swift - 如何为动画中的单个 SKTextures 设置持续时间

Question

我正在尝试为动画中的单个 SKTextures 设置持续时间。 armsAtlas 纹理图集下方。我想将 upTexture 随机设置为持续 1-4 秒，然后将 downTexture 设置为持续 0.3-1 秒。如何为各个纹理设置这些持续时间范围？

let armsAtlas = SKTextureAtlas(named: "arms")
let downTexture = armsAtlas.textureNamed("down")
let upTexture = armsAtlas.textureNamed("up")

Answer 1

你可以使用 SKAction 序列和它的 waitForDuration:withRange: 方法，像这样:

//By default, the sprite is initialized with downTexture
let sprite = SKSpriteNode(texture: downTexture)
sprite.position = CGPoint(x: 200, y: 200)
addChild(sprite)
let sequence = SKAction.sequence([

    SKAction.runBlock({NSLog("Up texture set")}), //Added just for debugging to print a current time
    SKAction.setTexture(upTexture),
    SKAction.waitForDuration(2.5, withRange: 3.0),  //Wait between 1.0 and 4.0 seconds
    SKAction.runBlock({NSLog("Down texture set")}),
    SKAction.setTexture(downTexture),
    SKAction.waitForDuration(0.65, withRange: 0.7),//Wait between 0.3 and 1.0 seconds
    ])

let action = SKAction.repeatActionForever(sequence)

sprite.runAction(action, withKey: "aKey")

这段代码的作用是创建一个 Sprite ，默认使用 downTexture 对其进行初始化，并且:

• 立即将纹理交换为upTexture
• 等待 1 到 4 秒
• 将纹理交换为downTexture
• 等待 0.3 到 1 秒
• 永远重复这一切

如果你想停止这个 Action ，你可以像这样访问它:

if sprite.actionForKey("aKey") != nil {
            removeActionForKey("aKey")
}