BIG MESS. changed Iclient interface so only one event is used to inform scene about position scale or rotation change by client (others can be added). Its served at SceneGraph that does permition checks, undostore and sends down to SOG. changed values are stored in a class (ObjectChangeData) and what is changed as a enum (ObjectChangeWhat) with bit fields and 'macros' of this for better readability (at top of scenegraph.cs lasy to find better place for now) this can be extended for other things clients changes and need undo/redo. SOG process acording to what is changed. Changed UNDO/redo to use this also (warning is only storing what is changed, previus stored all, this must be checked for side efects. to save all PRS change commented line in scenegraph). Still have excessive calls to ScheduleGroupForTerseUpdate. **** UNTESTED ****

5 files changed, 394 insertions, 126 deletions

diff --git a/OpenSim/Region/Framework/Scenes/Scene.cs b/OpenSim/Region/Framework/Scenes/Scene.cs
index 68c05f8..a3358a5 100644
--- a/OpenSim/Region/Framework/Scenes/Scene.cs
+++ b/OpenSim/Region/Framework/Scenes/Scene.cs
@@ -2811,6 +2811,8 @@ namespace OpenSim.Region.Framework.Scenes
             client.OnUpdatePrimGroupPosition += m_sceneGraph.UpdatePrimGroupPosition;
             client.OnUpdatePrimSinglePosition += m_sceneGraph.UpdatePrimSinglePosition;
 
+            client.onClientChangeObject += m_sceneGraph.ClientChangeObject;
+
             client.OnUpdatePrimGroupRotation += m_sceneGraph.UpdatePrimGroupRotation;
             client.OnUpdatePrimGroupMouseRotation += m_sceneGraph.UpdatePrimGroupRotation;
             client.OnUpdatePrimSingleRotation += m_sceneGraph.UpdatePrimSingleRotation;
@@ -2940,6 +2942,8 @@ namespace OpenSim.Region.Framework.Scenes
             client.OnUpdatePrimGroupPosition -= m_sceneGraph.UpdatePrimGroupPosition;
             client.OnUpdatePrimSinglePosition -= m_sceneGraph.UpdatePrimSinglePosition;
 
+            client.onClientChangeObject -= m_sceneGraph.ClientChangeObject;
+
             client.OnUpdatePrimGroupRotation -= m_sceneGraph.UpdatePrimGroupRotation;
             client.OnUpdatePrimGroupMouseRotation -= m_sceneGraph.UpdatePrimGroupRotation;
             client.OnUpdatePrimSingleRotation -= m_sceneGraph.UpdatePrimSingleRotation;
diff --git a/OpenSim/Region/Framework/Scenes/SceneGraph.cs b/OpenSim/Region/Framework/Scenes/SceneGraph.cs
index 3cd4a10..5e770ba 100644
--- a/OpenSim/Region/Framework/Scenes/SceneGraph.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneGraph.cs
@@ -47,6 +47,57 @@ namespace OpenSim.Region.Framework.Scenes
 
     public delegate void ChangedBackupDelegate(SceneObjectGroup sog);
 
+
+    public enum ObjectChangeWhat : uint
+    {
+        // bits definitions
+        Position = 0x01,
+        Rotation = 0x02,
+        Scale   = 0x04,
+        Group = 0x08,
+        UniformScale = 0x10,
+
+        // macros from above
+        // single prim
+        primP = 0x01,
+        primR = 0x02,
+        primPR = 0x03,
+        primS = 0x04,
+        primPS = 0x05,
+        primRS = 0x06,
+        primPSR = 0x07,
+
+        primUS = 0x14,
+        primPUS = 0x15,
+        primRUS = 0x16,
+        primPUSR = 0x17,
+
+        // group
+        groupP = 0x09,
+        groupR = 0x0A,
+        groupPR = 0x0B,
+        groupS = 0x0C,
+        groupPS = 0x0D,
+        groupRS = 0x0E,
+        groupPSR = 0x0F,
+
+        groupUS = 0x1C,
+        groupPUS = 0x1D,
+        groupRUS = 0x1E,
+        groupPUSR = 0x1F,
+
+        PRSmask = 0x07
+    }
+
+    public struct ObjectChangeData
+    {
+        public Quaternion rotation;
+        public Vector3 position;
+        public Vector3 scale;
+        public ObjectChangeWhat what;
+    }
+        
+   
     /// <summary>
     /// This class used to be called InnerScene and may not yet truly be a SceneGraph.  The non scene graph components
     /// should be migrated out over time.
@@ -1289,6 +1340,87 @@ namespace OpenSim.Region.Framework.Scenes
 
         #region Client Event handlers
 
+        protected internal void ClientChangeObject(uint localID, object odata, IClientAPI remoteClient)
+        {
+            SceneObjectPart part = GetSceneObjectPart(localID);
+            ObjectChangeData data = (ObjectChangeData)odata;
+
+            if (part != null)
+            {
+                SceneObjectGroup grp = part.ParentGroup;
+                if (grp != null)
+                {
+                    if (m_parentScene.Permissions.CanEditObject(grp.UUID, remoteClient.AgentId))
+                    {
+//                        part.StoreUndoState(data.what | ObjectChangeWhat.PRSmask); // for now save all to keep previus behavour ???
+                        part.StoreUndoState(data.what); // lets test only saving what we changed
+                        grp.doChangeObject(part, (ObjectChangeData)data);
+                    }
+                }
+            }
+        }
+
+/* moved to SOG
+        protected internal void doChangeObject(SceneObjectPart part, ObjectChangeData data)
+        {
+            if (part != null && part.ParentGroup != null)
+            {
+                ObjectChangeWhat what = data.what;
+                bool togroup = ((what & ObjectChangeWhat.Group) != 0);
+//                bool uniform = ((what & ObjectChangeWhat.UniformScale) != 0);  not in use
+
+                SceneObjectGroup group = part.ParentGroup;
+                PhysicsActor pha = group.RootPart.PhysActor;
+              
+                if (togroup)
+                {
+                    // related to group                  
+                    if ((what & ObjectChangeWhat.Position) != 0)
+                        group.AbsolutePosition = data.position;
+                    if ((what & ObjectChangeWhat.Rotation) != 0)
+                        group.RootPart.UpdateRotation(data.rotation);
+                    if ((what & ObjectChangeWhat.Scale) != 0)
+                    {
+                        if (pha != null)
+                            pha.Building = true;
+                        group.GroupResize(data.scale);
+                        if (pha != null)
+                            pha.Building = false;
+                    }
+                }
+                else
+                {
+                    // related to single prim in a link-set ( ie group)
+                    if (pha != null)
+                        pha.Building = true;
+
+                    // must deal with root part specially for position and rotation
+                    // so parts offset positions or rotations are fixed
+
+                    if (part == group.RootPart)
+                    {
+                        if ((what & ObjectChangeWhat.Position) != 0)
+                            group.UpdateRootPosition(data.position);
+                        if ((what & ObjectChangeWhat.Rotation) != 0)
+                            group.UpdateRootRotation(data.rotation);
+                    }
+                    else
+                    {
+                        if ((what & ObjectChangeWhat.Position) != 0)
+                            part.OffsetPosition = data.position;
+                        if ((what & ObjectChangeWhat.Rotation) != 0)
+                            part.UpdateRotation(data.rotation);
+                    }
+
+                    if ((what & ObjectChangeWhat.Scale) != 0)
+                        part.Resize(data.scale);
+
+                    if (pha != null)
+                        pha.Building = false;
+                }
+            }
+        }
+*/
         /// <summary>
         /// Update the scale of an individual prim.
         /// </summary>
@@ -1303,7 +1435,17 @@ namespace OpenSim.Region.Framework.Scenes
             {
                 if (m_parentScene.Permissions.CanEditObject(part.ParentGroup.UUID, remoteClient.AgentId))
                 {
+                    bool physbuild = false;
+                    if (part.ParentGroup.RootPart.PhysActor != null)
+                    {
+                        part.ParentGroup.RootPart.PhysActor.Building = true;
+                        physbuild = true;
+                    }
+
                     part.Resize(scale);
+
+                    if (physbuild)
+                        part.ParentGroup.RootPart.PhysActor.Building = false;
                 }
             }
         }
@@ -1315,7 +1457,17 @@ namespace OpenSim.Region.Framework.Scenes
             {
                 if (m_parentScene.Permissions.CanEditObject(group.UUID, remoteClient.AgentId))
                 {
+                    bool physbuild = false;
+                    if (group.RootPart.PhysActor != null)
+                    {
+                        group.RootPart.PhysActor.Building = true;
+                        physbuild = true;
+                    }
+
                     group.GroupResize(scale);
+
+                    if (physbuild)
+                        group.RootPart.PhysActor.Building = false;
                 }
             }
         }
diff --git a/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs b/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
index 5818798..92f2d54 100644
--- a/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
@@ -3124,10 +3124,6 @@ namespace OpenSim.Region.Framework.Scenes
         /// <param name="scale"></param>
         public void GroupResize(Vector3 scale)
         {
-//            m_log.DebugFormat(
-//                "[SCENE OBJECT GROUP]: Group resizing {0} {1} from {2} to {3}", Name, LocalId, RootPart.Scale, scale);
-//            RootPart.StoreUndoState(true);
-
             scale.X = Math.Min(scale.X, Scene.m_maxNonphys);
             scale.Y = Math.Min(scale.Y, Scene.m_maxNonphys);
             scale.Z = Math.Min(scale.Z, Scene.m_maxNonphys);
@@ -3152,7 +3148,6 @@ namespace OpenSim.Region.Framework.Scenes
                     SceneObjectPart obPart = parts[i];
                     if (obPart.UUID != m_rootPart.UUID)
                     {
-//                        obPart.IgnoreUndoUpdate = true;
                         Vector3 oldSize = new Vector3(obPart.Scale);
 
                         float f = 1.0f;
@@ -3216,8 +3211,6 @@ namespace OpenSim.Region.Framework.Scenes
                                 z *= a;
                             }
                         }
-
-//                        obPart.IgnoreUndoUpdate = false;
                     }
                 }
             }
@@ -3226,9 +3219,8 @@ namespace OpenSim.Region.Framework.Scenes
             prevScale.X *= x;
             prevScale.Y *= y;
             prevScale.Z *= z;
-//            RootPart.IgnoreUndoUpdate = true;
+
             RootPart.Resize(prevScale);
-//            RootPart.IgnoreUndoUpdate = false;
 
             parts = m_parts.GetArray();
             for (int i = 0; i < parts.Length; i++)
@@ -3237,8 +3229,6 @@ namespace OpenSim.Region.Framework.Scenes
 
                 if (obPart.UUID != m_rootPart.UUID)
                 {
-//                    obPart.IgnoreUndoUpdate = true;
-
                     Vector3 currentpos = new Vector3(obPart.OffsetPosition);
                     currentpos.X *= x;
                     currentpos.Y *= y;
@@ -3251,18 +3241,12 @@ namespace OpenSim.Region.Framework.Scenes
 
                     obPart.Resize(newSize);
                     obPart.UpdateOffSet(currentpos);
-
-//                    obPart.IgnoreUndoUpdate = false;                    
                 }
 
-//                obPart.IgnoreUndoUpdate = false;
                 HasGroupChanged = true;
                 m_rootPart.TriggerScriptChangedEvent(Changed.SCALE);
                 ScheduleGroupForTerseUpdate();
             }
-
-//            m_log.DebugFormat(
-//                "[SCENE OBJECT GROUP]: Finished group resizing {0} {1} to {2}", Name, LocalId, RootPart.Scale);
         }
 
         #endregion
@@ -3275,14 +3259,6 @@ namespace OpenSim.Region.Framework.Scenes
         /// <param name="pos"></param>
         public void UpdateGroupPosition(Vector3 pos)
         {
-//            m_log.DebugFormat("[SCENE OBJECT GROUP]: Updating group position on {0} {1} to {2}", Name, LocalId, pos);
-
-//            RootPart.StoreUndoState(true);
-
-//            SceneObjectPart[] parts = m_parts.GetArray();
-//            for (int i = 0; i < parts.Length; i++)
-//                parts[i].StoreUndoState();
-
             if (m_scene.EventManager.TriggerGroupMove(UUID, pos))
             {
                 if (IsAttachment)
@@ -3314,22 +3290,14 @@ namespace OpenSim.Region.Framework.Scenes
         /// </summary>
         /// <param name="pos"></param>
         /// <param name="localID"></param>
+        /// 
+
         public void UpdateSinglePosition(Vector3 pos, uint localID)
         {
             SceneObjectPart part = GetChildPart(localID);
 
-//            SceneObjectPart[] parts = m_parts.GetArray();
-//            for (int i = 0; i < parts.Length; i++)
-//                parts[i].StoreUndoState();
-
             if (part != null)
             {
-//                m_log.DebugFormat(
-//                    "[SCENE OBJECT GROUP]: Updating single position of {0} {1} to {2}", part.Name, part.LocalId, pos);
-
-//                part.StoreUndoState(false);
-//                part.IgnoreUndoUpdate = true;
-
 // unlock parts position change
                 if (m_rootPart.PhysActor != null)
                     m_rootPart.PhysActor.Building = true;
@@ -3347,7 +3315,6 @@ namespace OpenSim.Region.Framework.Scenes
                     m_rootPart.PhysActor.Building = false;
 
                 HasGroupChanged = true;
-//                part.IgnoreUndoUpdate = false;
             }
         }
 
@@ -3357,13 +3324,7 @@ namespace OpenSim.Region.Framework.Scenes
         /// <param name="pos"></param>
         public void UpdateRootPosition(Vector3 pos)
         {
-//            m_log.DebugFormat(
-//                "[SCENE OBJECT GROUP]: Updating root position of {0} {1} to {2}", Name, LocalId, pos);
-
-//            SceneObjectPart[] parts = m_parts.GetArray();
-//            for (int i = 0; i < parts.Length; i++)
-//                parts[i].StoreUndoState();
-
+            // needs to be called with phys building true
             Vector3 newPos = new Vector3(pos.X, pos.Y, pos.Z);
             Vector3 oldPos =
                 new Vector3(AbsolutePosition.X + m_rootPart.OffsetPosition.X,
@@ -3383,17 +3344,7 @@ namespace OpenSim.Region.Framework.Scenes
                     obPart.OffsetPosition = obPart.OffsetPosition + diff;
             }
 
-            //We have to set undoing here because otherwise an undo state will be saved
-//            if (!m_rootPart.Undoing)
-//            {
-//                m_rootPart.Undoing = true;
-                AbsolutePosition = newPos;
-//                m_rootPart.Undoing = false;
-//            }
-//            else
-//            {
-//                AbsolutePosition = newPos;
-//            }
+            AbsolutePosition = newPos;
 
             HasGroupChanged = true;
             if (m_rootPart.Undoing)
@@ -3416,17 +3367,6 @@ namespace OpenSim.Region.Framework.Scenes
         /// <param name="rot"></param>
         public void UpdateGroupRotationR(Quaternion rot)
         {
-//            m_log.DebugFormat(
-//                "[SCENE OBJECT GROUP]: Updating group rotation R of {0} {1} to {2}", Name, LocalId, rot);
-
-//            SceneObjectPart[] parts = m_parts.GetArray();
-//            for (int i = 0; i < parts.Length; i++)
-//                parts[i].StoreUndoState();
-
-//            m_rootPart.StoreUndoState(true);
-
-//            m_rootPart.UpdateRotation(rot);
-
             PhysicsActor actor = m_rootPart.PhysActor;
             if (actor != null)
             {
@@ -3445,16 +3385,6 @@ namespace OpenSim.Region.Framework.Scenes
         /// <param name="rot"></param>
         public void UpdateGroupRotationPR(Vector3 pos, Quaternion rot)
         {
-//            m_log.DebugFormat(
-//                "[SCENE OBJECT GROUP]: Updating group rotation PR of {0} {1} to {2}", Name, LocalId, rot);
-
-//            SceneObjectPart[] parts = m_parts.GetArray();
-//            for (int i = 0; i < parts.Length; i++)
-//                parts[i].StoreUndoState();
-
-//            RootPart.StoreUndoState(true);
-//            RootPart.IgnoreUndoUpdate = true;
-
             m_rootPart.UpdateRotation(rot);
 
             PhysicsActor actor = m_rootPart.PhysActor;
@@ -3468,8 +3398,6 @@ namespace OpenSim.Region.Framework.Scenes
 
             HasGroupChanged = true;
             ScheduleGroupForTerseUpdate();
-
-//            RootPart.IgnoreUndoUpdate = false;
         }
 
         /// <summary>
@@ -3484,9 +3412,6 @@ namespace OpenSim.Region.Framework.Scenes
 
             if (part != null)
             {
-//                m_log.DebugFormat(
-//                    "[SCENE OBJECT GROUP]: Updating single rotation of {0} {1} to {2}", part.Name, part.LocalId, rot);
-
                 if (m_rootPart.PhysActor != null)
                     m_rootPart.PhysActor.Building = true;
 
@@ -3514,30 +3439,13 @@ namespace OpenSim.Region.Framework.Scenes
             SceneObjectPart part = GetChildPart(localID);
             if (part != null)
             {
-//                m_log.DebugFormat(
-//                    "[SCENE OBJECT GROUP]: Updating single position and rotation of {0} {1} to {2}",
-//                    part.Name, part.LocalId, rot);
-
-//                part.StoreUndoState();
-//                part.IgnoreUndoUpdate = true;
-
                 if (m_rootPart.PhysActor != null)
                     m_rootPart.PhysActor.Building = true;
 
                 if (part.UUID == m_rootPart.UUID)
                 {
                     UpdateRootRotation(rot);
-/*                    if (!m_rootPart.Undoing)
-                    {
-                        m_rootPart.Undoing = true;
-                        AbsolutePosition = pos;
-                        m_rootPart.Undoing = false;
-                    }
-                    else
-                    {
- */
-                        AbsolutePosition = pos;
-//                    }
+                    AbsolutePosition = pos;
                 }
                 else
                 {
@@ -3547,8 +3455,6 @@ namespace OpenSim.Region.Framework.Scenes
 
                 if (m_rootPart.PhysActor != null)
                     m_rootPart.PhysActor.Building = false;
-
-//                part.IgnoreUndoUpdate = false;
             }
         }
 
@@ -3558,13 +3464,9 @@ namespace OpenSim.Region.Framework.Scenes
         /// <param name="rot"></param>
         public void UpdateRootRotation(Quaternion rot)
         {
-//            m_log.DebugFormat(
-//                "[SCENE OBJECT GROUP]: Updating root rotation of {0} {1} to {2}",
-//                Name, LocalId, rot);
-
+            // needs to be called with phys building true
             Quaternion axRot = rot;
             Quaternion oldParentRot = m_rootPart.RotationOffset;
-//            m_rootPart.StoreUndoState();
             
             //Don't use UpdateRotation because it schedules an update prematurely
             m_rootPart.RotationOffset = rot;
@@ -3580,8 +3482,6 @@ namespace OpenSim.Region.Framework.Scenes
                 SceneObjectPart prim = parts[i];
                 if (prim.UUID != m_rootPart.UUID)
                 {
-//                    prim.IgnoreUndoUpdate = true;
-
                     Quaternion NewRot = oldParentRot * prim.RotationOffset;
                     NewRot = Quaternion.Inverse(axRot) * NewRot;
                     prim.RotationOffset = NewRot;
@@ -3591,26 +3491,88 @@ namespace OpenSim.Region.Framework.Scenes
                     axPos *= oldParentRot;
                     axPos *= Quaternion.Inverse(axRot);
                     prim.OffsetPosition = axPos;
-
-//                    prim.IgnoreUndoUpdate = false;
                 }
             }
 
-//            for (int i = 0; i < parts.Length; i++)
-//            {
-//                SceneObjectPart childpart = parts[i];
-//                if (childpart != m_rootPart)
-//                {
-////                    childpart.IgnoreUndoUpdate = false;
-////                    childpart.StoreUndoState();
-//                }
-//            }
             HasGroupChanged = true;
             ScheduleGroupForFullUpdate();
+        }
 
-//            m_log.DebugFormat(
-//                "[SCENE OBJECT GROUP]: Updated root rotation of {0} {1} to {2}",
-//                Name, LocalId, rot);
+        public void doChangeObject(SceneObjectPart part, ObjectChangeData data)
+        {
+            // TODO  this still as excessive ScheduleGroupForTerseUpdate()s
+
+            if (part != null && part.ParentGroup != null)
+            {
+                ObjectChangeWhat what = data.what;
+                bool togroup = ((what & ObjectChangeWhat.Group) != 0);
+                //                bool uniform = ((what & ObjectChangeWhat.UniformScale) != 0);  not in use
+
+                SceneObjectGroup group = part.ParentGroup;
+                PhysicsActor pha = group.RootPart.PhysActor;
+
+                bool needgrpUpdate = false;
+
+                if (togroup)
+                {
+                    // related to group                  
+                    if ((what & ObjectChangeWhat.Position) != 0)
+                    {
+                        group.AbsolutePosition = data.position;
+                        needgrpUpdate = true;
+                    }
+                    if ((what & ObjectChangeWhat.Rotation) != 0)
+                        group.RootPart.UpdateRotation(data.rotation);
+                    if ((what & ObjectChangeWhat.Scale) != 0)
+                    {
+                        if (pha != null)
+                            pha.Building = true;
+                        group.GroupResize(data.scale);
+                        if (pha != null)
+                            pha.Building = false;
+                    }
+                }
+                else
+                {
+                    // related to single prim in a link-set ( ie group)
+                    if (pha != null)
+                        pha.Building = true;
+
+                    // must deal with root part specially for position and rotation
+                    // so parts offset positions or rotations are fixed
+
+                    if (part == group.RootPart)
+                    {
+                        if ((what & ObjectChangeWhat.Position) != 0)
+                            group.UpdateRootPosition(data.position);
+                        if ((what & ObjectChangeWhat.Rotation) != 0)
+                            group.UpdateRootRotation(data.rotation);
+                    }
+                    else
+                    {
+
+                        if ((what & ObjectChangeWhat.Position) != 0)
+                        {
+                            part.OffsetPosition = data.position;
+                            needgrpUpdate = true;
+                        }
+                        if ((what & ObjectChangeWhat.Rotation) != 0)
+                            part.UpdateRotation(data.rotation);
+                    }
+
+                    if ((what & ObjectChangeWhat.Scale) != 0)
+                        part.Resize(data.scale);
+
+                    if (pha != null)
+                        pha.Building = false;
+                }
+
+                if (needgrpUpdate)
+                {
+                    HasGroupChanged = true;
+                    ScheduleGroupForTerseUpdate();
+                }
+            }
         }
 
         #endregion
diff --git a/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs b/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
index 6622495..c806fda 100644
--- a/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
@@ -1944,6 +1944,7 @@ namespace OpenSim.Region.Framework.Scenes
 
                                 PhysActor.OnRequestTerseUpdate += PhysicsRequestingTerseUpdate;
                                 PhysActor.OnOutOfBounds += PhysicsOutOfBounds;
+
                                 if (ParentID != 0 && ParentID != LocalId)
                                 {
                                     if (ParentGroup.RootPart.PhysActor != null)
@@ -3656,7 +3657,7 @@ namespace OpenSim.Region.Framework.Scenes
             ParentGroup.ScheduleGroupForTerseUpdate();
             //ParentGroup.ScheduleGroupForFullUpdate();
         }
-
+/*
         public void StoreUndoState()
         {
             StoreUndoState(false);
@@ -3697,6 +3698,44 @@ namespace OpenSim.Region.Framework.Scenes
                 }
             }
         }
+*/
+
+
+        public void StoreUndoState(ObjectChangeWhat what)
+        {
+            if (!Undoing && !IgnoreUndoUpdate) // just to read better  - undo is in progress, or suspended
+            {
+                if (ParentGroup != null)
+                {
+                    lock (m_undo)
+                    {
+                        if (m_undo.Count > 0)
+                        {
+                            // see if we had a change
+
+                            UndoState last = m_undo.Peek();
+                            if (last != null)
+                            {
+                                if (last.Compare(this, what))
+                                {
+                                    return;
+                                }
+                            }
+                        }
+
+                        if (ParentGroup.GetSceneMaxUndo() > 0)
+                        {
+                            UndoState nUndo = new UndoState(this, what);
+
+                            m_undo.Push(nUndo);
+
+                            if (m_redo.Count > 0)
+                                m_redo.Clear();
+                        }
+                    }
+                }
+            }
+        }
 
         /// <summary>
         /// Return number of undos on the stack.  Here temporarily pending a refactor.
@@ -3725,10 +3764,10 @@ namespace OpenSim.Region.Framework.Scenes
                     if (goback != null)
                     {
                         UndoState nUndo = null;
-        
+       
                         if (ParentGroup.GetSceneMaxUndo() > 0)
                         {
-                            nUndo = new UndoState(this, goback.ForGroup);
+                            nUndo = new UndoState(this, goback.data.what);
                         }
 
                         goback.PlayState(this);
@@ -3760,7 +3799,7 @@ namespace OpenSim.Region.Framework.Scenes
                     {
                         if (ParentGroup.GetSceneMaxUndo() > 0)
                         {
-                            UndoState nUndo = new UndoState(this, gofwd.ForGroup);
+                            UndoState nUndo = new UndoState(this, gofwd.data.what);
     
                             m_undo.Push(nUndo);
                         }
diff --git a/OpenSim/Region/Framework/Scenes/UndoState.cs b/OpenSim/Region/Framework/Scenes/UndoState.cs
index 38474de..eb76ca5 100644
--- a/OpenSim/Region/Framework/Scenes/UndoState.cs
+++ b/OpenSim/Region/Framework/Scenes/UndoState.cs
@@ -48,6 +48,7 @@ namespace OpenSim.Region.Framework.Scenes
         STATE_ALL = 63       
     }
 
+/*
     public class UndoState
     {
         //        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
@@ -121,9 +122,16 @@ namespace OpenSim.Region.Framework.Scenes
         public void PlayState(SceneObjectPart part)
         {
             part.Undoing = true;
-
+            bool physbuilding = false;
+            
             if (part.ParentID == 0)
             {
+                if (!ForGroup && part.PhysActor != null)
+                {
+                    part.PhysActor.Building = true;
+                    physbuilding = true;
+                }
+
                 if (Position != Vector3.Zero)
                 {
                     if (ForGroup)
@@ -139,17 +147,34 @@ namespace OpenSim.Region.Framework.Scenes
 
                 if (Scale != Vector3.Zero)
                 {
+                    if (!physbuilding && part.PhysActor != null)
+                    {
+                        part.PhysActor.Building = true;
+                        physbuilding = true;
+                    }
+
                     if (ForGroup)
                         part.ParentGroup.GroupResize(Scale);
                     else
                         part.Resize(Scale);
                 }
+
+                if (physbuilding)
+                    part.PhysActor.Building = false;
+
                 part.ParentGroup.ScheduleGroupForTerseUpdate();
             }
             else
             {
                 if (ForGroup) // trap for group since seems parts can't do it
                     return;
+                
+                // changing a part invalidates entire object physical rep
+                if (part.ParentGroup != null && part.ParentGroup.RootPart != null && part.ParentGroup.RootPart.PhysActor != null)
+                {
+                    part.ParentGroup.RootPart.PhysActor.Building = true;
+                    physbuilding = true;
+                }
 
                 // Note: Updating these properties on sop automatically schedules an update if needed
                 part.OffsetPosition = Position;
@@ -158,12 +183,98 @@ namespace OpenSim.Region.Framework.Scenes
                 {
                     part.Resize(Scale);
                 }
+
+                if (physbuilding)
+                    part.ParentGroup.RootPart.PhysActor.Building = false;
+            }
+
+            part.Undoing = false;
+        }
+    }
+*/
+    public class UndoState
+    {
+        public ObjectChangeData data;
+        /// <summary>
+        /// Constructor.
+        /// </summary>
+        /// <param name="part"></param>
+        /// <param name="forGroup">True if the undo is for an entire group</param>
+        /// only for root parts ????
+        public UndoState(SceneObjectPart part, ObjectChangeWhat what)
+        {
+            data = new ObjectChangeData();
+
+            data.what = what;
+
+            if (part.ParentGroup.RootPart == part)
+            {
+                if ((what & ObjectChangeWhat.Position) != 0)
+                    data.position = part.ParentGroup.AbsolutePosition;
+                if ((what & ObjectChangeWhat.Rotation) != 0)
+                    data.rotation = part.RotationOffset;
+                if ((what & ObjectChangeWhat.Scale) != 0)
+                    data.scale = part.Shape.Scale;
+            }
+            else
+            {
+                if ((what & ObjectChangeWhat.Position) != 0)
+                    data.position = part.OffsetPosition;
+                if ((what & ObjectChangeWhat.Rotation) != 0)
+                    data.rotation = part.RotationOffset;
+                if ((what & ObjectChangeWhat.Scale) != 0)
+                    data.scale = part.Shape.Scale;
+            }
+        }
+
+        /// <summary>
+        /// Compare the relevant state in the given part to this state.
+        /// </summary>
+        /// <param name="part"></param>
+        /// <returns>true if both the part's position, rotation and scale match those in this undo state.  False otherwise.</returns>
+        public bool Compare(SceneObjectPart part, ObjectChangeWhat what)
+        {
+            if (data.what != what) // if diferent targets, then they are diferent
+                return false;
+
+            if (part != null)
+            {
+                if (part.ParentID == 0)
+                {
+                    if ((what & ObjectChangeWhat.Position) != 0 && data.position != part.ParentGroup.AbsolutePosition)
+                        return false;
+                }
+                else
+                {
+                    if ((what & ObjectChangeWhat.Position) != 0 && data.position != part.OffsetPosition)
+                        return false;
+                }
+
+                if ((what & ObjectChangeWhat.Rotation) != 0 && data.rotation != part.RotationOffset)
+                    return false;
+                if ((what & ObjectChangeWhat.Rotation) != 0 && data.scale == part.Shape.Scale)
+                    return false;
+                return true;
+
             }
+            return false;
+        }
 
+        public void PlayState(SceneObjectPart part)
+        {
+            part.Undoing = true;
+
+            SceneObjectGroup grp = part.ParentGroup;
+
+            if (grp != null)
+            {
+                grp.doChangeObject(part, data);              
+            }
             part.Undoing = false;
         }
     }
 
+
     public class LandUndoState
     {
         public ITerrainModule m_terrainModule;