BulletSim: add ClearCollisionProxyCache function to API.

Add proxy cache clearing when some properties are changed. This fixes
a problem where objects would stop colliding of they were moved
with setPosition mulitple times.

OpenSim/Region/Physics/BulletSPlugin/BSAPIUnman.cs

@@ -725,6 +725,13 @@ public override bool RemoveObjectFromWorld(BulletWorld world, BulletBody obj)
     return BSAPICPP.RemoveObjectFromWorld2(worldu.ptr, bodyu.ptr);
 }
 
+public override bool ClearCollisionProxyCache(BulletWorld world, BulletBody obj)
+{
+    BulletWorldUnman worldu = world as BulletWorldUnman;
+    BulletBodyUnman bodyu = obj as BulletBodyUnman;
+    return BSAPICPP.ClearCollisionProxyCache2(worldu.ptr, bodyu.ptr);
+}
+
 public override bool AddConstraintToWorld(BulletWorld world, BulletConstraint constrain, bool disableCollisionsBetweenLinkedObjects)
 {
     BulletWorldUnman worldu = world as BulletWorldUnman;
@@ -1712,6 +1719,9 @@ public static extern bool AddObjectToWorld2(IntPtr world, IntPtr obj);
 [DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
 public static extern bool RemoveObjectFromWorld2(IntPtr world, IntPtr obj);
 
+[DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
+public static extern bool ClearCollisionProxyCache2(IntPtr world, IntPtr obj);
+
 [DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
 public static extern bool AddConstraintToWorld2(IntPtr world, IntPtr constrain, bool disableCollisionsBetweenLinkedObjects);
 

OpenSim/Region/Physics/BulletSPlugin/BSAPIXNA.cs

@@ -169,6 +169,19 @@ private sealed class BulletConstraintXNA : BulletConstraint
         return true;
     }
 
+    public override bool ClearCollisionProxyCache(BulletWorld pWorld, BulletBody pBody)
+    {
+        DiscreteDynamicsWorld world = (pWorld as BulletWorldXNA).world;
+        RigidBody body = ((BulletBodyXNA)pBody).rigidBody;
+        CollisionObject collisionObject = ((BulletBodyXNA)pBody).body;
+        if (body != null && collisionObject != null && collisionObject.GetBroadphaseHandle() != null)
+        {
+            world.RemoveCollisionObject(collisionObject);
+            world.AddCollisionObject(collisionObject);
+        }
+        return true;
+    }
+
     public override bool AddConstraintToWorld(BulletWorld pWorld, BulletConstraint pConstraint, bool pDisableCollisionsBetweenLinkedObjects)
     {
         DiscreteDynamicsWorld world = (pWorld as BulletWorldXNA).world;

OpenSim/Region/Physics/BulletSPlugin/BSApiTemplate.cs

@@ -498,6 +498,8 @@ public abstract bool AddObjectToWorld(BulletWorld world, BulletBody obj);
 
 public abstract bool RemoveObjectFromWorld(BulletWorld world, BulletBody obj);
 
+public abstract bool ClearCollisionProxyCache(BulletWorld world, BulletBody obj);
+
 public abstract bool AddConstraintToWorld(BulletWorld world, BulletConstraint constrain, bool disableCollisionsBetweenLinkedObjects);
 
 public abstract bool RemoveConstraintFromWorld(BulletWorld world, BulletConstraint constrain);

OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs

@@ -300,8 +300,16 @@ public abstract class BSPhysObject : PhysicsActor
     // Called in taint-time!!
     public void ActivateIfPhysical(bool forceIt)
     {
-        if (IsPhysical && PhysBody.HasPhysicalBody)
+        if (PhysBody.HasPhysicalBody)
-            PhysScene.PE.Activate(PhysBody, forceIt);
+        {
+            // Clear the collision cache since we've changed some properties.
+            PhysScene.PE.ClearCollisionProxyCache(PhysScene.World, PhysBody);
+            if (IsPhysical)
+            {
+                // Physical objects might need activating
+                PhysScene.PE.Activate(PhysBody, forceIt);
+            }
+        }
     }
 
     // 'actors' act on the physical object to change or constrain its motion. These can range from