我的背景用完了怎么替换？

Question

var replacebg = SKAction.moveToY(bgTexture.size().height , duration: 0)
    var replacebgForever = SKAction.repeatActionForever(replacebg)

    bg.runAction(replacebgForever)

屏幕上的每一次触摸都会将背景向下移动 50 像素。我想在用完时使用相同的图像替换背景。我试过上面的代码，但它不起作用，而是停止了我所有的动画。有什么帮助吗？谢谢。

Answer 1

在SKScene中的update方法中，如果background离开屏幕，可以重置

。

override func update(currentTime: CFTimeInterval) {
    if bg.position.y + bg.size.height/2 < 0
    {
        bg.position.y = self.frame.height + bg.size.height/2

    }
}

要创建环绕效果，请创建两个背景精灵节点，如下所示。两个背景保持一个在另一个之上。

background1 = SKSpriteNode(texture: bgTexture)
background1.position = CGPoint(x:CGRectGetMidX(self.frame), y: CGRectGetMidY(self.frame))
background1.size.height = self.frame.height

background2 = SKSpriteNode(texture: bgTexture)
background2.position = CGPoint(x:CGRectGetMidX(self.frame) , y: CGRectGetMidY(self.frame)+ self.frame.size.height)
background2.size.height = self.frame.height

self.addChild(background1)
self.addChild(background2)

然后在touchesBegan函数中

if background1.position.y + background1.size.height/2 < 50
{
    let diff =  background1.position.y + background1.size.height/2 - 50
    background1.position.y = self.frame.height + background1.size.height/2 + diff
}
else
{
     background1.position.y -= 50
}
if background2.position.y + background2.size.height/2 < 50
{
    let diff =  background2.position.y + background2.size.height/2 - 50
    background2.position.y = self.frame.height + background2.size.height/2 + diff
}
else
{
    background2.position.y -= 50
}

以上代码可以更加模块化。但我把它留给你。

我的背景用完了怎么替换？

How do I replace my background when it runs out?

ios

swift

background

sprite-kit