8 files changed, 99 insertions, 2 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
index 9613fe0..3afd52e 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
@@ -79,6 +79,8 @@ public abstract class BSLinkset
         }
     }
 
+    public LinksetImplementation LinksetImpl { get; protected set; }
+
     public BSPrimLinkable LinksetRoot { get; protected set; }
 
     protected BSScene m_physicsScene { get; private set; }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
index 53c3584..085d195 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
@@ -42,6 +42,7 @@ public sealed class BSLinksetCompound : BSLinkset
     public BSLinksetCompound(BSScene scene, BSPrimLinkable parent)
         : base(scene, parent)
     {
+        LinksetImpl = LinksetImplementation.Compound;
     }
 
     // ================================================================
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetConstraints.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetConstraints.cs
index d98bf77..4bac222 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetConstraints.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetConstraints.cs
@@ -107,6 +107,7 @@ public sealed class BSLinksetConstraints : BSLinkset
 
     public BSLinksetConstraints(BSScene scene, BSPrimLinkable parent) : base(scene, parent)
     {
+        LinksetImpl = LinksetImplementation.Constraint;
     }
 
     // When physical properties are changed the linkset needs to recalculate
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index e92a1d2..a0b6abc 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -1541,6 +1541,50 @@ public class BSPrim : BSPhysObject
         PhysicalActors.RemoveDependencies();
     }
 
+    #region Extension
+    public override object Extension(string pFunct, params object[] pParams)
+    {
+        object ret = null;
+        switch (pFunct)
+        {
+            case BSScene.PhysFunctGetLinksetType:
+            {
+                BSPrimLinkable myHandle = this as BSPrimLinkable;
+                if (myHandle != null)
+                {
+                    ret = (object)myHandle.LinksetType;
+                }
+                m_log.DebugFormat("{0} Extension.physGetLinksetType, type={1}", LogHeader, ret);
+                break;
+            }
+            case BSScene.PhysFunctSetLinksetType:
+            {
+                if (pParams.Length > 0)
+                {
+                    BSLinkset.LinksetImplementation linksetType = (BSLinkset.LinksetImplementation)pParams[0];
+                    BSPrimLinkable myHandle = this as BSPrimLinkable;
+                    if (myHandle != null && myHandle.Linkset.IsRoot(myHandle))
+                    {
+                        PhysScene.TaintedObject("BSPrim.PhysFunctSetLinksetType", delegate()
+                        {
+                            // Cause the linkset type to change
+                            m_log.DebugFormat("{0} Extension.physSetLinksetType, oldType={1}, newType={2}",
+                                                LogHeader, myHandle.Linkset.LinksetImpl, linksetType);
+                            myHandle.ConvertLinkset(linksetType);
+                        });
+                    }
+                    ret = (object)(int)linksetType;
+                }
+                break;
+            }
+            default:
+                ret = base.Extension(pFunct, pParams);
+                break;
+        }
+        return ret;
+    }
+    #endregion  // Extension
+
     // The physics engine says that properties have updated. Update same and inform
     // the world that things have changed.
     // NOTE: BSPrim.UpdateProperties is overloaded by BSPrimLinkable which modifies updates from root and children prims.
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrimLinkable.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrimLinkable.cs
index 2f392da..c565998 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrimLinkable.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrimLinkable.cs
@@ -233,5 +233,35 @@ public class BSPrimLinkable : BSPrimDisplaced
             base.HasSomeCollision = value;
         }
     }
+
+    // Convert the existing linkset of this prim into a new type.
+    public bool ConvertLinkset(BSLinkset.LinksetImplementation newType)
+    {
+        bool ret = false;
+        if (LinksetType != newType)
+        {
+            BSLinkset oldLinkset = Linkset;
+            BSLinkset newLinkset = BSLinkset.Factory(PhysScene, this);
+
+            // Pick up any physical dependencies this linkset might have in the physics engine.
+            oldLinkset.RemoveDependencies(this);
+
+            // Copy the linkset children from the old linkset to the new (will be a new instance from the factory)
+            oldLinkset.ForEachLinkInfo((li) =>
+            {
+                oldLinkset.RemoveMeFromLinkset(li.member);
+                newLinkset.AddMeToLinkset(li.member);
+                li.member.Linkset = newLinkset;
+                return false;
+            });
+
+            this.Linkset = newLinkset;
+
+            // Force the shape and linkset to get reconstructed
+            newLinkset.Refresh(this);
+            this.ForceBodyShapeRebuild(true);
+        }
+        return ret;
+    }
 }
 }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
index 41aca3b..79ac5a5 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
@@ -862,6 +862,23 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
 
     public override bool IsThreaded { get { return false;  } }
 
+    #region Extensions
+    // =============================================================
+    // Per scene functions. See below.
+
+    // Per avatar functions. See BSCharacter.
+
+    // Per prim functions. See BSPrim.
+    public const string PhysFunctGetLinksetType = "BulletSim.GetLinksetType";
+    public const string PhysFunctSetLinksetType = "BulletSim.SetLinksetType";
+    // =============================================================
+
+    public override object Extension(string pFunct, params object[] pParams)
+    {
+        return base.Extension(pFunct, pParams);
+    }
+    #endregion // Extensions
+
     #region Taints
     // The simulation execution order is:
     // Simulate()
diff --git a/OpenSim/Region/Physics/Manager/PhysicsActor.cs b/OpenSim/Region/Physics/Manager/PhysicsActor.cs
index 2500f27..1750853 100644
--- a/OpenSim/Region/Physics/Manager/PhysicsActor.cs
+++ b/OpenSim/Region/Physics/Manager/PhysicsActor.cs
@@ -317,7 +317,8 @@ namespace OpenSim.Region.Physics.Manager
         // Extendable interface for new, physics engine specific operations
         public virtual object Extension(string pFunct, params object[] pParams)
         {
-            throw new NotImplementedException();
+            // A NOP of the physics engine does not implement this feature
+            return null;
         }
     }
 
diff --git a/OpenSim/Region/Physics/Manager/PhysicsScene.cs b/OpenSim/Region/Physics/Manager/PhysicsScene.cs
index 07a1d36..c93206d 100644
--- a/OpenSim/Region/Physics/Manager/PhysicsScene.cs
+++ b/OpenSim/Region/Physics/Manager/PhysicsScene.cs
@@ -338,7 +338,8 @@ namespace OpenSim.Region.Physics.Manager
         // Extendable interface for new, physics engine specific operations
         public virtual object Extension(string pFunct, params object[] pParams)
         {
-            throw new NotImplementedException();
+            // A NOP if the extension thing is not implemented by the physics engine
+            return null;
         }
     }
 }