1 files changed, 30 insertions, 10 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs
index e8575f6..821f470 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs
@@ -73,6 +73,8 @@ public abstract class BSPhysObject : PhysicsActor
 
         // A linkset of just me
         Linkset = BSLinkset.Factory(PhysicsScene, this);
+        PositionDisplacement = OMV.Vector3.Zero;
+
         LastAssetBuildFailed = false;
 
         // Default material type
@@ -135,6 +137,7 @@ public abstract class BSPhysObject : PhysicsActor
     public virtual OMV.Vector3 Scale { get; set; }
     public abstract bool IsSolid { get; }
     public abstract bool IsStatic { get; }
+    public abstract bool IsSelected { get; }
 
     // Materialness
     public MaterialAttributes.Material Material { get; private set; }
@@ -156,6 +159,14 @@ public abstract class BSPhysObject : PhysicsActor
     public abstract OMV.Vector3 RawPosition { get; set; }
     public abstract OMV.Vector3 ForcePosition { get; set; }
 
+    // Position is what the simulator thinks the positions of the prim is.
+    // Because Bullet needs the zero coordinate to be the center of mass of the linkset,
+    //     sometimes it is necessary to displace the position the physics engine thinks
+    //     the position is. PositionDisplacement must be added and removed from the
+    //     position as the simulator position is stored and fetched from the physics
+    //     engine. 
+    public virtual OMV.Vector3 PositionDisplacement { get; set; }
+
     public abstract OMV.Quaternion RawOrientation { get; set; }
     public abstract OMV.Quaternion ForceOrientation { get; set; }
 
@@ -371,10 +382,13 @@ public abstract class BSPhysObject : PhysicsActor
     {
         string identifier = op + "-" + id.ToString();
 
-        // Clean out any existing action
-        UnRegisterPreStepAction(op, id);
+        lock (RegisteredActions)
+        {
+            // Clean out any existing action
+            UnRegisterPreStepAction(op, id);
 
-        RegisteredActions[identifier] = actn;
+            RegisteredActions[identifier] = actn;
+        }
         PhysicsScene.BeforeStep += actn;
         DetailLog("{0},BSPhysObject.RegisterPreStepAction,id={1}", LocalID, identifier);
     }
@@ -384,22 +398,28 @@ public abstract class BSPhysObject : PhysicsActor
     {
         string identifier = op + "-" + id.ToString();
         bool removed = false;
-        if (RegisteredActions.ContainsKey(identifier))
+        lock (RegisteredActions)
         {
-            PhysicsScene.BeforeStep -= RegisteredActions[identifier];
-            RegisteredActions.Remove(identifier);
-            removed = true;
+            if (RegisteredActions.ContainsKey(identifier))
+            {
+                PhysicsScene.BeforeStep -= RegisteredActions[identifier];
+                RegisteredActions.Remove(identifier);
+                removed = true;
+            }
         }
         DetailLog("{0},BSPhysObject.UnRegisterPreStepAction,id={1},removed={2}", LocalID, identifier, removed);
     }
 
     protected void UnRegisterAllPreStepActions()
     {
-        foreach (KeyValuePair<string, BSScene.PreStepAction> kvp in RegisteredActions)
+        lock (RegisteredActions)
         {
-            PhysicsScene.BeforeStep -= kvp.Value;
+            foreach (KeyValuePair<string, BSScene.PreStepAction> kvp in RegisteredActions)
+            {
+                PhysicsScene.BeforeStep -= kvp.Value;
+            }
+            RegisteredActions.Clear();
         }
-        RegisteredActions.Clear();
         DetailLog("{0},BSPhysObject.UnRegisterAllPreStepActions,", LocalID);
     }