Moved ExtendedPhysics from OptionalModules to Bullet project, because it's very much an optional Bullet feature. This way, Bullet doesn't need to depend on the OptionalModules dll. No changes in configs or behavior.

1 files changed, 622 insertions, 0 deletions

diff --git a/OpenSim/Region/PhysicsModules/BulletS/ExtendedPhysics.cs b/OpenSim/Region/PhysicsModules/BulletS/ExtendedPhysics.cs
new file mode 100755
index 0000000..2ba3c5a
--- /dev/null
+++ b/OpenSim/Region/PhysicsModules/BulletS/ExtendedPhysics.cs
@@ -0,0 +1,622 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyrightD
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using System.Text;
+using System.Threading;
+
+using OpenSim.Framework;
+using OpenSim.Region.Framework;
+using OpenSim.Region.Framework.Interfaces;
+using OpenSim.Region.Framework.Scenes;
+using OpenSim.Region.PhysicsModules.SharedBase;
+
+using Mono.Addins;
+using Nini.Config;
+using log4net;
+using OpenMetaverse;
+
+namespace OpenSim.Region.PhysicsModule.BulletS
+{
+    [Extension(Path = "/OpenSim/RegionModules", NodeName = "RegionModule")]
+    public class ExtendedPhysics : INonSharedRegionModule
+    {
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+        private static string LogHeader = "[EXTENDED PHYSICS]";
+
+        // =============================================================
+        // Since BulletSim is a plugin, this these values aren't defined easily in one place.
+        // This table must correspond to an identical table in BSScene.
+
+        // Per scene functions. See BSScene.
+
+        // Per avatar functions. See BSCharacter.
+
+        // Per prim functions. See BSPrim.
+        public const string PhysFunctGetLinksetType = "BulletSim.GetLinksetType";
+        public const string PhysFunctSetLinksetType = "BulletSim.SetLinksetType";
+        public const string PhysFunctChangeLinkFixed = "BulletSim.ChangeLinkFixed";
+        public const string PhysFunctChangeLinkType = "BulletSim.ChangeLinkType";
+        public const string PhysFunctGetLinkType = "BulletSim.GetLinkType";
+        public const string PhysFunctChangeLinkParams = "BulletSim.ChangeLinkParams";
+        public const string PhysFunctAxisLockLimits = "BulletSim.AxisLockLimits";
+
+        // =============================================================
+
+        private IConfig Configuration { get; set; }
+        private bool Enabled { get; set; }
+        private Scene BaseScene { get; set; }
+        private IScriptModuleComms Comms { get; set; }
+
+        #region INonSharedRegionModule
+
+        public string Name { get { return this.GetType().Name; } }
+
+        public void Initialise(IConfigSource config)
+        {
+            BaseScene = null;
+            Enabled = false;
+            Configuration = null;
+            Comms = null;
+
+            try
+            {
+                if ((Configuration = config.Configs["ExtendedPhysics"]) != null)
+                {
+                    Enabled = Configuration.GetBoolean("Enabled", Enabled);
+                }
+            }
+            catch (Exception e)
+            {
+                m_log.ErrorFormat("{0} Initialization error: {0}", LogHeader, e);
+            }
+
+            m_log.InfoFormat("{0} module {1} enabled", LogHeader, (Enabled ? "is" : "is not"));
+        }
+
+        public void Close()
+        {
+            if (BaseScene != null)
+            {
+                BaseScene.EventManager.OnObjectAddedToScene -= EventManager_OnObjectAddedToScene;
+                BaseScene.EventManager.OnSceneObjectPartUpdated -= EventManager_OnSceneObjectPartUpdated;
+                BaseScene = null;
+            }
+        }
+
+        public void AddRegion(Scene scene)
+        {
+        }
+
+        public void RemoveRegion(Scene scene)
+        {
+            if (BaseScene != null && BaseScene == scene)
+            {
+                Close();
+            }
+        }
+
+        public void RegionLoaded(Scene scene)
+        {
+            if (!Enabled) return;
+
+            BaseScene = scene;
+
+            Comms = BaseScene.RequestModuleInterface<IScriptModuleComms>();
+            if (Comms == null)
+            {
+                m_log.WarnFormat("{0} ScriptModuleComms interface not defined", LogHeader);
+                Enabled = false;
+
+                return;
+            }
+ 
+            // Register as LSL functions all the [ScriptInvocation] marked methods.
+            Comms.RegisterScriptInvocations(this);
+            Comms.RegisterConstants(this);
+
+            // When an object is modified, we might need to update its extended physics parameters
+            BaseScene.EventManager.OnObjectAddedToScene += EventManager_OnObjectAddedToScene;
+            BaseScene.EventManager.OnSceneObjectPartUpdated += EventManager_OnSceneObjectPartUpdated;
+
+        }
+
+        public Type ReplaceableInterface { get { return null; } }
+
+        #endregion // INonSharedRegionModule
+
+        private void EventManager_OnObjectAddedToScene(SceneObjectGroup obj)
+        {
+        }
+
+        // Event generated when some property of a prim changes.
+        private void EventManager_OnSceneObjectPartUpdated(SceneObjectPart sop, bool isFullUpdate)
+        {
+        }
+
+        [ScriptConstant]
+        public const int PHYS_CENTER_OF_MASS =     1 << 0;
+
+        [ScriptInvocation]
+        public string physGetEngineType(UUID hostID, UUID scriptID)
+        {
+            string ret = string.Empty;
+
+            if (BaseScene.PhysicsScene != null)
+            {
+                ret = BaseScene.PhysicsScene.EngineType;
+            }
+
+            return ret;
+        }
+
+        // Code for specifying params.
+        // The choice if 14700 is arbitrary and only serves to catch parameter code misuse.
+        [ScriptConstant]
+        public const int PHYS_AXIS_LOCK_LINEAR     = 14700;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LOCK_LINEAR_X   = 14701;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LIMIT_LINEAR_X  = 14702;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LOCK_LINEAR_Y   = 14703;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LIMIT_LINEAR_Y  = 14704;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LOCK_LINEAR_Z   = 14705;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LIMIT_LINEAR_Z  = 14706;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LOCK_ANGULAR    = 14707;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LOCK_ANGULAR_X  = 14708;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LIMIT_ANGULAR_X = 14709;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LOCK_ANGULAR_Y  = 14710;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LIMIT_ANGULAR_Y = 14711;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LOCK_ANGULAR_Z  = 14712;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LIMIT_ANGULAR_Z = 14713;
+        [ScriptConstant]
+        public const int PHYS_AXIS_UNLOCK_LINEAR   = 14714;
+        [ScriptConstant]
+        public const int PHYS_AXIS_UNLOCK_LINEAR_X = 14715;
+        [ScriptConstant]
+        public const int PHYS_AXIS_UNLOCK_LINEAR_Y = 14716;
+        [ScriptConstant]
+        public const int PHYS_AXIS_UNLOCK_LINEAR_Z = 14717;
+        [ScriptConstant]
+        public const int PHYS_AXIS_UNLOCK_ANGULAR  = 14718;
+        [ScriptConstant]
+        public const int PHYS_AXIS_UNLOCK_ANGULAR_X = 14719;
+        [ScriptConstant]
+        public const int PHYS_AXIS_UNLOCK_ANGULAR_Y = 14720;
+        [ScriptConstant]
+        public const int PHYS_AXIS_UNLOCK_ANGULAR_Z = 14721;
+        [ScriptConstant]
+        public const int PHYS_AXIS_UNLOCK           = 14722;
+        // physAxisLockLimits()
+        [ScriptInvocation]
+        public int physAxisLock(UUID hostID, UUID scriptID, object[] parms)
+        {
+            int ret = -1;
+            if (!Enabled) return ret;
+
+            PhysicsActor rootPhysActor;
+            if (GetRootPhysActor(hostID, out rootPhysActor))
+            {
+                object[] parms2 = AddToBeginningOfArray(rootPhysActor, null, parms);
+                ret = MakeIntError(rootPhysActor.Extension(PhysFunctAxisLockLimits, parms2));
+            }
+
+            return ret;
+        }
+
+        [ScriptConstant]
+        public const int PHYS_LINKSET_TYPE_CONSTRAINT  = 0;
+        [ScriptConstant]
+        public const int PHYS_LINKSET_TYPE_COMPOUND    = 1;
+        [ScriptConstant]
+        public const int PHYS_LINKSET_TYPE_MANUAL      = 2;
+
+        [ScriptInvocation]
+        public int physSetLinksetType(UUID hostID, UUID scriptID, int linksetType)
+        {
+            int ret = -1;
+            if (!Enabled) return ret;
+
+            // The part that is requesting the change.
+            SceneObjectPart requestingPart = BaseScene.GetSceneObjectPart(hostID);
+
+            if (requestingPart != null)
+            {
+                // The change is always made to the root of a linkset.
+                SceneObjectGroup containingGroup = requestingPart.ParentGroup;
+                SceneObjectPart rootPart = containingGroup.RootPart;
+
+                if (rootPart != null)
+                {
+                    PhysicsActor rootPhysActor = rootPart.PhysActor;
+                    if (rootPhysActor != null)
+                    {
+                        if (rootPhysActor.IsPhysical)
+                        {
+                            // Change a physical linkset by making non-physical, waiting for one heartbeat so all
+                            //    the prim and linkset state is updated, changing the type and making the
+                            //    linkset physical again.
+                            containingGroup.ScriptSetPhysicsStatus(false);
+                            Thread.Sleep(150);  // longer than one heartbeat tick
+
+                            // A kludge for the moment.
+                            // Since compound linksets move the children but don't generate position updates to the
+                            //     simulator, it is possible for compound linkset children to have out-of-sync simulator
+                            //     and physical positions. The following causes the simulator to push the real child positions
+                            //     down into the physics engine to get everything synced.
+                            containingGroup.UpdateGroupPosition(containingGroup.AbsolutePosition);
+                            containingGroup.UpdateGroupRotationR(containingGroup.GroupRotation);
+
+                            object[] parms2 = { rootPhysActor, null, linksetType };
+                            ret = MakeIntError(rootPhysActor.Extension(PhysFunctSetLinksetType, parms2));
+                            Thread.Sleep(150);  // longer than one heartbeat tick
+
+                            containingGroup.ScriptSetPhysicsStatus(true);
+                        }
+                        else
+                        {
+                            // Non-physical linksets don't have a physical instantiation so there is no state to
+                            //    worry about being updated.
+                            object[] parms2 = { rootPhysActor, null, linksetType };
+                            ret = MakeIntError(rootPhysActor.Extension(PhysFunctSetLinksetType, parms2));
+                        }
+                    }
+                    else
+                    {
+                        m_log.WarnFormat("{0} physSetLinksetType: root part does not have a physics actor. rootName={1}, hostID={2}",
+                                            LogHeader, rootPart.Name, hostID);
+                    }
+                }
+                else
+                {
+                    m_log.WarnFormat("{0} physSetLinksetType: root part does not exist. RequestingPartName={1}, hostID={2}",
+                                        LogHeader, requestingPart.Name, hostID);
+                }
+            }
+            else
+            {
+                m_log.WarnFormat("{0} physSetLinsetType: cannot find script object in scene. hostID={1}", LogHeader, hostID);
+            }
+            return ret;
+        }
+
+        [ScriptInvocation]
+        public int physGetLinksetType(UUID hostID, UUID scriptID)
+        {
+            int ret = -1;
+            if (!Enabled) return ret;
+
+            PhysicsActor rootPhysActor;
+            if (GetRootPhysActor(hostID, out rootPhysActor))
+            {
+                object[] parms2 = { rootPhysActor, null };
+                ret = MakeIntError(rootPhysActor.Extension(PhysFunctGetLinksetType, parms2));
+            }
+            else
+            {
+                m_log.WarnFormat("{0} physGetLinsetType: cannot find script object in scene. hostID={1}", LogHeader, hostID);
+            }
+            return ret;
+        }
+
+        [ScriptConstant]
+        public const int PHYS_LINK_TYPE_FIXED  = 1234;
+        [ScriptConstant]
+        public const int PHYS_LINK_TYPE_HINGE  = 4;
+        [ScriptConstant]
+        public const int PHYS_LINK_TYPE_SPRING = 9;
+        [ScriptConstant]
+        public const int PHYS_LINK_TYPE_6DOF   = 6;
+        [ScriptConstant]
+        public const int PHYS_LINK_TYPE_SLIDER = 7;
+
+        // physChangeLinkType(integer linkNum, integer typeCode)
+        [ScriptInvocation]
+        public int physChangeLinkType(UUID hostID, UUID scriptID, int linkNum, int typeCode)
+        {
+            int ret = -1;
+            if (!Enabled) return ret;
+
+            PhysicsActor rootPhysActor;
+            PhysicsActor childPhysActor;
+
+            if (GetRootAndChildPhysActors(hostID, linkNum, out rootPhysActor, out childPhysActor))
+            {
+                object[] parms2 = { rootPhysActor, childPhysActor, typeCode };
+                ret = MakeIntError(rootPhysActor.Extension(PhysFunctChangeLinkType, parms2));
+            }
+
+            return ret;
+        }
+
+        // physGetLinkType(integer linkNum)
+        [ScriptInvocation]
+        public int physGetLinkType(UUID hostID, UUID scriptID, int linkNum)
+        {
+            int ret = -1;
+            if (!Enabled) return ret;
+
+            PhysicsActor rootPhysActor;
+            PhysicsActor childPhysActor;
+
+            if (GetRootAndChildPhysActors(hostID, linkNum, out rootPhysActor, out childPhysActor))
+            {
+                object[] parms2 = { rootPhysActor, childPhysActor };
+                ret = MakeIntError(rootPhysActor.Extension(PhysFunctGetLinkType, parms2));
+            }
+
+            return ret;
+        }
+
+        // physChangeLinkFixed(integer linkNum)
+        // Change the link between the root and the linkNum into a fixed, static physical connection.
+        [ScriptInvocation]
+        public int physChangeLinkFixed(UUID hostID, UUID scriptID, int linkNum)
+        {
+            int ret = -1;
+            if (!Enabled) return ret;
+
+            PhysicsActor rootPhysActor;
+            PhysicsActor childPhysActor;
+
+            if (GetRootAndChildPhysActors(hostID, linkNum, out rootPhysActor, out childPhysActor))
+            {
+                object[] parms2 = { rootPhysActor, childPhysActor , PHYS_LINK_TYPE_FIXED };
+                ret = MakeIntError(rootPhysActor.Extension(PhysFunctChangeLinkType, parms2));
+            }
+
+            return ret;
+        }
+
+        // Code for specifying params.
+        // The choice if 14400 is arbitrary and only serves to catch parameter code misuse.
+        public const int PHYS_PARAM_MIN                    = 14401;
+
+        [ScriptConstant]
+        public const int PHYS_PARAM_FRAMEINA_LOC           = 14401;
+        [ScriptConstant]
+        public const int PHYS_PARAM_FRAMEINA_ROT           = 14402;
+        [ScriptConstant]
+        public const int PHYS_PARAM_FRAMEINB_LOC           = 14403;
+        [ScriptConstant]
+        public const int PHYS_PARAM_FRAMEINB_ROT           = 14404;
+        [ScriptConstant]
+        public const int PHYS_PARAM_LINEAR_LIMIT_LOW       = 14405;
+        [ScriptConstant]
+        public const int PHYS_PARAM_LINEAR_LIMIT_HIGH      = 14406;
+        [ScriptConstant]
+        public const int PHYS_PARAM_ANGULAR_LIMIT_LOW      = 14407;
+        [ScriptConstant]
+        public const int PHYS_PARAM_ANGULAR_LIMIT_HIGH     = 14408;
+        [ScriptConstant]
+        public const int PHYS_PARAM_USE_FRAME_OFFSET       = 14409;
+        [ScriptConstant]
+        public const int PHYS_PARAM_ENABLE_TRANSMOTOR      = 14410;
+        [ScriptConstant]
+        public const int PHYS_PARAM_TRANSMOTOR_MAXVEL      = 14411;
+        [ScriptConstant]
+        public const int PHYS_PARAM_TRANSMOTOR_MAXFORCE    = 14412;
+        [ScriptConstant]
+        public const int PHYS_PARAM_CFM                    = 14413;
+        [ScriptConstant]
+        public const int PHYS_PARAM_ERP                    = 14414;
+        [ScriptConstant]
+        public const int PHYS_PARAM_SOLVER_ITERATIONS      = 14415;
+        [ScriptConstant]
+        public const int PHYS_PARAM_SPRING_AXIS_ENABLE     = 14416;
+        [ScriptConstant]
+        public const int PHYS_PARAM_SPRING_DAMPING         = 14417;
+        [ScriptConstant]
+        public const int PHYS_PARAM_SPRING_STIFFNESS       = 14418;
+        [ScriptConstant]
+        public const int PHYS_PARAM_LINK_TYPE              = 14419;
+        [ScriptConstant]
+        public const int PHYS_PARAM_USE_LINEAR_FRAMEA      = 14420;
+        [ScriptConstant]
+        public const int PHYS_PARAM_SPRING_EQUILIBRIUM_POINT = 14421;
+
+        public const int PHYS_PARAM_MAX                    = 14421;
+
+        // Used when specifying a parameter that has settings for the three linear and three angular axis
+        [ScriptConstant]
+        public const int PHYS_AXIS_ALL = -1;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LINEAR_ALL = -2;
+        [ScriptConstant]
+        public const int PHYS_AXIS_ANGULAR_ALL = -3;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LINEAR_X  = 0;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LINEAR_Y  = 1;
+        [ScriptConstant]
+        public const int PHYS_AXIS_LINEAR_Z  = 2;
+        [ScriptConstant]
+        public const int PHYS_AXIS_ANGULAR_X = 3;
+        [ScriptConstant]
+        public const int PHYS_AXIS_ANGULAR_Y = 4;
+        [ScriptConstant]
+        public const int PHYS_AXIS_ANGULAR_Z = 5;
+
+        // physChangeLinkParams(integer linkNum, [ PHYS_PARAM_*, value, PHYS_PARAM_*, value, ...])
+        [ScriptInvocation]
+        public int physChangeLinkParams(UUID hostID, UUID scriptID, int linkNum, object[] parms)
+        {
+            int ret = -1;
+            if (!Enabled) return ret;
+
+            PhysicsActor rootPhysActor;
+            PhysicsActor childPhysActor;
+
+            if (GetRootAndChildPhysActors(hostID, linkNum, out rootPhysActor, out childPhysActor))
+            {
+                object[] parms2 = AddToBeginningOfArray(rootPhysActor, childPhysActor, parms);
+                ret = MakeIntError(rootPhysActor.Extension(PhysFunctChangeLinkParams, parms2));
+            }
+
+            return ret;
+        }
+
+        private bool GetRootPhysActor(UUID hostID, out PhysicsActor rootPhysActor)
+        {
+            SceneObjectGroup containingGroup;
+            SceneObjectPart rootPart;
+            return GetRootPhysActor(hostID, out containingGroup, out rootPart, out rootPhysActor);
+        }
+
+        private bool GetRootPhysActor(UUID hostID, out SceneObjectGroup containingGroup, out SceneObjectPart rootPart, out PhysicsActor rootPhysActor)
+        {
+            bool ret = false;
+            rootPhysActor = null;
+            containingGroup = null;
+            rootPart = null;
+
+            SceneObjectPart requestingPart;
+
+            requestingPart = BaseScene.GetSceneObjectPart(hostID);
+            if (requestingPart != null)
+            {
+                // The type is is always on the root of a linkset.
+                containingGroup = requestingPart.ParentGroup;
+                if (containingGroup != null && !containingGroup.IsDeleted)
+                {
+                    rootPart = containingGroup.RootPart;
+                    if (rootPart != null)
+                    {
+                        rootPhysActor = rootPart.PhysActor;
+                        if (rootPhysActor != null)
+                        {
+                            ret = true;
+                        }
+                        else
+                        {
+                            m_log.WarnFormat("{0} GetRootAndChildPhysActors: Root part does not have a physics actor. rootName={1}, hostID={2}",
+                                            LogHeader, rootPart.Name, hostID);
+                        }
+                    }
+                    else
+                    {
+                        m_log.WarnFormat("{0} GetRootAndChildPhysActors: Root part does not exist. RequestingPartName={1}, hostID={2}",
+                                        LogHeader, requestingPart.Name, hostID);
+                    }
+                }
+                else
+                {
+                    m_log.WarnFormat("{0} GetRootAndChildPhysActors: Containing group missing or deleted. hostID={1}", LogHeader, hostID);
+                }
+            }
+            else
+            {
+                m_log.WarnFormat("{0} GetRootAndChildPhysActors: cannot find script object in scene. hostID={1}", LogHeader, hostID);
+            }
+
+            return ret;
+        }
+
+        // Find the root and child PhysActors based on the linkNum.
+        // Return 'true' if both are found and returned.
+        private bool GetRootAndChildPhysActors(UUID hostID, int linkNum, out PhysicsActor rootPhysActor, out PhysicsActor childPhysActor)
+        {
+            bool ret = false;
+            rootPhysActor = null;
+            childPhysActor = null;
+
+            SceneObjectGroup containingGroup;
+            SceneObjectPart rootPart;
+
+            if (GetRootPhysActor(hostID, out containingGroup, out rootPart, out rootPhysActor))
+            {
+                SceneObjectPart linkPart = containingGroup.GetLinkNumPart(linkNum);
+                if (linkPart != null)
+                {
+                    childPhysActor = linkPart.PhysActor;
+                    if (childPhysActor != null)
+                    {
+                        ret = true;
+                    }
+                    else
+                    {
+                        m_log.WarnFormat("{0} GetRootAndChildPhysActors: Link part has no physical actor. rootName={1}, hostID={2}, linknum={3}",
+                                            LogHeader, rootPart.Name, hostID, linkNum);
+                    }
+                }
+                else
+                {
+                    m_log.WarnFormat("{0} GetRootAndChildPhysActors: Could not find linknum part. rootName={1}, hostID={2}, linknum={3}",
+                                        LogHeader, rootPart.Name, hostID, linkNum);
+                }
+            }
+            else
+            {
+                m_log.WarnFormat("{0} GetRootAndChildPhysActors: Root part does not have a physics actor. rootName={1}, hostID={2}",
+                                LogHeader, rootPart.Name, hostID);
+            }
+
+            return ret;
+        }
+
+        // Return an array of objects with the passed object as the first object of a new array
+        private object[] AddToBeginningOfArray(object firstOne, object secondOne, object[] prevArray)
+        {
+            object[] newArray = new object[2 + prevArray.Length];
+            newArray[0] = firstOne;
+            newArray[1] = secondOne;
+            prevArray.CopyTo(newArray, 2);
+            return newArray;
+        }
+
+        // Extension() returns an object. Convert that object into the integer error we expect to return.
+        private int MakeIntError(object extensionRet)
+        {
+            int ret = -1;
+            if (extensionRet != null)
+            {
+                try
+                {
+                    ret = (int)extensionRet;
+                }
+                catch
+                {
+                    ret = -1;
+                }
+            }
+            return ret;
+        }
+    }
+}