spritekit/ios 中精灵上手指的连续最小速度跟踪

Question

在不抬起手指的情况下连续跟踪用户在精灵上上下移动手指的速度的好方法是什么？如果他们不够快（设置最小值）来执行操作。

Answer 1

这是一些代码，您可以使用这些代码以不同的速度在屏幕上拖动精灵，具体取决于您的手指加速度。您可以添加自己的代码来检测变化的幅度并执行您想要的任何操作..

class GameScene: SKScene {

    // time values
    var delta:NSTimeInterval = NSTimeInterval(0)
    var last_update_time:NSTimeInterval = NSTimeInterval(0)

    // our sprite
    let sprite = SKSpriteNode(color: SKColor.redColor(), size: CGSize(width: 20, height: 30))

    // tracking difference between touches
    var currentTouchY: CGFloat = CGFloat(0)
    var lastTouchY: CGFloat = CGFloat(0)

    // the magnitude of change between current and last touch
    var forceMag: CGFloat = CGFloat(0)
    // max mag so our sprite doesnt travel at crazy speed
    let forceMagMax: CGFloat = CGFloat(7)
    // direction of our sprites travel
    var forceDir: CGFloat = CGFloat(0)
    // arbitrary speed we want sprite to move
    let velocity: CGFloat = CGFloat(70)

    // we use this to stop moving our sprite when we let go
    var intervalsWithoutChange = 0

    override func didMoveToView(view: SKView) {
        sprite.position.x = 100
        sprite.position.y = size.width/2
        self.addChild(sprite)
    }

    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
        for touch: AnyObject in touches {
            let location = touch.locationInNode(self)
            let yCoord = location.y

            lastTouchY = yCoord
        }
    }

    override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
        for touch: AnyObject in touches {
            let location = touch.locationInNode(self)
            let yCoord = location.y

            intervalsWithoutChange = 0
            currentTouchY = yCoord
            let diff = currentTouchY - lastTouchY
            forceMag = abs(diff)
            forceMag = forceMag > forceMagMax ? forceMagMax : forceMag
            forceDir = diff < 0 ? -1 : 1
            lastTouchY = yCoord
        }
    }

    override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
        intervalsWithoutChange = 1
        currentTouchY = 0
        lastTouchY = 0
    }

    override func update(currentTime: NSTimeInterval) {

        if last_update_time == 0.0 {
            delta = 0
        } else {
            delta = currentTime - last_update_time
        }

        last_update_time = currentTime

        if intervalsWithoutChange > 0 {
            forceMag -= CGFloat(15) * CGFloat(delta)
        }

        if forceMag < 0.01 {
            forceMag = 0
        }

        let change = forceDir * pow(forceMag, 1.29)

        sprite.position.y += change * CGFloat(delta) * velocity
    }
}

spritekit/ios 中精灵上手指的连续最小速度跟踪

Continous minimum velocity tracking of a finger on a sprite in spritekit/ios

sprite-kit

sprite

uigesturerecognizer

swipe

gesture