如何让我的背景图像在 Swift 中永远重复？

Question

我有这两张图片是同一张图片，我希望它们重复，这样背景看起来就在移动。我有这段代码，但只有一个背景图像通过，然后它又回到灰屏。另一个背景图像不跟随第一个。我该如何解决？谢谢！ （这是在 swift xcode 中）

 func spawnBackground() {

    let cloud = SKSpriteNode(imageNamed: "CloudBg")
    let cloud2 = SKSpriteNode(imageNamed: "CloudBg2")


    cloud.position = CGPointMake(frame.size.width + cloud.frame.size.width / 2,cloud.frame.height / 2)
    cloud.setScale(1.35)
    cloud.zPosition = -15

    cloud2.position = CGPointMake(self.size.width/2, self.size.height/2)
    cloud2.setScale(1.35)
    cloud.zPosition = -15


    let moveTop = SKAction.moveByX(0, y: cloud.size.height, duration:   NSTimeInterval(CGFloat(gameSpeed) * cloud.size.height))
    cloud.runAction(SKAction.repeatActionForever(moveTop))
    cloud2.runAction(SKAction.repeatActionForever(moveTop))



    addChild(cloud)
    addChild(cloud2)


}

Answer 1

我认为您正在寻找这样的动作序列：

  let cloud = SKSpriteNode(imageNamed: "CloudBg")
        let cloud2 = SKSpriteNode(imageNamed: "CloudBg2")


        cloud.position = CGPointMake(frame.size.width + cloud.frame.size.width / 2,cloud.frame.height / 2)
        cloud.setScale(1.35)
        cloud.zPosition = -15

        cloud2.position = CGPointMake(self.size.width/2, self.size.height/2)
        cloud2.setScale(1.35)
        cloud.zPosition = -15

        var actionone = SKAction.moveToX(0, y: cloud.size.height, duration:   NSTimeInterval(CGFloat(gameSpeed) * cloud.size.height))

        var actiontwo = SKAction.runBlock({
            cloud.position = CGPointMake(frame.size.width + cloud.frame.size.width / 2,cloud.frame.height / 2)
        })

        cloud.runAction(SKAction.repeatForever(SKAction.sequence([actionone,actiontwo])))

当然，您必须编辑此代码才能在一个云到达某个点时另一个云开始的位置工作，但这是一般的想法。