在if語句中更改計時器的時間間隔

Question

我正在創建一個遊戲，其中涉及一個計時器，該計時器每秒鐘都會在屏幕下方產生對象。爲了獲得積分，你必須捕捉物體。

我希望一旦玩家達到一定數量的積分，就會增加產卵率。

我試圖做到這一點，通過分配定時器的間隔一個整數（SpeedNumber）值1秒開始並已創建，如果聲明，應該改變該整數爲0.5，一旦玩家達到一定點數。這對我有意義，但它不起作用。

爲什麼這不起作用，應該改變什麼？

import SpriteKit 

struct physicsCatagory { 
    static let person : UInt32 = 0x1 << 1 
    static let Ice : UInt32 = 0x1 << 2 
    static let IceTwo : UInt32 = 0x1 << 3 
    static let IceThree : UInt32 = 0x1 << 4 
    static let Score : UInt32 = 0x1 << 5 
} 


class GameScene: SKScene, SKPhysicsContactDelegate { 


    var scorenumber = Int() 
    var lifenumber = Int() 
    var SpeedNumber : Double = 0.5 
    var person = SKSpriteNode(imageNamed: "Person") 
    let Score = SKSpriteNode() 
    var ScoreLable = SKLabelNode() 


    override func didMoveToView(view: SKView) { 

     self.scene?.backgroundColor = UIColor.purpleColor() 

     physicsWorld.contactDelegate = self 

     self.scene?.size = CGSize(width: 640, height: 1136) 

     lifenumber = 0 
     SpeedNumber = 1 

     Score.size = CGSize(width: 648, height: 1) 
     Score.position = CGPoint(x: 320, y: -90) 
     Score.physicsBody = SKPhysicsBody(rectangleOfSize: Score.size) 
     Score.physicsBody?.affectedByGravity = false 
     Score.physicsBody?.dynamic = false 
     Score.physicsBody?.categoryBitMask = physicsCatagory.Score 
     Score.physicsBody?.collisionBitMask = 0 
     Score.physicsBody?.contactTestBitMask = physicsCatagory.IceThree 
     Score.color = SKColor.blueColor() 
     self.addChild(Score) 



     person.position = CGPointMake(self.size.width/2, self.size.height/12) 
     person.setScale(0.4) 
     person.physicsBody = SKPhysicsBody(rectangleOfSize: person.size) 
     person.physicsBody?.affectedByGravity = false 
     person.physicsBody?.categoryBitMask = physicsCatagory.person 
     person.physicsBody?.contactTestBitMask = physicsCatagory.Ice 
     person.physicsBody?.collisionBitMask = physicsCatagory.Ice 
     person.physicsBody?.dynamic = false 




     ScoreLable.position = CGPoint(x: self.frame.width/2, y: 1000) 
     ScoreLable.text = "\(scorenumber)" 
     ScoreLable.fontColor = UIColor.yellowColor() 
     ScoreLable.fontSize = 100 
     ScoreLable.fontName = "Zapfino " 
     self.addChild(ScoreLable) 



     var IceThreeTimer = NSTimer.scheduledTimerWithTimeInterval(SpeedNumber, target: self, selector: ("spawnThirdIce"), userInfo: nil, repeats: true) 


     self.addChild(person) 





    } 




    func didBeginContact(contact: SKPhysicsContact) { 
      let firstBody = contact.bodyA 
      let secondBody = contact.bodyB 


     if firstBody.categoryBitMask == physicsCatagory.person && secondBody.categoryBitMask == physicsCatagory.IceThree || firstBody.categoryBitMask == physicsCatagory.IceThree && secondBody.categoryBitMask == physicsCatagory.person{ 

      scorenumber++ 

      if scorenumber == 5 { 

       SpeedNumber = 0.5 


      } 


      ScoreLable.text = "\(scorenumber)" 
      CollisionWithPerson(firstBody.node as! SKSpriteNode, Person: secondBody.node as! SKSpriteNode) 


     } 

     if firstBody.categoryBitMask == physicsCatagory.Score && secondBody.categoryBitMask == physicsCatagory.IceThree || 
      firstBody.categoryBitMask == physicsCatagory.IceThree && secondBody.categoryBitMask == physicsCatagory.Score{ 
       lifenumber++ 

       if lifenumber == 3{ 

      self.view?.presentScene(EndScene()) 

     } 

       //self.view?.presentScene(EndScene()) 

     } 
    } 



    func CollisionWithPerson (Ice: SKSpriteNode, Person: SKSpriteNode){ 

     Person.removeFromParent() 

    } 



    func spawnThirdIce(){ 

     var Ice = SKSpriteNode(imageNamed: "Ice") 
     Ice.setScale(0.9) 
     Ice.physicsBody = SKPhysicsBody(rectangleOfSize: Ice.size) 
     Ice.physicsBody?.categoryBitMask = physicsCatagory.IceThree 
     Ice.physicsBody?.contactTestBitMask = physicsCatagory.person | physicsCatagory.Score 
     Ice.physicsBody?.affectedByGravity = false 
     Ice.physicsBody?.dynamic = true 
     let MinValue = self.size.width/8 
     let MaxValue = self.size.width - 20 
     let SpawnPoint = UInt32(MaxValue - MinValue) 
     Ice.position = CGPoint(x: CGFloat(arc4random_uniform(SpawnPoint)), y: self.size.height) 
     self.addChild(Ice) 

     let action = SKAction.moveToY(-85, duration: 2.5) 
     let actionDone = SKAction.removeFromParent() 
     Ice.runAction(SKAction.sequence([action,actionDone])) 


    } 



    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) { 


     for touch in touches { 
      let location = touch.locationInNode(self) 

     person.position.x = location.x 



        } 
    } 
    override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) { 

     for touch in touches { 
      let location = touch.locationInNode(self) 

      person.position.x = location.x 



     } 
    } 




    override func update(currentTime: CFTimeInterval) { 
     /* Called before each frame is rendered */ 
    } 
} 

Answer 1

你可以做你想做的，如下所示：

首先聲明2點的屬性（在你的類，但以外的所有函數定義）

var timeOfLastSpawn: CFTimeInterval = 0.0 
var timePerSpawn: CFTimeInterval = 1.0 

然後，在Update，請檢查如果timePerSpawn已被超過。如果是這樣，請與重生的過程，會生成新的對象，然後重置自上次產卵：

override func update(currentTime: CFTimeInterval) { 
    /* Called before each frame is rendered */ 
    if (currentTime - timeOfLastSpawn > timePerSpawn) { 
     spawnObject() 
     self.timeOfLastSpawn = currentTime 
    } 
} 

func spawnObject() { 
     // Your spawn code here 
} 

使產卵過程中一個獨立的功能，你可以從didMoveToView或任何其他地方調用它的優點在正常的時間控制週期之外產卵物體。

您可以根據需要更改timePerSpawn的值以控制生成對象的速率。

您也可以考慮創建一個SKAction，它在指定的時間間隔運行spawnObject，但我認爲要改變對象產生的速率，您必須刪除並重新創建SKAction，但是您可以做這在timePerSpawn的setter中。

您不應該使用NSTimer作爲SpriteKit，因爲SpriteKit引擎將不知道計時器正在做什麼並且無法控制它（例如，如果將場景設置爲暫停狀態，計時器會繼續運行） 。

Answer 2

你應該你的var IceThreeTimer聲明移到類級別（該方法之外，就在你申報SpeedNumber，這將確保你的手柄，指針會在兩個didMoveToView和didBeginContact可用的方法。

在didMoveToView你改變你的聲明：

// I removed the "var" 
IceThreeTimer = NSTimer.scheduledTimerWithTimeInterval(SpeedNumber, target: self, selector: ("spawnThirdIce"), userInfo: nil, repeats: true) 

然後在didBeginContact修改：

if scorenumber == 5 { 
    SpeedNumber = 0.5 
    // Stop the already running timer 
    IceThreeTimer.invalidate() 
    // Schedule a new timer 
    IceThreeTimer = NSTimer.scheduledTimerWithTimeInterval(SpeedNumber, target: self, selector: ("spawnThirdIce"), userInfo: nil, repeats: true) 
}