iphone sdk CGAffineTransform getting the angle of rotation of an object

Question

how do i calculate the angle of rotation for any given object (ie a uiimageview)?

Answer 1

I know this is very old question but, if anyone like me faces with this problem using CALayers and CATransform3D, you can get angle with:

extension CATransform3D {

    var xAxisAngle: CGFloat { get { return atan2(self.m23, self.m33) } }
    var yAxisAngle: CGFloat { get { return atan2(self.m31, self.m11) } }
    var zAxisAngle: CGFloat { get { return atan2(self.m12, self.m11) } }

}