快速的音频播放速度

Posted 2023-02-25

【中文标题】快速的音频播放速度

【英文标题】：Swift Audio Playback speed

【发布时间】：2017-06-04 03:54:41

【问题描述】：

我正在开发一个游戏，其中主要的精灵是一个旋转的***。我想将音频与随着车轮减速而改变音调的旋转车轮相关联。当车轮停止旋转时，我希望音效停止。有人能指出我正确的方向吗？

在我的游戏场景中，我有以下代码：

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) 

    for touch in touches 
        let location = touch.location(in: self)
        //Start spinning the wheel
        if atPoint(location).name == "play_button" 
            player?.physicsBody?.angularVelocity = 0
            player?.rotatePlayer()

            //Click back button
         else if atPoint(location).name == "back_button" 
            let play_scene = CharacterSelectScene(fileNamed: "CharacterSelect")
            play_scene?.scaleMode = .aspectFill
            self.view?.presentScene(play_scene!, transition: SKTransition.doorsOpenVertical(withDuration: 1))
         else if atPoint(location).name == "settings_button" 
            let play_scene = SettingsScene(fileNamed: "SettingsScene")
            play_scene?.scaleMode = .aspectFill
            self.view?.presentScene(play_scene!, transition: SKTransition.doorsOpenVertical(withDuration: 1))
        
    


override func didSimulatePhysics() 
    let speed = player?.physicsBody?.angularVelocity
    if (speed != CGFloat(0.0)) 
        if (speed! <= CGFloat(0.1))
            finishedRotation = true
        
    

override func didFinishUpdate() 
    if (finishedRotation == true) 
        let play_scene = QuestionScene(fileNamed: "QuestionScene")
        play_scene?.scaleMode = .aspectFill
        self.view?.presentScene(play_scene!, transition: SKTransition.doorsOpenVertical(withDuration: 1))
    

func didBegin(_ contact: SKPhysicsContact) 
    let defaults = UserDefaults.standard
    var firstBody = SKPhysicsBody()
    var secondBody = SKPhysicsBody()
    if (contact.bodyA.node?.name == "pin") 
        firstBody = contact.bodyA
        secondBody = contact.bodyB
     else 
        firstBody = contact.bodyB
        secondBody = contact.bodyA
    
    if (firstBody.node?.name == "pin" && secondBody.node?.name == "geography") 
        let set_topic = secondBody.node?.name
        defaults.set(set_topic, forKey: "Topic")
     else if (firstBody.node?.name == "pin" && secondBody.node?.name == "maths") 
        let set_topic = secondBody.node?.name
        defaults.set(set_topic, forKey: "Topic")
     else if (firstBody.node?.name == "pin" && secondBody.node?.name == "history") 
        let set_topic = secondBody.node?.name
        defaults.set(set_topic, forKey: "Topic")
     else if (firstBody.node?.name == "pin" && secondBody.node?.name == "science") 
        let set_topic = secondBody.node?.name
        defaults.set(set_topic, forKey: "Topic")
    

Player 类中的 rotatePlayer 方法定义如下：

func rotatePlayer() 
    let random = GKRandomDistribution(lowestValue: 20, highestValue: 120)
    let r = random.nextInt()
    self.physicsBody?.angularVelocity = 0
    self.physicsBody?.angularVelocity = CGFloat(r)
    self.physicsBody?.angularDamping = 1.02

【问题讨论】：

关于 AVAudioPlayer 的 rate 属性，Xcode 文档告诉你什么？

除了默认费率和启用费率之外，文档没有说明太多。如何将速率与纺车的速度联系起来以使其听起来逼真？

您的问题是因为一些原因而违反了 *** 的规则。 1）缺乏信息（例如，我们不知道你的***是如何工作的，所以我们不能确定如何用旋转速度映射速率/俯仰），2）到目前为止你尝试了什么？热心帮助的人可以提供帮助，但没有人愿意编写完整的解决方案......好吧，它发生了，但仍然，这不是这个网站的工作方式；）请参阅ask a good question

关于球场：developer.apple.com/reference/avfoundation/avaudiounittimepitch 但这可能不是你想要的。正如我所说，您必须提供更多信息。理想情况下，您提供可以重现问题的 MVP。

感谢旋风。我会尽快提供更多细节

【参考方案1】：

我已经解决了这个问题，代码如下：

func playSound() 
    let url = Bundle.main.url(forResource: "clicker", withExtension: "m4a")!

    do 
        SoundEffect = try AVAudioPlayer(contentsOf: url)
        guard let players = SoundEffect else  return 

        players.prepareToPlay()
        players.play()
     catch let error as NSError 
        print(error.description)
    

func didEnd(_ contact: SKPhysicsContact) 

    let defaults = UserDefaults.standard
    var firstBody = SKPhysicsBody()
    var secondBody = SKPhysicsBody()
    if (contact.bodyA.node?.name == "pin") 
        firstBody = contact.bodyA
        secondBody = contact.bodyB
     else 
        firstBody = contact.bodyB
        secondBody = contact.bodyA
    
    if (firstBody.node?.name == "pin" && secondBody.node?.name == "geography") 
        let set_topic = secondBody.node?.name
        defaults.set(set_topic, forKey: "Topic")
        playSound()
     else if (firstBody.node?.name == "pin" && secondBody.node?.name == "maths") 
        let set_topic = secondBody.node?.name
        defaults.set(set_topic, forKey: "Topic")
        playSound()
     else if (firstBody.node?.name == "pin" && secondBody.node?.name == "history") 
        let set_topic = secondBody.node?.name
        defaults.set(set_topic, forKey: "Topic")
        playSound()
     else if (firstBody.node?.name == "pin" && secondBody.node?.name == "science") 
        let set_topic = secondBody.node?.name
        defaults.set(set_topic, forKey: "Topic")
        playSound()
    

【讨论】：

然而，这会导致严重的延迟并冻结游戏。在设备上和模拟器中。

不确定是什么导致了延迟。当您真的只想要 1 次时，也许您会收到多次 didEnd 的调用。您可以尝试设置一个自定义标志以跳过 didEnd 直到它关闭一次后的下一帧...看看这是否有效。