在函数中获取Swift中的当前分数

Question

我正在尝试增加一个变量，我将其作为NSTimeInterval加时使用，得分上升20点

这是我目前的代码

/* Create and Spawn enemy birds */
func enemySpawn() {




enemyBirdPhysics()



    // ENEMY BIRD ONE
    // Random Height
    let maxHeight:UInt32 = UInt32(self.frame.size.height - enemyBird.size.height)
    let moveToEndAction = SKAction.moveToX(0 - enemyBird.size.width, duration: 1.5)
    let resetTostartAction = SKAction.runBlock { () -> Void in

        var randomHeight = CGFloat(arc4random() % maxHeight)
        if (randomHeight < self.frame.size.height*0.1) {
            randomHeight = self.frame.size.height*0.12
        }
        self.enemyBird.position = CGPointMake(self.frame.size.width+100,randomHeight)
        score++
        self.scoreLabel.text = "\(score)"

    }



    let moveToEndThenStartAgain = SKAction.repeatActionForever(SKAction.sequence([moveToEndAction,resetTostartAction]))
    enemyBird.runAction(SKAction.repeatActionForever(moveToEndThenStartAgain))
    enemyBird.position = CGPointMake(self.frame.size.width+100, 500)
    movingObjects.addChild(enemyBird)





    // ENEMY BIRD TWO
    var waitBird2 = SKAction.waitForDuration(0.75)
    var waitBird2run = SKAction.runBlock({

        // Random Height
        let maxHeight2:UInt32 = UInt32(self.frame.size.height - self.enemyBird.size.height)
        let moveToEndAction2 = SKAction.moveToX(0, duration: 1.5)
        let resetTostartAction2 = SKAction.runBlock { () -> Void in

            var randomHeight2 = CGFloat(arc4random() % maxHeight2)
            if (randomHeight2 < self.frame.size.height*0.1) {
                randomHeight2 = self.frame.size.height*0.12
            }
            self.enemyBird2.position = CGPointMake(self.frame.size.width+100,randomHeight2)
            score++
            self.scoreLabel.text = "\(score)"

        }



        let moveToEndThenStartAgain2 = SKAction.repeatActionForever(SKAction.sequence([moveToEndAction2,resetTostartAction2]))
        self.enemyBird2.runAction(SKAction.repeatActionForever(moveToEndThenStartAgain2))
        self.enemyBird2.position = CGPointMake((self.frame.size.width+100), 200)
    })

    var bird2Seq = SKAction.sequence([waitBird2, waitBird2run])
    enemyBird2.runAction(bird2Seq)
    enemyBird2.position = CGPointMake((self.frame.size.width+100), 500)
    movingObjects.addChild(enemyBird2)

}

下面的行是两个敌人产生的代码块中需要更改的内容：

let moveToEndAction = SKAction.moveToX(0 - enemyBird.size.width, duration: 1.5)

我希望持续时间基于我可以根据分数改变的变量。