Initial update to OpenSim 0.8.2.1 source code.

1 files changed, 613 insertions, 201 deletions

diff --git a/OpenSim/Region/CoreModules/World/Terrain/TerrainModule.cs b/OpenSim/Region/CoreModules/World/Terrain/TerrainModule.cs
index fd30c46..932652c 100644
--- a/OpenSim/Region/CoreModules/World/Terrain/TerrainModule.cs
+++ b/OpenSim/Region/CoreModules/World/Terrain/TerrainModule.cs
@@ -24,19 +24,24 @@
  * (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.IO;
 using System.Reflection;
 using System.Net;
+
 using log4net;
 using Nini.Config;
+
 using OpenMetaverse;
 using Mono.Addins;
+
+using OpenSim.Data;
 using OpenSim.Framework;
+using OpenSim.Framework.Console;
 using OpenSim.Region.CoreModules.Framework.InterfaceCommander;
 using OpenSim.Region.CoreModules.World.Terrain.FileLoaders;
+using OpenSim.Region.CoreModules.World.Terrain.Modifiers;
 using OpenSim.Region.CoreModules.World.Terrain.FloodBrushes;
 using OpenSim.Region.CoreModules.World.Terrain.PaintBrushes;
 using OpenSim.Region.Framework.Interfaces;
@@ -70,26 +75,112 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         #endregion
 
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
-        
-        private readonly Commander m_commander = new Commander("terrain");
 
+#pragma warning disable 414
+        private static readonly string LogHeader = "[TERRAIN MODULE]";
+#pragma warning restore 414
+
+        private readonly Commander m_commander = new Commander("terrain");
         private readonly Dictionary<StandardTerrainEffects, ITerrainFloodEffect> m_floodeffects =
             new Dictionary<StandardTerrainEffects, ITerrainFloodEffect>();
-
         private readonly Dictionary<string, ITerrainLoader> m_loaders = new Dictionary<string, ITerrainLoader>();
-
         private readonly Dictionary<StandardTerrainEffects, ITerrainPaintableEffect> m_painteffects =
             new Dictionary<StandardTerrainEffects, ITerrainPaintableEffect>();
-
-        private ITerrainChannel m_channel;
         private Dictionary<string, ITerrainEffect> m_plugineffects;
+        private Dictionary<string, ITerrainModifier> m_modifyOperations =
+            new Dictionary<string, ITerrainModifier>();
+        private ITerrainChannel m_channel;
         private ITerrainChannel m_revert;
         private Scene m_scene;
         private volatile bool m_tainted;
         private readonly Stack<LandUndoState> m_undo = new Stack<LandUndoState>(5);
-
         private String m_InitialTerrain = "pinhead-island";
 
+        // If true, send terrain patch updates to clients based on their view distance
+        private bool m_sendTerrainUpdatesByViewDistance = true;
+
+        // Class to keep the per client collection of terrain patches that must be sent.
+        // A patch is set to 'true' meaning it should be sent to the client. Once the
+        //    patch packet is queued to the client, the bit for that patch is set to 'false'.
+        private class PatchUpdates
+        {
+            private bool[,] updated;    // for each patch, whether it needs to be sent to this client
+            private int updateCount;    // number of patches that need to be sent
+            public ScenePresence Presence;   // a reference to the client to send to
+            public TerrainData Terrain; // reference to the underlying terrain
+            public PatchUpdates(TerrainData terrData, ScenePresence pPresence)
+            {
+                updated = new bool[terrData.SizeX / Constants.TerrainPatchSize, terrData.SizeY / Constants.TerrainPatchSize];
+                updateCount = 0;
+                Presence = pPresence;
+                Terrain = terrData;
+                // Initially, send all patches to the client
+                SetAll(true);
+            }
+            // Returns 'true' if there are any patches marked for sending
+            public bool HasUpdates()
+            {
+                return (updateCount > 0);
+            }
+
+            public void SetByXY(int x, int y, bool state)
+            {
+                this.SetByPatch(x / Constants.TerrainPatchSize, y / Constants.TerrainPatchSize, state);
+            }
+
+            public bool GetByPatch(int patchX, int patchY)
+            {
+                return updated[patchX, patchY];
+            }
+
+            public void SetByPatch(int patchX, int patchY, bool state)
+            {
+                bool prevState = updated[patchX, patchY];
+                if (!prevState && state)
+                    updateCount++;
+                if (prevState && !state)
+                    updateCount--;
+                updated[patchX, patchY] = state;
+            }
+
+            public void SetAll(bool state)
+            {
+                updateCount = 0;
+                for(int xx = 0; xx < updated.GetLength(0); xx++)
+                    for(int yy = 0; yy < updated.GetLength(1); yy++)
+                        updated[xx, yy] = state;
+                if (state)
+                    updateCount = updated.GetLength(0) * updated.GetLength(1);
+            }
+            // Logically OR's the terrain data's patch taint map into this client's update map.
+            public void SetAll(TerrainData terrData)
+            {
+                if (updated.GetLength(0) != (terrData.SizeX / Constants.TerrainPatchSize)
+                    || updated.GetLength(1) != (terrData.SizeY / Constants.TerrainPatchSize))
+                {
+                    throw new Exception(
+                        String.Format("{0} PatchUpdates.SetAll: patch array not same size as terrain. arr=<{1},{2}>, terr=<{3},{4}>",
+                                LogHeader, updated.GetLength(0), updated.GetLength(1),
+                                terrData.SizeX / Constants.TerrainPatchSize, terrData.SizeY / Constants.TerrainPatchSize)
+                    );
+                }
+                for(int xx = 0; xx < terrData.SizeX; xx += Constants.TerrainPatchSize)
+                {
+                    for(int yy = 0; yy < terrData.SizeY; yy += Constants.TerrainPatchSize)
+                    {
+                        // Only set tainted. The patch bit may be set if the patch was to be sent later.
+                        if (terrData.IsTaintedAt(xx, yy, false))
+                        {
+                            this.SetByXY(xx, yy, true);
+                        }
+                    }
+                }
+            }
+        }
+
+        // The flags of which terrain patches to send for each of the ScenePresence's
+        private Dictionary<UUID, PatchUpdates> m_perClientPatchUpdates = new Dictionary<UUID, PatchUpdates>();
+
         /// <summary>
         /// Human readable list of terrain file extensions that are supported.
         /// </summary>
@@ -100,8 +191,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
 
         #region ICommandableModule Members
 
-        public ICommander CommandInterface
-        {
+        public ICommander CommandInterface {
             get { return m_commander; }
         }
 
@@ -118,7 +208,10 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         {
             IConfig terrainConfig = config.Configs["Terrain"];
             if (terrainConfig != null)
+            {
                 m_InitialTerrain = terrainConfig.GetString("InitialTerrain", m_InitialTerrain);
+                m_sendTerrainUpdatesByViewDistance = terrainConfig.GetBoolean("SendTerrainUpdatesByViewDistance", m_sendTerrainUpdatesByViewDistance);
+            }
         }
 
         public void AddRegion(Scene scene)
@@ -126,26 +219,28 @@ namespace OpenSim.Region.CoreModules.World.Terrain
             m_scene = scene;
 
             // Install terrain module in the simulator
-            lock (m_scene)
+            lock(m_scene)
             {
                 if (m_scene.Heightmap == null)
                 {
-                    m_channel = new TerrainChannel(m_InitialTerrain);
+                    m_channel = new TerrainChannel(m_InitialTerrain, (int)m_scene.RegionInfo.RegionSizeX,
+                                                                     (int)m_scene.RegionInfo.RegionSizeY,
+                                                                     (int)m_scene.RegionInfo.RegionSizeZ);
                     m_scene.Heightmap = m_channel;
-                    m_revert = new TerrainChannel();
                     UpdateRevertMap();
                 }
                 else
                 {
                     m_channel = m_scene.Heightmap;
-                    m_revert = new TerrainChannel();
                     UpdateRevertMap();
                 }
 
                 m_scene.RegisterModuleInterface<ITerrainModule>(this);
                 m_scene.EventManager.OnNewClient += EventManager_OnNewClient;
+                m_scene.EventManager.OnClientClosed += EventManager_OnClientClosed;
                 m_scene.EventManager.OnPluginConsole += EventManager_OnPluginConsole;
                 m_scene.EventManager.OnTerrainTick += EventManager_OnTerrainTick;
+                m_scene.EventManager.OnFrame += EventManager_OnFrame;
             }
 
             InstallDefaultEffects();
@@ -156,7 +251,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
             string supportedFilesSeparatorForTileSave = "";
 
             m_supportFileExtensionsForTileSave = "";
-            foreach (KeyValuePair<string, ITerrainLoader> loader in m_loaders)
+            foreach(KeyValuePair<string, ITerrainLoader> loader in m_loaders)
             {
                 m_supportedFileExtensions += supportedFilesSeparator + loader.Key + " (" + loader.Value + ")";
                 supportedFilesSeparator = ", ";
@@ -179,13 +274,15 @@ namespace OpenSim.Region.CoreModules.World.Terrain
 
         public void RemoveRegion(Scene scene)
         {
-            lock (m_scene)
+            lock(m_scene)
             {
                 // remove the commands
                 m_scene.UnregisterModuleCommander(m_commander.Name);
                 // remove the event-handlers
+                m_scene.EventManager.OnFrame -= EventManager_OnFrame;
                 m_scene.EventManager.OnTerrainTick -= EventManager_OnTerrainTick;
                 m_scene.EventManager.OnPluginConsole -= EventManager_OnPluginConsole;
+                m_scene.EventManager.OnClientClosed -= EventManager_OnClientClosed;
                 m_scene.EventManager.OnNewClient -= EventManager_OnNewClient;
                 // remove the interface
                 m_scene.UnregisterModuleInterface<ITerrainModule>(this);
@@ -196,13 +293,11 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         {
         }
 
-        public Type ReplaceableInterface 
-        {
+        public Type ReplaceableInterface {
             get { return null; }
         }
 
-        public string Name
-        {
+        public string Name {
             get { return "TerrainModule"; }
         }
 
@@ -221,47 +316,46 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         /// <param name="filename">Filename to terrain file. Type is determined by extension.</param>
         public void LoadFromFile(string filename)
         {
-            foreach (KeyValuePair<string, ITerrainLoader> loader in m_loaders)
+            foreach(KeyValuePair<string, ITerrainLoader> loader in m_loaders)
             {
                 if (filename.EndsWith(loader.Key))
                 {
-                    lock (m_scene)
+                    lock(m_scene)
                     {
                         try
                         {
                             ITerrainChannel channel = loader.Value.LoadFile(filename);
-                            if (channel.Width != Constants.RegionSize || channel.Height != Constants.RegionSize)
+                            if (channel.Width != m_scene.RegionInfo.RegionSizeX || channel.Height != m_scene.RegionInfo.RegionSizeY)
                             {
                                 // TerrainChannel expects a RegionSize x RegionSize map, currently
                                 throw new ArgumentException(String.Format("wrong size, use a file with size {0} x {1}",
-                                                                          Constants.RegionSize, Constants.RegionSize));
+                                                                          m_scene.RegionInfo.RegionSizeX, m_scene.RegionInfo.RegionSizeY));
                             }
                             m_log.DebugFormat("[TERRAIN]: Loaded terrain, wd/ht: {0}/{1}", channel.Width, channel.Height);
                             m_scene.Heightmap = channel;
                             m_channel = channel;
                             UpdateRevertMap();
                         }
-                        catch (NotImplementedException)
+                        catch(NotImplementedException)
                         {
                             m_log.Error("[TERRAIN]: Unable to load heightmap, the " + loader.Value +
                                         " parser does not support file loading. (May be save only)");
                             throw new TerrainException(String.Format("unable to load heightmap: parser {0} does not support loading", loader.Value));
                         }
-                        catch (FileNotFoundException)
+                        catch(FileNotFoundException)
                         {
                             m_log.Error(
                                 "[TERRAIN]: Unable to load heightmap, file not found. (A directory permissions error may also cause this)");
                             throw new TerrainException(
                                 String.Format("unable to load heightmap: file {0} not found (or permissions do not allow access", filename));
                         }
-                        catch (ArgumentException e)
+                        catch(ArgumentException e)
                         {
                             m_log.ErrorFormat("[TERRAIN]: Unable to load heightmap: {0}", e.Message);
                             throw new TerrainException(
                                 String.Format("Unable to load heightmap: {0}", e.Message));
                         }
                     }
-                    CheckForTerrainUpdates();
                     m_log.Info("[TERRAIN]: File (" + filename + ") loaded successfully");
                     return;
                 }
@@ -279,7 +373,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         {
             try
             {
-                foreach (KeyValuePair<string, ITerrainLoader> loader in m_loaders)
+                foreach(KeyValuePair<string, ITerrainLoader> loader in m_loaders)
                 {
                     if (filename.EndsWith(loader.Key))
                     {
@@ -289,7 +383,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
                     }
                 }
             }
-            catch (IOException ioe)
+            catch(IOException ioe)
             {
                 m_log.Error(String.Format("[TERRAIN]: Unable to save to {0}, {1}", filename, ioe.Message));
             }
@@ -309,27 +403,32 @@ namespace OpenSim.Region.CoreModules.World.Terrain
             LoadFromStream(filename, URIFetch(pathToTerrainHeightmap));
         }
 
+        public void LoadFromStream(string filename, Stream stream)
+        {
+            LoadFromStream(filename, Vector3.Zero, 0f, Vector2.Zero, stream);
+        }
+
         /// <summary>
         /// Loads a terrain file from a stream and installs it in the scene.
         /// </summary>
         /// <param name="filename">Filename to terrain file. Type is determined by extension.</param>
         /// <param name="stream"></param>
-        public void LoadFromStream(string filename, Stream stream)
+        public void LoadFromStream(string filename, Vector3 displacement,
+                                float radianRotation, Vector2 rotationDisplacement, Stream stream)
         {
-            foreach (KeyValuePair<string, ITerrainLoader> loader in m_loaders)
+            foreach(KeyValuePair<string, ITerrainLoader> loader in m_loaders)
             {
                 if (filename.EndsWith(loader.Key))
                 {
-                    lock (m_scene)
+                    lock(m_scene)
                     {
                         try
                         {
                             ITerrainChannel channel = loader.Value.LoadStream(stream);
-                            m_scene.Heightmap = channel;
-                            m_channel = channel;
+                            m_channel.Merge(channel, displacement, radianRotation, rotationDisplacement);
                             UpdateRevertMap();
                         }
-                        catch (NotImplementedException)
+                        catch(NotImplementedException)
                         {
                             m_log.Error("[TERRAIN]: Unable to load heightmap, the " + loader.Value +
                                         " parser does not support file loading. (May be save only)");
@@ -337,7 +436,6 @@ namespace OpenSim.Region.CoreModules.World.Terrain
                         }
                     }
 
-                    CheckForTerrainUpdates();
                     m_log.Info("[TERRAIN]: File (" + filename + ") loaded successfully");
                     return;
                 }
@@ -390,7 +488,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         {
             try
             {
-                foreach (KeyValuePair<string, ITerrainLoader> loader in m_loaders)
+                foreach(KeyValuePair<string, ITerrainLoader> loader in m_loaders)
                 {
                     if (filename.EndsWith(loader.Key))
                     {
@@ -399,18 +497,56 @@ namespace OpenSim.Region.CoreModules.World.Terrain
                     }
                 }
             }
-            catch (NotImplementedException)
+            catch(NotImplementedException)
             {
                 m_log.Error("Unable to save to " + filename + ", saving of this file format has not been implemented.");
                 throw new TerrainException(String.Format("Unable to save heightmap: saving of this file format not implemented"));
             }
         }
 
-        public void TaintTerrain ()
+        // Someone diddled terrain outside the normal code paths. Set the taintedness for all clients.
+        // ITerrainModule.TaintTerrain()
+        public void TaintTerrain()
         {
-            CheckForTerrainUpdates();
+            lock(m_perClientPatchUpdates)
+            {
+                // Set the flags for all clients so the tainted patches will be sent out
+                foreach(PatchUpdates pups in m_perClientPatchUpdates.Values)
+                {
+                    pups.SetAll(m_scene.Heightmap.GetTerrainData());
+                }
+            }
         }
 
+        // ITerrainModule.PushTerrain()
+        public void PushTerrain(IClientAPI pClient)
+        {
+            // If view distance based, set the modified patch bits and the frame event will send the updates
+            if (m_sendTerrainUpdatesByViewDistance)
+            {
+                ScenePresence presence = m_scene.GetScenePresence(pClient.AgentId);
+                if (presence != null)
+                {
+                    lock(m_perClientPatchUpdates)
+                    {
+                        PatchUpdates pups;
+                        if (!m_perClientPatchUpdates.TryGetValue(pClient.AgentId, out pups))
+                        {
+                            // There is a ScenePresence without a send patch map. Create one.
+                            pups = new PatchUpdates(m_scene.Heightmap.GetTerrainData(), presence);
+                            m_perClientPatchUpdates.Add(presence.UUID, pups);
+                        }
+                        // By setting all to modified, the next update tick will send the patches
+                        pups.SetAll(true);
+                    }
+                }
+            }
+            else
+            {
+                // The traditional way is to call into the protocol stack to send them all.
+                pClient.SendLayerData(new float[10]);
+            }
+        }
         #region Plugin Loading Methods
 
         private void LoadPlugins()
@@ -418,13 +554,13 @@ namespace OpenSim.Region.CoreModules.World.Terrain
             m_plugineffects = new Dictionary<string, ITerrainEffect>();
             LoadPlugins(Assembly.GetCallingAssembly());
             string plugineffectsPath = "Terrain";
-            
+
             // Load the files in the Terrain/ dir
             if (!Directory.Exists(plugineffectsPath))
                 return;
-            
+
             string[] files = Directory.GetFiles(plugineffectsPath);
-            foreach (string file in files)
+            foreach(string file in files)
             {
                 m_log.Info("Loading effects in " + file);
                 try
@@ -432,7 +568,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
                     Assembly library = Assembly.LoadFrom(file);
                     LoadPlugins(library);
                 }
-                catch (BadImageFormatException)
+                catch(BadImageFormatException)
                 {
                 }
             }
@@ -440,7 +576,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
 
         private void LoadPlugins(Assembly library)
         {
-            foreach (Type pluginType in library.GetTypes())
+            foreach(Type pluginType in library.GetTypes())
             {
                 try
                 {
@@ -462,7 +598,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
                         m_log.Info("L ... " + typeName);
                     }
                 }
-                catch (AmbiguousMatchException)
+                catch(AmbiguousMatchException)
                 {
                 }
             }
@@ -470,7 +606,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
 
         public void InstallPlugin(string pluginName, ITerrainEffect effect)
         {
-            lock (m_plugineffects)
+            lock(m_plugineffects)
             {
                 if (!m_plugineffects.ContainsKey(pluginName))
                 {
@@ -513,6 +649,15 @@ namespace OpenSim.Region.CoreModules.World.Terrain
             m_floodeffects[StandardTerrainEffects.Flatten] = new FlattenArea();
             m_floodeffects[StandardTerrainEffects.Revert] = new RevertArea(m_revert);
 
+            // Terrain Modifier operations
+            m_modifyOperations["min"] = new MinModifier(this);
+            m_modifyOperations["max"] = new MaxModifier(this);
+            m_modifyOperations["raise"] = new RaiseModifier(this);
+            m_modifyOperations["lower"] = new LowerModifier(this);
+            m_modifyOperations["fill"] = new FillModifier(this);
+            m_modifyOperations["smooth"] = new SmoothModifier(this);
+            m_modifyOperations["noise"] = new NoiseModifier(this);
+
             // Filesystem load/save loaders
             m_loaders[".r32"] = new RAW32();
             m_loaders[".f32"] = m_loaders[".r32"];
@@ -532,6 +677,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         /// </summary>
         public void UpdateRevertMap()
         {
+            /*
             int x;
             for (x = 0; x < m_channel.Width; x++)
             {
@@ -541,6 +687,8 @@ namespace OpenSim.Region.CoreModules.World.Terrain
                     m_revert[x, y] = m_channel[x, y];
                 }
             }
+             */
+            m_revert = m_channel.MakeCopy();
         }
 
         /// <summary>
@@ -553,22 +701,22 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         /// <param name="fileStartY">Where to begin our slice</param>
         public void LoadFromFile(string filename, int fileWidth, int fileHeight, int fileStartX, int fileStartY)
         {
-            int offsetX = (int) m_scene.RegionInfo.RegionLocX - fileStartX;
-            int offsetY = (int) m_scene.RegionInfo.RegionLocY - fileStartY;
+            int offsetX = (int)m_scene.RegionInfo.RegionLocX - fileStartX;
+            int offsetY = (int)m_scene.RegionInfo.RegionLocY - fileStartY;
 
             if (offsetX >= 0 && offsetX < fileWidth && offsetY >= 0 && offsetY < fileHeight)
             {
                 // this region is included in the tile request
-                foreach (KeyValuePair<string, ITerrainLoader> loader in m_loaders)
+                foreach(KeyValuePair<string, ITerrainLoader> loader in m_loaders)
                 {
                     if (filename.EndsWith(loader.Key))
                     {
-                        lock (m_scene)
+                        lock(m_scene)
                         {
                             ITerrainChannel channel = loader.Value.LoadFile(filename, offsetX, offsetY,
                                                                             fileWidth, fileHeight,
-                                                                            (int) Constants.RegionSize,
-                                                                            (int) Constants.RegionSize);
+                                                                            (int)m_scene.RegionInfo.RegionSizeX,
+                                                                            (int)m_scene.RegionInfo.RegionSizeY);
                             m_scene.Heightmap = channel;
                             m_channel = channel;
                             UpdateRevertMap();
@@ -607,23 +755,23 @@ namespace OpenSim.Region.CoreModules.World.Terrain
             }
 
             // this region is included in the tile request
-            foreach (KeyValuePair<string, ITerrainLoader> loader in m_loaders)
+            foreach(KeyValuePair<string, ITerrainLoader> loader in m_loaders)
             {
                 if (filename.EndsWith(loader.Key) && loader.Value.SupportsTileSave())
                 {
-                    lock (m_scene)
+                    lock(m_scene)
                     {
                         loader.Value.SaveFile(m_channel, filename, offsetX, offsetY,
                                               fileWidth, fileHeight,
-                                              (int)Constants.RegionSize,
-                                              (int)Constants.RegionSize);
+                                              (int)m_scene.RegionInfo.RegionSizeX,
+                                              (int)m_scene.RegionInfo.RegionSizeY);
 
                         MainConsole.Instance.OutputFormat(
                             "Saved terrain from ({0},{1}) to ({2},{3}) from {4} to {5}",
                             fileStartX, fileStartY, fileStartX + fileWidth - 1, fileStartY + fileHeight - 1,
                             m_scene.RegionInfo.RegionName, filename);
                     }
-                    
+
                     return;
                 }
             }
@@ -634,7 +782,44 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         }
 
         /// <summary>
+        /// Called before processing of every simulation frame.
+        /// This is used to check to see of any of the terrain is tainted and, if so, schedule
+        /// updates for all the presences.
+        /// This also checks to see if there are updates that need to be sent for each presence.
+        /// This is where the logic is to send terrain updates to clients.
+        /// </summary>
+        private void EventManager_OnFrame()
+        {
+            TerrainData terrData = m_channel.GetTerrainData();
+
+            bool shouldTaint = false;
+            for(int x = 0; x < terrData.SizeX; x += Constants.TerrainPatchSize)
+            {
+                for(int y = 0; y < terrData.SizeY; y += Constants.TerrainPatchSize)
+                {
+                    if (terrData.IsTaintedAt(x, y))
+                    {
+                        // Found a patch that was modified. Push this flag into the clients.
+                        SendToClients(terrData, x, y);
+                        shouldTaint = true;
+                    }
+                }
+            }
+
+            // This event also causes changes to be sent to the clients
+            CheckSendingPatchesToClients();
+
+            // If things changes, generate some events
+            if (shouldTaint)
+            {
+                m_scene.EventManager.TriggerTerrainTainted();
+                m_tainted = true;
+            }
+        }
+
+        /// <summary>
         /// Performs updates to the region periodically, synchronising physics and other heightmap aware sections
+        /// Called infrequently (like every 5 seconds or so). Best used for storing terrain.
         /// </summary>
         private void EventManager_OnTerrainTick()
         {
@@ -665,7 +850,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
 
                 string[] tmpArgs = new string[args.Length - 2];
                 int i;
-                for (i = 2; i < args.Length; i++)
+                for(i = 2; i < args.Length; i++)
                     tmpArgs[i - 2] = args[i];
 
                 m_commander.ProcessConsoleCommand(args[1], tmpArgs);
@@ -683,56 +868,50 @@ namespace OpenSim.Region.CoreModules.World.Terrain
             client.OnLandUndo += client_OnLandUndo;
             client.OnUnackedTerrain += client_OnUnackedTerrain;
         }
-        
+
         /// <summary>
-        /// Checks to see if the terrain has been modified since last check
-        /// but won't attempt to limit those changes to the limits specified in the estate settings
-        /// currently invoked by the command line operations in the region server only
+        /// Installs terrain brush hook to IClientAPI
         /// </summary>
-        private void CheckForTerrainUpdates()
+        /// <param name="client"></param>
+        private void EventManager_OnClientClosed(UUID client, Scene scene)
         {
-            CheckForTerrainUpdates(false);
+            ScenePresence presence = scene.GetScenePresence(client);
+            if (presence != null)
+            {
+                presence.ControllingClient.OnModifyTerrain -= client_OnModifyTerrain;
+                presence.ControllingClient.OnBakeTerrain -= client_OnBakeTerrain;
+                presence.ControllingClient.OnLandUndo -= client_OnLandUndo;
+                presence.ControllingClient.OnUnackedTerrain -= client_OnUnackedTerrain;
+            }
+
+            lock(m_perClientPatchUpdates)
+                m_perClientPatchUpdates.Remove(client);
         }
 
         /// <summary>
-        /// Checks to see if the terrain has been modified since last check.
-        /// If it has been modified, every all the terrain patches are sent to the client.
-        /// If the call is asked to respect the estate settings for terrain_raise_limit and
-        /// terrain_lower_limit, it will clamp terrain updates between these values
-        /// currently invoked by client_OnModifyTerrain only and not the Commander interfaces
-        /// <param name="respectEstateSettings">should height map deltas be limited to the estate settings limits</param>
+        /// Scan over changes in the terrain and limit height changes. This enforces the
+        ///     non-estate owner limits on rate of terrain editting.
+        /// Returns 'true' if any heights were limited.
         /// </summary>
-        private void CheckForTerrainUpdates(bool respectEstateSettings)
+        private bool EnforceEstateLimits()
         {
-            bool shouldTaint = false;
-            float[] serialised = m_channel.GetFloatsSerialised();
-            int x;
-            for (x = 0; x < m_channel.Width; x += Constants.TerrainPatchSize)
+            TerrainData terrData = m_channel.GetTerrainData();
+
+            bool wasLimited = false;
+            for(int x = 0; x < terrData.SizeX; x += Constants.TerrainPatchSize)
             {
-                int y;
-                for (y = 0; y < m_channel.Height; y += Constants.TerrainPatchSize)
+                for(int y = 0; y < terrData.SizeY; y += Constants.TerrainPatchSize)
                 {
-                    if (m_channel.Tainted(x, y))
+                    if (terrData.IsTaintedAt(x, y, false /* clearOnTest */))
                     {
-                        // if we should respect the estate settings then
-                        // fixup and height deltas that don't respect them
-                        if (respectEstateSettings && LimitChannelChanges(x, y))
-                        {
-                            // this has been vetoed, so update
-                            // what we are going to send to the client
-                            serialised = m_channel.GetFloatsSerialised();
-                        }
-
-                        SendToClients(serialised, x, y);
-                        shouldTaint = true;
+                        // If we should respect the estate settings then
+                        //     fixup and height deltas that don't respect them.
+                        // Note that LimitChannelChanges() modifies the TerrainChannel with the limited height values.
+                        wasLimited |= LimitChannelChanges(terrData, x, y);
                     }
                 }
             }
-            if (shouldTaint)
-            {
-                m_scene.EventManager.TriggerTerrainTainted();
-                m_tainted = true;
-            }
+            return wasLimited;
         }
 
         /// <summary>
@@ -740,31 +919,30 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         /// are all within the current estate limits
         /// <returns>true if changes were limited, false otherwise</returns>
         /// </summary>
-        private bool LimitChannelChanges(int xStart, int yStart)
+        private bool LimitChannelChanges(TerrainData terrData, int xStart, int yStart)
         {
             bool changesLimited = false;
-            double minDelta = m_scene.RegionInfo.RegionSettings.TerrainLowerLimit;
-            double maxDelta = m_scene.RegionInfo.RegionSettings.TerrainRaiseLimit;
+            float minDelta = (float)m_scene.RegionInfo.RegionSettings.TerrainLowerLimit;
+            float maxDelta = (float)m_scene.RegionInfo.RegionSettings.TerrainRaiseLimit;
 
             // loop through the height map for this patch and compare it against
             // the revert map
-            for (int x = xStart; x < xStart + Constants.TerrainPatchSize; x++)
+            for(int x = xStart; x < xStart + Constants.TerrainPatchSize; x++)
             {
-                for (int y = yStart; y < yStart + Constants.TerrainPatchSize; y++)
+                for(int y = yStart; y < yStart + Constants.TerrainPatchSize; y++)
                 {
-
-                    double requestedHeight = m_channel[x, y];
-                    double bakedHeight = m_revert[x, y];
-                    double requestedDelta = requestedHeight - bakedHeight;
+                    float requestedHeight = terrData[x, y];
+                    float bakedHeight = (float)m_revert[x, y];
+                    float requestedDelta = requestedHeight - bakedHeight;
 
                     if (requestedDelta > maxDelta)
                     {
-                        m_channel[x, y] = bakedHeight + maxDelta;
+                        terrData[x, y] = bakedHeight + maxDelta;
                         changesLimited = true;
                     }
                     else if (requestedDelta < minDelta)
                     {
-                        m_channel[x, y] = bakedHeight + minDelta; //as lower is a -ve delta
+                        terrData[x, y] = bakedHeight + minDelta; //as lower is a -ve delta
                         changesLimited = true;
                     }
                 }
@@ -775,7 +953,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
 
         private void client_OnLandUndo(IClientAPI client)
         {
-            lock (m_undo)
+            lock(m_undo)
             {
                 if (m_undo.Count > 0)
                 {
@@ -792,14 +970,177 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         /// <param name="serialised">A copy of the terrain as a 1D float array of size w*h</param>
         /// <param name="x">The patch corner to send</param>
         /// <param name="y">The patch corner to send</param>
-        private void SendToClients(float[] serialised, int x, int y)
+        private void SendToClients(TerrainData terrData, int x, int y)
         {
-            m_scene.ForEachClient(
-                delegate(IClientAPI controller)
-                    { controller.SendLayerData(
-                        x / Constants.TerrainPatchSize, y / Constants.TerrainPatchSize, serialised);
+            if (m_sendTerrainUpdatesByViewDistance)
+            {
+                // Add that this patch needs to be sent to the accounting for each client.
+                lock(m_perClientPatchUpdates)
+                {
+                    m_scene.ForEachScenePresence(presence =>
+                    {
+                        PatchUpdates thisClientUpdates;
+                        if (!m_perClientPatchUpdates.TryGetValue(presence.UUID, out thisClientUpdates))
+                        {
+                            // There is a ScenePresence without a send patch map. Create one.
+                            thisClientUpdates = new PatchUpdates(terrData, presence);
+                            m_perClientPatchUpdates.Add(presence.UUID, thisClientUpdates);
+                        }
+                        thisClientUpdates.SetByXY(x, y, true);
                     }
-            );
+                    );
+                }
+            }
+            else
+            {
+                // Legacy update sending where the update is sent out as soon as noticed
+                // We know the actual terrain data that is passed is ignored so this passes a dummy heightmap.
+                //float[] heightMap = terrData.GetFloatsSerialized();
+                float[] heightMap = new float[10];
+                m_scene.ForEachClient(
+                    delegate(IClientAPI controller)
+                    {
+                        controller.SendLayerData(x / Constants.TerrainPatchSize,
+                                                 y / Constants.TerrainPatchSize,
+                                                 heightMap);
+                    }
+                );
+            }
+        }
+
+        private class PatchesToSend : IComparable<PatchesToSend>
+        {
+            public int PatchX;
+            public int PatchY;
+            public float Dist;
+
+            public PatchesToSend(int pX, int pY, float pDist)
+            {
+                PatchX = pX;
+                PatchY = pY;
+                Dist = pDist;
+            }
+
+            public int CompareTo(PatchesToSend other)
+            {
+                return Dist.CompareTo(other.Dist);
+            }
+        }
+
+        // Called each frame time to see if there are any patches to send to any of the
+        //    ScenePresences.
+        // We know this is only called if we are doing view distance patch sending so some
+        //    tests are not made.
+        // Loop through all the per-client info and send any patches necessary.
+        private void CheckSendingPatchesToClients()
+        {
+            lock(m_perClientPatchUpdates)
+            {
+                foreach(PatchUpdates pups in m_perClientPatchUpdates.Values)
+                {
+                    if (pups.HasUpdates())
+                    {
+                        // There is something that could be sent to this client.
+                        List<PatchesToSend> toSend = GetModifiedPatchesInViewDistance(pups);
+                        if (toSend.Count > 0)
+                        {
+                            // m_log.DebugFormat("{0} CheckSendingPatchesToClient: sending {1} patches to {2} in region {3}",
+                            //                     LogHeader, toSend.Count, pups.Presence.Name, m_scene.RegionInfo.RegionName);
+                            // Sort the patches to send by the distance from the presence
+                            toSend.Sort();
+                            /* old way that sent individual patches
+                            foreach (PatchesToSend pts in toSend)
+                            {
+                                pups.Presence.ControllingClient.SendLayerData(pts.PatchX, pts.PatchY, null);
+                                // presence.ControllingClient.SendLayerData(xs.ToArray(), ys.ToArray(), null, TerrainPatch.LayerType.Land);
+                            }
+                            */
+
+                            // new way that sends all patches to the protocol so they can be sent in one block
+                            int[] xPieces = new int[toSend.Count];
+                            int[] yPieces = new int[toSend.Count];
+                            float[] patchPieces = new float[toSend.Count * 2];
+                            int pieceIndex = 0;
+                            foreach(PatchesToSend pts in toSend)
+                            {
+                                patchPieces[pieceIndex++] = pts.PatchX;
+                                patchPieces[pieceIndex++] = pts.PatchY;
+                            }
+                            pups.Presence.ControllingClient.SendLayerData(-toSend.Count, 0, patchPieces);
+                        }
+                    }
+                }
+            }
+        }
+
+        // Compute a list of modified patches that are within our view distance.
+        private List<PatchesToSend> GetModifiedPatchesInViewDistance(PatchUpdates pups)
+        {
+            List<PatchesToSend> ret = new List<PatchesToSend>();
+
+            ScenePresence presence = pups.Presence;
+            if (presence == null)
+                return ret;
+
+            Vector3 presencePos = presence.AbsolutePosition;
+
+            // Before this distance check, the whole region just showed up. Adding the distance
+            //   check causes different things to happen for the current and adjacent regions.
+            //   So, to keep legacy views, if the region is legacy sized, don't do distance check.
+            bool isLegacySizedRegion = pups.Terrain.SizeX == Constants.RegionSize && pups.Terrain.SizeY == Constants.RegionSize;
+            bool shouldCheckViewDistance = m_sendTerrainUpdatesByViewDistance && !isLegacySizedRegion;
+
+            int startX = 0;
+            int endX = (int)m_scene.RegionInfo.RegionSizeX / Constants.TerrainPatchSize;
+            int startY = 0;
+            int endY = (int)m_scene.RegionInfo.RegionSizeY / Constants.TerrainPatchSize;
+
+            // The following only reduces the size of area scanned for updates. Only significant for very large varregions.
+            if (shouldCheckViewDistance)
+            {
+                // Compute the area of patches within our draw distance
+                startX = (((int)(presencePos.X - presence.DrawDistance)) / Constants.TerrainPatchSize) - 2;
+                startX = Math.Max(startX, 0);
+                startX = Math.Min(startX, (int)m_scene.RegionInfo.RegionSizeX / Constants.TerrainPatchSize);
+                startY = (((int)(presencePos.Y - presence.DrawDistance)) / Constants.TerrainPatchSize) - 2;
+                startY = Math.Max(startY, 0);
+                startY = Math.Min(startY, (int)m_scene.RegionInfo.RegionSizeY / Constants.TerrainPatchSize);
+                endX = (((int)(presencePos.X + presence.DrawDistance)) / Constants.TerrainPatchSize) + 2;
+                endX = Math.Max(endX, 0);
+                endX = Math.Min(endX, (int)m_scene.RegionInfo.RegionSizeX / Constants.TerrainPatchSize);
+                endY = (((int)(presencePos.Y + presence.DrawDistance)) / Constants.TerrainPatchSize) + 2;
+                endY = Math.Max(endY, 0);
+                endY = Math.Min(endY, (int)m_scene.RegionInfo.RegionSizeY / Constants.TerrainPatchSize);
+            }
+
+            // m_log.DebugFormat("{0} GetModifiedPatchesInViewDistance. rName={1}, ddist={2}, apos={3}, cpos={4}, isChild={5}, start=<{6},{7}>, end=<{8},{9}>",
+            //                                     LogHeader, m_scene.RegionInfo.RegionName,
+            //                                     presence.DrawDistance, presencePos, presence.CameraPosition,
+            //                                     isLegacySizeChildRegion,
+            //                                     startX, startY, endX, endY);
+            for(int x = startX; x < endX; x++)
+            {
+                for(int y = startY; y < endY; y++)
+                {
+                    //Need to make sure we don't send the same ones over and over
+                    Vector3 patchPos = new Vector3(x * Constants.TerrainPatchSize, y * Constants.TerrainPatchSize, presencePos.Z);
+                    if (pups.GetByPatch(x, y))
+                    {
+                        //Check which has less distance, camera or avatar position, both have to be done.
+                        //Its not a radius, its a diameter and we add 50 so that it doesn't look like it cuts off
+                        if (!shouldCheckViewDistance
+                            || Util.DistanceLessThan(presencePos, patchPos, presence.DrawDistance + 50)
+                            || Util.DistanceLessThan(presence.CameraPosition, patchPos, presence.DrawDistance + 50))
+                        {
+                            //They can see it, send it to them
+                            pups.SetByPatch(x, y, false);
+                            float dist = Vector3.DistanceSquared(presencePos, patchPos);
+                            ret.Add(new PatchesToSend(x, y, dist));
+                        }
+                    }
+                }
+            }
+            return ret;
         }
 
         private void client_OnModifyTerrain(UUID user, float height, float seconds, byte size, byte action,
@@ -809,28 +1150,28 @@ namespace OpenSim.Region.CoreModules.World.Terrain
             bool allowed = false;
             if (north == south && east == west)
             {
-                if (m_painteffects.ContainsKey((StandardTerrainEffects) action))
+                if (m_painteffects.ContainsKey((StandardTerrainEffects)action))
                 {
-                    bool[,] allowMask = new bool[m_channel.Width,m_channel.Height];
+                    bool[,] allowMask = new bool[m_channel.Width, m_channel.Height];
                     allowMask.Initialize();
                     int n = size + 1;
                     if (n > 2)
                         n = 4;
 
-                    int zx = (int) (west + 0.5);
-                    int zy = (int) (north + 0.5);
+                    int zx = (int)(west + 0.5);
+                    int zy = (int)(north + 0.5);
 
                     int dx;
-                    for (dx=-n; dx<=n; dx++)
+                    for(dx=-n; dx<=n; dx++)
                     {
                         int dy;
-                        for (dy=-n; dy<=n; dy++)
+                        for(dy=-n; dy<=n; dy++)
                         {
                             int x = zx + dx;
                             int y = zy + dy;
-                            if (x>=0 && y>=0 && x<m_channel.Width && y<m_channel.Height)
+                            if (x >= 0 && y >= 0 && x < m_channel.Width && y < m_channel.Height)
                             {
-                                if (m_scene.Permissions.CanTerraformLand(agentId, new Vector3(x,y,0)))
+                                if (m_scene.Permissions.CanTerraformLand(agentId, new Vector3(x, y, 0)))
                                 {
                                     allowMask[x, y] = true;
                                     allowed = true;
@@ -841,10 +1182,12 @@ namespace OpenSim.Region.CoreModules.World.Terrain
                     if (allowed)
                     {
                         StoreUndoState();
-                        m_painteffects[(StandardTerrainEffects) action].PaintEffect(
+                        m_painteffects[(StandardTerrainEffects)action].PaintEffect(
                             m_channel, allowMask, west, south, height, size, seconds);
 
-                        CheckForTerrainUpdates(!god); //revert changes outside estate limits
+                        //revert changes outside estate limits
+                        if (!god)
+                            EnforceEstateLimits();
                     }
                 }
                 else
@@ -854,22 +1197,22 @@ namespace OpenSim.Region.CoreModules.World.Terrain
             }
             else
             {
-                if (m_floodeffects.ContainsKey((StandardTerrainEffects) action))
+                if (m_floodeffects.ContainsKey((StandardTerrainEffects)action))
                 {
-                    bool[,] fillArea = new bool[m_channel.Width,m_channel.Height];
+                    bool[,] fillArea = new bool[m_channel.Width, m_channel.Height];
                     fillArea.Initialize();
 
                     int x;
-                    for (x = 0; x < m_channel.Width; x++)
+                    for(x = 0; x < m_channel.Width; x++)
                     {
                         int y;
-                        for (y = 0; y < m_channel.Height; y++)
+                        for(y = 0; y < m_channel.Height; y++)
                         {
                             if (x < east && x > west)
                             {
                                 if (y < north && y > south)
                                 {
-                                    if (m_scene.Permissions.CanTerraformLand(agentId, new Vector3(x,y,0)))
+                                    if (m_scene.Permissions.CanTerraformLand(agentId, new Vector3(x, y, 0)))
                                     {
                                         fillArea[x, y] = true;
                                         allowed = true;
@@ -882,10 +1225,11 @@ namespace OpenSim.Region.CoreModules.World.Terrain
                     if (allowed)
                     {
                         StoreUndoState();
-                        m_floodeffects[(StandardTerrainEffects) action].FloodEffect(
-                            m_channel, fillArea, size);
+                        m_floodeffects[(StandardTerrainEffects)action].FloodEffect(m_channel, fillArea, size);
 
-                        CheckForTerrainUpdates(!god); //revert changes outside estate limits
+                        //revert changes outside estate limits
+                        if (!god)
+                            EnforceEstateLimits();
                     }
                 }
                 else
@@ -905,16 +1249,18 @@ namespace OpenSim.Region.CoreModules.World.Terrain
                 InterfaceBakeTerrain(null); //bake terrain does not use the passed in parameter
             }
         }
-        
+
         protected void client_OnUnackedTerrain(IClientAPI client, int patchX, int patchY)
         {
             //m_log.Debug("Terrain packet unacked, resending patch: " + patchX + " , " + patchY);
-             client.SendLayerData(patchX, patchY, m_scene.Heightmap.GetFloatsSerialised());
+            // SendLayerData does not use the heightmap parameter. This kludge is so as to not change IClientAPI.
+            float[] heightMap = new float[10];
+            client.SendLayerData(patchX, patchY, heightMap);
         }
 
         private void StoreUndoState()
         {
-            lock (m_undo)
+            lock(m_undo)
             {
                 if (m_undo.Count > 0)
                 {
@@ -935,23 +1281,21 @@ namespace OpenSim.Region.CoreModules.World.Terrain
 
         private void InterfaceLoadFile(Object[] args)
         {
-            LoadFromFile((string) args[0]);
-            CheckForTerrainUpdates();
+            LoadFromFile((string)args[0]);
         }
 
         private void InterfaceLoadTileFile(Object[] args)
         {
-            LoadFromFile((string) args[0],
-                         (int) args[1],
-                         (int) args[2],
-                         (int) args[3],
-                         (int) args[4]);
-            CheckForTerrainUpdates();
+            LoadFromFile((string)args[0],
+                         (int)args[1],
+                         (int)args[2],
+                         (int)args[3],
+                         (int)args[4]);
         }
 
         private void InterfaceSaveFile(Object[] args)
         {
-            SaveToFile((string) args[0]);
+            SaveToFile((string)args[0]);
         }
 
         private void InterfaceSaveTileFile(Object[] args)
@@ -971,11 +1315,10 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         private void InterfaceRevertTerrain(Object[] args)
         {
             int x, y;
-            for (x = 0; x < m_channel.Width; x++)
-                for (y = 0; y < m_channel.Height; y++)
+            for(x = 0; x < m_channel.Width; x++)
+                for(y = 0; y < m_channel.Height; y++)
                     m_channel[x, y] = m_revert[x, y];
 
-            CheckForTerrainUpdates();
         }
 
         private void InterfaceFlipTerrain(Object[] args)
@@ -984,39 +1327,36 @@ namespace OpenSim.Region.CoreModules.World.Terrain
 
             if (direction.ToLower().StartsWith("y"))
             {
-                for (int x = 0; x < Constants.RegionSize; x++)
+                for(int x = 0; x < m_channel.Width; x++)
                 {
-                    for (int y = 0; y < Constants.RegionSize / 2; y++)
+                    for(int y = 0; y < m_channel.Height / 2; y++)
                     {
                         double height = m_channel[x, y];
-                        double flippedHeight = m_channel[x, (int)Constants.RegionSize - 1 - y];
+                        double flippedHeight = m_channel[x, (int)m_channel.Height - 1 - y];
                         m_channel[x, y] = flippedHeight;
-                        m_channel[x, (int)Constants.RegionSize - 1 - y] = height;
+                        m_channel[x, (int)m_channel.Height - 1 - y] = height;
 
                     }
                 }
             }
             else if (direction.ToLower().StartsWith("x"))
             {
-                for (int y = 0; y < Constants.RegionSize; y++)
+                for(int y = 0; y < m_channel.Height; y++)
                 {
-                    for (int x = 0; x < Constants.RegionSize / 2; x++)
+                    for(int x = 0; x < m_channel.Width / 2; x++)
                     {
                         double height = m_channel[x, y];
-                        double flippedHeight = m_channel[(int)Constants.RegionSize - 1 - x, y];
+                        double flippedHeight = m_channel[(int)m_channel.Width - 1 - x, y];
                         m_channel[x, y] = flippedHeight;
-                        m_channel[(int)Constants.RegionSize - 1 - x, y] = height;
+                        m_channel[(int)m_channel.Width - 1 - x, y] = height;
 
                     }
                 }
             }
             else
             {
-                m_log.Error("Unrecognised direction - need x or y");
+                MainConsole.Instance.OutputFormat("ERROR: Unrecognised direction {0} - need x or y", direction);
             }
-
-
-            CheckForTerrainUpdates();
         }
 
         private void InterfaceRescaleTerrain(Object[] args)
@@ -1042,9 +1382,9 @@ namespace OpenSim.Region.CoreModules.World.Terrain
                 int width = m_channel.Width;
                 int height = m_channel.Height;
 
-                for (int x = 0; x < width; x++)
+                for(int x = 0; x < width; x++)
                 {
-                    for (int y = 0; y < height; y++)
+                    for(int y = 0; y < height; y++)
                     {
                         double currHeight = m_channel[x, y];
                         if (currHeight < currMin)
@@ -1065,16 +1405,15 @@ namespace OpenSim.Region.CoreModules.World.Terrain
                 //m_log.InfoFormat("Scale = {0}", scale);
 
                 // scale the heightmap accordingly
-                for (int x = 0; x < width; x++)
+                for(int x = 0; x < width; x++)
                 {
-                    for (int y = 0; y < height; y++)
+                    for(int y = 0; y < height; y++)
                     {
-                            double currHeight = m_channel[x, y] - currMin;
-                            m_channel[x, y] = desiredMin + (currHeight * scale);
+                        double currHeight = m_channel[x, y] - currMin;
+                        m_channel[x, y] = desiredMin + (currHeight * scale);
                     }
                 }
 
-                CheckForTerrainUpdates();
             }
 
         }
@@ -1082,64 +1421,73 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         private void InterfaceElevateTerrain(Object[] args)
         {
             int x, y;
-            for (x = 0; x < m_channel.Width; x++)
-                for (y = 0; y < m_channel.Height; y++)
-                    m_channel[x, y] += (double) args[0];
-            CheckForTerrainUpdates();
+            for(x = 0; x < m_channel.Width; x++)
+                for(y = 0; y < m_channel.Height; y++)
+                    m_channel[x, y] += (double)args[0];
         }
 
         private void InterfaceMultiplyTerrain(Object[] args)
         {
             int x, y;
-            for (x = 0; x < m_channel.Width; x++)
-                for (y = 0; y < m_channel.Height; y++)
-                    m_channel[x, y] *= (double) args[0];
-            CheckForTerrainUpdates();
+            for(x = 0; x < m_channel.Width; x++)
+                for(y = 0; y < m_channel.Height; y++)
+                    m_channel[x, y] *= (double)args[0];
         }
 
         private void InterfaceLowerTerrain(Object[] args)
         {
             int x, y;
-            for (x = 0; x < m_channel.Width; x++)
-                for (y = 0; y < m_channel.Height; y++)
-                    m_channel[x, y] -= (double) args[0];
-            CheckForTerrainUpdates();
+            for(x = 0; x < m_channel.Width; x++)
+                for(y = 0; y < m_channel.Height; y++)
+                    m_channel[x, y] -= (double)args[0];
         }
 
-        private void InterfaceFillTerrain(Object[] args)
+        public void InterfaceFillTerrain(Object[] args)
         {
             int x, y;
 
-            for (x = 0; x < m_channel.Width; x++)
-                for (y = 0; y < m_channel.Height; y++)
-                    m_channel[x, y] = (double) args[0];
-            CheckForTerrainUpdates();
+            for(x = 0; x < m_channel.Width; x++)
+                for(y = 0; y < m_channel.Height; y++)
+                    m_channel[x, y] = (double)args[0];
         }
 
         private void InterfaceMinTerrain(Object[] args)
         {
             int x, y;
-            for (x = 0; x < m_channel.Width; x++)
+            for(x = 0; x < m_channel.Width; x++)
             {
-                for (y = 0; y < m_channel.Height; y++)
+                for(y = 0; y < m_channel.Height; y++)
                 {
                     m_channel[x, y] = Math.Max((double)args[0], m_channel[x, y]);
                 }
             }
-            CheckForTerrainUpdates();
         }
 
         private void InterfaceMaxTerrain(Object[] args)
         {
             int x, y;
-            for (x = 0; x < m_channel.Width; x++)
+            for(x = 0; x < m_channel.Width; x++)
             {
-                for (y = 0; y < m_channel.Height; y++)
+                for(y = 0; y < m_channel.Height; y++)
                 {
                     m_channel[x, y] = Math.Min((double)args[0], m_channel[x, y]);
                 }
             }
-            CheckForTerrainUpdates();
+        }
+
+        private void InterfaceShow(Object[] args)
+        {
+            Vector2 point;
+
+            if (!ConsoleUtil.TryParseConsole2DVector((string)args[0], null, out point))
+            {
+                Console.WriteLine("ERROR: {0} is not a valid vector", args[0]);
+                return;
+            }
+
+            double height = m_channel[(int)point.X, (int)point.Y];
+
+            Console.WriteLine("Terrain height at {0} is {1}", point, height);
         }
 
         private void InterfaceShowDebugStats(Object[] args)
@@ -1149,10 +1497,10 @@ namespace OpenSim.Region.CoreModules.World.Terrain
             double sum = 0;
 
             int x;
-            for (x = 0; x < m_channel.Width; x++)
+            for(x = 0; x < m_channel.Width; x++)
             {
                 int y;
-                for (y = 0; y < m_channel.Height; y++)
+                for(y = 0; y < m_channel.Height; y++)
                 {
                     sum += m_channel[x, y];
                     if (max < m_channel[x, y])
@@ -1164,13 +1512,13 @@ namespace OpenSim.Region.CoreModules.World.Terrain
 
             double avg = sum / (m_channel.Height * m_channel.Width);
 
-            m_log.Info("Channel " + m_channel.Width + "x" + m_channel.Height);
-            m_log.Info("max/min/avg/sum: " + max + "/" + min + "/" + avg + "/" + sum);
+            MainConsole.Instance.OutputFormat("Channel {0}x{1}", m_channel.Width, m_channel.Height);
+            MainConsole.Instance.OutputFormat("max/min/avg/sum: {0}/{1}/{2}/{3}", max, min, avg, sum);
         }
 
         private void InterfaceEnableExperimentalBrushes(Object[] args)
         {
-            if ((bool) args[0])
+            if ((bool)args[0])
             {
                 m_painteffects[StandardTerrainEffects.Revert] = new WeatherSphere();
                 m_painteffects[StandardTerrainEffects.Flatten] = new OlsenSphere();
@@ -1185,28 +1533,30 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         private void InterfaceRunPluginEffect(Object[] args)
         {
             string firstArg = (string)args[0];
+
             if (firstArg == "list")
             {
-                m_log.Info("List of loaded plugins");
-                foreach (KeyValuePair<string, ITerrainEffect> kvp in m_plugineffects)
+                MainConsole.Instance.Output("List of loaded plugins");
+                foreach(KeyValuePair<string, ITerrainEffect> kvp in m_plugineffects)
                 {
-                    m_log.Info(kvp.Key);
+                    MainConsole.Instance.Output(kvp.Key);
                 }
                 return;
             }
+
             if (firstArg == "reload")
             {
                 LoadPlugins();
                 return;
             }
+
             if (m_plugineffects.ContainsKey(firstArg))
             {
                 m_plugineffects[firstArg].RunEffect(m_channel);
-                CheckForTerrainUpdates();
             }
             else
             {
-                m_log.Warn("No such plugin effect loaded.");
+                MainConsole.Instance.Output("WARNING: No such plugin effect {0} loaded.", firstArg);
             }
         }
 
@@ -1295,12 +1645,17 @@ namespace OpenSim.Region.CoreModules.World.Terrain
                 new Command("stats", CommandIntentions.COMMAND_STATISTICAL, InterfaceShowDebugStats,
                             "Shows some information about the regions heightmap for debugging purposes.");
 
+            Command showCommand =
+                new Command("show", CommandIntentions.COMMAND_NON_HAZARDOUS, InterfaceShow,
+                            "Shows terrain height at a given co-ordinate.");
+            showCommand.AddArgument("point", "point in <x>,<y> format with no spaces (e.g. 45,45)", "String");
+
             Command experimentalBrushesCommand =
                 new Command("newbrushes", CommandIntentions.COMMAND_HAZARDOUS, InterfaceEnableExperimentalBrushes,
                             "Enables experimental brushes which replace the standard terrain brushes. WARNING: This is a debug setting and may be removed at any time.");
             experimentalBrushesCommand.AddArgument("Enabled?", "true / false - Enable new brushes", "Boolean");
 
-            //Plugins
+            // Plugins
             Command pluginRunCommand =
                 new Command("effect", CommandIntentions.COMMAND_HAZARDOUS, InterfaceRunPluginEffect, "Runs a specified plugin effect");
             pluginRunCommand.AddArgument("name", "The plugin effect you wish to run, or 'list' to see all plugins", "String");
@@ -1316,6 +1671,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
             m_commander.RegisterCommand("bake", bakeRegionCommand);
             m_commander.RegisterCommand("revert", revertRegionCommand);
             m_commander.RegisterCommand("newbrushes", experimentalBrushesCommand);
+            m_commander.RegisterCommand("show", showCommand);
             m_commander.RegisterCommand("stats", showDebugStatsCommand);
             m_commander.RegisterCommand("effect", pluginRunCommand);
             m_commander.RegisterCommand("flip", flipCommand);
@@ -1325,10 +1681,66 @@ namespace OpenSim.Region.CoreModules.World.Terrain
 
             // Add this to our scene so scripts can call these functions
             m_scene.RegisterModuleCommander(m_commander);
+
+            // Add Modify command to Scene, since Command object requires fixed-length arglists
+            m_scene.AddCommand("Terrain", this, "terrain modify",
+                               "terrain modify <operation> <value> [<area>] [<taper>]",
+                               "Modifies the terrain as instructed." +
+                               "\nEach operation can be limited to an area of effect:" +
+                               "\n * -ell=x,y,rx[,ry] constrains the operation to an ellipse centred at x,y" +
+                               "\n * -rec=x,y,dx[,dy] constrains the operation to a rectangle based at x,y" +
+                               "\nEach operation can have its effect tapered based on distance from centre:" +
+                               "\n * elliptical operations taper as cones" +
+                               "\n * rectangular operations taper as pyramids"
+                               ,
+                               ModifyCommand);
+
         }
 
+        public void ModifyCommand(string module, string[] cmd)
+        {
+            string result;
+            Scene scene = SceneManager.Instance.CurrentScene;
+            if ((scene != null) && (scene != m_scene))
+            {
+                result = String.Empty;
+            }
+            else if (cmd.Length > 2)
+            {
+                string operationType = cmd[2];
 
-        #endregion
+
+                ITerrainModifier operation;
+                if (!m_modifyOperations.TryGetValue(operationType, out operation))
+                {
+                    result = String.Format("Terrain Modify \"{0}\" not found.", operationType);
+                }
+                else if ((cmd.Length > 3) && (cmd[3] == "usage"))
+                {
+                    result = "Usage: " + operation.GetUsage();
+                }
+                else
+                {
+                    result = operation.ModifyTerrain(m_channel, cmd);
+                }
+
+                if (result == String.Empty)
+                {
+                    result = "Modified terrain";
+                    m_log.DebugFormat("Performed terrain operation {0}", operationType);
+                }
+            }
+            else
+            {
+                result = "Usage: <operation-name> <arg1> <arg2>...";
+            }
+            if (result != String.Empty)
+            {
+                MainConsole.Instance.Output(result);
+            }
+        }
+
+#endregion
 
     }
 }