1 files changed, 30 insertions, 21 deletions

diff --git a/OpenSim/Region/ScriptEngine/Common/LSL_BuiltIn_Commands.cs b/OpenSim/Region/ScriptEngine/Common/LSL_BuiltIn_Commands.cs
index 7745d95..bea805e 100644
--- a/OpenSim/Region/ScriptEngine/Common/LSL_BuiltIn_Commands.cs
+++ b/OpenSim/Region/ScriptEngine/Common/LSL_BuiltIn_Commands.cs
@@ -427,32 +427,41 @@ namespace OpenSim.Region.ScriptEngine.Common
             int f=0;
                         // Important Note: q1=<x,y,z,s> is equal to q2=<-x,-y,-z,-s>
                         // Computing quaternion x,y,z,s values        
-                x=((fwd.x-left.y-up.z+1)/4);
-                x*=x;
-                x=Math.Sqrt(Math.Sqrt(x));
-                y=((1-up.z)/2-x*x);
-                y*=y;
-                y=Math.Sqrt(Math.Sqrt(y));
-                z=((1-left.y)/2-x*x);
-                z*=z;
-                z=Math.Sqrt(Math.Sqrt(z));
-                s=(1-x*x-y*y-z*z);
-                s*=s;
-                s=Math.Sqrt(Math.Sqrt(s));
-                
+            x = ((fwd.x - left.y - up.z + 1) / 4);
+            x *= x;
+            x = Math.Sqrt(Math.Sqrt(x));
+            y = ((1 - up.z) / 2 - x * x);
+            y *= y;
+            y = Math.Sqrt(Math.Sqrt(y));
+            z = ((1 - left.y) / 2 - x * x);
+            z *= z;
+            z = Math.Sqrt(Math.Sqrt(z));
+            s = (1 - x * x - y * y - z * z);
+            s *= s;
+            s = Math.Sqrt(Math.Sqrt(s));
+
                         // Set f for signs detection         
                 if (fwd.y+left.x >= 0){f+=1;}
                 if (fwd.z+up.x >= 0){f+=2;}
                 if (left.z-up.y >= 0){f+=4;}
                         // Set correct quaternion signs based on f value
-                if (f==0){x=-x;}
-                if (f==1){x=-x;y=-y;}
-                if (f==2){x=-x;z=-z;}
-                if (f==3){s=-s;}
-                if (f==4){x=-x;s=-s;}
-                if (f==5){z=-z;}
-                if (f==6){y=-y;}
-                return new LSL_Types.Quaternion(x, y, z, s);
+            if (f == 0) { x = -x; }
+            if (f == 1) { x = -x; y = -y; }
+            if (f == 2) { x = -x; z = -z; }
+            if (f == 3) { s = -s; }
+            if (f == 4) { x = -x; s = -s; }
+            if (f == 5) { z = -z; }
+            if (f == 6) { y = -y; }
+
+            LSL_Types.Quaternion result = new LSL_Types.Quaternion(x, y, z, s);
+
+            // a hack to correct a few questionable angles :(
+            LSL_Types.Vector3 fwdTest = new LSL_Types.Vector3(1, 0, 0);
+            LSL_Types.Vector3 leftTest = new LSL_Types.Vector3(0, 1, 0);
+            if (llVecDist(fwdTest * result, fwd) > 0.001 || llVecDist(leftTest * result, left) > 0.001)
+                result.s = -s;
+
+                return result;
         }
         
         public LSL_Types.Vector3 llRot2Fwd(LSL_Types.Quaternion r)