确定SpriteNode何时离开屏幕？

Question

我想从屏幕上删除所有对象。 目前，我使用带有“障碍”的接触检测。

我在屏幕周围初始化障碍，当SpriteNode与其中一个接触时，会将其从场景中移除。 但是这种方法效果不佳，导致游戏崩溃。

您知道是否有一种简单的方法可以将所有对象从屏幕上删除吗？

这是我的带有障碍的代码：

// declarations
var barrierLeft:SKSpriteNode = SKSpriteNode()
var barrierRight:SKSpriteNode = SKSpriteNode()
var barrierTop:SKSpriteNode = SKSpriteNode()

// In didMoveToView method
barrierLeft.size = CGSizeMake(1, self.frame.height*2)
barrierLeft.physicsBody = SKPhysicsBody (rectangleOfSize: barrierLeft.size)
barrierRight.position = CGPointMake(0, 0)

barrierLeft.physicsBody?.dynamic = false
barrierLeft.physicsBody?.categoryBitMask = barrierCategory
barrierLeft.physicsBody?.contactTestBitMask = flechetteCategory
addChild(barrierLeft)

barrierRight.size = CGSizeMake(1, self.frame.height*2)
barrierRight.physicsBody = SKPhysicsBody (rectangleOfSize: barrierLeft.size)
barrierRight.position = CGPointMake(self.size.width+10, 0)
barrierRight.physicsBody?.dynamic = false
barrierRight.physicsBody?.categoryBitMask = barrierCategory
barrierRight.physicsBody?.contactTestBitMask = flechetteCategory
addChild(barrierRight)

//     
func didBeginContact(contact: SKPhysicsContact!)
{
    var firstBody: SKPhysicsBody
    var secondBody: SKPhysicsBody


    if (contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask)
    {
        firstBody = contact.bodyA
        secondBody = contact.bodyB

    }
    else
    {
        firstBody = contact.bodyB
        secondBody = contact.bodyA
    }

    if ((firstBody.categoryBitMask & flechetteCategory) != 0 && (secondBody.categoryBitMask & barrierCategory) != 0)
    {
        flecheDidCollideWithbarrier(firstBody.node as SKSpriteNode, barrier: secondBody.node as SKSpriteNode)
    }

//

func flecheDidCollideWithbarrier (fleche: SKSpriteNode, barrier: SKSpriteNode)
{
    println("barrière")
    counterGainTime = 0
    fleche.removeFromParent()


}

谢谢您帮忙 ！

Answer 1

您可以检查每个节点的位置以确定它是否在场景中。 然后，您可以相应地删除节点。

override func update(currentTime: CFTimeInterval) {
    // Loop over all nodes in the scene
    self.enumerateChildNodesWithName("*") {
        node, stop in
        if (node is SKSpriteNode) {
            let sprite = node as SKSpriteNode
            // Check if the node is not in the scene
            if (sprite.position.x < -sprite.size.width/2.0 || sprite.position.x > self.size.width+sprite.size.width/2.0
                || sprite.position.y < -sprite.size.height/2.0 || sprite.position.y > self.size.height+sprite.size.height/2.0) {
                    sprite.removeFromParent()
            }
        }
    }
}