file mode 100644 index 0000000..d2965ed --- /dev/null +++ b/src/3rdparty/Box2D/Collision/b2BroadPhase.h @@ -0,0 +1,257 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.box2d.org +* +* 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. +*/ + +#ifndef B2_BROAD_PHASE_H +#define B2_BROAD_PHASE_H + +#include "Box2D/Common/b2Settings.h" +#include "Box2D/Collision/b2Collision.h" +#include "Box2D/Collision/b2DynamicTree.h" +#include <algorithm> + +struct b2Pair +{ + int32 proxyIdA; + int32 proxyIdB; +}; + +/// The broad-phase is used for computing pairs and performing volume queries and ray casts. +/// This broad-phase does not persist pairs. Instead, this reports potentially new pairs. +/// It is up to the client to consume the new pairs and to track subsequent overlap. +class b2BroadPhase +{ +public: + + enum + { + e_nullProxy = -1 + }; + + b2BroadPhase(); + ~b2BroadPhase(); + + /// Create a proxy with an initial AABB. Pairs are not reported until + /// UpdatePairs is called. + int32 CreateProxy(const b2AABB& aabb, void* userData); + + /// Destroy a proxy. It is up to the client to remove any pairs. + void DestroyProxy(int32 proxyId); + + /// Call MoveProxy as many times as you like, then when you are done + /// call UpdatePairs to finalized the proxy pairs (for your time step). + void MoveProxy(int32 proxyId, const b2AABB& aabb, const b2Vec2& displacement); + + /// Call to trigger a re-processing of it's pairs on the next call to UpdatePairs. + void TouchProxy(int32 proxyId); + + /// Get the fat AABB for a proxy. + const b2AABB& GetFatAABB(int32 proxyId) const; + + /// Get user data from a proxy. Returns nullptr if the id is invalid. + void* GetUserData(int32 proxyId) const; + + /// Test overlap of fat AABBs. + bool TestOverlap(int32 proxyIdA, int32 proxyIdB) const; + + /// Get the number of proxies. + int32 GetProxyCount() const; + + /// Update the pairs. This results in pair callbacks. This can only add pairs. + template <typename T> + void UpdatePairs(T* callback); + + /// Query an AABB for overlapping proxies. The callback class + /// is called for each proxy that overlaps the supplied AABB. + template <typename T> + void Query(T* callback, const b2AABB& aabb) const; + + /// Ray-cast against the proxies in the tree. This relies on the callback + /// to perform a exact ray-cast in the case were the proxy contains a shape. + /// The callback also performs the any collision filtering. This has performance + /// roughly equal to k * log(n), where k is the number of collisions and n is the + /// number of proxies in the tree. + /// @param input the ray-cast input data. The ray extends from p1 to p1 + maxFraction * (p2 - p1). + /// @param callback a callback class that is called for each proxy that is hit by the ray. + template <typename T> + void RayCast(T* callback, const b2RayCastInput& input) const; + + /// Get the height of the embedded tree. + int32 GetTreeHeight() const; + + /// Get the balance of the embedded tree. + int32 GetTreeBalance() const; + + /// Get the quality metric of the embedded tree. + float32 GetTreeQuality() const; + + /// Shift the world origin. Useful for large worlds. + /// The shift formula is: position -= newOrigin + /// @param newOrigin the new origin with respect to the old origin + void ShiftOrigin(const b2Vec2& newOrigin); + +private: + + friend class b2DynamicTree; + + void BufferMove(int32 proxyId); + void UnBufferMove(int32 proxyId); + + bool QueryCallback(int32 proxyId); + + b2DynamicTree m_tree; + + int32 m_proxyCount; + + int32* m_moveBuffer; + int32 m_moveCapacity; + int32 m_moveCount; + + b2Pair* m_pairBuffer; + int32 m_pairCapacity; + int32 m_pairCount; + + int32 m_queryProxyId; +}; + +/// This is used to sort pairs. +inline bool b2PairLessThan(const b2Pair& pair1, const b2Pair& pair2) +{ + if (pair1.proxyIdA < pair2.proxyIdA) + { + return true; + } + + if (pair1.proxyIdA == pair2.proxyIdA) + { + return pair1.proxyIdB < pair2.proxyIdB; + } + + return false; +} + +inline void* b2BroadPhase::GetUserData(int32 proxyId) const +{ + return m_tree.GetUserData(proxyId); +} + +inline bool b2BroadPhase::TestOverlap(int32 proxyIdA, int32 proxyIdB) const +{ + const b2AABB& aabbA = m_tree.GetFatAABB(proxyIdA); + const b2AABB& aabbB = m_tree.GetFatAABB(proxyIdB); + return b2TestOverlap(aabbA, aabbB); +} + +inline const b2AABB& b2BroadPhase::GetFatAABB(int32 proxyId) const +{ + return m_tree.GetFatAABB(proxyId); +} + +inline int32 b2BroadPhase::GetProxyCount() const +{ + return m_proxyCount; +} + +inline int32 b2BroadPhase::GetTreeHeight() const +{ + return m_tree.GetHeight(); +} + +inline int32 b2BroadPhase::GetTreeBalance() const +{ + return m_tree.GetMaxBalance(); +} + +inline float32 b2BroadPhase::GetTreeQuality() const +{ + return m_tree.GetAreaRatio(); +} + +template <typename T> +void b2BroadPhase::UpdatePairs(T* callback) +{ + // Reset pair buffer + m_pairCount = 0; + + // Perform tree queries for all moving proxies. + for (int32 i = 0; i < m_moveCount; ++i) + { + m_queryProxyId = m_moveBuffer[i]; + if (m_queryProxyId == e_nullProxy) + { + continue; + } + + // We have to query the tree with the fat AABB so that + // we don't fail to create a pair that may touch later. + const b2AABB& fatAABB = m_tree.GetFatAABB(m_queryProxyId); + + // Query tree, create pairs and add them pair buffer. + m_tree.Query(this, fatAABB); + } + + // Reset move buffer + m_moveCount = 0; + + // Sort the pair buffer to expose duplicates. + std::sort(m_pairBuffer, m_pairBuffer + m_pairCount, b2PairLessThan); + + // Send the pairs back to the client. + int32 i = 0; + while (i < m_pairCount) + { + b2Pair* primaryPair = m_pairBuffer + i; + void* userDataA = m_tree.GetUserData(primaryPair->proxyIdA); + void* userDataB = m_tree.GetUserData(primaryPair->proxyIdB); + + callback->AddPair(userDataA, userDataB); + ++i; + + // Skip any duplicate pairs. + while (i < m_pairCount) + { + b2Pair* pair = m_pairBuffer + i; + if (pair->proxyIdA != primaryPair->proxyIdA || pair->proxyIdB != primaryPair->proxyIdB) + { + break; + } + ++i; + } + } + + // Try to keep the tree balanced. + //m_tree.Rebalance(4); +} + +template <typename T> +inline void b2BroadPhase::Query(T* callback, const b2AABB& aabb) const +{ + m_tree.Query(callback, aabb); +} + +template <typename T> +inline void b2BroadPhase::RayCast(T* callback, const b2RayCastInput& input) const +{ + m_tree.RayCast(callback, input); +} + +inline void b2BroadPhase::ShiftOrigin(const b2Vec2& newOrigin) +{ + m_tree.ShiftOrigin(newOrigin); +} + +#endif |