Parameterizes the view distance used to compute and manage

child agents in neighbor regions. This means you can extend
the view on a simulator beyond the default 3x3 regions.

This uses a region default draw distance and should be
replaced at some point by the avatar specified draw distance.
That will require more careful, dynamic recomputation of child
agents every time the draw distance changes.

WARNING: this is experimental and has known instabilities. specifically
all regions "within site" should be running the same default draw distance
or agents will not be closed correctly.

2 files changed, 28 insertions, 13 deletions

diff --git a/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs b/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
index 98aa563..95c771e 100644
--- a/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
+++ b/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
@@ -318,7 +318,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                     agentCircuit.Id0 = currentAgentCircuit.Id0;
                 }
 
-                if (NeedsNewAgent(oldRegionX, newRegionX, oldRegionY, newRegionY))
+                if (NeedsNewAgent(sp.DrawDistance, oldRegionX, newRegionX, oldRegionY, newRegionY))
                 {
                     // brand new agent, let's create a new caps seed
                     agentCircuit.CapsPath = CapsUtil.GetRandomCapsObjectPath();
@@ -336,7 +336,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                 // OK, it got this agent. Let's close some child agents
                 sp.CloseChildAgents(newRegionX, newRegionY);
                 IClientIPEndpoint ipepClient;  
-                if (NeedsNewAgent(oldRegionX, newRegionX, oldRegionY, newRegionY))
+                if (NeedsNewAgent(sp.DrawDistance, oldRegionX, newRegionX, oldRegionY, newRegionY))
                 {
                     //sp.ControllingClient.SendTeleportProgress(teleportFlags, "Creating agent...");
                     #region IP Translation for NAT
@@ -447,7 +447,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
 
                 // Finally, let's close this previously-known-as-root agent, when the jump is outside the view zone
 
-                if (NeedsClosing(oldRegionX, newRegionX, oldRegionY, newRegionY, reg))
+                if (NeedsClosing(sp.DrawDistance, oldRegionX, newRegionX, oldRegionY, newRegionY, reg))
                 {
                     Thread.Sleep(5000);
                     sp.Close();
@@ -521,14 +521,14 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
             return region;
         }
 
-        protected virtual bool NeedsNewAgent(uint oldRegionX, uint newRegionX, uint oldRegionY, uint newRegionY)
+        protected virtual bool NeedsNewAgent(float drawdist, uint oldRegionX, uint newRegionX, uint oldRegionY, uint newRegionY)
         {
-            return Util.IsOutsideView(oldRegionX, newRegionX, oldRegionY, newRegionY);
+            return Util.IsOutsideView(drawdist, oldRegionX, newRegionX, oldRegionY, newRegionY);
         }
 
-        protected virtual bool NeedsClosing(uint oldRegionX, uint newRegionX, uint oldRegionY, uint newRegionY, GridRegion reg)
+        protected virtual bool NeedsClosing(float drawdist, uint oldRegionX, uint newRegionX, uint oldRegionY, uint newRegionY, GridRegion reg)
         {
-            return Util.IsOutsideView(oldRegionX, newRegionX, oldRegionY, newRegionY);
+            return Util.IsOutsideView(drawdist, oldRegionX, newRegionX, oldRegionY, newRegionY);
         }
 
         protected virtual bool IsOutsideRegion(Scene s, Vector3 pos)
@@ -1045,7 +1045,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
 
             if (m_regionInfo != null)
             {
-                neighbours = RequestNeighbours(sp.Scene, m_regionInfo.RegionLocX, m_regionInfo.RegionLocY);
+                neighbours = RequestNeighbours(sp, m_regionInfo.RegionLocX, m_regionInfo.RegionLocY);
             }
             else
             {
@@ -1272,8 +1272,9 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
         /// <param name="pRegionLocX"></param>
         /// <param name="pRegionLocY"></param>
         /// <returns></returns>        
-        protected List<GridRegion> RequestNeighbours(Scene pScene, uint pRegionLocX, uint pRegionLocY)
+        protected List<GridRegion> RequestNeighbours(ScenePresence avatar, uint pRegionLocX, uint pRegionLocY)
         {
+            Scene pScene = avatar.Scene;
             RegionInfo m_regionInfo = pScene.RegionInfo;
 
             Border[] northBorders = pScene.NorthBorders.ToArray();
@@ -1281,10 +1282,24 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
             Border[] eastBorders = pScene.EastBorders.ToArray();
             Border[] westBorders = pScene.WestBorders.ToArray();
 
-            // Legacy one region.  Provided for simplicity while testing the all inclusive method in the else statement.
+            // Leaving this as a "megaregions" computation vs "non-megaregions" computation; it isn't
+            // clear what should be done with a "far view" given that megaregions already extended the
+            // view to include everything in the megaregion
             if (northBorders.Length <= 1 && southBorders.Length <= 1 && eastBorders.Length <= 1 && westBorders.Length <= 1)
             {
-                return pScene.GridService.GetNeighbours(m_regionInfo.ScopeID, m_regionInfo.RegionID);
+                int dd = avatar.DrawDistance < Constants.RegionSize ? (int)Constants.RegionSize : (int)avatar.DrawDistance;
+
+                int startX = (int)pRegionLocX * (int)Constants.RegionSize - dd + (int)(Constants.RegionSize/2);
+                int startY = (int)pRegionLocY * (int)Constants.RegionSize - dd + (int)(Constants.RegionSize/2);
+
+                int endX = (int)pRegionLocX * (int)Constants.RegionSize + dd + (int)(Constants.RegionSize/2);
+                int endY = (int)pRegionLocY * (int)Constants.RegionSize + dd + (int)(Constants.RegionSize/2);
+
+                List<GridRegion> neighbours =
+                    avatar.Scene.GridService.GetRegionRange(m_regionInfo.ScopeID, startX, endX, startY, endY);
+
+                neighbours.RemoveAll(delegate(GridRegion r) { return r.RegionID == m_regionInfo.RegionID; });
+                return neighbours;
             }
             else
             {
diff --git a/OpenSim/Region/CoreModules/Framework/EntityTransfer/HGEntityTransferModule.cs b/OpenSim/Region/CoreModules/Framework/EntityTransfer/HGEntityTransferModule.cs
index 35dcd95..79e76b4 100644
--- a/OpenSim/Region/CoreModules/Framework/EntityTransfer/HGEntityTransferModule.cs
+++ b/OpenSim/Region/CoreModules/Framework/EntityTransfer/HGEntityTransferModule.cs
@@ -130,9 +130,9 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
             return region;
         }
 
-        protected override bool NeedsClosing(uint oldRegionX, uint newRegionX, uint oldRegionY, uint newRegionY, GridRegion reg)
+        protected override bool NeedsClosing(float drawdist, uint oldRegionX, uint newRegionX, uint oldRegionY, uint newRegionY, GridRegion reg)
         {
-            if (base.NeedsClosing(oldRegionX, newRegionX, oldRegionY, newRegionY, reg))
+            if (base.NeedsClosing(drawdist, oldRegionX, newRegionX, oldRegionY, newRegionY, reg))
                 return true;
 
             int flags = m_aScene.GridService.GetRegionFlags(m_aScene.RegionInfo.ScopeID, reg.RegionID);