ios - swift :如何使子弹在玩家武器上生成？

我有一个CharacterCreator类，它使播放器起作用，并且在其中具有使播放器射击的以下功能:

func shoot(scene: SKScene) {
    if (playerArmed) {
        let bullet = self.createBullet()
        scene.addChild(bullet)
        bullet.position = playerWeaponBarrel.position
        bullet.physicsBody?.velocity = CGVectorMake(200, 0)
    }
}

func createBullet() -> SKShapeNode {
    let bullet = SKShapeNode(circleOfRadius: 2)
    bullet.fillColor = SKColor.blueColor()
    bullet.physicsBody = SKPhysicsBody(circleOfRadius: bullet.frame.height / 2)
    bullet.physicsBody?.affectedByGravity = false
    bullet.physicsBody?.dynamic = true
    bullet.physicsBody?.categoryBitMask = PhysicsCategory.Bullet
    bullet.physicsBody?.contactTestBitMask = PhysicsCategory.Ground
    bullet.physicsBody?.collisionBitMask = PhysicsCategory.Ground
    return bullet
}

子项目应在playerWeaponBarrel子节点处生成。发生的是，当我在GameScene中调用shoot()函数时:

override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
    /* Called when a touch begins */
    for touch: AnyObject in touches {
        let location = touch.locationInNode(self)
        let touchedNode = self.nodeAtPoint(location)

        if (touchedNode == fireButton) {
            Player.shoot(self.scene!)
        }

它只是不会在playerWeaponBarrel上创建项目符号。我如何做到这一点？

最佳答案

您的问题是playerWeaponBarrel.position是相对于其 super 节点的，这可能是player。但是，您希望bullet绝对位于场景中，而不是相对于player。因此，您需要做的是将playerWeaponBarrel.position从其本地坐标系转换为scene坐标系:

bullet.position = scene.convertPoint(playerWeaponBarrel.position, fromNode: playerWeaponBarrel.parent!)