ios - spritekit didBeginContact 三个对象不起作用

Question

我正在尝试通过三个节点 [didBeginContact]。我在代码下写的。但不能正常工作。当白色矩形没有击中黑色或白色矩形时，println("black") 和 println("blue") 工作...当白色矩形碰到黑色矩形时，println("blue") 工作...

import SpriteKit

class GameScene: SKScene, SKPhysicsContactDelegate {

let blackCategory:    UInt32 = 0x1 << 0
let whiteCategory:  UInt32 = 0x1 << 1
let blueCategory:   UInt32 = 0x1 << 2

override func didMoveToView(view: SKView) {

    self.physicsWorld.contactDelegate = self

    self.size = view.bounds.size
    self.physicsBody = SKPhysicsBody(edgeLoopFromRect: self.frame)
    self.physicsWorld.gravity = CGVectorMake(0.0, -3.0)

    let blackSquare = SKSpriteNode(color: UIColor.blackColor(), size: CGSizeMake(50, 50))
    blackSquare.position = CGPoint(
        x: CGRectGetMidX(self.frame),
        y: CGRectGetMidY(self.frame)
    )
    blackSquare.physicsBody = SKPhysicsBody(rectangleOfSize: CGSizeMake(50, 50))
    blackSquare.physicsBody?.affectedByGravity = false
    blackSquare.physicsBody?.dynamic = false

    blackSquare.physicsBody?.categoryBitMask = blackCategory
    blackSquare.physicsBody?.contactTestBitMask = whiteCategory

    let blueSquare = SKSpriteNode(color: UIColor.blueColor(), size: CGSizeMake(50, 50))
    blueSquare.position = CGPoint(
        x: CGRectGetMidX(self.frame) - 100,
        y: CGRectGetMidY(self.frame) - 100
    )
    blueSquare.physicsBody = SKPhysicsBody(rectangleOfSize: CGSizeMake(50, 50))
    blueSquare.physicsBody?.affectedByGravity = false
    blueSquare.physicsBody?.dynamic = false

    blackSquare.physicsBody?.categoryBitMask = blueCategory
    blackSquare.physicsBody?.contactTestBitMask = whiteCategory

    self.addChild(blackSquare)
    self.addChild(blueSquare)
}

override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {


    for touch in touches {

        let location = touch.locationInNode(self)
        let whiteRectangle = SKSpriteNode(color: UIColor.whiteColor(), size: CGSizeMake(50, 50))
        whiteRectangle.position = location
        whiteRectangle.physicsBody = SKPhysicsBody(rectangleOfSize: CGSizeMake(50, 50))


        whiteRectangle.physicsBody?.categoryBitMask = whiteCategory
        whiteRectangle.physicsBody?.contactTestBitMask = blackCategory
        whiteRectangle.physicsBody?.contactTestBitMask = blueCategory

        self.addChild(whiteRectangle)
    }

}

override func update(currentTime: CFTimeInterval) {
}


func didBeginContact(contact: SKPhysicsContact!) {

    var firstBody, secondBody, thirdBody: SKPhysicsBody


    if contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask {
        firstBody = contact.bodyA
        secondBody = contact.bodyB
        thirdBody = contact.bodyB
    } else {
        firstBody = contact.bodyB
        secondBody = contact.bodyA
        thirdBody = contact.bodyA
    }

    if firstBody.categoryBitMask & whiteCategory != 0 &&
        secondBody.categoryBitMask & blackCategory != 0 {
            //secondBody.node?.removeFromParent()
            println("black")
    }

    if firstBody.categoryBitMask & whiteCategory != 0 &&
        thirdBody.categoryBitMask & blueCategory != 0 {
            //secondBody.node?.removeFromParent()
            println("blue")
    }
}
}

Answer 1

1) 根据您的联系人处理程序，您应该将类​​别设置为

    let whiteCategory:  UInt32 = 0x1 << 0
    let blackCategory:  UInt32 = 0x1 << 1
    let blueCategory:   UInt32 = 0x1 << 2

2) 你两次错误地设置了 blackSquare 的 physicsBody 的位掩码

    blackSquare.physicsBody?.categoryBitMask = blueCategory
    blackSquare.physicsBody?.contactTestBitMask = whiteCategory

上面应该是

    blueSquare.physicsBody?.categoryBitMask = blueCategory
    blueSquare.physicsBody?.contactTestBitMask = whiteCategory

3) 这里不需要第三个接触体。

func didBeginContact(contact: SKPhysicsContact!) {

    var firstBody, secondBody: SKPhysicsBody

    if contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask {
        firstBody = contact.bodyA
        secondBody = contact.bodyB
    } else {
        firstBody = contact.bodyB
        secondBody = contact.bodyA
    }

    if ((firstBody.categoryBitMask & whiteCategory) != 0 &&
        (secondBody.categoryBitMask & blackCategory != 0)) {
            //secondBody.node?.removeFromParent()
            println("black")
    }


    if ((firstBody.categoryBitMask & whiteCategory != 0) &&
        (secondBody.categoryBitMask & blueCategory != 0)) {
            //secondBody.node?.removeFromParent()
            println("blue")
    }
}

4) 以下是不需要的(在touchesBegan)。为蓝色和黑色节点设置接触位掩码就足够了。

    whiteRectangle.physicsBody?.contactTestBitMask = blackCategory
    whiteRectangle.physicsBody?.contactTestBitMask = blueCategory