swift - 具有/多个间隔的更新功能(SWIFT)

Question

我是编程新手，所以请帮忙。我正在尝试设置间隔以在整个游戏中创建各种 Sprite 节点(使用更新功能)。但是，每个 Sprite 节点需要以不同的间隔生成。我有一堆“if”语句，它似乎导致我的帧速率下降并导致应用程序滞后。有人可以告诉我如何解决这个问题吗？如果可能，还请向我解释为什么这样做，以便我更好地理解编码过程。谢谢!

var timeBetweenBirds: Int!
var timeBetweenBadBirds: Int!
var timeBetweenSubtractTimeBirds: Int!
var timeBetweenAddTimeBirds: Int!
var timeBetweenBonusBirds: Int!

var now : NSDate?
var nextTime : NSDate?
var badBirdNextTime: NSDate?
var subtractTimeBirdNextTime: NSDate?
var addTimeBirdNextTime: NSDate?
var bonusBirdNextTime: NSDate?

override func update(currentTime: CFTimeInterval) {

 timeBetweenBirds = Int(arc4random_uniform(3))
 timeBetweenBadBirds = Int(arc4random_uniform(3) + 2)
 timeBetweenSubtractTimeBirds = Int(arc4random_uniform(3) + 2)
 timeBetweenAddTimeBirds = Int(arc4random_uniform(1) + 5)
 timeBetweenBonusBirds = Int(arc4random_uniform(20) + 20)


now = NSDate()

  if now?.timeIntervalSince1970 > nextTime?.timeIntervalSince1970 {

        nextTime = now?.dateByAddingTimeInterval(NSTimeInterval(timeBetweenBirds))

        createBird()
    }

    if now?.timeIntervalSince1970 > badBirdNextTime?.timeIntervalSince1970 {

        badBirdNextTime = now?.dateByAddingTimeInterval(NSTimeInterval(timeBetweenBadBirds))

        createBadBird()

    }

    if now?.timeIntervalSince1970 > subtractTimeBirdNextTime?.timeIntervalSince1970 {

        subtractTimeBirdNextTime = now?.dateByAddingTimeInterval(NSTimeInterval(timeBetweenSubtractTimeBirds))

        createSubtractTimeBird()

    }

    if now?.timeIntervalSince1970 > addTimeBirdNextTime?.timeIntervalSince1970 {

        addTimeBirdNextTime = now?.dateByAddingTimeInterval(NSTimeInterval(timeBetweenAddTimeBirds))

        createAddTimeBird()

    }

    if now?.timeIntervalSince1970 > bonusBirdNextTime?.timeIntervalSince1970 {

        bonusBirdNextTime = now?.dateByAddingTimeInterval(NSTimeInterval(timeBetweenBonusBirds))

        createBonusBird()

    }

Answer 1

也许这不是正确的解决方案，但它至少会简化事情。

有几件事需要考虑。

• 现在，您正在每个 update 循环中生成一个新的 timeBetweenBirds 值，但只有在 结束时才使用它如果语句

  override func update(currentTime: CFTimeInterval) {
  
      timeBetweenBirds = Int(arc4random_uniform(3)) //Created on each update loop
      ...
      now = NSDate()
  
      if now?.timeIntervalSince1970 > nextTime?.timeIntervalSince1970 {
          //Only used here           
          nextTime = now?.dateByAddingTimeInterval(NSTimeInterval(timeBetweenBirds)) 
          createBird()
      }
  

  因此，可以从仅在需要时更新 timeBetweenBirds 值开始。

• 在我看来，您不需要创建所有这些日期并在它们之间进行比较。

  每次调用 update 时，您都会免费获得一个 currentTime 属性 :-) 此属性可用于检查 nextTime像这样的变量:

  var nextTime: CFTimeInterval = 0
  ...
  override func update(currentTime: CFTimeInterval) {
      if currentTime > nextTime {
          nextTime = currentTime + CFTimeInterval(arc4random_uniform(3))
          createBird()
      }
      //And so on with your other if statements
  }
  

正如我所说，我不知道这是否会加快速度，但它会简化您的代码，这总是好的 :-)