diff options
Diffstat (limited to 'thirdparty/bullet/BulletCollision/CollisionDispatch/btUnionFind.h')
| -rw-r--r-- | thirdparty/bullet/BulletCollision/CollisionDispatch/btUnionFind.h | 172 |
1 files changed, 83 insertions, 89 deletions
diff --git a/thirdparty/bullet/BulletCollision/CollisionDispatch/btUnionFind.h b/thirdparty/bullet/BulletCollision/CollisionDispatch/btUnionFind.h index ef2a29202f..d422ef55eb 100644 --- a/thirdparty/bullet/BulletCollision/CollisionDispatch/btUnionFind.h +++ b/thirdparty/bullet/BulletCollision/CollisionDispatch/btUnionFind.h @@ -23,107 +23,101 @@ subject to the following restrictions: ///see for discussion of static island optimizations by Vroonsh here: http://code.google.com/p/bullet/issues/detail?id=406 #define STATIC_SIMULATION_ISLAND_OPTIMIZATION 1 -struct btElement +struct btElement { - int m_id; - int m_sz; + int m_id; + int m_sz; }; ///UnionFind calculates connected subsets // Implements weighted Quick Union with path compression // optimization: could use short ints instead of ints (halving memory, would limit the number of rigid bodies to 64k, sounds reasonable) class btUnionFind - { - private: - btAlignedObjectArray<btElement> m_elements; - - public: - - btUnionFind(); - ~btUnionFind(); - - - //this is a special operation, destroying the content of btUnionFind. - //it sorts the elements, based on island id, in order to make it easy to iterate over islands - void sortIslands(); - - void reset(int N); - - SIMD_FORCE_INLINE int getNumElements() const - { - return int(m_elements.size()); - } - SIMD_FORCE_INLINE bool isRoot(int x) const - { - return (x == m_elements[x].m_id); - } - - btElement& getElement(int index) - { - return m_elements[index]; - } - const btElement& getElement(int index) const - { - return m_elements[index]; - } - - void allocate(int N); - void Free(); - - - - - int find(int p, int q) - { - return (find(p) == find(q)); - } - - void unite(int p, int q) - { - int i = find(p), j = find(q); - if (i == j) - return; +{ +private: + btAlignedObjectArray<btElement> m_elements; + +public: + btUnionFind(); + ~btUnionFind(); + + //this is a special operation, destroying the content of btUnionFind. + //it sorts the elements, based on island id, in order to make it easy to iterate over islands + void sortIslands(); + + void reset(int N); + + SIMD_FORCE_INLINE int getNumElements() const + { + return int(m_elements.size()); + } + SIMD_FORCE_INLINE bool isRoot(int x) const + { + return (x == m_elements[x].m_id); + } + + btElement& getElement(int index) + { + return m_elements[index]; + } + const btElement& getElement(int index) const + { + return m_elements[index]; + } + + void allocate(int N); + void Free(); + + int find(int p, int q) + { + return (find(p) == find(q)); + } + + void unite(int p, int q) + { + int i = find(p), j = find(q); + if (i == j) + return; #ifndef USE_PATH_COMPRESSION - //weighted quick union, this keeps the 'trees' balanced, and keeps performance of unite O( log(n) ) - if (m_elements[i].m_sz < m_elements[j].m_sz) - { - m_elements[i].m_id = j; m_elements[j].m_sz += m_elements[i].m_sz; - } - else - { - m_elements[j].m_id = i; m_elements[i].m_sz += m_elements[j].m_sz; - } -#else - m_elements[i].m_id = j; m_elements[j].m_sz += m_elements[i].m_sz; -#endif //USE_PATH_COMPRESSION + //weighted quick union, this keeps the 'trees' balanced, and keeps performance of unite O( log(n) ) + if (m_elements[i].m_sz < m_elements[j].m_sz) + { + m_elements[i].m_id = j; + m_elements[j].m_sz += m_elements[i].m_sz; + } + else + { + m_elements[j].m_id = i; + m_elements[i].m_sz += m_elements[j].m_sz; } +#else + m_elements[i].m_id = j; + m_elements[j].m_sz += m_elements[i].m_sz; +#endif //USE_PATH_COMPRESSION + } + + int find(int x) + { + //btAssert(x < m_N); + //btAssert(x >= 0); - int find(int x) - { + while (x != m_elements[x].m_id) + { + //not really a reason not to use path compression, and it flattens the trees/improves find performance dramatically + +#ifdef USE_PATH_COMPRESSION + const btElement* elementPtr = &m_elements[m_elements[x].m_id]; + m_elements[x].m_id = elementPtr->m_id; + x = elementPtr->m_id; +#else // + x = m_elements[x].m_id; +#endif //btAssert(x < m_N); //btAssert(x >= 0); - - while (x != m_elements[x].m_id) - { - //not really a reason not to use path compression, and it flattens the trees/improves find performance dramatically - - #ifdef USE_PATH_COMPRESSION - const btElement* elementPtr = &m_elements[m_elements[x].m_id]; - m_elements[x].m_id = elementPtr->m_id; - x = elementPtr->m_id; - #else// - x = m_elements[x].m_id; - #endif - //btAssert(x < m_N); - //btAssert(x >= 0); - - } - return x; } + return x; + } +}; - - }; - - -#endif //BT_UNION_FIND_H +#endif //BT_UNION_FIND_H |