Add new angles calculation method suggested by Yoran.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@2861 dfc29bdd-3216-0410-991c-e03cc46cb475

include/vector3d.h

@@ -277,23 +277,47 @@ namespace core
 
 			angle.Y = (T)(atan2(X, Z) * (T) RADTODEG64);
 
-			if (angle.Y < 0.0f)
-				angle.Y += 360.0f;
-			if (angle.Y >= 360.0f)
-				angle.Y -= 360.0f;
+			if (angle.Y < 0)
+				angle.Y += 360;
+			if (angle.Y >= 360)
+				angle.Y -= 360;
 
 			const T z1 = core::squareroot(X*X + Z*Z);
 
-			angle.X = (T)(atan2(z1, (T)Y) * (T) RADTODEG64 - (T) 90.0);
+			angle.X = (T)(atan2((f64)z1, (f64)Y) * RADTODEG64 - 90.0);
 
-			if (angle.X < (T) 0.0)
-				angle.X += (T) 360.0;
-			if (angle.X >= (T) 360.0)
-				angle.X -= (T) 360.0;
+			if (angle.X < 0)
+				angle.X += 360;
+			if (angle.X >= 360)
+				angle.X -= 360;
 
 			return angle;
 		}
 
+		//! Get the spherical coordinate angles 
+		/** This returns Euler degrees for the point represented by
+		this vector.  The calculation assumes the pole at (0,1,0) and
+		returns the angles in X and Y.
+		*/
+		vector3d<T> getSphericalCoordinateAngles()
+		{
+			vector3d<T> angle;
+			const T length=getLength();
+
+			if (length)
+			{
+				if (X!=0)
+				{
+					angle.Y = (T)(atan2(Z,X) * RADTODEG64);
+				}
+				else if (Z<0)
+					angle.Y=180;
+
+				angle.X = (T)(acos(Y / length) * RADTODEG);
+			}
+			return angle;
+		} 
+
 		//! Builds a direction vector from (this) rotation vector.
 		/** This vector is assumed to be a rotation vector composed of 3 Euler angle rotations, in degrees.
 		The implementation performs the same calculations as using a matrix to do the rotation.