1
我试图做到这一点,以便当精灵的一个实例在屏幕的中心从顶部到底部时,程序将打印一些东西给控制台检查一个spritenode的实例是否在屏幕上的某个位置
var sprite = SKSpriteNode()
override func didMoveToView(view: SKView) {
//spawns an instance of the sprite
NSTimer.scheduledTimerWithTimeInterval(0.3, target: self, selector: Selector("spawnObject"), userInfo: nil, repeats: true)
//call the check middle function
checkMiddle()
}
//spawns a sprite
func spawnObject() {
let size = CGSizeMake(self.frame.size.width/3, self.frame.size.width3)
self.physicsWorld.gravity = CGVectorMake(0, -CGFloat(objectSpeed))
sprite = SKSpriteNode(imageNamed: "spriteImage")
sprite.position = CGPointMake(CGFloat(100), self.frame.height)
sprite.size = size
sprite.physicsBody = SKPhysicsBody(circleOfRadius: self.frame.size.width)
sprite.physicsBody?.affectedByGravity = true
addChild(self.sprite)
}
//PRINT WHEN SPRITE IS IN THE CENTER OF SCREEN FROM TOP TO BOTTOM
func checkMiddle() {
if sprite.position.y == self.frame.size.height/2 {
print("center")
}
}