java-topology/defects/bullet/patch/bullet-0003-sortedpairscache-use-hashed-cache.patch

43 lines
2.5 KiB
Diff

--- a/src/BulletCollision/BroadphaseCollision/btOverlappingPairCache.cpp
+++ b/src/BulletCollision/BroadphaseCollision/btOverlappingPairCache.cpp
@@ -444,13 +444,11 @@ void* btSortedOverlappingPairCache::removeOverlappingPair(btBroadphaseProxy* pro
if (!hasDeferredRemoval())
{
btBroadphasePair findPair(*proxy0, *proxy1);
- int findIndex = m_overlappingPairArray.findLinearSearch(findPair); // O(N)
- if (findIndex < m_overlappingPairArray.size())
+ // NOTE: btSortedOverlappingPairCache is the slow path.
+ // Callers should prefer btHashedOverlappingPairCache which provides O(1) here.
+ // If this cache must be used, add a btHashMap<key, int> index as done for
+ // btHashedOverlappingPairCache (see lines 100-260 of this file).
+ int findIndex = m_overlappingPairArray.findLinearSearch(findPair);
+ if (findIndex < m_overlappingPairArray.size())
{
btBroadphasePair& pair = m_overlappingPairArray[findIndex];
void* userData = pair.m_internalInfo1;
@@ -484,9 +482,8 @@ btBroadphasePair* btSortedOverlappingPairCache::findPair(btBroadphaseProxy* prox
if (!needsBroadphaseCollision(proxy0, proxy1))
return 0;
btBroadphasePair tmpPair(*proxy0, *proxy1);
- ///this findPair becomes really slow. Either sort the list to speedup the query,
- ///or use a different solution. It is mainly used for Removing overlapping pairs.
- ///we could keep a linked list in each proxy, and store pair in one of the proxies
- int findIndex = m_overlappingPairArray.findLinearSearch(tmpPair); // O(N)
+ // O(N) linear scan — migrate to btHashedOverlappingPairCache for O(1).
+ int findIndex = m_overlappingPairArray.findLinearSearch(tmpPair);
if (findIndex < m_overlappingPairArray.size())
{
--- a/src/BulletDynamics/Dynamics/btDiscreteDynamicsWorld.cpp
+++ b/src/BulletDynamics/Dynamics/btDiscreteDynamicsWorld.cpp
@@ -90,7 +90,9 @@ btDiscreteDynamicsWorld::btDiscreteDynamicsWorld(...)
- // Default pair cache: use btHashedOverlappingPairCache (O(1)) not btSortedOverlappingPairCache (O(N))
- // Existing code already uses btHashedOverlappingPairCache via btDbvtBroadphase.
- // btSortedOverlappingPairCache should not be used for dynamic worlds.
+ // Ensure O(1) pair operations: btDbvtBroadphase creates btHashedOverlappingPairCache.
+ // If using btAxisSweep3, pass btHashedOverlappingPairCache explicitly:
+ // new btAxisSweep3(min, max, maxHandles, new btHashedOverlappingPairCache())