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标题: ios - 试图制造我可以从下面跳过但可以降落在上面的平台。无法微调逻辑 [打印本页]

作者: 菜鸟教程小白    时间: 2022-12-13 15:30
标题: ios - 试图制造我可以从下面跳过但可以降落在上面的平台。无法微调逻辑

我的目标是在 .sks 文件中设置我的所有平台,以便更轻松地设计我的关卡。


这是在游戏 scene.swift 的顶部在 didMove 之前声明的:

private var JumpThroughPlatformObject = SKSpriteNode()

这是在 DidMove 中:

if let JumpThroughPlatformObjectNode = self.childNode(withName: "//jumpThroughPlatform1") as? SKSpriteNode {
        JumpThroughPlatformObject = JumpThroughPlatformObjectNode} 

我引用平台以从 .sks 中获取它的高度,因为我的所有平台都将是相同的高度,我只需要从一个中获取它。

下面是我试图在我的更新方法中使用来关闭碰撞,直到我的播放器完全位于平台之上。仅检查我的玩家速度是否大于零的主要问题是:玩家是否处于跳跃的峰值(他的速度减慢到零)。如果发生这种情况并且玩家在一个平台内,他要么立即弹到平台顶部,要么向下发射。

我不希望我的平台必须是 1 像素高的线。我还需要让玩家拥有一个完整的碰撞盒,因为他将与其他类型的环境进行交互。这让我相信我只需要将平台的顶部注册为碰撞盒,而不是整个平台。

我写的这个 if 语句应该采用平台的 y 位置并将其高度的一半添加到它,因为 y 位置基于 Sprite 的中心,我认为这会将平台的碰撞放在它的顶部边界。

我对播放器做了同样的事情,但反过来。将玩家碰撞仅放在其边界的底部。但它不能完美地工作,我现在不知道为什么。

if (JumpThroughPlatformObject.position.y + (JumpThroughPlatformObject.size.height / 2)) > (player.position.y - (player.size.height / 2))

下面的函数给了我三个主要问题:

  1. 我的玩家跳跃总是 dy = 80。如果我要跳到那个 position.y = 90 的平台,玩家跳跃的高峰会停在平台中间,但他会传送到而不是继续倒在地上。

  2. 如果我摔倒,平台的左右边缘仍然会与玩家完全碰撞

  3. 如果我的播放器在一个平台上,而我正上方有另一个播放器,则播放器无法跳过它。

    设零:CGFloat = 0

        if let body = player.physicsBody {
            let dy = player.physicsBody?.velocity.dy
    
            // when I jump dy is greater than zero else I'm falling
    
           if (dy! >= zero) {
    
               if (JumpThroughPlatformObject.position.y + (JumpThroughPlatformObject.size.height / 2)) > (player.position.y - (player.size.height / 2)) {
    
                    print(" platform y: \(JumpThroughPlatformObject.position.y)")
                    print ("player position: \(player.position.y)")
    
                    // Prevent collisions if the hero is jumping
                    body.collisionBitMask = CollisionTypes.saw.rawValue | CollisionTypes.ground.rawValue
    
                }
    
           }
            else {
                // Allow collisions if the hero is falling
                body.collisionBitMask = CollisionTypes.platform.rawValue | CollisionTypes.ground.rawValue | CollisionTypes.saw.rawValue
            }
        } 
    

任何建议将不胜感激。这几天我一直在扯头发。

在 didBegin 和 didEnd 中编辑:

   func didBegin(_ contact: SKPhysicsContact) {

    if let body = player.physicsBody {
        let dy = player.physicsBody?.velocity.dy
        let platform = JumpThroughPlatformObject
        let zero:CGFloat = 0


    if contact.bodyA.node == player {
      // playerCollided(with: contact.bodyB.node!)

            if (dy! > zero || body.node!.intersects(platform)) && ((body.node?.position.y)! - player.size.height / 2 < platform.position.y + platform.size.height / 2) {

                body.collisionBitMask &= ~CollisionTypes.platform.rawValue

            }



    } else if contact.bodyB.node == player {
     //  playerCollided(with: contact.bodyA.node!)
        isPlayerOnGround = true

        if (dy! > zero || body.node!.intersects(platform)) && ((body.node?.position.y)! - player.size.height / 2 < platform.position.y + platform.size.height / 2) {

            body.collisionBitMask &= ~CollisionTypes.platform.rawValue}
        }
    }
}

func didEnd(_ contact: SKPhysicsContact) {

    if let body = player.physicsBody {
//            let dy = player.physicsBody?.velocity.dy
//            let platform = JumpThroughPlatformObject

    if contact.bodyA.node == player {


        body.collisionBitMask |= CollisionTypes.platform.rawValue

    }else if contact.bodyB.node == player {

        body.collisionBitMask |= CollisionTypes.platform.rawValue

    }
    }
}

添加我所做的,玩家不能再跳过平台。



Best Answer-推荐答案


这是我为 macOS 和 iOS 目标制作的项目的链接:
https://github.com/fluidityt/JumpUnderPlatform

基本上,这一切都与

  1. 检测平台碰撞
  2. 然后判断你的播放器是否在平台下
  3. 让您的玩家通过平台(然后登陆平台)

--

SK Physics 使这有点复杂:

  1. 在碰撞检测中,您的播放器的 .position.y.velocity.dy 可能已经更改为“假”状态,以满足上面的 #2 检查(意味着 #3 永远不会发生)。此外,您的播放器会在第一次接触时从平台反弹。

  2. 没有“自动”的方式来确定你的玩家何时完成通过物体(从而允许玩家降落在平台上)

--

因此,为了让一切顺利进行,必须使用一点创造力和独创性!


1:检测平台碰撞:

所以,解决1是最简单的:我们只需要使用内置的didBegin(contact

我们将严重依赖 3 大位掩码、联系人、类别和碰撞:

(仅供引用,我不喜欢在物理中使用枚举和位数学,因为我是个叛逆的白痴):

struct BitMasks {
  static let playerCategory = UInt32(2)
  static let jupCategory    = UInt32(4) // JUP = JumpUnderPlatform 
}

override func didBegin(_ contact: SKPhysicsContact) {

  // Crappy way to do "bit-math":
  let contactedSum = contact.bodyA.categoryBitMask + contact.bodyB.categoryBitMask

  switch contactedSum {

  case BitMasks.jupCategory + BitMasks.playerCategory:
  // ...
}  

--

现在,你说你想使用 SKSEditor,所以我已经适应了你:

enter image description here enter image description here enter image description here enter image description here

// Do all the fancy stuff you want here...
class JumpUnderPlatform: SKSpriteNode {

  var pb: SKPhysicsBody { return self.physicsBody! } // If you see this on a crash, then WHY DOES JUP NOT HAVE A PB??

  // NOTE: I could not properly configure any SKNode properties here..
  // it's like they all get RESET if you put them in here...
  required init?(coder aDecoder: NSCoder) { super.init(coder: aDecoder) }   
}

--

现在给玩家:

class Player: SKSpriteNode {

  // If you see this on a crash, then WHY DOES PLAYER NOT HAVE A PB??
  var pb: SKPhysicsBody { return self.physicsBody! }

  static func makePlayer() -> Player {

    let newPlayer = Player(color: .blue, size: CGSize(width: 50, height: 50))
    let newPB = SKPhysicsBody(rectangleOf: newPlayer.size)

    newPB.categoryBitMask = BitMasks.playerCategory
    newPB.usesPreciseCollisionDetection = true

    newPlayer.physicsBody = newPB
    newPlayer.position.y -= 200 // For demo purposes.

    return newPlayer
  }
}


2。 (并处理#4):确定是否在接触平台下:

有很多方法可以做到这一点,但我选择使用 KOD 提到的 player.pb.velocity.dy 方法来跟踪玩家的位置......如果你的 dy 是超过 0,那么你在跳跃(在平台下),如果不是,那么你要么静止不动,要么跌倒(需要与平台接触并坚持下去)。

要实现这一点,我们必须掌握更多技术知识,因为物理系统和 SK 在其循环中的工作方式并不总是 100% 与我们认为应该工作的方式相吻合.

基本上,我必须为播放器创建一个 initialDY 属性,该属性在 update

中的每一帧中不断更新

initialDY 将为我们提供第一次接触平台所需的正确数据,让我们告诉我们更改碰撞掩码,并将玩家的 CURRENT dy 重置为首字母 dy(因此玩家不会反弹)。


3。 (并处理#5):允许玩家通过平台

要通过平台,我们需要使用 collisionBitMasks。我选择让玩家的碰撞 mask = 玩家的 categoryMask,这可能不是正确的做法,但它适用于这个演示。

你会在 didBegin 中得到这样的魔法:

  // Check if jumping; if not, then just land on platform normally.
  guard player.initialDY > 0 else { return }

  // Gives us the ability to pass through the platform!
  player.pb.collisionBitMask = BitMasks.playerCategory

现在,处理 #5 将需要我们向我们的播放器类添加另一个状态。我们需要临时存储接触到的平台,以便我们可以检查播放器是否已成功完成通过平台(所以我们可以重置碰撞掩码)

然后我们只需检查 didFinishUpdate 是否玩家的框架高于该平台,如果是,我们重置掩码。

这里是所有文件,还有一个github链接:
https://github.com/fluidityt/JumpUnderPlatform



Player.swift:

class Player: SKSpriteNode {

  // If you see this on a crash, then WHY DOES PLAYER NOT HAVE A PB??
  var pb: SKPhysicsBody { return self.physicsBody! }

  // This is set when we detect contact with a platform, but are underneath it (jumping up)
  weak var platformToPassThrough: JumpUnderPlatform?

  // For use inside of gamescene's didBeginContact (because current DY is altered by the time we need it)
  var initialDY = CGFloat(0)
}

// MARK: - Funkys:
extension Player {
  static func makePlayer() -> Player {

    let newPlayer = Player(color: .blue, size: CGSize(width: 50, height: 50))
    let newPB = SKPhysicsBody(rectangleOf: newPlayer.size)

    newPB.categoryBitMask = BitMasks.playerCategory
    newPB.usesPreciseCollisionDetection = true

    newPlayer.physicsBody = newPB
    newPlayer.position.y -= 200 // For demo purposes.

    return newPlayer
  }


  func isAbovePlatform() -> Bool {
    guard let platform = platformToPassThrough else { fatalError("wtf is the platform!") }

    if frame.minY > platform.frame.maxY { return true  }
    else                                { return false }
  }

  func landOnPlatform() {
      print("resetting stuff!")
      platformToPassThrough = nil
      pb.collisionBitMask = BitMasks.jupCategory
  }
}

// MARK: - Player GameLoop:
extension Player {

  func _update() {
    // We have to keep track of this for proper detection of when to pass-through platform
    initialDY = pb.velocity.dy
  }

  func _didFinishUpdate() {

    // Check if we need to reset our collision mask (allow us to land on platform again)
    if platformToPassThrough != nil {
      if isAbovePlatform() { landOnPlatform() }
    }
  }
}


JumpUnderPlatform 和 BitMasks.swift(分别

// Do all the fancy stuff you want here...
class JumpUnderPlatform: SKSpriteNode {

  var pb: SKPhysicsBody { return self.physicsBody! } // If you see this on a crash, then WHY DOES JUP NOT HAVE A PB??

  required init?(coder aDecoder: NSCoder) { super.init(coder: aDecoder) }

}

struct BitMasks {
  static let playerCategory = UInt32(2)
  static let jupCategory    = UInt32(4)
}


GameScene.swift:

-

确保您的 SKS 编辑器中有两个节点: enter image description here enter image description here

-

// MARK: - Props:
class GameScene: SKScene, SKPhysicsContactDelegate {

  // Because I hate crashes related to spelling errors.
  let names = (jup: "jup", resetLabel: "resetLabel")

  let player = Player.makePlayer()
}


// MARK: - Physics handling:
extension GameScene {

  private func findJup(contact: SKPhysicsContact) -> JumpUnderPlatform? {
    guard let nodeA = contact.bodyA.node, let nodeB = contact.bodyB.node else { fatalError("how did this happne!!??") }

    if      nodeA.name == names.jup { return (nodeA as! JumpUnderPlatform) }
    else if nodeB.name == names.jup { return (nodeB as! JumpUnderPlatform) }
    else                            { return nil }
  }

  // Player is 2, platform is 4:
  private func doContactPlayer_X_Jup(platform: JumpUnderPlatform) {

    // Check if jumping; if not, then just land on platform normally.
    guard player.initialDY > 0 else { return }

    // Gives us the ability to pass through the platform!
    player.physicsBody!.collisionBitMask = BitMasks.playerCategory

    // Will push the player through the platform (instead of bouncing off) on first hit
    if player.platformToPassThrough == nil { player.pb.velocity.dy = player.initialDY }
    player.platformToPassThrough = platform
  }

func _didBegin(_ contact: SKPhysicsContact) {

  // Crappy way to do bit-math:
  let contactedSum = contact.bodyA.categoryBitMask + contact.bodyB.categoryBitMask

  switch contactedSum {

  case BitMasks.jupCategory + BitMasks.playerCategory:
      guard let platform = findJup(contact: contact) else { fatalError("must be platform!") }
      doContactPlayer_X_Jup(platform: platform)

    // Put your other contact cases here...
    // case BitMasks.xx + BitMasks.yy:

    default: ()
    }
  }
}

// MARK: - Game loop:
extension GameScene {

  // Scene setup:
  override func didMove(to view: SKView) {
    physicsWorld.contactDelegate = self
    physicsBody = SKPhysicsBody(edgeLoopFrom: frame)
    addChild(player)
  }

  // Touch handling: (convert to touchesBegan for iOS):
  override func mouseDown(with event: NSEvent) {
    // Make player jump:
    player.pb.applyImpulse(CGVector(dx: 0, dy: 50))

    // Reset player on label click (from sks file): 
    if nodes(at: event.location(in: self)).first?.name == names.resetLabel {
      player.position.y = frame.minY + player.size.width/2 + CGFloat(1)
    }
  }

  override func update(_ currentTime: TimeInterval) {
    player._update()
  }

  func didBegin(_ contact: SKPhysicsContact) {
    self._didBegin(contact)
  }

  override func didFinishUpdate() {
    player._didFinishUpdate()
  }
}

我希望这会有所帮助!

关于ios - 试图制造我可以从下面跳过但可以降落在上面的平台。无法微调逻辑,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/44913398/






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