使用Swift + SpriteKit将节点移至手指

使用Swift + SpriteKit将节点移至手指

使用以下命令可以为您省去很多麻烦

myShip.physicsBody.applyImpluse(vector)

。它的工作方式就像您

myShip

在方向

vector

点上施加了推力一样。如果您计算的

vector

是从上次触摸位置到的x距离

myShip

，则它会加速，减速，改变方向等。与您描述的方式非常接近，因为它只会在正确的方向上进行少量推动每个

update

。

基本上，您存储了最后一次触摸的位置，然后在

update

函数中计算了

CGVector

从

myShip

到的指向，

lastTouch

并将其作为对物理身体的冲动。

就像是：

var lastTouch: CGPoint? = niloverride func touchesBegan(touches: NSSet, withEvent event: UIEvent) {    let touch = touches.anyObject() as UITouch    let touchLocation = touch.locationInNode(self)    lastTouch = touchLocation}override func touchesMoved(touches: NSSet!, withEvent event: UIEvent!) {    let touch = touches.anyObject() as UITouch    let touchLocation = touch.locationInNode(self)    lastTouch = touchLocation}// Be sure to clear lastTouch when touches end so that the impulses stop being appliesoverride func touchesEnded(touches: NSSet!, withEvent event: UIEvent!) {    lastTouch = nil}override func update(currentTime: CFTimeInterval) {    // only add an impulse if there's a lastTouch stored    if let touch = lastTouch {        let impulseVector = CGVector(touch.x - myShip.position.x, 0)        // If myShip starts moving too fast or too slow, you can multiply impulseVector by a constant or clamp its range        myShip.physicsBody.applyImpluse(impulseVector)    }}

您可能还想使用

linearDamping

和的

angularDamping

值

myShip.physicsBody

。它们将帮助确定

myShip

加速和减速的速度。

我最大化了

1.0

我的应用程序中的值：

myShip.physicsBody.linearDamping = 1.0myShip.physicsBody.angularDamping = 1.0

如果

myShip

不能足够快地停止，您还可以尝试对

update

函数进行一些中断：

override func update(currentTime: CFTimeInterval) {    // only add an impulse if there's a lastTouch stored    if let touch = lastTouch {        let impulseVector = CGVector(touch.x - myShip.position.x, 0)        // If myShip starts moving too fast or too slow, you can multiply impulseVector by a constant or clamp its range        myShip.physicsBody.applyImpluse(impulseVector)    } else if !myShip.physicsBody.resting {        // Adjust the -0.5 constant accordingly        let impulseVector = CGVector(myShip.physicsBody.velocity.dx * -0.5, 0)        myShip.physicsBody.applyImpulse(impulseVector)    }}