I want to know the way to detect a transform of view is flipped or not.

I've read [this question](https://stackoverflow.com/questions/19855422/how-to-detect-when-uiimageview-flip-vertically) but there is no answer I expected.

And also tried to detect using with a 3 by 3 matrix of [CGAffineTransform](https://developer.apple.com/library/ios/documentation/GraphicsImaging/Reference/CGAffineTransform/index.html#//apple_ref/doc/c_ref/CGAffineTransform).
But I'm not good at math and this kind of matrix....

So Cloud anyone please help me...