How to find the scale from a CGAffineTransform
If you have a CGAffineTransform and want to know what its scale component is – regardless of whether it has been rotated or translated – use this code:
func scale(from transform: CGAffineTransform) -> Double {
return sqrt(Double(transform.a * transform.a + transform.c * transform.c))
}Available from iOS 2.0
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