Add a custom path

CustomPath.swift

func customPath() -> UIBezierPath {
    let path = UIBezierPath()
    
    path.move(to: CGPoint(x: 0, y: 200))
    
    let endPoint = CGPoint(x: 500, y: 200)
    
    let randomYShift = 200 + drand48() * 300
    let cp1 = CGPoint(x: 100, y: 100 - randomYShift)
    let cp2 = CGPoint(x: 200, y: 100 + randomYShift + 400)
    
    path.addCurve(to: endPoint, controlPoint1: cp1, controlPoint2: cp2)
    return path
}

class CurvedView: UIView {
    
    override func draw(_ rect: CGRect) {
        //do some fancy curve drawing
        let path = customPath()
        path.lineWidth = 3
        path.stroke()
    }
    
}