随机化节点移动持续时间 [英] Randomizing node movement duration

问题描述

我正在 SpriteKit 中制作游戏，我有一个节点在屏幕上来回移动并使用代码重复:

I am making a game in SpriteKit and I have a node that is moving back and forth across the screen and repeating using the code:

    let moveRight = SKAction.moveByX(frame.size.width/2.8, y: 0, duration: 1.5)
    let moveLeft = SKAction.moveByX(-frame.size.width/2.8, y: 0, duration: 1.5)
    let texRight = SKAction.setTexture(SKTexture(imageNamed: "Drake2"))
    let texLeft = SKAction.setTexture(SKTexture(imageNamed: "Drake1"))
    let moveBackAndForth = SKAction.repeatActionForever(SKAction.sequence([texRight, moveRight, texLeft, moveLeft,]))
    Drake1.runAction(moveBackAndForth)

我想弄清楚我可以使用什么方法来随机化持续时间.每次 moveBackandForth 运行时，我希望它使用不同的持续时间重新运行(在游戏内，而不是在游戏之间).如果有人可以给我一些示例代码来尝试，我将不胜感激.

I am trying to figure out what method I can use to randomize the duration. Every time moveBackandForth runs, I want it to rerun using a different duration, (within games, not between). If someone could give me some example code to try I would really appreciate it.

arc4Random 也可以正常工作，但它不会在游戏内随机化，只会在游戏之间随机化.

Also arc4Random works fine, but it doesn't randomize within the game, only between games.

推荐答案

当您运行示例中的操作并使用 arc4Random 之类的东西随机化持续时间参数时，这实际上正在发生:

When you run actions like from your example and randomize duration parameter with something like arc4Random this is actually happening:

• 随机持续时间设置并存储在动作中.
• 然后在给定持续时间的序列中重复使用操作.

因为动作被原样重复使用，持续时间参数随着时间的推移保持不变，移动速度不是随机的.

Because the action is reused as it is, duration parameter remains the same over time and moving speed is not randomized.

解决这个问题的一种方法(我个人更喜欢)是创建一个递归操作"，或者更好地说，创建一个方法来运行所需的序列并像这样递归地调用它:

One way to solve this (which I prefer personally) would be to create a "recursive action", or it is better to say, to create a method to run desired sequence and to call it recursively like this :

import SpriteKit

class GameScene: SKScene {

    let  shape = SKSpriteNode(color: UIColor.redColor(), size: CGSize(width: 20, height: 20))

    override func didMoveToView(view: SKView) {


       shape.position = CGPointMake(CGRectGetMidX(self.frame) , CGRectGetMidY(self.frame)+60 )

       self.addChild(shape)

       move()
    }


    func randomNumber() ->UInt32{

        var time = arc4random_uniform(3) + 1
        println(time)
        return time
    }

    func move(){

        let recursive = SKAction.sequence([

            SKAction.moveByX(frame.size.width/2.8, y: 0, duration: NSTimeInterval(randomNumber())),
            SKAction.moveByX(-frame.size.width/2.8, y: 0, duration: NSTimeInterval(randomNumber())),
            SKAction.runBlock({self.move()})])

        shape.runAction(recursive, withKey: "move")
    }

}

要停止动作，请移除它的键(move").

To stop the action, you remove its key ("move").

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