如何使语句仅适用于 Sprite Kit 中的选定级别

Question

所以我有这段代码

 if collision == PhysicsCategory.Cat | PhysicsCategory.Bed {
            print("SUCCESS")
            win()
            if currentLevel < 10 {
                currentLevel += 1
            }

基本上这个说法适用于我拥有的每个级别。我只想做一个级别

 if collision == PhysicsCategory.Cat | PhysicsCategory.Bed| PhysicsCategory.Bottle {
            print("SUCCESS")
            win()
            if currentLevel < 10 {
                currentLevel += 1
            }

但是如果我要用它就意味着每个关卡都需要与瓶子碰撞，但是我只想在一个关卡中使用它

我正在使用swift

谢谢！

为@Mundi

这是GameScene中的代码

 import SpriteKit
Game scene
protocol EventListenerNode {
    func didMoveToScene()
}
protocol InteractiveNode {
    func interact()
}

struct PhysicsCategory {
    static let None:  UInt32 = 0
    static let Cat:   UInt32 = 0b1 // 1
    static let Block: UInt32 = 0b10 // 2
    static let Bed:   UInt32 = 0b100 // 4
    static let Edge:  UInt32 = 0b1000 // 8
    static let Label: UInt32 = 0b10000 // 16
    static let Spring:UInt32 = 0b100000 //32
    static let Hook: UInt32 = 0b1000000 //64
    static let Bottle: UInt32 = 0b10000000 //64

}

class GameScene: SKScene, SKPhysicsContactDelegate {

    var bedNode: BedNode!
    var catNode: CatNode!
    var lineNode: LineNode!
    var bottleNode: BottleNode!
    var desiredCollision = PhysicsCategory.Cat | PhysicsCategory.Bed


    var playable = true

    override func didMove(to view: SKView) {
        // Calculate playable margin
        let maxAspectRatio: CGFloat = 16.0/9.0
        let maxAspectRatioHeight = size.width / maxAspectRatio
        let playableMargin: CGFloat = (size.height - maxAspectRatioHeight)/2
        let playableRect = CGRect(x: 0, y: playableMargin,
                                  width: size.width, height: size.height-playableMargin*2)
        physicsBody = SKPhysicsBody(edgeLoopFrom: playableRect)
        physicsWorld.contactDelegate = self
        physicsBody!.categoryBitMask = PhysicsCategory.Edge

        enumerateChildNodes(withName: "//*", using: { node, _ in
            if let eventListenerNode = node as? EventListenerNode {
                eventListenerNode.didMoveToScene()


            }

        })

        bedNode = childNode(withName: "bed") as! BedNode
        catNode = childNode(withName: "//cat_body") as! CatNode
        bottleNode = childNode(withName: "bottle") as! BottleNode




   func didBegin(_ contact: SKPhysicsContact) {
        let collision = contact.bodyA.categoryBitMask | contact.bodyB.categoryBitMask

        if collision == PhysicsCategory.Label | PhysicsCategory.Edge {

            let labelNode = contact.bodyA.categoryBitMask == PhysicsCategory.Label ?
                contact.bodyA.node :
                contact.bodyB.node

            if let message = labelNode as? MessageNode {
                message.didBounce()
            }
        }

        if !playable {
            return
        }


        if currentLevel == 20 { // or whatever level you want
            desiredCollision |= PhysicsCategory.Bottle

        }

        if collision == desiredCollision {
            print ("Win")
            win()


        } else if collision == PhysicsCategory.Cat | PhysicsCategory.Edge {
            print("FAIL")
            lose()

这是我的 BottleBode 中的代码

导入 SpriteKit

class BottleNode: SKSpriteNode, EventListenerNode {
    func didMoveToScene() {
        print("bottle added to scene")

        let bedBodySize = CGSize(width: 40.0, height: 30.0)
        physicsBody = SKPhysicsBody(rectangleOf: bedBodySize)
        physicsBody!.isDynamic = true

        physicsBody!.categoryBitMask = PhysicsCategory.Bottle
        physicsBody!.collisionBitMask = PhysicsCategory.Block | PhysicsCategory.Edge | PhysicsCategory.Spring | PhysicsCategory.Spring
        parent!.physicsBody!.contactTestBitMask = PhysicsCategory.Bed | PhysicsCategory.Edge

    }
}

我按照你告诉我的做了，但它仍然不起作用，当 CatNode 接触地面时，我失去了条件，我收到错误消息。

这是它如何不起作用的图片 https://i.stack.imgur.com/0JrMJ.png

这是一个错误。

https://i.stack.imgur.com/8VGRd.png

你能告诉我哪里错了吗？

非常感谢

Answer 1

您可以使用嵌套的 if-else 语句首先检查它是否是特殊级别，然后根据结果决定使用哪个版本。它看起来像这样：

var useSpecialCollision: bool // Change this to true/false based on when the level changes

if useSpecialCollision == true {

     if collision == PhysicsCategory.Cat | PhysicsCategory.Bed| PhysicsCategory.Bottle {
            print("SUCCESS")
            win()
            if currentLevel < 10 {
                currentLevel += 1
            }
     }

} else {

     if collision == PhysicsCategory.Cat | PhysicsCategory.Bed {
        print("SUCCESS")
        win()
        if currentLevel < 10 {
            currentLevel += 1
        }
     }

}

这会将您的 if statements/code 放入另一个 if 语句以确定要运行的代码。不是很复杂...也不是最简洁的...

Answer 2

可能没有特殊变量并且更简洁：

var desiredCollision = PhysicsCategory.Cat | PhysicsCategory.Bed
if currentLevel == 7 { // or whatever level you want
   desiredCollision |= PhysicsCategory.Bottle
}

if collision = desiredCollision { 
// ...

如何使语句仅适用于 Sprite Kit 中的选定级别

How to make statement work only for the selected level in Sprite Kit

collision-detection

sprite-kit

swift