* Initial commit of BulletSimN (BulletSNPlugin). Purely C# implementation of BulletSim. This is designed to be /as close as possible/ to the BulletSim plugin while still being entirely in the managed space to make keeping it up to date easy as possible (no thinking work). This implementation is /slower/ then the c++ version just because it's fully managed, so it's not appropriate for huge sims, but it will run small ones OK. At the moment, it supports all known features of BulletSim. Think of it like.. POS but everything works. To use this plugin, set the physics plugin to BulletSimN.

1 files changed, 333 insertions, 0 deletions

diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSLinkset.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSLinkset.cs
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+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSLinkset.cs
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+/*
+ * 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.Text;
+
+using OMV = OpenMetaverse;
+
+namespace OpenSim.Region.Physics.BulletSNPlugin
+{
+
+// A BSPrim can get individual information about its linkedness attached
+//    to it through an instance of a subclass of LinksetInfo.
+// Each type of linkset will define the information needed for its type.
+public abstract class BSLinksetInfo
+{
+    public virtual void Clear() { }
+}
+
+public abstract class BSLinkset
+{
+    // private static string LogHeader = "[BULLETSIM LINKSET]";
+
+    public enum LinksetImplementation
+    {
+        Constraint   = 0,   // linkset tied together with constraints
+        Compound     = 1,   // linkset tied together as a compound object
+        Manual       = 2    // linkset tied together manually (code moves all the pieces)
+    }
+    // Create the correct type of linkset for this child
+    public static BSLinkset Factory(BSScene physScene, BSPhysObject parent)
+    {
+        BSLinkset ret = null;
+
+        switch ((int)BSParam.LinksetImplementation)
+        {
+            case (int)LinksetImplementation.Constraint:
+                ret = new BSLinksetConstraints(physScene, parent);
+                break;
+            case (int)LinksetImplementation.Compound:
+                ret = new BSLinksetCompound(physScene, parent);
+                break;
+            case (int)LinksetImplementation.Manual:
+                // ret = new BSLinksetManual(physScene, parent);
+                break;
+            default:
+                ret = new BSLinksetCompound(physScene, parent);
+                break;
+        }
+        return ret;
+    }
+
+    public BSPhysObject LinksetRoot { get; protected set; }
+
+    public BSScene PhysicsScene { get; private set; }
+
+    static int m_nextLinksetID = 1;
+    public int LinksetID { get; private set; }
+
+    // The children under the root in this linkset.
+    protected HashSet<BSPhysObject> m_children;
+
+    // We lock the diddling of linkset classes to prevent any badness.
+    // This locks the modification of the instances of this class. Changes
+    //    to the physical representation is done via the tainting mechenism.
+    protected object m_linksetActivityLock = new Object();
+
+    // Some linksets have a preferred physical shape.
+    // Returns SHAPE_UNKNOWN if there is no preference. Causes the correct shape to be selected.
+    public virtual BSPhysicsShapeType PreferredPhysicalShape(BSPhysObject requestor)
+    {
+        return BSPhysicsShapeType.SHAPE_UNKNOWN;
+    }
+
+    // We keep the prim's mass in the linkset structure since it could be dependent on other prims
+    protected float m_mass;
+    public float LinksetMass
+    {
+        get
+        {
+            return m_mass;
+        }
+    }
+
+    public virtual bool LinksetIsColliding { get { return false; } }
+
+    public OMV.Vector3 CenterOfMass
+    {
+        get { return ComputeLinksetCenterOfMass(); }
+    }
+
+    public OMV.Vector3 GeometricCenter
+    {
+        get { return ComputeLinksetGeometricCenter(); }
+    }
+
+    protected BSLinkset(BSScene scene, BSPhysObject parent)
+    {
+        // A simple linkset of one (no children)
+        LinksetID = m_nextLinksetID++;
+        // We create LOTS of linksets.
+        if (m_nextLinksetID <= 0)
+            m_nextLinksetID = 1;
+        PhysicsScene = scene;
+        LinksetRoot = parent;
+        m_children = new HashSet<BSPhysObject>();
+        m_mass = parent.RawMass;
+        Rebuilding = false;
+    }
+
+    // Link to a linkset where the child knows the parent.
+    // Parent changing should not happen so do some sanity checking.
+    // We return the parent's linkset so the child can track its membership.
+    // Called at runtime.
+    public BSLinkset AddMeToLinkset(BSPhysObject child)
+    {
+        lock (m_linksetActivityLock)
+        {
+            // Don't add the root to its own linkset
+            if (!IsRoot(child))
+                AddChildToLinkset(child);
+            m_mass = ComputeLinksetMass();
+        }
+        return this;
+    }
+
+    // Remove a child from a linkset.
+    // Returns a new linkset for the child which is a linkset of one (just the
+    //    orphened child).
+    // Called at runtime.
+    public BSLinkset RemoveMeFromLinkset(BSPhysObject child)
+    {
+        lock (m_linksetActivityLock)
+        {
+            if (IsRoot(child))
+            {
+                // Cannot remove the root from a linkset.
+                return this;
+            }
+            RemoveChildFromLinkset(child);
+            m_mass = ComputeLinksetMass();
+        }
+
+        // The child is down to a linkset of just itself
+        return BSLinkset.Factory(PhysicsScene, child);
+    }
+
+    // Return 'true' if the passed object is the root object of this linkset
+    public bool IsRoot(BSPhysObject requestor)
+    {
+        return (requestor.LocalID == LinksetRoot.LocalID);
+    }
+
+    public int NumberOfChildren { get { return m_children.Count; } }
+
+    // Return 'true' if this linkset has any children (more than the root member)
+    public bool HasAnyChildren { get { return (m_children.Count > 0); } }
+
+    // Return 'true' if this child is in this linkset
+    public bool HasChild(BSPhysObject child)
+    {
+        bool ret = false;
+        lock (m_linksetActivityLock)
+        {
+            ret = m_children.Contains(child);
+            /* Safer version but the above should work
+            foreach (BSPhysObject bp in m_children)
+            {
+                if (child.LocalID == bp.LocalID)
+                {
+                    ret = true;
+                    break;
+                }
+            }
+             */
+        }
+        return ret;
+    }
+
+    // Perform an action on each member of the linkset including root prim.
+    // Depends on the action on whether this should be done at taint time.
+    public delegate bool ForEachMemberAction(BSPhysObject obj);
+    public virtual bool ForEachMember(ForEachMemberAction action)
+    {
+        bool ret = false;
+        lock (m_linksetActivityLock)
+        {
+            action(LinksetRoot);
+            foreach (BSPhysObject po in m_children)
+            {
+                if (action(po))
+                    break;
+            }
+        }
+        return ret;
+    }
+
+    // I am the root of a linkset and a new child is being added
+    // Called while LinkActivity is locked.
+    protected abstract void AddChildToLinkset(BSPhysObject child);
+    
+    // I am the root of a linkset and one of my children is being removed.
+    // Safe to call even if the child is not really in my linkset.
+    protected abstract void RemoveChildFromLinkset(BSPhysObject child);
+
+    // When physical properties are changed the linkset needs to recalculate
+    //   its internal properties.
+    // May be called at runtime or taint-time.
+    public abstract void Refresh(BSPhysObject requestor);
+
+    // Flag denoting the linkset is in the process of being rebuilt.
+    // Used to know not the schedule a rebuild in the middle of a rebuild.
+    protected bool Rebuilding { get; set; }
+
+    // The object is going dynamic (physical). Do any setup necessary
+    //     for a dynamic linkset.
+    // Only the state of the passed object can be modified. The rest of the linkset
+    //     has not yet been fully constructed.
+    // Return 'true' if any properties updated on the passed object.
+    // Called at taint-time!
+    public abstract bool MakeDynamic(BSPhysObject child);
+
+    // The object is going static (non-physical). Do any setup necessary
+    //     for a static linkset.
+    // Return 'true' if any properties updated on the passed object.
+    // Called at taint-time!
+    public abstract bool MakeStatic(BSPhysObject child);
+
+    // Called when a parameter update comes from the physics engine for any object
+    //      of the linkset is received.
+    // Passed flag is update came from physics engine (true) or the user (false).
+    // Called at taint-time!!
+    public abstract void UpdateProperties(BSPhysObject physObject, bool physicalUpdate);
+
+    // Routine used when rebuilding the body of the root of the linkset
+    // Destroy all the constraints have have been made to root.
+    // This is called when the root body is changing.
+    // Returns 'true' of something was actually removed and would need restoring
+    // Called at taint-time!!
+    public abstract bool RemoveBodyDependencies(BSPrim child);
+
+    // Companion to RemoveBodyDependencies(). If RemoveBodyDependencies() returns 'true',
+    //     this routine will restore the removed constraints.
+    // Called at taint-time!!
+    public abstract void RestoreBodyDependencies(BSPrim child);
+
+    // ================================================================
+    protected virtual float ComputeLinksetMass()
+    {
+        float mass = LinksetRoot.RawMass;
+        if (HasAnyChildren)
+        {
+            lock (m_linksetActivityLock)
+            {
+                foreach (BSPhysObject bp in m_children)
+                {
+                    mass += bp.RawMass;
+                }
+            }
+        }
+        return mass;
+    }
+
+    protected virtual OMV.Vector3 ComputeLinksetCenterOfMass()
+    {
+        OMV.Vector3 com;
+        lock (m_linksetActivityLock)
+        {
+            com = LinksetRoot.Position * LinksetRoot.RawMass;
+            float totalMass = LinksetRoot.RawMass;
+
+            foreach (BSPhysObject bp in m_children)
+            {
+                com += bp.Position * bp.RawMass;
+                totalMass += bp.RawMass;
+            }
+            if (totalMass != 0f)
+                com /= totalMass;
+        }
+
+        return com;
+    }
+
+    protected virtual OMV.Vector3 ComputeLinksetGeometricCenter()
+    {
+        OMV.Vector3 com;
+        lock (m_linksetActivityLock)
+        {
+            com = LinksetRoot.Position;
+
+            foreach (BSPhysObject bp in m_children)
+            {
+                com += bp.Position * bp.RawMass;
+            }
+            com /= (m_children.Count + 1);
+        }
+
+        return com;
+    }
+
+    // Invoke the detailed logger and output something if it's enabled.
+    protected void DetailLog(string msg, params Object[] args)
+    {
+        if (PhysicsScene.PhysicsLogging.Enabled)
+            PhysicsScene.DetailLog(msg, args);
+    }
+
+}
+}