1 files changed, 135 insertions, 258 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
index 087b9bb..c984824 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
@@ -32,29 +32,56 @@ using OMV = OpenMetaverse;
 
 namespace OpenSim.Region.Physics.BulletSPlugin
 {
-public class BSLinkset
+public abstract class BSLinkset
 {
-    private static string LogHeader = "[BULLETSIM LINKSET]";
+    // private static string LogHeader = "[BULLETSIM LINKSET]";
 
-    private BSPrim m_linksetRoot;
-    public BSPrim LinksetRoot { get { return m_linksetRoot; } }
+    // Create the correct type of linkset for this child
+    public static BSLinkset Factory(BSScene physScene, BSPhysObject parent)
+    {
+        BSLinkset ret = null;
+        /*
+        if (parent.IsPhysical)
+            ret = new BSLinksetConstraints(physScene, parent);
+        else
+            ret = new BSLinksetManual(physScene, parent);
+         */
+
+        // at the moment, there is only one
+        ret = new BSLinksetConstraints(physScene, parent);
+
+        return ret;
+    }
+
+    public BSPhysObject LinksetRoot { get; protected set; }
+
+    public BSScene PhysicsScene { get; private set; }
 
-    private BSScene m_physicsScene;
-    public BSScene PhysicsScene { get { return m_physicsScene; } }
+    static int m_nextLinksetID = 1;
+    public int LinksetID { get; private set; }
 
-    // The children under the root in this linkset
-    private List<BSPrim> m_children;
+    // The children under the root in this linkset.
+    // There are two lists of children: the current children at runtime
+    //    and the children at taint-time. For instance, if you delink a
+    //    child from the linkset, the child is removed from m_children
+    //    but the constraint won't be removed until taint time.
+    //    Two lists lets this track the 'current' children and
+    //    the physical 'taint' children separately.
+    // After taint processing and before the simulation step, these
+    //    two lists must be the same.
+    protected HashSet<BSPhysObject> m_children;
+    protected HashSet<BSPhysObject> m_taintChildren;
 
     // 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.
-    private object m_linksetActivityLock = new Object();
+    protected object m_linksetActivityLock = new Object();
 
     // We keep the prim's mass in the linkset structure since it could be dependent on other prims
-    private float m_mass;
-    public float LinksetMass 
-    { 
-        get 
+    protected float m_mass;
+    public float LinksetMass
+    {
+        get
         {
             m_mass = ComputeLinksetMass();
             return m_mass;
@@ -71,23 +98,31 @@ public class BSLinkset
         get { return ComputeLinksetGeometricCenter(); }
     }
 
-    public BSLinkset(BSScene scene, BSPrim parent)
+    protected void Initialize(BSScene scene, BSPhysObject parent)
     {
         // A simple linkset of one (no children)
-        m_physicsScene = scene;
-        m_linksetRoot = parent;
-        m_children = new List<BSPrim>();
+        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_taintChildren = new HashSet<BSPhysObject>();
         m_mass = parent.MassRaw;
     }
 
     // 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.
-    public BSLinkset AddMeToLinkset(BSPrim child)
+    // Called at runtime.
+    public BSLinkset AddMeToLinkset(BSPhysObject child)
     {
         lock (m_linksetActivityLock)
         {
-            AddChildToLinkset(child);
+            // Don't add the root to its own linkset
+            if (!IsRoot(child))
+                AddChildToLinkset(child);
         }
         return this;
     }
@@ -95,36 +130,28 @@ public class BSLinkset
     // Remove a child from a linkset.
     // Returns a new linkset for the child which is a linkset of one (just the
     //    orphened child).
-    public BSLinkset RemoveMeFromLinkset(BSPrim child)
+    // Called at runtime.
+    public BSLinkset RemoveMeFromLinkset(BSPhysObject child)
     {
         lock (m_linksetActivityLock)
         {
             if (IsRoot(child))
             {
-                // if root of linkset, take the linkset apart
-                while (m_children.Count > 0)
-                {
-                    // Note that we don't do a foreach because the remove routine
-                    //    takes it out of the list.
-                    RemoveChildFromOtherLinkset(m_children[0]);
-                }
-                m_children.Clear(); // just to make sure
-            }
-            else
-            {
-                // Just removing a child from an existing linkset
-                RemoveChildFromLinkset(child);
+                // Cannot remove the root from a linkset.
+                return this;
             }
+
+            RemoveChildFromLinkset(child);
         }
 
         // The child is down to a linkset of just itself
-        return new BSLinkset(PhysicsScene, child);
+        return BSLinkset.Factory(PhysicsScene, child);
     }
 
     // Return 'true' if the passed object is the root object of this linkset
-    public bool IsRoot(BSPrim requestor)
+    public bool IsRoot(BSPhysObject requestor)
     {
-        return (requestor.LocalID == m_linksetRoot.LocalID);
+        return (requestor.LocalID == LinksetRoot.LocalID);
     }
 
     public int NumberOfChildren { get { return m_children.Count; } }
@@ -133,12 +160,15 @@ public class BSLinkset
     public bool HasAnyChildren { get { return (m_children.Count > 0); } }
 
     // Return 'true' if this child is in this linkset
-    public bool HasChild(BSPrim child)
+    public bool HasChild(BSPhysObject child)
     {
         bool ret = false;
         lock (m_linksetActivityLock)
         {
-            foreach (BSPrim bp in m_children)
+            if (m_children.Contains(child))
+                    ret = true;
+            /*
+            foreach (BSPhysObject bp in m_children)
             {
                 if (child.LocalID == bp.LocalID)
                 {
@@ -146,28 +176,73 @@ public class BSLinkset
                     break;
                 }
             }
+             */
         }
         return ret;
     }
 
-    private float ComputeLinksetMass()
+    // When physical properties are changed the linkset needs to recalculate
+    //   its internal properties.
+    // May be called at runtime or taint-time (just pass the appropriate flag).
+    public abstract void Refresh(BSPhysObject requestor, bool inTaintTime);
+
+    // 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.
+    // Called at taint-time!!
+    public abstract void UpdateProperties(BSPhysObject physObject);
+
+    // 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);
+
+    // ================================================================
+    // Below this point is internal magic
+
+    protected virtual float ComputeLinksetMass()
     {
-        float mass = m_linksetRoot.MassRaw;
-        foreach (BSPrim bp in m_children)
+        float mass;
+        lock (m_linksetActivityLock)
         {
-            mass += bp.MassRaw;
+            mass = LinksetRoot.MassRaw;
+            foreach (BSPhysObject bp in m_taintChildren)
+            {
+                mass += bp.MassRaw;
+            }
         }
         return mass;
     }
 
-    private OMV.Vector3 ComputeLinksetCenterOfMass()
+    protected virtual OMV.Vector3 ComputeLinksetCenterOfMass()
     {
-        OMV.Vector3 com = m_linksetRoot.Position * m_linksetRoot.MassRaw;
-        float totalMass = m_linksetRoot.MassRaw;
-
+        OMV.Vector3 com;
         lock (m_linksetActivityLock)
         {
-            foreach (BSPrim bp in m_children)
+            com = LinksetRoot.Position * LinksetRoot.MassRaw;
+            float totalMass = LinksetRoot.MassRaw;
+
+            foreach (BSPhysObject bp in m_taintChildren)
             {
                 com += bp.Position * bp.MassRaw;
                 totalMass += bp.MassRaw;
@@ -179,241 +254,43 @@ public class BSLinkset
         return com;
     }
 
-    private OMV.Vector3 ComputeLinksetGeometricCenter()
+    protected virtual OMV.Vector3 ComputeLinksetGeometricCenter()
     {
-        OMV.Vector3 com = m_linksetRoot.Position;
-
+        OMV.Vector3 com;
         lock (m_linksetActivityLock)
         {
-            foreach (BSPrim bp in m_children)
+            com = LinksetRoot.Position;
+
+            foreach (BSPhysObject bp in m_taintChildren)
             {
                 com += bp.Position * bp.MassRaw;
             }
-            com /= (m_children.Count + 1);
+            com /= (m_taintChildren.Count + 1);
         }
 
         return com;
     }
 
-    // When physical properties are changed the linkset needs to recalculate
-    //   its internal properties.
-    public void Refresh(BSPrim requestor)
-    {
-        // If there are no children, there aren't any constraints to recompute
-        if (!HasAnyChildren)
-            return;
-
-        // Only the root does the recomputation
-        if (IsRoot(requestor))
-        {
-            PhysicsScene.TaintedObject("BSLinkSet.Refresh", delegate()
-            {
-                RecomputeLinksetConstraintVariables();
-            });
-        }
-    }
-
-    // Call each of the constraints that make up this linkset and recompute the
-    //    various transforms and variables. Used when objects are added or removed
-    //    from a linkset to make sure the constraints know about the new mass and
-    //    geometry.
-    // Must only be called at taint time!!
-    private bool RecomputeLinksetConstraintVariables()
-    {
-        float linksetMass = LinksetMass;
-        lock (m_linksetActivityLock)
-        {
-            foreach (BSPrim child in m_children)
-            {
-                BSConstraint constrain;
-                if (m_physicsScene.Constraints.TryGetConstraint(LinksetRoot.Body, child.Body, out constrain))
-                {
-                    // DetailLog("{0},BSLinkset.RecomputeLinksetConstraintVariables,taint,child={1},mass={2},A={3},B={4}", 
-                    //         LinksetRoot.LocalID, child.LocalID, linksetMass, constrain.Body1.ID, constrain.Body2.ID);
-                    constrain.RecomputeConstraintVariables(linksetMass);
-                }
-                else
-                {
-                    // Non-fatal error that can happen when children are being added to the linkset but
-                    //    their constraints have not been created yet.
-                    // Caused by the fact that m_children is built at run time but building constraints
-                    //    happens at taint time.
-                    // m_physicsScene.Logger.ErrorFormat("[BULLETSIM LINKSET] RecomputeLinksetConstraintVariables: constraint not found for root={0}, child={1}",
-                    //                                 m_linksetRoot.Body.ID, child.Body.ID);
-                }
-            }
-        }
-        return false;
-    }
-
     // I am the root of a linkset and a new child is being added
     // Called while LinkActivity is locked.
-    private void AddChildToLinkset(BSPrim child)
-    {
-        if (!HasChild(child))
-        {
-            m_children.Add(child);
-
-            BSPrim rootx = LinksetRoot; // capture the root as of now
-            BSPrim childx = child;
-            m_physicsScene.TaintedObject("AddChildToLinkset", delegate()
-            {
-                // DebugLog("{0}: AddChildToLinkset: adding child {1} to {2}", LogHeader, child.LocalID, m_linksetRoot.LocalID);
-                // DetailLog("{0},AddChildToLinkset,taint,child={1}", m_linksetRoot.LocalID, child.LocalID);
-                PhysicallyLinkAChildToRoot(rootx, childx);     // build the physical binding between me and the child
-            });
-        }
-        return;
-    }
+    protected abstract void AddChildToLinkset(BSPhysObject child);
 
     // Forcefully removing a child from a linkset.
     // This is not being called by the child so we have to make sure the child doesn't think
     //    it's still connected to the linkset.
     // Normal OpenSimulator operation will never do this because other SceneObjectPart information
-    //    has to be updated also (like pointer to prim's parent).
-    private void RemoveChildFromOtherLinkset(BSPrim pchild)
-    {
-        pchild.Linkset = new BSLinkset(m_physicsScene, pchild);
-        RemoveChildFromLinkset(pchild);
-    }
+    //    also has to be updated (like pointer to prim's parent).
+    protected abstract void RemoveChildFromOtherLinkset(BSPhysObject pchild);
 
     // 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.
-    private void RemoveChildFromLinkset(BSPrim child)
-    {
-        if (m_children.Remove(child))
-        {
-            BSPrim rootx = LinksetRoot; // capture the root as of now
-            BSPrim childx = child;
-            m_physicsScene.TaintedObject("RemoveChildFromLinkset", delegate()
-            {
-                // DebugLog("{0}: RemoveChildFromLinkset: Removing constraint to {1}", LogHeader, child.LocalID);
-                // DetailLog("{0},RemoveChildFromLinkset,taint,child={1}", m_linksetRoot.LocalID, child.LocalID);
-
-                PhysicallyUnlinkAChildFromRoot(rootx, childx);
-            });
-
-            RecomputeLinksetConstraintVariables();
-        }
-        else
-        {
-            // This will happen if we remove the root of the linkset first. Non-fatal occurance.
-            // PhysicsScene.Logger.ErrorFormat("{0}: Asked to remove child from linkset that was not in linkset", LogHeader);
-        }
-        return;
-    }
-
-    // Create a constraint between me (root of linkset) and the passed prim (the child).
-    // Called at taint time!
-    private void PhysicallyLinkAChildToRoot(BSPrim rootPrim, BSPrim childPrim)
-    {
-        // Zero motion for children so they don't interpolate
-        childPrim.ZeroMotion();
-
-        // Relative position normalized to the root prim
-        // Essentually a vector pointing from center of rootPrim to center of childPrim
-        OMV.Vector3 childRelativePosition = childPrim.Position - rootPrim.Position;
-
-        // real world coordinate of midpoint between the two objects
-        OMV.Vector3 midPoint = rootPrim.Position + (childRelativePosition / 2);
-
-        // create a constraint that allows no freedom of movement between the two objects
-        // http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?t=4818
-        // DebugLog("{0}: CreateLinkset: Adding a constraint between root prim {1} and child prim {2}", LogHeader, LocalID, childPrim.LocalID);
-        DetailLog("{0},PhysicallyLinkAChildToRoot,taint,root={1},child={2},rLoc={3},cLoc={4},midLoc={5}", 
-            rootPrim.LocalID, rootPrim.LocalID, childPrim.LocalID, rootPrim.Position, childPrim.Position, midPoint);
-        BS6DofConstraint constrain = new BS6DofConstraint(
-                        m_physicsScene.World, rootPrim.Body, childPrim.Body,
-                        midPoint,
-                        true,
-                        true
-                        );
-        /* NOTE: attempt to build constraint with full frame computation, etc.
-         *     Using the midpoint is easier since it lets the Bullet code use the transforms
-         *     of the objects.
-         * Code left here as an example.
-        // ==================================================================================
-        // relative position normalized to the root prim
-        OMV.Quaternion invThisOrientation = OMV.Quaternion.Inverse(rootPrim.Orientation);
-        OMV.Vector3 childRelativePosition = (childPrim.Position - rootPrim.Position) * invThisOrientation;
-
-        // relative rotation of the child to the parent
-        OMV.Quaternion childRelativeRotation = invThisOrientation * childPrim.Orientation;
-        OMV.Quaternion inverseChildRelativeRotation = OMV.Quaternion.Inverse(childRelativeRotation);
-
-        // create a constraint that allows no freedom of movement between the two objects
-        // http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?t=4818
-        // DebugLog("{0}: CreateLinkset: Adding a constraint between root prim {1} and child prim {2}", LogHeader, LocalID, childPrim.LocalID);
-        DetailLog("{0},PhysicallyLinkAChildToRoot,taint,root={1},child={2}", rootPrim.LocalID, rootPrim.LocalID, childPrim.LocalID);
-        BS6DofConstraint constrain = new BS6DofConstraint(
-                        PhysicsScene.World, rootPrim.Body, childPrim.Body,
-                        OMV.Vector3.Zero,
-                        OMV.Quaternion.Inverse(rootPrim.Orientation),
-                        OMV.Vector3.Zero,
-                        OMV.Quaternion.Inverse(childPrim.Orientation),
-                        // A point half way between the parent and child
-                        // childRelativePosition/2,
-                        // childRelativeRotation,
-                        // childRelativePosition/2,
-                        // inverseChildRelativeRotation,
-                        true,
-                        true
-                        );
-        // ==================================================================================
-        */
-
-        m_physicsScene.Constraints.AddConstraint(constrain);
-
-        // zero linear and angular limits makes the objects unable to move in relation to each other
-        constrain.SetLinearLimits(OMV.Vector3.Zero, OMV.Vector3.Zero);
-        constrain.SetAngularLimits(OMV.Vector3.Zero, OMV.Vector3.Zero);
-
-        // tweek the constraint to increase stability
-        constrain.UseFrameOffset(PhysicsScene.BoolNumeric(PhysicsScene.Params.linkConstraintUseFrameOffset));
-        constrain.TranslationalLimitMotor(PhysicsScene.BoolNumeric(PhysicsScene.Params.linkConstraintEnableTransMotor),
-                        PhysicsScene.Params.linkConstraintTransMotorMaxVel,
-                        PhysicsScene.Params.linkConstraintTransMotorMaxForce);
-        constrain.SetCFMAndERP(PhysicsScene.Params.linkConstraintCFM, PhysicsScene.Params.linkConstraintERP);
-
-        RecomputeLinksetConstraintVariables();
-    }
-
-    // Remove linkage between myself and a particular child
-    // Called at taint time!
-    private void PhysicallyUnlinkAChildFromRoot(BSPrim rootPrim, BSPrim childPrim)
-    {
-        // DebugLog("{0}: PhysicallyUnlinkAChildFromRoot: RemoveConstraint between root prim {1} and child prim {2}", 
-        //             LogHeader, rootPrim.LocalID, childPrim.LocalID);
-        DetailLog("{0},PhysicallyUnlinkAChildFromRoot,taint,root={1},child={2}", rootPrim.LocalID, rootPrim.LocalID, childPrim.LocalID);
-
-        // Find the constraint for this link and get rid of it from the overall collection and from my list
-        m_physicsScene.Constraints.RemoveAndDestroyConstraint(rootPrim.Body, childPrim.Body);
-
-        // Make the child refresh its location
-        BulletSimAPI.PushUpdate2(childPrim.Body.Ptr);
-    }
-
-    // Remove linkage between myself and any possible children I might have
-    // Called at taint time!
-    private void PhysicallyUnlinkAllChildrenFromRoot(BSPrim rootPrim)
-    {
-        // DebugLog("{0}: PhysicallyUnlinkAllChildren:", LogHeader);
-        DetailLog("{0},PhysicallyUnlinkAllChildren,taint", rootPrim.LocalID);
-
-        m_physicsScene.Constraints.RemoveAndDestroyConstraint(rootPrim.Body);
-    }
-
-    // Invoke the detailed logger and output something if it's enabled.
-    private void DebugLog(string msg, params Object[] args)
-    {
-        if (m_physicsScene.ShouldDebugLog)
-            m_physicsScene.Logger.DebugFormat(msg, args);
-    }
+    protected abstract void RemoveChildFromLinkset(BSPhysObject child);
 
     // Invoke the detailed logger and output something if it's enabled.
-    private void DetailLog(string msg, params Object[] args)
+    protected void DetailLog(string msg, params Object[] args)
     {
-        m_physicsScene.PhysicsLogging.Write(msg, args);
+        if (PhysicsScene.PhysicsLogging.Enabled)
+            PhysicsScene.DetailLog(msg, args);
     }
 
 }