gistfile1.txt

struct ProgressKeyframes {
    var progress: Double = 0.0
}

@State private var currentProgress: Double = 0.0
@State private var animationStartTime: Date = Date()

private var progressTimeline: KeyframeTimeline<ProgressKeyframes> {
    KeyframeTimeline(initialValue: ProgressKeyframes()) {
        KeyframeTrack(\.progress) {
            CubicKeyframe(0.8, duration: 2.0)
            LinearKeyframe(1.0, duration: 3.0)
        }
    }
}