Fixes Mantis #3255. Thank you kindly, MCortez, for a patch that:

Changes to IWindModule interface: Change from assuming a single array of 
256 Vector2 values to a lookup function that takes region x, y, z and returns a Vector3
* Changed llWind() to use new lookup method of IWindModule
* Moved logic for determining the wind at a given point in the data array from 
llWind() to the Wind Module itself.

OpenSim/Region/CoreModules/World/Wind/WindModule.cs

@@ -45,7 +45,10 @@ namespace OpenSim.Region.CoreModules
         private Random rndnums = new Random(Environment.TickCount);
         private Scene m_scene = null;
         private bool ready = false;
+
+        // Simplified windSpeeds based on the fact that the client protocal tracks at a resolution of 16m
         private Vector2[] windSpeeds = new Vector2[16 * 16];
+
         private Dictionary<UUID, ulong> m_rootAgents = new Dictionary<UUID, ulong>();
      
         public void Initialise(Scene scene, IConfigSource config)
@@ -89,9 +92,32 @@ namespace OpenSim.Region.CoreModules
             get { return false; }
         }
 
-        public Vector2[] WindSpeeds
+        /// <summary>
+        /// Retrieve the wind speed at the given region coordinate.  This 
+        /// implimentation ignores Z.
+        /// </summary>
+        /// <param name="x">0...255</param>
+        /// <param name="y">0...255</param>
+        /// <returns></returns>
+        public Vector3 WindSpeed(int x, int y, int z)
         {
-            get { return windSpeeds; }
+            Vector3 windVector = new Vector3(0.0f, 0.0f, 0.0f);
+            
+            x /= 16;
+            y /= 16;
+            if (x < 0) x = 0;
+            if (x > 15) x = 15;
+            if (y < 0) y = 0;
+            if (y > 15) y = 15;
+
+            if (windSpeeds != null)
+            {
+                windVector.X = windSpeeds[y * 16 + x].X;
+                windVector.Y = windSpeeds[y * 16 + x].Y;
+            }
+
+
+            return windVector;
         }
 
         public void WindToClient(IClientAPI client)

OpenSim/Region/Framework/Interfaces/IWindModule.cs

@@ -31,9 +31,10 @@ namespace OpenSim.Region.Framework.Interfaces
 {
     public interface IWindModule : IRegionModule
     {
-        Vector2[] WindSpeeds
-        {
-            get;
-        }
+        
+        /// <summary>
+        /// Retrieves the current wind speed at the given Region Coordinates
+        /// </summary>
+        Vector3 WindSpeed(int x, int y, int z);
     }
 }

OpenSim/Region/ScriptEngine/Shared/Api/Implementation/LSL_Api.cs

@@ -1031,17 +1031,16 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
             m_host.AddScriptLPS(1);
             LSL_Vector wind = new LSL_Vector(0, 0, 0);
             IWindModule module = World.RequestModuleInterface<IWindModule>();
-            if (module != null && module.WindSpeeds != null)
+            if (module != null)
             {
                 Vector3 pos = m_host.GetWorldPosition();
-                int x = (int)((pos.X + offset.x)/ 16);
-                int y = (int)((pos.Y + offset.y)/ 16);
-                if (x < 0) x = 0;
-                if (x > 15) x = 15;
-                if (y < 0) y = 0;
-                if (y > 15) y = 15;
-                wind.x = module.WindSpeeds[y * 16 + x].X;
-                wind.y = module.WindSpeeds[y * 16 + x].Y;
+                int x = (int)(pos.X + offset.x);
+                int y = (int)(pos.Y + offset.y);
+
+                Vector3 windSpeed = module.WindSpeed(x, y, 0);
+
+                wind.x = windSpeed.X;
+                wind.y = windSpeed.Y;
             }
             return wind;
         }