static IMPORT_C TInt ATan(TReal &aTrg, const TReal &aSrcY, const TReal &aSrcX);
Calculates the angle between the x-axis and a line drawn from the origin to a point represented by its (x,y) co-ordinates.
The co-ordinates are passed as arguments to the function. This function returns the same result as arctan(y/x), but:
1. it adds +/-pi to the result, if x is negative
2. it sets the result to +/-pi/2, if x is zero but y is non-zero.
TReal &aTrg A reference containing the result in radians, a value between -pi exclusive and +pi inclusive.
const TReal &aSrcY The y argument of the arctan(y/x) function.
const TReal &aSrcX The x argument of the arctan(y/x) function.
TInt KErrNone if successful, otherwise another of the system-wide error codes.