BulletSim: remember to release the physical body and shape when a prim is destroyed. This fixes many problems with physical linksets.

OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs

@@ -154,8 +154,9 @@ public sealed class BSPrim : BSPhysObject
         PhysicsScene.TaintedObject("BSPrim.destroy", delegate()
         {
             DetailLog("{0},BSPrim.Destroy,taint,", LocalID);
-            // everything in the C# world will get garbage collected. Tell the C++ world to free stuff.
+            // If there are physical body and shape, release my use of same.
-            BulletSimAPI.DestroyObject(PhysicsScene.WorldID, LocalID);
+            PhysicsScene.Shapes.DereferenceBody(BSBody, true, null);
+            PhysicsScene.Shapes.DereferenceShape(BSShape, true, null);
         });
     }
 
@@ -251,9 +252,6 @@ public sealed class BSPrim : BSPhysObject
         _rotationalVelocity = OMV.Vector3.Zero;
 
         // Zero some other properties directly into the physics engine
-        BulletSimAPI.SetLinearVelocity2(BSBody.ptr, OMV.Vector3.Zero);
-        BulletSimAPI.SetAngularVelocity2(BSBody.ptr, OMV.Vector3.Zero);
-        BulletSimAPI.SetInterpolationVelocity2(BSBody.ptr, OMV.Vector3.Zero, OMV.Vector3.Zero);
         BulletSimAPI.ClearForces2(BSBody.ptr);
     }
 
@@ -1108,9 +1106,8 @@ public sealed class BSPrim : BSPhysObject
         ShapeData shapeData;
         FillShapeInfo(out shapeData);
 
-        // Undo me from any possible linkset so, if body is rebuilt, the link will get restored.
+        // If this prim is part of a linkset, we must remove and restore the physical
-        // NOTE that the new linkset is not set. This saves the handle to the linkset
+        //    links of the body is rebuilt.
-        //     so we can add ourselves back when shape mangling is complete.
         bool needToRestoreLinkset = false;
 
         // Create the correct physical representation for this type of object.
@@ -1119,12 +1116,15 @@ public sealed class BSPrim : BSPhysObject
                         null, delegate(BulletBody dBody)
         {
             // Called if the current prim body is about to be destroyed.
-            // The problem is the constraints for Linksets which need to be updated for the new body.
+            // Remove all the physical dependencies on the old body.
             needToRestoreLinkset = Linkset.RemoveBodyDependencies(this);
         });
 
         if (needToRestoreLinkset)
+        {
+            // If physical body dependencies were removed, restore them
             Linkset.RestoreBodyDependencies(this);
+        }
 
         // Make sure the properties are set on the new object
         UpdatePhysicalParameters();

OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs

@@ -120,25 +120,25 @@ public class BSShapeCollection : IDisposable
     // Track another user of a body
     // We presume the caller has allocated the body.
     // Bodies only have one user so the reference count is either 1 or 0.
-    public void ReferenceBody(BulletBody shape, bool atTaintTime)
+    public void ReferenceBody(BulletBody body, bool atTaintTime)
     {
         lock (m_collectionActivityLock)
         {
             BodyDesc bodyDesc;
-            if (Bodies.TryGetValue(shape.ID, out bodyDesc))
+            if (Bodies.TryGetValue(body.ID, out bodyDesc))
             {
                 bodyDesc.referenceCount++;
-                DetailLog("{0},BSShapeCollection.ReferenceBody,existingBody,ref={1}", shape.ID, bodyDesc.referenceCount);
+                DetailLog("{0},BSShapeCollection.ReferenceBody,existingBody,body={1},ref={2}", body.ID, body, bodyDesc.referenceCount);
             }
             else
             {
                 // New entry
-                bodyDesc.ptr = shape.ptr;
+                bodyDesc.ptr = body.ptr;
                 bodyDesc.referenceCount = 1;
-                DetailLog("{0},BSShapeCollection.ReferenceBody,newBody,ref={1}", shape.ID, bodyDesc.referenceCount);
+                DetailLog("{0},BSShapeCollection.ReferenceBody,newBody,ref={1}", body.ID, body, bodyDesc.referenceCount);
             }
             bodyDesc.lastReferenced = System.DateTime.Now;
-            Bodies[shape.ID] = bodyDesc;
+            Bodies[body.ID] = bodyDesc;
         }
 }
 
@@ -256,7 +256,7 @@ public class BSShapeCollection : IDisposable
 
     // Release the usage of a shape.
     // The collisionObject is released since it is a copy of the real collision shape.
-    private void DereferenceShape(BulletShape shape, bool atTaintTime, ShapeDestructionCallback shapeCallback)
+    public void DereferenceShape(BulletShape shape, bool atTaintTime, ShapeDestructionCallback shapeCallback)
     {
         if (shape.ptr == IntPtr.Zero)
             return;