swift - 绘制多个圆 SpriteKit

Question

我正在开发基于玩家绘画背景的简单游戏。在左角和右角会有将角色向左或向右移动的按钮。我已经实现了这一点(角色在移动并且在后面留下了绘制的背景)，但是添加另一个圆圈 fps 的下降非常快。有什么解决办法吗？

    import SpriteKit

class GameScene: SKScene {
    var playerDot:PlayerDot = PlayerDot(imageNamed:"player")
    var isTurningLeft:Bool = false
    var isTurningRight:Bool = false
    var lastLocation:CGPoint = CGPoint()

    override func didMoveToView(view: SKView) {
        /* Setup your scene here */
        let myLabel = SKLabelNode(fontNamed:"Helvetica")
        myLabel.name = "left"
        myLabel.text = "Left"
        myLabel.fontSize = 30
        myLabel.horizontalAlignmentMode = .Left
        myLabel.position = CGPoint(x:CGRectGetMinX(self.frame), y:CGRectGetMinY(self.frame))
        self.addChild(myLabel)

        let myLabel2 = SKLabelNode(fontNamed:"Helvetica")
        myLabel2.name = "right"
        myLabel2.text = "Right"
        myLabel2.fontSize = 30
        myLabel2.horizontalAlignmentMode = .Right
        myLabel2.position = CGPoint(x:CGRectGetMaxX(self.frame), y:CGRectGetMinY(self.frame))
        self.addChild(myLabel2)

        playerDot.position = CGPoint(x:CGRectGetMaxX(self.frame)/2, y:CGRectGetMinY(self.frame))
        self.addChild(playerDot)
    }



    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
        for touch in touches {
            let location = touch.locationInNode(self)
            if let theName = self.nodeAtPoint(location).name {
                if theName == "left" {
                   isTurningLeft = true
                    isTurningRight = false
                }
                else if theName == "right" {
                    isTurningRight = true
                    isTurningLeft = false
                }
            }
        }
    }

    override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
        for touch in touches {
            let location = touch.locationInNode(self)
            if let theName = self.nodeAtPoint(location).name {
                if theName == "left" {
                    isTurningLeft = false
                }
                else if theName == "right" {
                    isTurningRight = false
                }
            }
        }
    }

    override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
        for touch in touches {
            let location = touch.locationInNode(self)
            if let theName = self.nodeAtPoint(location).name {
                if theName == "left" {
                    isTurningLeft = false
                }
                else if theName == "right" {
                    isTurningRight = false
                }
            }
        }
    }


    override func update(currentTime: CFTimeInterval) {
        if(isTurningLeft){
            playerDot.increaseAngle()
        } else if (isTurningRight){
           playerDot.decreaseAngle()
        }
        //calculates new character position based on angle of movement changed
        playerDot.updatePosition()
        drawCircle()
    }

    func drawCircle(){
        if(distanceFromCGPoints(lastLocation, b: playerDot.position)>2){
        let circle = SKShapeNode(circleOfRadius: 10 )
        circle.position = playerDot.position
        circle.fillColor = SKColor.orangeColor()
        circle.strokeColor = SKColor.orangeColor()
        self.addChild(circle)
        lastLocation = playerDot.position
        }
    }

    func distanceFromCGPoints(a:CGPoint,b:CGPoint)->CGFloat{
        return sqrt(pow(a.x-b.x,2)+pow(a.y-b.y,2));
    }

    func random() -> CGFloat {
        return CGFloat(Float(arc4random()) / 0xFFFFFFFF)
    }

    func random(min min: CGFloat, max: CGFloat) -> CGFloat {
        return random() * (max - min) + min
    }
}

编辑:将 SKShapeNode 替换为 SKSpriteNote 的 drawCircle

func drawCircle(){
    if(distanceFromCGPoints(lastLocation, b: playerDot.position)>2){
    let playerDot2 = SKSpriteNode(imageNamed:"player")
    playerDot2.position = playerDot.position
    self.addChild(playerDot2)
    lastLocation = playerDot.position
    }
}

Answer 1

如果您的帧速率下降，那么您的代码的某些部分会大大降低执行速度。你需要优化你的代码。使用 Instruments (Time Profiler) 找出导致速度问题的线路/功能。如果您在阅读之前从未使用过它并使用过几次以了解要点，那么我建议您观看 WWDC 视频 Profiling In-Depth