* Created a way that the OpenSimulator scene can ask the physics scene to do a raycast test safely.

* Test for prim obstructions between the avatar and camera.  If there are obstructions, inform the client to move the camera closer.  This makes it so that walls and objects don't obstruct your view while you're moving around.   Try walking inside a hollowed tori.   You'll see how much easier it is now because your camera automatically moves closer so you can still see.
* Created a way to know if the user's camera is alt + cammed or just following the avatar.
* Changes IClientAPI interface by adding SendCameraConstraint(Vector4 CameraConstraint)

2 files changed, 317 insertions, 1 deletions

diff --git a/OpenSim/Region/Physics/OdePlugin/ODERayCastRequestManager.cs b/OpenSim/Region/Physics/OdePlugin/ODERayCastRequestManager.cs
new file mode 100644
index 0000000..3a4bb02
--- /dev/null
+++ b/OpenSim/Region/Physics/OdePlugin/ODERayCastRequestManager.cs
@@ -0,0 +1,295 @@
+/*
+ * 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 copyright
+ *       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.Reflection;
+using System.Runtime.InteropServices;
+using System.Text;
+using OpenMetaverse;
+using OpenSim.Region.Physics.Manager;
+using Ode.NET;
+using log4net;
+
+namespace OpenSim.Region.Physics.OdePlugin
+{
+    /// <summary>
+    /// Processes raycast requests as ODE is in a state to be able to do them.
+    /// This ensures that it's thread safe and there will be no conflicts.
+    /// Requests get returned by a different thread then they were requested by.
+    /// </summary>
+    public class ODERayCastRequestManager
+    {
+        /// <summary>
+        /// Pending Raycast Requests
+        /// </summary>
+        protected List<ODERayCastRequest> m_PendingRequests = new List<ODERayCastRequest>();
+
+        /// <summary>
+        /// Scene that created this object.
+        /// </summary>
+        private OdeScene m_scene;
+
+        /// <summary>
+        /// ODE contact array to be filled by the collision testing
+        /// </summary>
+        d.ContactGeom[] contacts = new d.ContactGeom[5];
+
+        /// <summary>
+        /// ODE near callback delegate
+        /// </summary>
+        private d.NearCallback nearCallback;
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+        private List<ContactResult> m_contactResults = new List<ContactResult>();
+
+
+        public ODERayCastRequestManager( OdeScene pScene)
+        {
+            m_scene = pScene;
+            nearCallback = near;
+            
+        }
+
+        /// <summary>
+        /// Queues a raycast
+        /// </summary>
+        /// <param name="position">Origin of Ray</param>
+        /// <param name="direction">Ray normal</param>
+        /// <param name="length">Ray length</param>
+        /// <param name="retMethod">Return method to send the results</param>
+        public void QueueRequest(Vector3 position, Vector3 direction, float length, RaycastCallback retMethod)
+        {
+            lock (m_PendingRequests)
+            {
+                ODERayCastRequest req = new ODERayCastRequest();
+                req.callbackMethod = retMethod;
+                req.length = length;
+                req.Normal = direction;
+                req.Origin = position;
+
+                m_PendingRequests.Add(req);
+            }
+        }
+
+        /// <summary>
+        /// Process all queued raycast requests
+        /// </summary>
+        /// <returns>Time in MS the raycasts took to process.</returns>
+        public int ProcessQueuedRequests()
+        {
+            int time = System.Environment.TickCount;
+            lock (m_PendingRequests)
+            {
+                if (m_PendingRequests.Count > 0)
+                {
+                    foreach (ODERayCastRequest req in m_PendingRequests)
+                    {
+                        if (req.callbackMethod != null) // quick optimization here, don't raycast 
+                            RayCast(req);               // if there isn't anyone to send results to
+                            
+                    }
+
+                    m_PendingRequests.Clear();
+                }
+            }
+
+            lock (m_contactResults)
+                m_contactResults.Clear();
+
+            return System.Environment.TickCount - time;
+        }
+
+        /// <summary>
+        /// Method that actually initiates the raycast
+        /// </summary>
+        /// <param name="req"></param>
+        private void RayCast(ODERayCastRequest req)
+        {
+            // Create the ray
+            IntPtr ray = d.CreateRay(m_scene.space, req.length);
+            d.GeomRaySet(ray, req.Origin.X, req.Origin.Y, req.Origin.Z, req.Normal.X, req.Normal.Y, req.Normal.Z);
+
+            // Collide test
+            d.SpaceCollide2(m_scene.space, ray, IntPtr.Zero, nearCallback);
+
+            // Remove Ray
+            d.GeomDestroy(ray);
+
+
+            // Define default results
+            bool hitYN = false;
+            uint hitConsumerID = 0;
+            float distance = 999999999999f;
+            Vector3 closestcontact = new Vector3(99999f, 99999f, 99999f);
+
+            // Find closest contact and object.
+            lock (m_contactResults)
+            {
+                foreach(ContactResult cResult in m_contactResults)
+                {
+                    if (Vector3.Distance(req.Origin, cResult.Pos) < Vector3.Distance(req.Origin, closestcontact))
+                    {
+                        closestcontact = cResult.Pos;
+                        hitConsumerID = cResult.ConsumerID;
+                        distance = cResult.Depth;
+                        hitYN = true;
+                    }
+                }
+
+                m_contactResults.Clear();
+            }
+
+            // Return results
+            if (req.callbackMethod != null)
+                req.callbackMethod(hitYN, closestcontact, hitConsumerID, distance);
+        }
+
+        // This is the standard Near.   Uses space AABBs to speed up detection.
+        private void near(IntPtr space, IntPtr g1, IntPtr g2)
+        {
+            // Raytest against AABBs of spaces first, then dig into the spaces it hits for actual geoms.
+            if (d.GeomIsSpace(g1) || d.GeomIsSpace(g2))
+            {
+                if (g1 == IntPtr.Zero || g2 == IntPtr.Zero)
+                    return;
+                
+                // Separating static prim geometry spaces.
+                // We'll be calling near recursivly if one
+                // of them is a space to find all of the
+                // contact points in the space
+                try
+                {
+                    d.SpaceCollide2(g1, g2, IntPtr.Zero, nearCallback);
+                }
+                catch (AccessViolationException)
+                {
+                    m_log.Warn("[PHYSICS]: Unable to collide test a space");
+                    return;
+                }
+                //Colliding a space or a geom with a space or a geom. so drill down
+
+                //Collide all geoms in each space..
+                //if (d.GeomIsSpace(g1)) d.SpaceCollide(g1, IntPtr.Zero, nearCallback);
+                //if (d.GeomIsSpace(g2)) d.SpaceCollide(g2, IntPtr.Zero, nearCallback);
+                return;
+            }
+
+            if (g1 == IntPtr.Zero || g2 == IntPtr.Zero)
+                return;
+
+            int count = 0;
+            try
+            {
+                
+                if (g1 == g2)
+                    return; // Can't collide with yourself
+
+                lock (contacts)
+                {
+                    count = d.Collide(g1, g2, contacts.GetLength(0), contacts, d.ContactGeom.SizeOf);
+                }
+            }
+            catch (SEHException)
+            {
+                m_log.Error("[PHYSICS]: The Operating system shut down ODE because of corrupt memory.  This could be a result of really irregular terrain.  If this repeats continuously, restart using Basic Physics and terrain fill your terrain.  Restarting the sim.");
+            }
+            catch (Exception e)
+            {
+                m_log.WarnFormat("[PHYSICS]: Unable to collide test an object: {0}", e.Message);
+                return;
+            }
+
+            PhysicsActor p1 = null;
+            PhysicsActor p2 = null;
+
+            if (g1 != IntPtr.Zero)
+                m_scene.actor_name_map.TryGetValue(g1, out p1);
+
+            if (g2 != IntPtr.Zero)
+                m_scene.actor_name_map.TryGetValue(g1, out p2);
+
+            // Loop over contacts, build results.
+            for (int i = 0; i < count; i++)
+            {
+                if (p1 != null) { 
+                    if (p1 is OdePrim)
+                    {
+                        ContactResult collisionresult = new ContactResult();
+                    
+                        collisionresult.ConsumerID = ((OdePrim)p1).m_localID;
+                        collisionresult.Pos = new Vector3(contacts[i].pos.X, contacts[i].pos.Y, contacts[i].pos.Z);
+                        collisionresult.Depth = contacts[i].depth;
+                        
+                        lock (m_contactResults)
+                            m_contactResults.Add(collisionresult);
+                    }
+                }
+
+                if (p2 != null)
+                {
+                    if (p2 is OdePrim)
+                    {
+                        ContactResult collisionresult = new ContactResult();
+
+                        collisionresult.ConsumerID = ((OdePrim)p2).m_localID;
+                        collisionresult.Pos = new Vector3(contacts[i].pos.X, contacts[i].pos.Y, contacts[i].pos.Z);
+                        collisionresult.Depth = contacts[i].depth;
+
+                        lock (m_contactResults)
+                            m_contactResults.Add(collisionresult);
+                    }
+                }
+
+                
+            }
+
+        }
+
+        /// <summary>
+        /// Dereference the creator scene so that it can be garbage collected if needed.
+        /// </summary>
+        internal void Dispose()
+        {
+            m_scene = null;
+        }
+    }
+
+    public struct ODERayCastRequest
+    {
+        public Vector3 Origin;
+        public Vector3 Normal;
+        public float length;
+        public RaycastCallback callbackMethod;
+    }
+
+    public struct ContactResult
+    {
+        public Vector3 Pos;
+        public float Depth;
+        public uint ConsumerID;
+    }
+}
diff --git a/OpenSim/Region/Physics/OdePlugin/OdePlugin.cs b/OpenSim/Region/Physics/OdePlugin/OdePlugin.cs
index 889afb6..87357a3 100644
--- a/OpenSim/Region/Physics/OdePlugin/OdePlugin.cs
+++ b/OpenSim/Region/Physics/OdePlugin/OdePlugin.cs
@@ -306,6 +306,8 @@ namespace OpenSim.Region.Physics.OdePlugin
 
         private volatile int m_global_contactcount = 0;
 
+        private ODERayCastRequestManager m_rayCastManager;
+
         /// <summary>
         /// Initiailizes the scene
         /// Sets many properties that ODE requires to be stable
@@ -321,7 +323,7 @@ namespace OpenSim.Region.Physics.OdePlugin
             nearCallback = near;
             triCallback = TriCallback;
             triArrayCallback = TriArrayCallback;
-
+            m_rayCastManager = new ODERayCastRequestManager(this);
             lock (OdeLock)
             {
                 // Create the world and the first space
@@ -2833,6 +2835,8 @@ namespace OpenSim.Region.Physics.OdePlugin
                                 //if ((framecount % m_randomizeWater) == 0)
                                    // randomizeWater(waterlevel);
 
+                                int RayCastTimeMS = m_rayCastManager.ProcessQueuedRequests();
+
                                 collision_optimized(timeStep);
 
                                 lock (_collisionEventPrim)
@@ -3377,6 +3381,9 @@ namespace OpenSim.Region.Physics.OdePlugin
 
         public override void Dispose()
         {
+            m_rayCastManager.Dispose();
+            m_rayCastManager = null;
+
             lock (OdeLock)
             {
                 lock (_prims)
@@ -3417,6 +3424,20 @@ namespace OpenSim.Region.Physics.OdePlugin
             }
             return returncolliders;
         }
+
+        public override bool SupportsRayCast()
+        {
+            return true;
+        }
+
+        public override void RaycastWorld(Vector3 position, Vector3 direction, float length, RaycastCallback retMethod)
+        {
+            if (retMethod != null)
+            {
+                m_rayCastManager.QueueRequest(position, direction, length, retMethod);
+            }
+        }
+
 #if USE_DRAWSTUFF
         // Keyboard callback
         public void command(int cmd)