* Apply http://opensimulator.org/mantis/view.php?id=3427

* Return different values for llCloud() over time based on a cellular automation system.
* Thanks aduffy70!

OpenSim/Region/CoreModules/World/Cloud/CloudModule.cs

@@ -39,7 +39,8 @@ namespace OpenSim.Region.CoreModules
     {
 //        private static readonly log4net.ILog m_log 
 //            = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
-
+        private uint m_frame = 0;
+        private int m_frameUpdateRate = 1000;
         private Random m_rndnums = new Random(Environment.TickCount);
         private Scene m_scene = null;
         private bool m_ready = false;
@@ -57,6 +58,7 @@ namespace OpenSim.Region.CoreModules
             {
                 m_enabled = cloudConfig.GetBoolean("enabled", false);
                 m_cloudDensity = cloudConfig.GetFloat("density", 0.5F);
+                m_frameUpdateRate = cloudConfig.GetInt("cloud_update_rate", 1000);
             }
 
             if (m_enabled)
@@ -68,6 +70,7 @@ namespace OpenSim.Region.CoreModules
                 scene.EventManager.OnAvatarEnteringNewParcel += AvatarEnteringParcel;
                 scene.EventManager.OnClientClosed += ClientLoggedOut;
                 scene.RegisterModuleInterface<ICloudModule>(this);
+                scene.EventManager.OnFrame += CloudUpdate;
 
                 GenerateCloudCover();
 
@@ -90,6 +93,7 @@ namespace OpenSim.Region.CoreModules
                 m_scene.EventManager.OnMakeChildAgent -= MakeChildAgent;
                 m_scene.EventManager.OnAvatarEnteringNewParcel -= AvatarEnteringParcel;
                 m_scene.EventManager.OnClientClosed -= ClientLoggedOut;
+                m_scene.EventManager.OnFrame -= CloudUpdate;
             }
         }
 
@@ -122,6 +126,72 @@ namespace OpenSim.Region.CoreModules
             return cover;
         }
 
+        private void UpdateCloudCover()
+        {
+            float[] newCover = new float[16 * 16];
+            int rowAbove = new int();
+            int rowBelow = new int();
+            int columnLeft = new int();
+            int columnRight = new int();
+            for (int x = 0; x < 16; x++)
+            {
+                if (x == 0)
+                {
+                    columnRight = x + 1;
+                    columnLeft = 15;
+                }
+                else if (x == 15)
+                {
+                    columnRight = 0;
+                    columnLeft = x - 1;
+                }
+                else 
+                {
+                    columnRight = x + 1;
+                    columnLeft = x - 1;
+                }
+                for (int y = 0; y< 16; y++)
+                {
+                    if (y == 0)
+                    {
+                        rowAbove = y + 1;
+                        rowBelow = 15;
+                    }
+                    else if (y == 15)
+                    {
+                        rowAbove = 0;
+                        rowBelow = y - 1;
+                    }
+                    else
+                    {
+                        rowAbove = y + 1;
+                        rowBelow = y - 1;
+                    }
+                    float neighborAverage = (cloudCover[rowBelow * 16 + columnLeft] + 
+                                             cloudCover[y * 16 + columnLeft] + 
+                                             cloudCover[rowAbove * 16 + columnLeft] + 
+                                             cloudCover[rowBelow * 16 + x] + 
+                                             cloudCover[rowAbove * 16 + x] + 
+                                             cloudCover[rowBelow * 16 + columnRight] + 
+                                             cloudCover[y * 16 + columnRight] + 
+                                             cloudCover[rowAbove * 16 + columnRight] + 
+                                             cloudCover[y * 16 + x]) / 9;
+                    newCover[y * 16 + x] = ((neighborAverage / m_cloudDensity) + 0.175f) % 1.0f;
+                    newCover[y * 16 + x] *= m_cloudDensity;
+                }
+            }
+            Array.Copy(newCover, cloudCover, 16 * 16);
+        }
+  
+       private void CloudUpdate()
+       {
+           if (((m_frame++ % m_frameUpdateRate) != 0) || !m_ready || (m_cloudDensity == 0))
+           {
+               return;
+           }
+           UpdateCloudCover();
+        }
+
         public void CloudsToClient(IClientAPI client)
         {
             if (m_ready)

bin/OpenSim.ini.example

@@ -746,6 +746,9 @@
     ; Density of cloud cover 0.0 to 1.0
     density = 0.5
 
+    ; update interval for the cloud cover data returned by llCloud().  
+    ; default is 1000
+    cloud_update_rate = 1000
 
 [Trees]
     ; Enable this to allow the tree module to manage your sim trees, including growing, reproducing and dying