Формула Parallax

var parallaxImageHeight: CGFloat {
let maxOffset = (sqrt( cellHeight * cellHeight + 4 * parallaxSpeed * self.tableView.frame.height) - cellHeight) / 2
return maxOffset + self.cellHeight
}

Учимся анимировать сокращая при этом код.

typealias Animation = (TimeInterval, ()->Void)

let animation: Animation = (5.0, {
    
})

internal class Node<T> {
    var data: T
    var next: Node<T>?
    
    init(data: T){
        self.data = data
    }
}

internal struct Queue<T> {
    var first, last: Node<T>?
    
    mutating func dequeue() -> T? {
        let pop = first?.data
        first = first?.next
        
        if first == nil {
            last = nil
        }
        
        return pop
    }
    
    mutating func enqueue(data: T){
        if last == nil {
            first = Node(data: data)
            last = first
        } else {
            last?.next = Node( data: data)
            last = last?.next
        }
    }
}

var animations: Queue = Queue<Animation>()

Чтобы поиграться с анимацией не создавая проект приложения достаточно использовать playground

import UIKit
import PlaygroundSupport

let containerView = UIView(frame: CGRect(x: 0.0, y: 0.0, width: 375.0, height: 667.0))


let circle = UIView(frame: CGRect(x: 0.0, y: 0.0, width: 50.0, height: 50.0))
circle.center = containerView.center
circle.layer.cornerRadius = 25.0

let startingColor = UIColor(red: (253.0/255.0), green: (159.0/255.0), blue: (47.0/255.0), alpha: 1.0)
circle.backgroundColor = startingColor

containerView.addSubview(circle);

let rectangle = UIView(frame: CGRect(x: 0.0, y: 0.0, width: 50.0, height: 50.0))
rectangle.center = containerView.center
rectangle.layer.cornerRadius = 5.0

rectangle.backgroundColor = UIColor.white

containerView.addSubview(rectangle)

UIView.animate(withDuration: 2.0, animations: { () -> Void in
    let endingColor = UIColor(red: (255.0/255.0), green: (61.0/255.0), blue: (24.0/255.0), alpha: 1.0)
    circle.backgroundColor = endingColor
    
    let scaleTransform = CGAffineTransform(scaleX: 5.0, y: 5.0)
    
    circle.transform = scaleTransform
    
    let rotationTransform = CGAffineTransform(rotationAngle: 3.14)
    
    rectangle.transform = rotationTransform
})

PlaygroundPage.current.liveView =  containerView