ios - 为什么我不能在函数更新中调用函数？

Question

请帮帮我!我试图在更新函数中调用我在 GameScene 类中声明的函数。但它不识别该功能，我想知道这是否与类有关，或者因为我想在每一帧运行该功能(但必须为每个单独的 spriteCopy 更新，取决于它自己的运动)到确保 Sprite 副本都遵循函数并无限地继续。

提前感谢您的帮助。

这是在一定程度上起作用的函数代码:

    func touchUp(atPoint pos : CGPoint) {

    if let spriteCopy = self.sprite?.copy() as! SKShapeNode? {
        spriteCopy.fillColor = UIColor.white
        spriteCopy.position = initialTouch
        spriteCopy.physicsBody?.restitution = 0.5
        spriteCopy.physicsBody?.friction = 0
        spriteCopy.physicsBody?.affectedByGravity = false
        spriteCopy.physicsBody?.linearDamping = 0
        spriteCopy.physicsBody?.angularDamping = 0
        spriteCopy.physicsBody?.angularVelocity = 0
        spriteCopy.physicsBody?.isDynamic = true
        spriteCopy.physicsBody?.categoryBitMask = 1 //active
        spriteCopy.isHidden = false

        touchUp = pos

        xAxisLength = initialTouch.x - touchUp.x
        yAxisLength = initialTouch.y - touchUp.y
        xUnitVector = xAxisLength / distanceBetweenTouch * power * 300
        yUnitVector = yAxisLength / distanceBetweenTouch * power * 300
        spriteCopy.physicsBody?.velocity = CGVector(dx: xUnitVector, dy: yUnitVector)


        func directionRotation() {
            if let body = spriteCopy.physicsBody {
                if (body.velocity.speed() > 0.01) {
                    spriteCopy.zRotation = body.velocity.angle()
                }
            }
        }

        directionRotation() //When I run the function with this line, the spriteCopy 
                            //is spawned initially with the right angle (in the direction 
                            //of movement) but doesn't stay updating the angle


        sprite?.isHidden = true

        self.addChild(spriteCopy)


    }

}

这里是函数更新中未被识别的函数:

override func update(_ currentTime: TimeInterval) {

    directionRotation() //this line has error saying "use of unresolved identifier" 

    // Called before each frame is rendered
}

编辑:我在想也许有一种方法可以在没有“copy()”方法的情况下生成多个 spriteCopy，这样在生成后不会限制对 spriteCopy 属性的访问？同时记住它们仍然必须是单独的 SpriteNode，以便可以将 directionRotation 函数独立应用于它们中的每一个(仅供引用:用户可以生成超过 50 个 Sprite 节点)

Answer 1

您已指定局部函数。你需要移出touchUp功能实现directionRotation

func directionRotation() {
    if let body = spriteCopy.physicsBody {
        if (body.velocity.speed() > 0.01) {
            spriteCopy.zRotation = body.velocity.angle()
        }
    }
}
func touchUp(atPoint pos : CGPoint) {

 ...
}

编辑

我的意思是你需要像这样思考:

func directionRotation(node:SKNode) {
    if let body = node.physicsBody {
        if (body.velocity.speed() > 0.01) {
            node.zRotation = body.velocity.angle()
        }
    }
}
override func update(_ currentTime: TimeInterval) {

    for node in self.children
    {
        directionRotation(node) 
    }
}