clippedImageForRect.swift

func clippedImageForRect(clipRect: CGRect, inView view: UIView) -> UIImage? {
        UIGraphicsBeginImageContextWithOptions(clipRect.size, true, UIScreen.main.scale)
        if let ctx = UIGraphicsGetCurrentContext(){
            ctx.translateBy(x: -clipRect.origin.x, y: -clipRect.origin.y);
            view.layer.render(in: ctx)
            let img = UIGraphicsGetImageFromCurrentImageContext()
            UIGraphicsEndImageContext()
            return img
        }
        return nil
}