【swift】UIView カスタム描画と背景透過

十字のマークを描いてみた、もっと効率のよい背景透過のやり方はあるのだろうか?

class CrossDraw: UIView {

override func draw(_ rect: CGRect) {

    let myRect1: UIBezierPath = UIBezierPath(roundedRect: CGRect(x: 0, y: 10, width: 30, height: 10), cornerRadius: 5)
    UIColor.orange.setFill()
    myRect1.fill()

    let myRect2: UIBezierPath = UIBezierPath(roundedRect: CGRect(x: 10, y: 0, width: 10, height: 30), cornerRadius: 5)
    UIColor.orange.setFill()
    myRect2.fill()

}

}

class CrossView: UIView {

required init?(coder aDecoder: NSCoder) {

    super.init(coder: aDecoder)

    let crossDraw = CrossDraw(frame: CGRect(x: 35, y: 35, width: 30, height: 30))
    crossDraw.isOpaque = false
    crossDraw.backgroundColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0)

    self.addSubview(crossDraw)
    self.isUserInteractionEnabled = false

}

}