varregion: plug in TerrainData class and modify TerrainModule and LLClientView to use same. This passes a terrain info class around rather than passing a one dimensional array thus allowing variable regions. Update the database storage for variable region sizes. This should be downward compatible (same format for 256x256 regions).

7 files changed, 126 insertions, 210 deletions

diff --git a/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs b/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs
index fea9ddf..7984acc 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs
@@ -34,11 +34,13 @@ using System.Text;
 using System.Threading;
 using System.Timers;
 using System.Xml;
+
 using log4net;
 using OpenMetaverse;
 using OpenMetaverse.Packets;
 using OpenMetaverse.Messages.Linden;
 using OpenMetaverse.StructuredData;
+
 using OpenSim.Framework;
 using OpenSim.Framework.Client;
 using OpenSim.Framework.Monitoring;
@@ -48,7 +50,6 @@ using OpenSim.Services.Interfaces;
 using Timer = System.Timers.Timer;
 using AssetLandmark = OpenSim.Framework.AssetLandmark;
 using RegionFlags = OpenMetaverse.RegionFlags;
-using Nini.Config;
 
 using System.IO;
 using PermissionMask = OpenSim.Framework.PermissionMask;
@@ -307,6 +308,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         private const float m_sunPainDaHalfOrbitalCutoff = 4.712388980384689858f;
 
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+        private static string LogHeader = "[LLCLIENTVIEW]";
         protected static Dictionary<PacketType, PacketMethod> PacketHandlers = new Dictionary<PacketType, PacketMethod>(); //Global/static handlers for all clients
 
         /// <summary>
@@ -447,7 +449,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
 //        ~LLClientView()
 //        {
-//            m_log.DebugFormat("[LLCLIENTVIEW]: Destructor called for {0}, circuit code {1}", Name, CircuitCode);
+//            m_log.DebugFormat("{0} Destructor called for {1}, circuit code {2}", LogHeader, Name, CircuitCode);
 //        }
 
         /// <summary>
@@ -513,9 +515,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 // there is some unidentified connection problem, not where we have issues due to deadlock
                 if (!IsActive && !force)
                 {
-                    m_log.DebugFormat(
-                        "[CLIENT]: Not attempting to close inactive client {0} in {1} since force flag is not set", 
-                        Name, m_scene.Name);
+                    m_log.DebugFormat( "{0} Not attempting to close inactive client {1} in {2} since force flag is not set", 
+                        LogHeader, Name, m_scene.Name);
 
                     return;
                 }
@@ -1162,10 +1163,11 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// <param name="o"></param>
         private void DoSendLayerData(object o)
         {
-            float[] map = LLHeightFieldMoronize((float[])o);
+            float[] map = (float[])o;
 
             try
             {
+                // Send LayerData in typerwriter pattern
                 //for (int y = 0; y < 16; y++)
                 //{
                 //    for (int x = 0; x < 16; x++)
@@ -1230,7 +1232,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         // }
 
         /// <summary>
-        /// Sends a specified patch to a client
+        /// Sends a terrain packet for the point specified.
+        /// This is a legacy call that has refarbed the terrain into a flat map of floats.
+        /// We just use the terrain from the region we know about.
         /// </summary>
         /// <param name="px">Patch coordinate (x) 0..15</param>
         /// <param name="py">Patch coordinate (y) 0..15</param>
@@ -1239,10 +1243,11 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         {
             try
             {
-                int[] patches = new int[] { py * 16 + px };
-                float[] heightmap = (map.Length == 65536) ? map : LLHeightFieldMoronize(map);
-
-                LayerDataPacket layerpack = TerrainCompressor.CreateLandPacket(heightmap, patches);
+                // For unknown reasons, after this point, patch numbers are swapped X for y.
+                //    That means, that for <patchNumX, patchNumY, the array location is computed as map[patchNumY * 16 + patchNumX].
+                //    TODO: someday straighten the below implementation to keep the X row order for patch numbers.
+                // Since this is passing only one patch, we just swap the patch numbers.
+                LayerDataPacket layerpack = OpenSimTerrainCompressor.CreateLandPacket(m_scene.Heightmap.GetTerrainData(), px, py);
                 
                 // When a user edits the terrain, so much data is sent, the data queues up fast and presents a sub optimal editing experience.  
                 // To alleviate this issue, when the user edits the terrain, we start skipping the queues until they're done editing the terrain.
@@ -1260,14 +1265,12 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 if (m_justEditedTerrain)
                 {
                     layerpack.Header.Reliable = false;
-                    OutPacket(layerpack,
-                               ThrottleOutPacketType.Unknown );
+                    OutPacket(layerpack, ThrottleOutPacketType.Unknown );
                 }
                 else
                 {
                     layerpack.Header.Reliable = true;
-                    OutPacket(layerpack,
-                               ThrottleOutPacketType.Land);
+                    OutPacket(layerpack, ThrottleOutPacketType.Land);
                 }
             }
             catch (Exception e)
@@ -1277,38 +1280,6 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         }
 
         /// <summary>
-        /// Munges heightfield into the LLUDP backed in restricted heightfield.
-        /// </summary>
-        /// <param name="map">float array in the base; Constants.RegionSize</param>
-        /// <returns>float array in the base 256</returns>
-        internal float[] LLHeightFieldMoronize(float[] map)
-        {
-            if (map.Length == 65536)
-                return map;
-            else
-            {
-                float[] returnmap = new float[65536];
-
-                if (map.Length < 65535)
-                {
-                    // rebase the vector stride to 256
-                    for (int i = 0; i < Constants.RegionSize; i++)
-                        Array.Copy(map, i * (int)Constants.RegionSize, returnmap, i * 256, (int)Constants.RegionSize);
-                }
-                else
-                {
-                    for (int i = 0; i < 256; i++)
-                        Array.Copy(map, i * (int)Constants.RegionSize, returnmap, i * 256, 256);
-                }
-
-                //Array.Copy(map,0,returnmap,0,(map.Length < 65536)? map.Length : 65536);
-
-                return returnmap;
-            }
-
-        }
-
-        /// <summary>
         ///  Send the wind matrix to the client
         /// </summary>
         /// <param name="windSpeeds">16x16 array of wind speeds</param>
@@ -2780,8 +2751,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         {
             if (req.AssetInf.Data == null)
             {
-                m_log.ErrorFormat("Cannot send asset {0} ({1}), asset data is null",
-                    req.AssetInf.ID, req.AssetInf.Metadata.ContentType);
+                m_log.ErrorFormat("{0} Cannot send asset {1} ({2}), asset data is null",
+                                LogHeader, req.AssetInf.ID, req.AssetInf.Metadata.ContentType);
                 return;
             }
 
diff --git a/OpenSim/Region/CoreModules/World/Terrain/TerrainModule.cs b/OpenSim/Region/CoreModules/World/Terrain/TerrainModule.cs
index 2fff4c1..eb6187b 100644
--- a/OpenSim/Region/CoreModules/World/Terrain/TerrainModule.cs
+++ b/OpenSim/Region/CoreModules/World/Terrain/TerrainModule.cs
@@ -30,10 +30,14 @@ 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.Region.CoreModules.Framework.InterfaceCommander;
 using OpenSim.Region.CoreModules.World.Terrain.FileLoaders;
@@ -130,8 +134,9 @@ namespace OpenSim.Region.CoreModules.World.Terrain
             {
                 if (m_scene.Heightmap == null)
                 {
-                    m_channel = new TerrainChannel(m_InitialTerrain, 
-                            m_scene.RegionInfo.RegionSizeX, m_scene.RegionInfo.RegionSizeY, m_scene.RegionInfo.RegionSizeZ);
+                    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;
                     UpdateRevertMap();
                 }
@@ -707,7 +712,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
         private void CheckForTerrainUpdates(bool respectEstateSettings)
         {
             bool shouldTaint = false;
-            float[] serialised = m_channel.GetFloatsSerialised();
+            float[] terrData = m_channel.GetFloatsSerialised();
             int x;
             for (x = 0; x < m_channel.Width; x += Constants.TerrainPatchSize)
             {
@@ -716,16 +721,16 @@ namespace OpenSim.Region.CoreModules.World.Terrain
                 {
                     if (m_channel.Tainted(x, y))
                     {
-                        // if we should respect the estate settings then
-                        // fixup and height deltas that don't respect them
+                        // 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.
                         if (respectEstateSettings && LimitChannelChanges(x, y))
                         {
-                            // this has been vetoed, so update
-                            // what we are going to send to the client
-                            serialised = m_channel.GetFloatsSerialised();
+                            // Terrain heights were modified. Refetch the terrain info.
+                            terrData = m_channel.GetFloatsSerialised();
                         }
 
-                        SendToClients(serialised, x, y);
+                        SendToClients(terrData, x, y);
                         shouldTaint = true;
                     }
                 }
@@ -794,13 +799,11 @@ 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(float[] heightMap, int x, int y)
         {
             m_scene.ForEachClient(
                 delegate(IClientAPI controller)
-                    { controller.SendLayerData(
-                        x / Constants.TerrainPatchSize, y / Constants.TerrainPatchSize, serialised);
-                    }
+                    { controller.SendLayerData( x / Constants.TerrainPatchSize, y / Constants.TerrainPatchSize, heightMap); }
             );
         }
 
diff --git a/OpenSim/Region/Framework/Interfaces/ISimulationDataStore.cs b/OpenSim/Region/Framework/Interfaces/ISimulationDataStore.cs
index 847d245..5ba5b31 100644
--- a/OpenSim/Region/Framework/Interfaces/ISimulationDataStore.cs
+++ b/OpenSim/Region/Framework/Interfaces/ISimulationDataStore.cs
@@ -136,24 +136,4 @@ namespace OpenSim.Region.Framework.Interfaces
         void Shutdown();
     }
 
-    // The terrain is stored as a blob in the database with a 'revision' field.
-    // Some implementations of terrain storage would fill the revision field with
-    //    the time the terrain was stored. When real revisions were added and this
-    //    feature removed, that left some old entries with the time in the revision
-    //    field.
-    // Thus, if revision is greater than 'RevisionHigh' then terrain db entry is
-    //    left over and it is presumed to be 'Legacy256'.
-    // Numbers are arbitrary and are chosen to to reduce possible mis-interpretation.
-    // If a revision does not match any of these, it is assumed to be Legacy256.
-    public enum DBTerrainRevision
-    {
-        // Terrain is 'double[256,256]'
-        Legacy256 = 11,
-        // Terrain is 'int32, int32, float[,]' where the shorts are X and Y dimensions
-        // The dimensions are presumed to be multiples of 16 and, more likely, multiples of 256.
-        Variable2D = 22,
-        // A revision that is not listed above or any revision greater than this value is 'Legacy256'.
-        RevisionHigh = 1234
-    }
-
 }
diff --git a/OpenSim/Region/Framework/Interfaces/ITerrainChannel.cs b/OpenSim/Region/Framework/Interfaces/ITerrainChannel.cs
index 3c060a4..cc8a236 100644
--- a/OpenSim/Region/Framework/Interfaces/ITerrainChannel.cs
+++ b/OpenSim/Region/Framework/Interfaces/ITerrainChannel.cs
@@ -25,6 +25,8 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+using OpenSim.Framework;
+
 namespace OpenSim.Region.Framework.Interfaces
 {
     public interface ITerrainChannel
@@ -35,18 +37,20 @@ namespace OpenSim.Region.Framework.Interfaces
 
         double this[int x, int y] { get; set; }
 
+        // Return the packaged terrain data for passing into lower levels of communication
+        TerrainData GetTerrainData();
+
         /// <summary>
         /// Squash the entire heightmap into a single dimensioned array
         /// </summary>
         /// <returns></returns>
         float[] GetFloatsSerialised();
-        // Get version of map as a single dimensioned array and each value compressed
-        //     into an int (compressedHeight = (int)(floatHeight * Constants.TerrainCompression);)
-        // This is done to make the map smaller as it can get pretty larger for variable sized regions.
-        short[] GetCompressedMap();
 
         double[,] GetDoubles();
+
+        // Check if a location has been updated. Clears the taint flag as a side effect.
         bool Tainted(int x, int y);
+
         ITerrainChannel MakeCopy();
         string SaveToXmlString();
         void LoadFromXmlString(string data);
diff --git a/OpenSim/Region/Framework/Scenes/Scene.cs b/OpenSim/Region/Framework/Scenes/Scene.cs
index 49e32c6..e2880e3 100644
--- a/OpenSim/Region/Framework/Scenes/Scene.cs
+++ b/OpenSim/Region/Framework/Scenes/Scene.cs
@@ -1905,7 +1905,7 @@ namespace OpenSim.Region.Framework.Scenes
                         m_InitialTerrain = terrainConfig.GetString("InitialTerrain", m_InitialTerrain);
 
                     m_log.InfoFormat("[TERRAIN]: No default terrain. Generating a new terrain {0}.", m_InitialTerrain);
-                    Heightmap = new TerrainChannel(m_InitialTerrain, RegionInfo.RegionSizeX, RegionInfo.RegionSizeY, RegionInfo.RegionSizeZ);
+                    Heightmap = new TerrainChannel(m_InitialTerrain, (int)RegionInfo.RegionSizeX, (int)RegionInfo.RegionSizeY, (int)RegionInfo.RegionSizeZ);
 
                     SimulationDataService.StoreTerrain(Heightmap.GetDoubles(), RegionInfo.RegionID);
                 }
diff --git a/OpenSim/Region/Framework/Scenes/TerrainChannel.cs b/OpenSim/Region/Framework/Scenes/TerrainChannel.cs
index fef93bf..65e890f 100644
--- a/OpenSim/Region/Framework/Scenes/TerrainChannel.cs
+++ b/OpenSim/Region/Framework/Scenes/TerrainChannel.cs
@@ -25,14 +25,19 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-using OpenSim.Framework;
-using OpenSim.Region.Framework.Interfaces;
 using System;
+using System.IO;
 using System.Text;
+using System.Reflection;
 using System.Xml;
-using System.IO;
 using System.Xml.Serialization;
 
+using OpenSim.Data;
+using OpenSim.Framework;
+using OpenSim.Region.Framework.Interfaces;
+
+using log4net;
+
 namespace OpenSim.Region.Framework.Scenes
 {
     /// <summary>
@@ -40,18 +45,20 @@ namespace OpenSim.Region.Framework.Scenes
     /// </summary>
     public class TerrainChannel : ITerrainChannel
     {
-        protected bool[,] m_taint;
-        protected short[] m_map;
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+        private static string LogHeader = "[TERRAIN CHANNEL]";
 
-        public int Width { get; private set; }  // X dimension
+        protected TerrainData m_terrainData;
+
+        public int Width { get { return m_terrainData.SizeX; } }  // X dimension
         // Unfortunately, for historical reasons, in this module 'Width' is X and 'Height' is Y
-        public int Height { get; private set; } // Y dimension
-        public int Altitude { get; private set; } // Y dimension
+        public int Height { get { return m_terrainData.SizeY; } } // Y dimension
+        public int Altitude { get { return m_terrainData.SizeZ; } } // Y dimension
 
         // Default, not-often-used builder
         public TerrainChannel()
         {
-            InitializeStructures(Constants.RegionSize, Constants.RegionSize, Constants.RegionHeight, false);
+            m_terrainData = new HeightmapTerrainData((int)Constants.RegionSize, (int)Constants.RegionSize, (int)Constants.RegionHeight);
             FlatLand();
             // PinHeadIsland();
         }
@@ -59,27 +66,23 @@ namespace OpenSim.Region.Framework.Scenes
         // Create terrain of given size
         public TerrainChannel(int pX, int pY)
         {
-            InitializeStructures((uint)pX, (uint)pY, Constants.RegionHeight, true);
+            m_terrainData = new HeightmapTerrainData(pX, pY, (int)Constants.RegionHeight);
         }
 
         // Create terrain of specified size and initialize with specified terrain.
         // TODO: join this with the terrain initializers.
-        public TerrainChannel(String type, uint pX, uint pY, uint pZ)
+        public TerrainChannel(String type, int pX, int pY, int pZ)
         {
-            InitializeStructures(pX, pY, pZ, false);
+            m_terrainData = new HeightmapTerrainData(pX, pY, pZ);
             if (type.Equals("flat"))
                 FlatLand();
             else
                 PinHeadIsland();
         }
 
-        public TerrainChannel(double[,] pM, uint pH)
+        public TerrainChannel(double[,] pM, uint pAltitude)
         {
-            InitializeStructures((uint)pM.GetLength(0), (uint)pM.GetLength(1), pH, false);
-            int idx = 0;
-            for (int ii = 0; ii < Height; ii++)
-                for (int jj = 0; jj < Width; jj++)
-                    m_map[idx++] = ToCompressedHeight(pM[ii, jj]);
+            m_terrainData = new HeightmapTerrainData(pM);
         }
 
         #region ITerrainChannel Members
@@ -90,20 +93,23 @@ namespace OpenSim.Region.Framework.Scenes
             return this.Copy();
         }
 
-        // ITerrainChannel.GetCompressedMap()
-        public short[] GetCompressedMap()
+        // ITerrainChannel.GetTerrainData()
+        public TerrainData GetTerrainData()
         {
-            return m_map;
+            return m_terrainData;
         }
 
         // ITerrainChannel.GetFloatsSerialized()
+        // NOTICE that the one dimensional form is ordered by Y!!
         public float[] GetFloatsSerialised()
         {
             int points = Width * Height;
             float[] heights = new float[points];
 
-            for (int ii = 0; ii < points; ii++)
-                heights[ii] = FromCompressedHeight(m_map[ii]);
+            int idx = 0;
+            for (int ii = 0; ii < Height; ii++)
+                for (int jj = 0; jj < Width; jj++)
+                    heights[idx++] = m_terrainData[jj, ii];
 
             return heights;
         }
@@ -116,11 +122,11 @@ namespace OpenSim.Region.Framework.Scenes
             double[,] heights = new double[w, l];
 
             int idx = 0; // index into serialized array
-            for (int ii = 0; ii < l; ii++)
+            for (int ii = 0; ii < w; ii++)
             {
-                for (int jj = 0; jj < w; jj++)
+                for (int jj = 0; jj < l; jj++)
                 {
-                    heights[ii, jj] = (double)FromCompressedHeight(m_map[idx]);
+                    heights[ii, jj] = (double)m_terrainData[ii, jj];
                     idx++;
                 }
             }
@@ -131,31 +137,20 @@ namespace OpenSim.Region.Framework.Scenes
         // ITerrainChannel.this[x,y]
         public double this[int x, int y]
         {
-            get { return m_map[x * Width + y]; }
+            get { return (double)m_terrainData[x, y]; }
             set
             {
-                // Will "fix" terrain hole problems. Although not fantastically.
                 if (Double.IsNaN(value) || Double.IsInfinity(value))
                     return;
 
-                int idx = x * Width + y;
-                if (m_map[idx] != value)
-                {
-                    m_taint[x / Constants.TerrainPatchSize, y / Constants.TerrainPatchSize] = true;
-                    m_map[idx] = ToCompressedHeight(value);
-                }
+                m_terrainData[x, y] = (float)value;
             }
         }
 
         // ITerrainChannel.Tainted()
         public bool Tainted(int x, int y)
         {
-            if (m_taint[x / Constants.TerrainPatchSize, y / Constants.TerrainPatchSize])
-            {
-                m_taint[x / Constants.TerrainPatchSize, y / Constants.TerrainPatchSize] = false;
-                return true;
-            }
-            return false;
+            return m_terrainData.IsTaintedAt(x, y);
         }
 
         // ITerrainChannel.SaveToXmlString()
@@ -188,49 +183,25 @@ namespace OpenSim.Region.Framework.Scenes
 
         #endregion
 
-        private void InitializeStructures(uint pX, uint pY, uint pZ, bool shouldInitializeHeightmap)
-        {
-            Width = (int)pX;
-            Height = (int)pY;
-            Altitude = (int)pZ;
-            m_map = new short[Width * Height];
-            m_taint = new bool[Width / Constants.TerrainPatchSize, Height / Constants.TerrainPatchSize];
-            ClearTaint();
-            if (shouldInitializeHeightmap)
-            {
-                FlatLand();
-            }
-        }
-
-        public void ClearTaint()
-        {
-            for (int ii = 0; ii < Width / Constants.TerrainPatchSize; ii++)
-                for (int jj = 0; jj < Height / Constants.TerrainPatchSize; jj++)
-                    m_taint[ii, jj] = false;
-        }
-
+        /*
         // To save space (especially for large regions), keep the height as a short integer
         //    that is coded as the float height times the compression factor (usually '100'
         //    to make for two decimal points).
-        public short ToCompressedHeight(double pHeight)
+        public static short ToCompressedHeight(double pHeight)
         {
             return (short)(pHeight * Constants.TerrainCompression);
         }
 
-        public float FromCompressedHeight(short pHeight)
+        public static float FromCompressedHeight(short pHeight)
         {
             return ((float)pHeight) / Constants.TerrainCompression;
         }
+         */
 
         public TerrainChannel Copy()
         {
             TerrainChannel copy = new TerrainChannel();
-            copy.m_map = (short[])m_map.Clone();
-            copy.m_taint = (bool[,])m_taint.Clone();
-            copy.Width = Width;
-            copy.Height = Height;
-            copy.Altitude = Altitude;
-
+            copy.m_terrainData = m_terrainData.Clone();
             return copy;
         }
 
@@ -289,6 +260,8 @@ namespace OpenSim.Region.Framework.Scenes
             byte[] dataArray = (byte[])serializer.Deserialize(xmlReader);
             int index = 0;
 
+            m_terrainData = new HeightmapTerrainData(Width, Height, Altitude);
+            
             for (int y = 0; y < Height; y++)
             {
                 for (int x = 0; x < Width; x++)
@@ -321,7 +294,7 @@ namespace OpenSim.Region.Framework.Scenes
         // New terrain serialization format that includes the width and length.
         private void ToXml2(XmlWriter xmlWriter)
         {
-            TerrainChannelXMLPackage package = new TerrainChannelXMLPackage(Width, Height, Altitude, m_map);
+            TerrainChannelXMLPackage package = new TerrainChannelXMLPackage(Width, Height, Altitude, m_terrainData.GetCompressedMap());
             XmlSerializer serializer = new XmlSerializer(typeof(TerrainChannelXMLPackage));
             serializer.Serialize(xmlWriter, package);
         }
@@ -331,38 +304,32 @@ namespace OpenSim.Region.Framework.Scenes
         {
             XmlSerializer serializer = new XmlSerializer(typeof(TerrainChannelXMLPackage));
             TerrainChannelXMLPackage package = (TerrainChannelXMLPackage)serializer.Deserialize(xmlReader);
-            Width = package.SizeX;
-            Height = package.SizeY;
-            Altitude = package.SizeZ;
-            m_map = package.Map;
+            m_terrainData = new HeightmapTerrainData(package.Map, package.SizeX, package.SizeY, package.SizeZ);
         }
 
         // Fill the heightmap with the center bump terrain
         private void PinHeadIsland()
         {
-            int x;
-            for (x = 0; x < Width; x++)
+            for (int x = 0; x < Width; x++)
             {
-                int y;
-                for (y = 0; y < Height; y++)
+                for (int y = 0; y < Height; y++)
                 {
-                    int idx = x * (int)Width + y;
-                    m_map[idx] = ToCompressedHeight(TerrainUtil.PerlinNoise2D(x, y, 2, 0.125) * 10);
-                    short spherFacA = ToCompressedHeight(TerrainUtil.SphericalFactor(x, y, Constants.RegionSize / 2.0, Constants.RegionSize / 2.0, 50) * 0.01);
-                    short spherFacB = ToCompressedHeight(TerrainUtil.SphericalFactor(x, y, Constants.RegionSize / 2.0, Constants.RegionSize / 2.0, 100) * 0.001);
-                    if (m_map[idx] < spherFacA)
-                        m_map[idx] = spherFacA;
-                    if (m_map[idx] < spherFacB)
-                        m_map[idx] = spherFacB;
+                    m_terrainData[x, y] = (float)TerrainUtil.PerlinNoise2D(x, y, 2, 0.125) * 10;
+                    float spherFacA = (float)(TerrainUtil.SphericalFactor(x, y, m_terrainData.SizeX / 2.0, m_terrainData.SizeY / 2.0, 50) * 0.01d);
+                    float spherFacB = (float)(TerrainUtil.SphericalFactor(x, y, m_terrainData.SizeX / 2.0, m_terrainData.SizeY / 2.0, 100) * 0.001d);
+                    if (m_terrainData[x, y]< spherFacA)
+                        m_terrainData[x, y]= spherFacA;
+                    if (m_terrainData[x, y]< spherFacB)
+                        m_terrainData[x, y] = spherFacB;
                 }
             }
         }
 
         private void FlatLand()
         {
-            short flatHeight = ToCompressedHeight(21);
-            for (int ii = 0; ii < m_map.Length; ii++)
-                m_map[ii] = flatHeight;
+            for (int xx = 0; xx < Width; xx++)
+                for (int yy = 0; yy < Height; yy++)
+                    m_terrainData[xx, yy] = 21;
         }
     }
 }
diff --git a/OpenSim/Region/Framework/Scenes/TerrainCompressor.cs b/OpenSim/Region/Framework/Scenes/TerrainCompressor.cs
index 2e856bc..511745d 100644
--- a/OpenSim/Region/Framework/Scenes/TerrainCompressor.cs
+++ b/OpenSim/Region/Framework/Scenes/TerrainCompressor.cs
@@ -113,22 +113,17 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         //     routines (like IClientAPI) only pass the float array of heights around. This entry
         //     converts that legacy representation into the more compact represenation used in
         //     TerrainChannel. Someday fix the plumbing between here and the scene.
-        public static LayerDataPacket CreateLandPacket(float[] heightmap, int patchX, int patchY, uint sizeX, uint sizeY)
+        public static LayerDataPacket CreateLandPacket(TerrainData terrData, int patchX, int patchY)
         {
             int[] xPieces = new int[1];
             int[] yPieces = new int[1];
-
-            short[] newmap = new short[heightmap.Length];
-            for (int ii = 0; ii < heightmap.Length; ii++)
-                newmap[ii] = TerrainChannel.ToCompressedHeight(heightmap[ii]);
-
             xPieces[0] = patchX;  // patch X dimension
             yPieces[0] = patchY;
 
             m_log.DebugFormat("{0} CreateLandPacket. patchX={1}, patchY={2}, sizeX={3}, sizeY={4}",
-                                    LogHeader, patchX, patchY, sizeX, sizeY);
+                                    LogHeader, patchX, patchY, terrData.SizeX, terrData.SizeY);
 
-            return CreateLandPacket(newmap, xPieces, yPieces, (int)TerrainPatch.LayerType.Land, sizeX, sizeY);
+            return CreateLandPacket(terrData, xPieces, yPieces, (int)TerrainPatch.LayerType.Land);
         }
 
         /// <summary>
@@ -153,8 +148,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// <param name="pRegionSizeX"></param>
         /// <param name="pRegionSizeY"></param>
         /// <returns></returns>
-        public static LayerDataPacket CreateLandPacket(short[] heightmap, int[] x, int[] y, byte type,
-                                        uint pRegionSizeX, uint pRegionSizeY)
+        public static LayerDataPacket CreateLandPacket(TerrainData terrData, int[] x, int[] y, byte type)
         {
             LayerDataPacket layer = new LayerDataPacket {LayerID = {Type = type}};
 
@@ -168,7 +162,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             bitpack.PackBits(type, 8);
 
             for (int i = 0; i < x.Length; i++)
-                CreatePatchFromHeightmap(bitpack, heightmap, x[i], y[i], pRegionSizeX, pRegionSizeY);
+                CreatePatchFromHeightmap(bitpack, terrData, x[i], y[i]);
 
             bitpack.PackBits(END_OF_PATCHES, 8);
 
@@ -217,14 +211,13 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// </param>
         /// <param name="pRegionSizeX"></param>
         /// <param name="pRegionSizeY"></param>
-        public static void CreatePatchFromHeightmap(BitPack output, short[] heightmap, int patchX, int patchY,
-                                        uint pRegionSizeX, uint pRegionSizeY)
+        public static void CreatePatchFromHeightmap(BitPack output, TerrainData terrData, int patchX, int patchY)
         {
-            TerrainPatch.Header header = PrescanPatch(heightmap, patchX, patchY, pRegionSizeX, pRegionSizeY);
+            TerrainPatch.Header header = PrescanPatch(terrData, patchX, patchY);
             header.QuantWBits = 136;
 
             // If larger than legacy region size, pack patch X and Y info differently.
-            if (pRegionSizeX > Constants.RegionSize || pRegionSizeY > Constants.RegionSize)
+            if (terrData.SizeX > Constants.RegionSize || terrData.SizeY > Constants.RegionSize)
             {
                 header.PatchIDs = (patchY & 0xFFFF);
                 header.PatchIDs += (patchX << 16);
@@ -237,8 +230,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             // NOTE: No idea what prequant and postquant should be or what they do
             int wbits;
-            int[] patch = CompressPatch(heightmap, patchX, patchY, header, 10, pRegionSizeX, pRegionSizeY, out wbits);
-            wbits = EncodePatchHeader(output, header, patch, pRegionSizeX, pRegionSizeY, wbits);
+            int[] patch = CompressPatch(terrData, patchX, patchY, header, 10, out wbits);
+            wbits = EncodePatchHeader(output, header, patch, (uint)terrData.SizeX, (uint)terrData.SizeY, wbits);
             EncodePatch(output, patch, 0, wbits);
         }
 
@@ -262,19 +255,18 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         }
 
         // Scan the height info we're returning and return a patch packet header for this patch.
-        // TODO. Why are patches ordered Y,X rather than X,Y?
-        private static TerrainPatch.Header PrescanPatch(short[] heightmap, int patchX, int patchY,
-                                uint pRegionSizeX, uint pRegionSizeY)
+        private static TerrainPatch.Header PrescanPatch(TerrainData terrData, int patchX, int patchY)
         {
             TerrainPatch.Header header = new TerrainPatch.Header();
-            short zmax = -32767;
-            short zmin = 32767;
+            float zmax = -99999999.0f;
+            float zmin = 99999999.0f;
 
             for (int j = patchY*16; j < (patchY + 1)*16; j++)
             {
                 for (int i = patchX*16; i < (patchX + 1)*16; i++)
                 {
-                    short val = heightmap[j*pRegionSizeX + i];
+                    // short val = heightmap[j*pRegionSizeX + i];
+                    float val = terrData[j, i];
                     if (val > zmax) zmax = val;
                     if (val < zmin) zmin = val;
                 }
@@ -282,8 +274,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             // Since the the min and max values are the shorts, rescale to be real values.
             // TODO: all this logic should go into the class wrapping the short values.
-            header.DCOffset = TerrainChannel.FromCompressedHeight(zmin);
-            header.Range = (int)(TerrainChannel.FromCompressedHeight(zmax) - TerrainChannel.FromCompressedHeight(zmin) + 1.0f);
+            header.DCOffset = zmin;
+            header.Range = (int)(zmax - zmin + 1.0f);
 
             return header;
         }
@@ -812,8 +804,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             return itemp;
         }
 
-        private static int[] CompressPatch(short[] heightmap, int patchX, int patchY, TerrainPatch.Header header,
-                                           int prequant, uint pRegionSizeX, uint pRegionSizeY, out int wbits)
+        private static int[] CompressPatch(TerrainData terrData, int patchX, int patchY, TerrainPatch.Header header,
+                                                               int prequant, out int wbits)
         {
             float[] block = new float[Constants.TerrainPatchSize*Constants.TerrainPatchSize];
             int wordsize = prequant;
@@ -827,19 +819,17 @@ namespace OpenSim.Region.ClientStack.LindenUDP
 
             int k = 0;
 
-            premult /= Constants.TerrainCompression; // put here short to float factor
-
             int jPatchLimit = patchY;
-            if (patchY >= (pRegionSizeY / Constants.TerrainPatchSize))
+            if (patchY >= (terrData.SizeY / Constants.TerrainPatchSize))
             {
-                jPatchLimit = (int)(pRegionSizeY - Constants.TerrainPatchSize) / Constants.TerrainPatchSize;
+                jPatchLimit = (int)(terrData.SizeY - Constants.TerrainPatchSize) / Constants.TerrainPatchSize;
             }
             jPatchLimit = (jPatchLimit + 1) * Constants.TerrainPatchSize;
 
             int iPatchLimit = patchX;
-            if (patchX >= (pRegionSizeX / Constants.TerrainPatchSize))
+            if (patchX >= (terrData.SizeX / Constants.TerrainPatchSize))
             {
-                iPatchLimit = (int)(pRegionSizeX - Constants.TerrainPatchSize) / Constants.TerrainPatchSize;
+                iPatchLimit = (int)(terrData.SizeX - Constants.TerrainPatchSize) / Constants.TerrainPatchSize;
             }
             iPatchLimit = (iPatchLimit + 1) * Constants.TerrainPatchSize;
 
@@ -847,7 +837,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             {
                 for (int i = patchX * Constants.TerrainPatchSize; i < iPatchLimit; i++)
                 {
-                    block[k++] = (heightmap[j*pRegionSizeX + i])*premult - sub;
+                    // block[k++] = (heightmap[j*pRegionSizeX + i])*premult - sub;
+                    block[k++] = terrData[j, i] - sub;
                 }
             }