swift - 在 if 语句中更改计时器的时间间隔

Question

我正在创建一个游戏，其中涉及一个计时器，该计时器每秒都会生成从屏幕上掉落的对象。要获得积分，您必须捕获物体。

我希望一旦玩家达到一定数量的分数，产卵率就会增加。

我尝试通过为计时器的间隔分配一个整数(SpeedNumber)值 1 秒来开始，并创建了 if 语句，一旦玩家达到一定数量，该语句应该将该整数更改为 0.5点。这对我来说很有意义，但不起作用。

为什么这不起作用？我应该更改什么？

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

您可以按如下方式执行您想要的操作:

首先声明 2 个属性(在类中但在所有函数定义之外)

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

然后，在Update中检查是否超出了timePerSpawn。如果是这样，请调用生成新对象的生成过程，然后重置自上次生成以来的时间:

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
}

使生成过程成为一个单独的函数的优点是，您可以从 didMoveToView 或任何其他位置调用它，以在正常时间控制周期之外生成对象。

您可以根据需要更改 timePerSpawn 的值，以控制生成对象的速率。

您还可以考虑创建一个在指定时间间隔运行 spawnObject 的 SKAction ，但我认为要更改生成对象的速率，您将拥有删除并重新创建 SKAction，但您可以在 timePerSpawn 的 setter 中执行此操作。

你不应该在 SpriteKit 中真正使用 NSTimer，因为 SpriteKit 引擎将不知道计时器在做什么并且无法控制它(一个例子是，如果将场景设置为暂停，计时器会继续运行)。