If reusing dynamic textures, do not reuse small data length textures that fall below current viewer discard level 2 thresholds.

Viewer LL 3.3.4 and before sometimes fail to properly redisplay dynamic textures that have a small data length compared to pixel size when pulled from cache.
This appears to happen when the data length is smaller than the estimate discard level 2 size the viewer uses when making this GetTexture request.
This commit works around this by always regenerating dynamic textures that fall below this threshold rather than reusing them if ReuseDynamicTextures = true
This can be controlled by the [Textures] ReuseDynamicLowDataTextures config setting which defaults to false.

OpenSim/Region/CoreModules/Scripting/VectorRender/Tests/VectorRenderModuleTests.cs

@@ -57,6 +57,7 @@ namespace OpenSim.Region.CoreModules.Scripting.VectorRender.Tests
 
             m_dtm = new DynamicTextureModule();
             m_dtm.ReuseTextures = reuseTextures;
+//            m_dtm.ReuseLowDataTextures = reuseTextures;
 
             m_vrm = new VectorRenderModule();
 
@@ -201,6 +202,7 @@ namespace OpenSim.Region.CoreModules.Scripting.VectorRender.Tests
         public void TestRepeatSameDrawReusingTexture()
         {
             TestHelpers.InMethod();
+//            TestHelpers.EnableLogging();
 
             string dtText = "PenColour BLACK; MoveTo 40,220; FontSize 32; Text Hello World;";
 
@@ -228,6 +230,46 @@ namespace OpenSim.Region.CoreModules.Scripting.VectorRender.Tests
             Assert.That(firstDynamicTextureID, Is.EqualTo(so.RootPart.Shape.Textures.GetFace(0).TextureID));
         }
 
+        /// <summary>
+        /// Test a low data dynamically generated texture such that it is treated as a low data texture that causes
+        /// problems for current viewers.
+        /// </summary>
+        /// <remarks>
+        /// As we do not set DynamicTextureModule.ReuseLowDataTextures = true in this test, it should not reuse the
+        /// texture
+        /// </remarks>
+        [Test]
+        public void TestRepeatSameDrawLowDataTexture()
+        {
+            TestHelpers.InMethod();
+//            TestHelpers.EnableLogging();
+
+            string dtText = "PenColour BLACK; MoveTo 40,220; FontSize 32; Text Hello World;";
+
+            SetupScene(true);
+            SceneObjectGroup so = SceneHelpers.AddSceneObject(m_scene);
+
+            m_dtm.AddDynamicTextureData(
+                m_scene.RegionInfo.RegionID,
+                so.UUID,
+                m_vrm.GetContentType(),
+                dtText,
+                "1024",
+                0);
+
+            UUID firstDynamicTextureID = so.RootPart.Shape.Textures.GetFace(0).TextureID;
+
+            m_dtm.AddDynamicTextureData(
+                m_scene.RegionInfo.RegionID,
+                so.UUID,
+                m_vrm.GetContentType(),
+                dtText,
+                "1024",
+                0);
+
+            Assert.That(firstDynamicTextureID, Is.Not.EqualTo(so.RootPart.Shape.Textures.GetFace(0).TextureID));
+        }
+
         [Test]
         public void TestRepeatSameDrawDifferentExtraParamsReusingTexture()
         {

OpenSim/Region/CoreModules/Scripting/VectorRender/VectorRenderModule.cs

@@ -35,6 +35,7 @@ using System.Net;
 using Nini.Config;
 using OpenMetaverse;
 using OpenMetaverse.Imaging;
+using OpenSim.Region.CoreModules.Scripting.DynamicTexture;
 using OpenSim.Region.Framework.Interfaces;
 using OpenSim.Region.Framework.Scenes;
 using log4net;
@@ -85,20 +86,14 @@ namespace OpenSim.Region.CoreModules.Scripting.VectorRender
 //            return lines.Any((str, r) => str.StartsWith("Image"));
 //        }
 
-        public byte[] ConvertUrl(string url, string extraParams)
+        public IDynamicTexture ConvertUrl(string url, string extraParams)
         {
             return null;
         }
 
-        public byte[] ConvertData(string bodyData, string extraParams)
+        public IDynamicTexture ConvertData(string bodyData, string extraParams)
         {
-            bool reuseable;
-            return Draw(bodyData, extraParams, out reuseable);
-        }
-
-        private byte[] ConvertData(string bodyData, string extraParams, out bool reuseable)
-        {
-            return Draw(bodyData, extraParams, out reuseable);
+            return Draw(bodyData, extraParams);
         }
 
         public bool AsyncConvertUrl(UUID id, string url, string extraParams)
@@ -109,10 +104,7 @@ namespace OpenSim.Region.CoreModules.Scripting.VectorRender
         public bool AsyncConvertData(UUID id, string bodyData, string extraParams)
         {
             // XXX: This isn't actually being done asynchronously!
-            bool reuseable;
-            byte[] data = ConvertData(bodyData, extraParams, out reuseable);
-
-            m_textureManager.ReturnData(id, data, reuseable);
+            m_textureManager.ReturnData(id, ConvertData(bodyData, extraParams));
 
             return true;
         }
@@ -191,7 +183,7 @@ namespace OpenSim.Region.CoreModules.Scripting.VectorRender
 
         #endregion
 
-        private byte[] Draw(string data, string extraParams, out bool reuseable)
+        private IDynamicTexture Draw(string data, string extraParams)
         {
             // We need to cater for old scripts that didnt use extraParams neatly, they use either an integer size which represents both width and height, or setalpha
             // we will now support multiple comma seperated params in the form  width:256,height:512,alpha:255
@@ -334,6 +326,7 @@ namespace OpenSim.Region.CoreModules.Scripting.VectorRender
 
             Bitmap bitmap = null;
             Graphics graph = null;
+            bool reuseable = false;
 
             try
             {
@@ -396,7 +389,8 @@ namespace OpenSim.Region.CoreModules.Scripting.VectorRender
                         e.Message, e.StackTrace);
                 }
 
-                return imageJ2000;
+                return new OpenSim.Region.CoreModules.Scripting.DynamicTexture.DynamicTexture(
+                    data, extraParams, imageJ2000, new Size(width, height), reuseable);
             }
             finally
             {