问将SKLabelNode作为SKShapeNode的裁剪节点

EN

override func didMoveToView(view: SKView) {

        backgroundColor = .blackColor()

        let cropNode = SKCropNode()
        cropNode.position = CGPoint(x: frame.midX, y: frame.midY)
        cropNode.zPosition = 1

        let mask = SKLabelNode(fontNamed: "ArialMT")
        mask.text = "MASK"
        mask.fontColor = .greenColor()
        mask.fontSize = 28

        cropNode.maskNode = mask


        let nodeToMask = SKSpriteNode(color: .purpleColor(), size: CGSize(width: 200, height: 200))
        nodeToMask.position = CGPoint(x: 0, y: 0)
        nodeToMask.name = "character"
        cropNode.addChild(nodeToMask)
        //Now colorize the sprite which acts like background
        let colorize = SKAction.sequence([
                SKAction.colorizeWithColor(.orangeColor(), colorBlendFactor: 0, duration: 1),
                SKAction.colorizeWithColor(.purpleColor(), colorBlendFactor: 0, duration: 1)
        ])

        nodeToMask.runAction(SKAction.repeatActionForever(colorize), withKey: "colorizing")

        addChild(cropNode)

}