swift - SKAction 遵循 UIBezierPath 函数不起作用 SpriteKit - Swift

Question

在我的应用程序中，我有一个 Sprite 围绕另一个 Sprite 旋转。我希望这个 Sprite 在按住屏幕时加速。我已经实现了加速功能，但我似乎无法弄清楚为什么当单击屏幕和松开屏幕时 Sprite 会重置回某个位置。我有一种感觉，我知道为什么，但我已经尝试修复它，但似乎无法更接近解决方案。代码如下。

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

    let dx = Slider.accessibilityActivationPoint.x
    let dy = Slider.accessibilityActivationPoint.y

    let rad = atan2(dx, dy)

    let Path = UIBezierPath(arcCenter: CGPoint(x: self.frame.width / 2, y: self.frame.height / 2), radius: 90, startAngle: rad, endAngle: rad + CGFloat(M_PI * 4), clockwise: true)

    let follow = SKAction.followPath(Path.CGPath, asOffset: false, orientToPath: true, speed: 400)
    //let rotate = SKAction.rotateByAngle(75, duration: 100)

    Slider.runAction(SKAction.repeatActionForever(follow).reversedAction())
}

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


    let dx = Slider.accessibilityActivationPoint.x
    let dy = Slider.accessibilityActivationPoint.y

    let rad = atan2(dy, dx)

    let Path = UIBezierPath(arcCenter: CGPoint(x: self.frame.width / 2, y: self.frame.height / 2), radius: 90, startAngle: 9, endAngle: rad + CGFloat(M_PI * 4), clockwise: true)

    let follow = SKAction.followPath(Path.CGPath, asOffset: false, orientToPath: true, speed: 150)


    Slider.runAction(SKAction.repeatActionForever(follow).reversedAction())
}

func moveClockWise(){

    let dx = Slider.position.x / 2
    let dy = Slider.position.y / 2

    let rad = atan2(dy, dx)


    let Path = UIBezierPath(arcCenter: CGPoint(x: self.frame.width / 2, y: self.frame.height / 2), radius: 90, startAngle: rad, endAngle: rad + CGFloat(M_PI * 4), clockwise: true)

    let follow = SKAction.followPath(Path.CGPath, asOffset: false, orientToPath: true, speed: 150)
    //let rotate = SKAction.rotateByAngle(75, duration: 100)

    Slider.runAction(SKAction.repeatActionForever(follow).reversedAction())
    //Slider.runAction(SKAction.repeatActionForever(rotate).reversedAction())
}

Answer 1

旁注:变量不应该使用大写。大写字母保留用于类名称..

例如:

let slider = Slider()

这是几乎所有编程语言都使用的命名约定:)

无论如何..尝试一下

import SpriteKit

class GameScene: SKScene {

    let Slider = SKSpriteNode(color: SKColor.redColor(), size: CGSizeMake(10, 10))

    override func didMoveToView(view: SKView) {
        Slider.position = CGPointMake(size.width/2, size.height/2)
        addChild(Slider)
    }

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


        let dx = Slider.accessibilityActivationPoint.x
        let dy = Slider.accessibilityActivationPoint.y

        let rad = atan2(dx, dy)

        let Path = UIBezierPath(arcCenter: CGPoint(x: self.frame.width / 2, y: self.frame.height / 2), radius: 90, startAngle: rad, endAngle: rad + CGFloat(M_PI * 4), clockwise: true)

        let follow = SKAction.followPath(Path.CGPath, asOffset: false, orientToPath: true, speed: 400)
        //let rotate = SKAction.rotateByAngle(75, duration: 100)

        if !Slider.hasActions() {
            Slider.runAction(SKAction.repeatActionForever(follow).reversedAction())
        } else {
            Slider.runAction(SKAction.speedTo(1, duration: 0))
        }



    }

    override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
        Slider.runAction(SKAction.speedTo(0.4, duration: 0))

    }

    func moveClockWise(){

        let dx = Slider.position.x / 2
        let dy = Slider.position.y / 2

        let rad = atan2(dy, dx)


        let Path = UIBezierPath(arcCenter: CGPoint(x: self.frame.width / 2, y: self.frame.height / 2), radius: 90, startAngle: rad, endAngle: rad + CGFloat(M_PI * 4), clockwise: true)

        let follow = SKAction.followPath(Path.CGPath, asOffset: false, orientToPath: true, speed: 150)
        //let rotate = SKAction.rotateByAngle(75, duration: 100)

        Slider.runAction(SKAction.repeatActionForever(follow).reversedAction())
        //Slider.runAction(SKAction.repeatActionForever(rotate).reversedAction())

    }
}