* 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, 396 insertions, 0 deletions

diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSLinksetCompound.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSLinksetCompound.cs
new file mode 100644
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--- /dev/null
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSLinksetCompound.cs
@@ -0,0 +1,396 @@
+/*
+ * 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 OpenSim.Framework;
+
+using OMV = OpenMetaverse;
+
+namespace OpenSim.Region.Physics.BulletSNPlugin
+{
+
+// When a child is linked, the relationship position of the child to the parent
+//    is remembered so the child's world position can be recomputed when it is
+//    removed from the linkset.
+sealed class BSLinksetCompoundInfo : BSLinksetInfo
+{
+    public OMV.Vector3 OffsetPos;
+    public OMV.Quaternion OffsetRot;
+    public BSLinksetCompoundInfo(OMV.Vector3 p, OMV.Quaternion r)
+    {
+        OffsetPos = p;
+        OffsetRot = r;
+    }
+    public override void Clear()
+    {
+        OffsetPos = OMV.Vector3.Zero;
+        OffsetRot = OMV.Quaternion.Identity;
+    }
+    public override string ToString()
+    {
+        StringBuilder buff = new StringBuilder();
+        buff.Append("<p=");
+        buff.Append(OffsetPos.ToString());
+        buff.Append(",r=");
+        buff.Append(OffsetRot.ToString());
+        buff.Append(">");
+        return buff.ToString();
+    }
+};
+
+public sealed class BSLinksetCompound : BSLinkset
+{
+    private static string LogHeader = "[BULLETSIM LINKSET COMPOUND]";
+
+    public BSLinksetCompound(BSScene scene, BSPhysObject parent) : base(scene, parent)
+    {
+    }
+
+    // For compound implimented linksets, if there are children, use compound shape for the root.
+    public override BSPhysicsShapeType PreferredPhysicalShape(BSPhysObject requestor)
+    { 
+        // Returning 'unknown' means we don't have a preference.
+        BSPhysicsShapeType ret = BSPhysicsShapeType.SHAPE_UNKNOWN;
+        if (IsRoot(requestor) && HasAnyChildren)
+        {
+            ret = BSPhysicsShapeType.SHAPE_COMPOUND;
+        }
+        // DetailLog("{0},BSLinksetCompound.PreferredPhysicalShape,call,shape={1}", LinksetRoot.LocalID, ret);
+        return ret;
+    }
+
+    // When physical properties are changed the linkset needs to recalculate
+    //   its internal properties.
+    public override void Refresh(BSPhysObject requestor)
+    {
+        // Something changed so do the rebuilding thing
+        // ScheduleRebuild();
+    }
+
+    // Schedule a refresh to happen after all the other taint processing.
+    private void ScheduleRebuild(BSPhysObject requestor)
+    {
+        DetailLog("{0},BSLinksetCompound.Refresh,schedulingRefresh,rebuilding={1}", 
+                            requestor.LocalID, Rebuilding);
+        // When rebuilding, it is possible to set properties that would normally require a rebuild.
+        //    If already rebuilding, don't request another rebuild.
+        if (!Rebuilding)
+        {
+            PhysicsScene.PostTaintObject("BSLinksetCompound.Refresh", LinksetRoot.LocalID, delegate()
+            {
+                if (HasAnyChildren)
+                    RecomputeLinksetCompound();
+            });
+        }
+    }
+
+    // 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 override bool MakeDynamic(BSPhysObject child)
+    {
+        bool ret = false;
+        DetailLog("{0},BSLinksetCompound.MakeDynamic,call,IsRoot={1}", child.LocalID, IsRoot(child));
+        if (IsRoot(child))
+        {
+            // The root is going dynamic. Make sure mass is properly set.
+            m_mass = ComputeLinksetMass();
+            ScheduleRebuild(LinksetRoot);
+        }
+        else
+        {
+            // The origional prims are removed from the world as the shape of the root compound
+            //     shape takes over.
+            BulletSimAPI.AddToCollisionFlags2(child.PhysBody.ptr, CollisionFlags.CF_NO_CONTACT_RESPONSE);
+            BulletSimAPI.ForceActivationState2(child.PhysBody.ptr, ActivationState.DISABLE_SIMULATION);
+            // We don't want collisions from the old linkset children.
+            BulletSimAPI.RemoveFromCollisionFlags2(child.PhysBody.ptr, CollisionFlags.BS_SUBSCRIBE_COLLISION_EVENTS);
+
+            child.PhysBody.collisionType = CollisionType.LinksetChild;
+
+            ret = true;
+        }
+        return ret;
+    }
+
+    // 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.
+    // This doesn't normally happen -- OpenSim removes the objects from the physical
+    //     world if it is a static linkset.
+    // Called at taint-time!
+    public override bool MakeStatic(BSPhysObject child)
+    {
+        bool ret = false;
+        DetailLog("{0},BSLinksetCompound.MakeStatic,call,IsRoot={1}", child.LocalID, IsRoot(child));
+        if (IsRoot(child))
+        {
+            ScheduleRebuild(LinksetRoot);
+        }
+        else
+        {
+            // The non-physical children can come back to life.
+            BulletSimAPI.RemoveFromCollisionFlags2(child.PhysBody.ptr, CollisionFlags.CF_NO_CONTACT_RESPONSE);
+
+            child.PhysBody.collisionType = CollisionType.LinksetChild;
+
+            // Don't force activation so setting of DISABLE_SIMULATION can stay if used.
+            BulletSimAPI.Activate2(child.PhysBody.ptr, false);
+            ret = true;
+        }
+        return ret;
+    }
+
+    public override void UpdateProperties(BSPhysObject updated, bool physicalUpdate)
+    {
+        // The user moving a child around requires the rebuilding of the linkset compound shape
+        // One problem is this happens when a border is crossed -- the simulator implementation
+        //    is to store the position into the group which causes the move of the object
+        //    but it also means all the child positions get updated.
+        //    What would cause an unnecessary rebuild so we make sure the linkset is in a
+        //    region before bothering to do a rebuild.
+        if (!IsRoot(updated) 
+                && !physicalUpdate 
+                && PhysicsScene.TerrainManager.IsWithinKnownTerrain(LinksetRoot.RawPosition))
+        {
+            updated.LinksetInfo = null;
+            ScheduleRebuild(updated);
+        }
+    }
+
+    // Routine called when rebuilding the body of some member of the linkset.
+    // Since we don't keep in world relationships, do nothing unless it's a child changing.
+    // Returns 'true' of something was actually removed and would need restoring
+    // Called at taint-time!!
+    public override bool RemoveBodyDependencies(BSPrim child)
+    {
+        bool ret = false;
+
+        DetailLog("{0},BSLinksetCompound.RemoveBodyDependencies,refreshIfChild,rID={1},rBody={2},isRoot={3}",
+                        child.LocalID, LinksetRoot.LocalID, LinksetRoot.PhysBody.ptr.ToString(), IsRoot(child));
+
+        if (!IsRoot(child))
+        {
+            // Because it is a convenient time, recompute child world position and rotation based on
+            //    its position in the linkset.
+            RecomputeChildWorldPosition(child, true);
+        }
+
+        // Cannot schedule a refresh/rebuild here because this routine is called when
+        //     the linkset is being rebuilt.
+        // InternalRefresh(LinksetRoot);
+
+        return ret;
+    }
+
+    // Companion to RemoveBodyDependencies(). If RemoveBodyDependencies() returns 'true',
+    //     this routine will restore the removed constraints.
+    // Called at taint-time!!
+    public override void RestoreBodyDependencies(BSPrim child)
+    {
+    }
+
+    // When the linkset is built, the child shape is added to the compound shape relative to the
+    //    root shape. The linkset then moves around but this does not move the actual child
+    //    prim. The child prim's location must be recomputed based on the location of the root shape.
+    private void RecomputeChildWorldPosition(BSPhysObject child, bool inTaintTime)
+    {
+        BSLinksetCompoundInfo lci = child.LinksetInfo as BSLinksetCompoundInfo;
+        if (lci != null)
+        {
+            if (inTaintTime)
+            {
+                OMV.Vector3 oldPos = child.RawPosition;
+                child.ForcePosition = LinksetRoot.RawPosition + lci.OffsetPos;
+                child.ForceOrientation = LinksetRoot.RawOrientation * lci.OffsetRot;
+                DetailLog("{0},BSLinksetCompound.RecomputeChildWorldPosition,oldPos={1},lci={2},newPos={3}",
+                                            child.LocalID, oldPos, lci, child.RawPosition);
+            }
+            else
+            {
+                // TaintedObject is not used here so the raw position is set now and not at taint-time.
+                child.Position = LinksetRoot.RawPosition + lci.OffsetPos;
+                child.Orientation = LinksetRoot.RawOrientation * lci.OffsetRot;
+            }
+        }
+        else
+        {
+            // This happens when children have been added to the linkset but the linkset
+            //     has not been constructed yet. So like, at taint time, adding children to a linkset
+            //     and then changing properties of the children (makePhysical, for instance)
+            //     but the post-print action of actually rebuilding the linkset has not yet happened.
+            // PhysicsScene.Logger.WarnFormat("{0} Restoring linkset child position failed because of no relative position computed. ID={1}",
+            //                                 LogHeader, child.LocalID);
+            DetailLog("{0},BSLinksetCompound.recomputeChildWorldPosition,noRelativePositonInfo", child.LocalID);
+        }
+    }
+
+    // ================================================================
+
+    // Add a new child to the linkset.
+    // Called while LinkActivity is locked.
+    protected override void AddChildToLinkset(BSPhysObject child)
+    {
+        if (!HasChild(child))
+        {
+            m_children.Add(child);
+
+            DetailLog("{0},BSLinksetCompound.AddChildToLinkset,call,child={1}", LinksetRoot.LocalID, child.LocalID);
+
+            // Rebuild the compound shape with the new child shape included
+            ScheduleRebuild(child);
+        }
+        return;
+    }
+
+    // Remove the specified child from the linkset.
+    // Safe to call even if the child is not really in the linkset.
+    protected override void RemoveChildFromLinkset(BSPhysObject child)
+    {
+        if (m_children.Remove(child))
+        {
+            DetailLog("{0},BSLinksetCompound.RemoveChildFromLinkset,call,rID={1},rBody={2},cID={3},cBody={4}",
+                            child.LocalID,
+                            LinksetRoot.LocalID, LinksetRoot.PhysBody.ptr.ToString(),
+                            child.LocalID, child.PhysBody.ptr.ToString());
+
+            // Cause the child's body to be rebuilt and thus restored to normal operation
+            RecomputeChildWorldPosition(child, false);
+            child.ForceBodyShapeRebuild(false);
+
+            if (!HasAnyChildren)
+            {
+                // The linkset is now empty. The root needs rebuilding.
+                LinksetRoot.ForceBodyShapeRebuild(false);
+            }
+            else
+            {
+                // Rebuild the compound shape with the child removed
+                ScheduleRebuild(child);
+            }
+        }
+        return;
+    }
+
+    // Called before the simulation step to make sure the compound based linkset
+    //    is all initialized.
+    // Constraint linksets are rebuilt every time.
+    // Note that this works for rebuilding just the root after a linkset is taken apart.
+    // Called at taint time!!
+    private void RecomputeLinksetCompound()
+    {
+        try
+        {
+            // Suppress rebuilding while rebuilding
+            Rebuilding = true;
+
+            // Cause the root shape to be rebuilt as a compound object with just the root in it
+            LinksetRoot.ForceBodyShapeRebuild(true);
+
+            DetailLog("{0},BSLinksetCompound.RecomputeLinksetCompound,start,rBody={1},rShape={2},numChildren={3}",
+                            LinksetRoot.LocalID, LinksetRoot.PhysBody, LinksetRoot.PhysShape, NumberOfChildren);
+
+            // Add a shape for each of the other children in the linkset
+            ForEachMember(delegate(BSPhysObject cPrim)
+            {
+                if (!IsRoot(cPrim))
+                {
+                    // Compute the displacement of the child from the root of the linkset.
+                    // This info is saved in the child prim so the relationship does not
+                    //    change over time and the new child position can be computed
+                    //    when the linkset is being disassembled (the linkset may have moved).
+                    BSLinksetCompoundInfo lci = cPrim.LinksetInfo as BSLinksetCompoundInfo;
+                    if (lci == null)
+                    {
+                        // Each child position and rotation is given relative to the root.
+                        OMV.Quaternion invRootOrientation = OMV.Quaternion.Inverse(LinksetRoot.RawOrientation);
+                        OMV.Vector3 displacementPos = (cPrim.RawPosition - LinksetRoot.RawPosition) * invRootOrientation;
+                        OMV.Quaternion displacementRot = cPrim.RawOrientation * invRootOrientation;
+
+                        // Save relative position for recomputing child's world position after moving linkset.
+                        lci = new BSLinksetCompoundInfo(displacementPos, displacementRot);
+                        cPrim.LinksetInfo = lci;
+                        DetailLog("{0},BSLinksetCompound.RecomputeLinksetCompound,creatingRelPos,lci={1}", cPrim.LocalID, lci);
+                    }
+
+                    DetailLog("{0},BSLinksetCompound.RecomputeLinksetCompound,addMemberToShape,mID={1},mShape={2},dispPos={3},dispRot={4}",
+                        LinksetRoot.LocalID, cPrim.LocalID, cPrim.PhysShape, lci.OffsetPos, lci.OffsetRot);
+
+                    if (cPrim.PhysShape.isNativeShape)
+                    {
+                        // A native shape is turning into a hull collision shape because native
+                        //    shapes are not shared so we have to hullify it so it will be tracked
+                        //    and freed at the correct time. This also solves the scaling problem
+                        //    (native shapes scaled but hull/meshes are assumed to not be).
+                        // TODO: decide of the native shape can just be used in the compound shape.
+                        //    Use call to CreateGeomNonSpecial().
+                        BulletShape saveShape = cPrim.PhysShape;
+                        cPrim.PhysShape.Clear();        // Don't let the create free the child's shape
+                        // PhysicsScene.Shapes.CreateGeomNonSpecial(true, cPrim, null);
+                        PhysicsScene.Shapes.CreateGeomMeshOrHull(cPrim, null);
+                        BulletShape newShape = cPrim.PhysShape;
+                        cPrim.PhysShape = saveShape;
+                        BulletSimAPI.AddChildShapeToCompoundShape2(LinksetRoot.PhysShape.ptr, newShape.ptr, lci.OffsetPos, lci.OffsetRot);
+                    }
+                    else
+                    {
+                        // For the shared shapes (meshes and hulls), just use the shape in the child.
+                        // The reference count added here will be decremented when the compound shape
+                        //     is destroyed in BSShapeCollection (the child shapes are looped over and dereferenced).
+                        if (PhysicsScene.Shapes.ReferenceShape(cPrim.PhysShape))
+                        {
+                            PhysicsScene.Logger.ErrorFormat("{0} Rebuilt sharable shape when building linkset! Region={1}, primID={2}, shape={3}",
+                                                LogHeader, PhysicsScene.RegionName, cPrim.LocalID, cPrim.PhysShape);
+                        }
+                        BulletSimAPI.AddChildShapeToCompoundShape2(LinksetRoot.PhysShape.ptr, cPrim.PhysShape.ptr, lci.OffsetPos, lci.OffsetRot);
+                    }
+                }
+                return false;   // 'false' says to move onto the next child in the list
+            });
+
+            // With all of the linkset packed into the root prim, it has the mass of everyone.
+            float linksetMass = LinksetMass;
+            LinksetRoot.UpdatePhysicalMassProperties(linksetMass);
+        }
+        finally
+        {
+            Rebuilding = false;
+        }
+
+        BulletSimAPI.RecalculateCompoundShapeLocalAabb2(LinksetRoot.PhysShape.ptr);
+
+        // DEBUG: see of inter-linkset collisions are causing problems for constraint linksets.
+        // BulletSimAPI.SetCollisionFilterMask2(LinksetRoot.BSBody.ptr, 
+        //                     (uint)CollisionFilterGroups.LinksetFilter, (uint)CollisionFilterGroups.LinksetMask);
+
+    }
+}
+}
\ No newline at end of file