Math to animate Navigation bar on Scrolling

navigationfadeonscrolling.swift

    override func scrollViewDidScroll(_ scrollView: UIScrollView) {
        
        let safeAreaTop = UIApplication.shared.windows.filter { $0.isKeyWindow }.first?.safeAreaInsets.top ?? 0
        let navigationNeededOfset: CGFloat = safeAreaTop// + (navigationController?.navigationBar.frame.height ?? 0)
        let offset = scrollView.contentOffset.y + navigationNeededOfset
        let alpha = 1 - ((scrollView.contentOffset.y + navigationNeededOfset) / navigationNeededOfset)
        
        // Use the alpha here
        navigationController?.navigationBar.backgroundColor = .blue
        navigationController?.navigationBar.transform = .init(translationX: 0, y: min(0, -offset))
    }