Mantis#1768. Thank you kindly, Junta_Kohime for a patch that:

llRot2Fwd function modified, using fast algebric calculations 
instead of vectors and quaternions products. The accuracy is 
the same. Normalization is now implemented.

2 files changed, 30 insertions, 2 deletions

diff --git a/OpenSim/Region/ScriptEngine/Common/LSL_BuiltIn_Commands.cs b/OpenSim/Region/ScriptEngine/Common/LSL_BuiltIn_Commands.cs
index b53f6c0..3ae1f3a 100644
--- a/OpenSim/Region/ScriptEngine/Common/LSL_BuiltIn_Commands.cs
+++ b/OpenSim/Region/ScriptEngine/Common/LSL_BuiltIn_Commands.cs
@@ -430,7 +430,21 @@ namespace OpenSim.Region.ScriptEngine.Common
         public LSL_Types.Vector3 llRot2Fwd(LSL_Types.Quaternion r)
         {
             m_host.AddScriptLPS(1);
-            return (new LSL_Types.Vector3(1,0,0) * r);
+            double x,y,z,m;
+            m = Math.Sqrt(r.x*r.x+r.y*r.y+r.z*r.z+r.s*r.s);
+            // m is always greater than zero
+            if (m!=1) // if m is not equal to 1 then Rotation needs to be normalized
+            {
+                r.x/=m;
+                r.y/=m;
+                r.z/=m;
+                r.s/=m;
+            }
+            // Fast Algebric Calculations instead of Vectors & Quaternions Product
+            x = r.x*r.x-r.y*r.y-r.z*r.z+r.s*r.s;
+            y = 2*(r.x*r.y+r.z*r.s);
+            z = 2*(r.x*r.z-r.y*r.s);
+            return (new LSL_Types.Vector3(x,y,z)); 
         }
 
         public LSL_Types.Vector3 llRot2Left(LSL_Types.Quaternion r)
diff --git a/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/LSL_Api.cs b/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/LSL_Api.cs
index 260457b..e7313e1 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/LSL_Api.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/LSL_Api.cs
@@ -417,7 +417,21 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
         public LSL_Types.Vector3 llRot2Fwd(LSL_Types.Quaternion r)
         {
             m_host.AddScriptLPS(1);
-            return (new LSL_Types.Vector3(1,0,0) * r);
+            double x,y,z,m;
+            m = Math.Sqrt(r.x*r.x+r.y*r.y+r.z*r.z+r.s*r.s);
+            // m is always greater than zero
+            if (m!=1) // if m is not equal to 1 then Rotation needs to be normalized
+            {
+                r.x/=m;
+                r.y/=m;
+                r.z/=m;
+                r.s/=m;
+            }
+            // Fast Algebric Calculations instead of Vectors & Quaternions Product
+            x = r.x*r.x-r.y*r.y-r.z*r.z+r.s*r.s;
+            y = 2*(r.x*r.y+r.z*r.s);
+            z = 2*(r.x*r.z-r.y*r.s);
+            return (new LSL_Types.Vector3(x,y,z)); 
         }
 
         public LSL_Types.Vector3 llRot2Left(LSL_Types.Quaternion r)