Draw the Golden Spiral in Swift

Golden

let 𝜋 = M_PI
let ɸ = (1 + sqrt(5))/2

func drawTiles(tileCount: Int, height: Double, context: CGContext) {
    let red = CGFloat(arc4random_uniform(100)) / 100.0
    let green = CGFloat(arc4random_uniform(100)) / 100.0
    let blue = CGFloat(arc4random_uniform(100)) / 100.0
    
    context.setFillColor(red: red, green: green, blue: blue, alpha: 1.0)
    let rect = CGRect(x: 0, y: 0, width: height, height: height) // CGFloat, Double, Int
    context.fill(rect)

    
    let arc = UIBezierPath();
    let center = CGPoint(x: height, y: height)
    arc.addArc(withCenter: center,
                         radius: CGFloat(height),
                         startAngle: -(CGFloat)(𝜋),
                         endAngle: CGFloat(-𝜋/2),
                         clockwise: true)
    arc.stroke()
    
    let scale = 1 / ɸ
    if (tileCount > 0){
        context.rotate(by: CGFloat(𝜋/2))
        context.translateBy (x: 0 , y: -CGFloat(height) * CGFloat((1+scale)));
        context.scaleBy(x: CGFloat(scale), y: CGFloat(scale))
        drawTiles( tileCount: (tileCount-1), height: height, context: context)
    }
}

func drawGoldenSpiral(tileCount: Int, height: Double) -> UIImage {
    
    UIGraphicsBeginImageContext(CGSize(width: height * ɸ, height: height))
    
    drawTiles(tileCount: tileCount, height: height, context: UIGraphicsGetCurrentContext()!)
    
    let spiralImage = UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    
    return spiralImage!
}

let spiralImage = drawGoldenSpiral(tileCount: 12, height: 1000.0)