1

这似乎几乎令人难以置信,但是,

let pb = model.physicsBody?.copy() as! SKPhysicsBody
print("orig .. \(model.physicsBody!.linearDamping)")
print("pb .. \(pb.linearDamping)")

他们不一样。不完全是。

这太奇怪了,我一定做错了什么。我究竟做错了什么?

除了手动复制所有属性,并随着代码的发展而永久维护代码之外,如何做到这一点?


如果有人需要,这是一个 dupe-qualities 功能,可以节省打字。(这是 2017 年的——当然,随着苹果增加品质,它必须永远保持下去。)

extension SKSpriteNode
{
    func dupe() -> Any {

        // annoyingly, Apple does not provide a dupe function as you would use
        // when spawning from a model.

        let c = self.copy() as! SKSpriteNode

        c.physicsBody = self.physicsBody!.copy() as? SKPhysicsBody

        c.physicsBody?.affectedByGravity = self.physicsBody!.affectedByGravity
        c.physicsBody?.allowsRotation = self.physicsBody!.allowsRotation
        c.physicsBody?.isDynamic = self.physicsBody!.isDynamic

        c.physicsBody?.pinned = self.physicsBody!.pinned

        c.physicsBody?.mass = self.physicsBody!.mass
        c.physicsBody?.density = self.physicsBody!.density
        c.physicsBody?.friction = self.physicsBody!.friction
        c.physicsBody?.restitution = self.physicsBody!.restitution
        c.physicsBody?.linearDamping = self.physicsBody!.linearDamping
        c.physicsBody?.angularDamping = self.physicsBody!.angularDamping

        c.physicsBody?.categoryBitMask = self.physicsBody!.categoryBitMask
        c.physicsBody?.collisionBitMask = self.physicsBody!.collisionBitMask
        c.physicsBody?.fieldBitMask = self.physicsBody!.fieldBitMask
        c.physicsBody?.contactTestBitMask = self.physicsBody!.contactTestBitMask

        return c
    }
}

(只是一个人的意见,我觉得最好不要仅仅覆盖 NSCopy,因为整个事情是一个敏感的问题,为了下一位工程师,最好简单明了。“欺骗”是很常见的一个游戏对象对另一个游戏对象的品质,所以,这很好。)

4

1 回答 1

1

它与SKPhysicsBody成为包装类有关PKPhysicsBody

本质上,当您创建 的副本时SKPhysicsBody,它会创建 的新实例PKPhysicsBody,而不是它的副本。

为了解决这个问题,您需要编写一个扩展来为您填充值:

extension SKPhysicsBody
{
    override open func copy() -> Any {
        guard let body = super.copy() as? SKPhysicsBody else {fatalError("SKPhysicsBody.copy() failed")}
        body.affectedbyGravity = affectedByGravity
        body.allowsRotation= allowsRotation
        body.isDynamic= isDynamic
        body.mass= mass
        body.density = density
        body.friction = friction
        body.restitution = restitution
        body.linearDamping = linearDamping
        body.angularDamping = angularDamping

        return body
    }
}

请注意,我是手动输入的,此时我没有可用的 XCode 来测试它是否有效。

于 2017-10-23T14:46:34.417 回答