|y||The y coordinate to calculate.|
|x||The x coordinate to calculate.|
This function returns the inverse tangent of an angle y/x, where
y = Opposite side of triangle and x = Adjacent side of triangle.
Unlike arctan(x) the function arctan2(y, x) is valid for all angles
and so may be used to convert a vector to an angle without risking
division by zero, and it also returns a result in the correct
NOTE: The value returned is in radians, not degrees.
val = arctan2(1, 1);
This will set val to the correct angle, in this case 0.79.