Question

我已经想出如何每隔x秒连续生成一个节点。但是，我希望减少等待游戏继续创建节点的时间，以增加难度。例如，我在didMoveToView中调用此函数：

func createSequentialEnemies(){
    runAction(SKAction.repeatActionForever(
        SKAction.sequence([
            SKAction.runBlock(createEnemy),
            SKAction.waitForDuration(2.0)
            ])
        ))
}

这会每2秒产生一个敌人，但我想任意减少这个持续时间。例如，假设经过30秒的游戏后我想要每1.5秒产生一次敌人。我如何动态更改持续时间？

Answer 1

在场景类中创建spawnDuration属性和键引用。

class SomeClass: SKScene {

       private var spawnDuration: NSTimeInterval = 2.0
       private let spawnKey = "SpawnKey"

}

比调整产生代码以使用此spawn属性和键。我稍微改变了语法，使其在我看来更清晰。

func createSequentialEnemies(){
      removeActionForKey(spawnKey) // remove previous action if running. This way you can adjust the spawn duration property and call this method again and it will cancel previous action.

      let spawnAction = SKAction.runBlock(createEnemy)
      let spawnDelay = SKAction.waitForDuration(spawnDuration)
      let spawnSequence = SKAction.sequence([spawnAction, spawnDelay])
      runAction(SKAction.repeatActionForever(spawnSequence), withKey: spawnKey) // run action with key so you can cancel it later
}

当你想要改变你创建的产卵持续时间属性时，你必须添加一些逻辑。

基于时间可能是这样的功能，你也可以在DidMoveToView中调用一次

 func startDifficultyTimer() {

     let difficultyTimerKey = "DifficultyTimerKey"

     let action1 = SKAction.waitForDuration(30)
     let action2 = SKAction.runBlock { [unowned self] in

          guard self.spawnDuration > 0.2 else {  // set a min limit
              removeActionForKey(difficultyTimerKey) // if min duration has been reached than you might as well stop running this timer.
              return 
          } 

          self.spawnDuration -= 0.5 // reduce by half a second
          self.createSequentialEnemies() // spawn enemies again

     }
     let sequence = SKAction.sequence([action1, action2])
     runAction(SKAction.repeatActionForever(sequence), withKey: difficultyTimerKey)
 }

希望这有帮助

随着时间的推移，swift spritekit会增加节点创建的频率

1 个答案: