如何在CATiledLayer中绘制平铺图案图像？

let tiledLayer = CATiledLayer()
view.layer.addSublayer(tiledLayer)

tiledLayer.delegate = self

func draw(_ layer: CALayer, in ctx: CGContext) {
    // 获取当前瓦片的rect
    let bounds = ctx.boundingBoxOfClipPath
    
    // 绘制瓦片的内容
    // ...
}

func draw(_ layer: CALayer, in ctx: CGContext) {
    let bounds = ctx.boundingBoxOfClipPath
    
    // 绘制图案或图像
    let patternColor = UIColor(patternImage: UIImage(named: "pattern.png")!)
    patternColor.setFill()
    ctx.fill(bounds)
}

tiledLayer.tileSize = CGSize(width: 256, height: 256) // 设置瓦片的大小
tiledLayer.levelsOfDetail = 4 // 设置缩放级别
tiledLayer.levelsOfDetailBias = 4 // 设置缩放级别的偏移量

view.setNeedsDisplay()