From: Christopher Yeoh <yeohc@au1.ibm.com>

The attached patch implements osGetDrawStringSize that looks like:

vector osGetDrawStringSize(string contentType, string text, string
fontName, int fontSize)

in LSL. It is meant to be used in conjunction with the osDraw*
functions. It returns accurate information on the size that a given
string will be rendered given the specified font and font size.
This allows for nicely formatted and positioned text on the generated
image.

OpenSim/Region/CoreModules/Scripting/DynamicTexture/DynamicTextureModule.cs

@@ -143,6 +143,18 @@ namespace OpenSim.Region.CoreModules.Scripting.DynamicTexture
             return UUID.Zero;
         }
 
+
+        public void GetDrawStringSize(string contentType, string text, string fontName, int fontSize,
+                                      out double xSize, out double ySize)
+        {
+            xSize = 0;
+            ySize = 0;
+            if (RenderPlugins.ContainsKey(contentType))
+            {
+                RenderPlugins[contentType].GetDrawStringSize(text, fontName, fontSize, out xSize, out ySize);
+            }
+        }
+
         #endregion
 
         #region IRegionModule Members

OpenSim/Region/CoreModules/Scripting/LoadImageURL/LoadImageURLModule.cs

@@ -84,6 +84,13 @@ namespace OpenSim.Region.CoreModules.Scripting.LoadImageURL
             return false;
         }
 
+        public void GetDrawStringSize(string text, string fontName, int fontSize, 
+                                      out double xSize, out double ySize)
+        {
+            xSize = 0;
+            ySize = 0;
+        }
+
         #endregion
 
         #region IRegionModule Members

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

@@ -89,6 +89,20 @@ namespace OpenSim.Region.CoreModules.Scripting.VectorRender
             return true;
         }
 
+        public void GetDrawStringSize(string text, string fontName, int fontSize, 
+                                      out double xSize, out double ySize)
+        {
+            Bitmap bitmap = new Bitmap(1024, 1024, PixelFormat.Format32bppArgb);
+            Graphics graph = Graphics.FromImage(bitmap);
+
+            Font myFont = new Font(fontName, fontSize);
+            SizeF stringSize = new SizeF();
+            stringSize = graph.MeasureString(text, myFont);
+            xSize = stringSize.Width;
+            ySize = stringSize.Height;
+        }
+
+
         #endregion
 
         #region IRegionModule Members

OpenSim/Region/Framework/Interfaces/IDynamicTextureManager.cs

@@ -43,6 +43,8 @@ namespace OpenSim.Region.Framework.Interfaces
                                      int updateTimer);
         UUID AddDynamicTextureData(UUID simID, UUID primID, string contentType, string data, string extraParams,
                                     int updateTimer, bool SetBlending, byte AlphaValue);
+        void GetDrawStringSize(string contentType, string text, string fontName, int fontSize,
+                               out double xSize, out double ySize);
     }
 
     public interface IDynamicTextureRender
@@ -54,5 +56,7 @@ namespace OpenSim.Region.Framework.Interfaces
         byte[] ConvertStream(Stream data, string extraParams);
         bool AsyncConvertUrl(UUID id, string url, string extraParams);
         bool AsyncConvertData(UUID id, string bodyData, string extraParams);
+        void GetDrawStringSize(string text, string fontName, int fontSize, 
+                               out double xSize, out double ySize);
     }
 }

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

@@ -677,6 +677,24 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
             return drawList;
         }
 
+        public LSL_Vector osGetDrawStringSize(string contentType, string text, string fontName, int fontSize)
+        {
+            CheckThreatLevel(ThreatLevel.VeryLow, "osGetDrawStringSize");
+            m_host.AddScriptLPS(1);
+
+            LSL_Vector vec = new LSL_Vector(0,0,0);
+            IDynamicTextureManager textureManager = World.RequestModuleInterface<IDynamicTextureManager>();
+            if (textureManager != null) 
+            {
+                double xSize, ySize;
+                textureManager.GetDrawStringSize(contentType, text, fontName, fontSize,
+                                                 out xSize, out ySize);
+                vec.x = xSize;
+                vec.y = ySize;
+            }
+            return vec;
+        }
+
         public void osSetStateEvents(int events)
         {
             // This function is a hack. There is no reason for it's existence

OpenSim/Region/ScriptEngine/Shared/Api/Interface/IOSSL_Api.cs

@@ -88,6 +88,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api.Interfaces
         string osSetPenSize(string drawList, int penSize);
         string osSetPenColour(string drawList, string colour);
         string osDrawImage(string drawList, int width, int height, string imageUrl);
+        vector osGetDrawStringSize(string contentType, string text, string fontName, int fontSize);
         void osSetStateEvents(int events);
 
         double osList2Double(LSL_Types.list src, int index);

OpenSim/Region/ScriptEngine/Shared/Api/Runtime/OSSL_Stub.cs

@@ -212,6 +212,12 @@ namespace OpenSim.Region.ScriptEngine.Shared.ScriptBase
         {
             return m_OSSL_Functions.osDrawImage(drawList, width, height, imageUrl);
         }
+
+        public vector osGetDrawStringSize(string contentType, string text, string fontName, int fontSize)
+        {
+            return m_OSSL_Functions.osGetDrawStringSize(contentType, text, fontName, fontSize);
+        }
+
         public void osSetStateEvents(int events)
         {
             m_OSSL_Functions.osSetStateEvents(events);