如何在没有物理学的情况下检测碰撞

Question

我想在不使用 didBeginContact() 函数的情况下检测两个物体何时接触

我尝试使用 CGRectIntersectsRect() 没有任何效果。

class GameScene: SKScene, SKPhysicsContactDelegate {

    // Player
    var _player = SKNode()
    var platform = SKNode()

    let heroCategory: UInt32 = 1 << 0
    let platformCategory: UInt32 = 1 << 1

    override func didMoveToView(view: SKView) {

        /* Setup your scene here */

        // Setup
        self.anchorPoint = CGPointMake(0.5, 0.5)
        self.physicsWorld.gravity = CGVectorMake(0.0, -2.0);
        self.physicsWorld.contactDelegate = self

        // Start populating
        _player = creatPlayer()
        self.addChild(_player)

        platform = creatPlatform(1, atPosition: CGPoint(x: 0, y: -200))
        self.addChild(platform)


        let platformTwo = creatPlatform(2, atPosition: CGPoint(x: 0, y: 200))
        self.addChild(platformTwo)

    }

    func creatPlatform(type: Int, atPosition: CGPoint) -> PlatformNode {

        let node = PlatformNode()
        node.platformType = type
        node.position = atPosition
        let sprite = SKSpriteNode(color: UIColor.redColor(), size: CGSize(width: 200, height: 50))
        node.addChild(sprite)

        node.physicsBody = SKPhysicsBody(rectangleOfSize: sprite.size)
        node.physicsBody?.dynamic = false;
        node.physicsBody?.categoryBitMask = platformCategory
        node.physicsBody?.contactTestBitMask = heroCategory
        node.physicsBody?.collisionBitMask = 0;

        return node

    }

    func creatPlayer() -> SKNode {

        let playerNode = SKNode()
        let sprite = SKSpriteNode(color: UIColor.whiteColor(), size: CGSize(width: 50, height: 50))
        playerNode.addChild(sprite)

        playerNode.physicsBody = SKPhysicsBody(rectangleOfSize: sprite.size)
        playerNode.physicsBody?.dynamic = false
        playerNode.physicsBody?.allowsRotation = false
        playerNode.physicsBody?.restitution = 1.0
        playerNode.physicsBody?.friction = 0.0
        playerNode.physicsBody?.angularDamping = 0.0
        playerNode.physicsBody?.linearDamping = 0.0
        playerNode.physicsBody?.categoryBitMask = heroCategory
        playerNode.physicsBody?.contactTestBitMask = platformCategory
        playerNode.physicsBody?.collisionBitMask = 0;

        return playerNode

    }

    override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {

        /* Called when a touch begins */
        _player.physicsBody?.dynamic = true

    }

    override func update(currentTime: CFTimeInterval) {

        /* Called before each frame is rendered */
        if(CGRectIntersectsRect(platform.frame, _player.frame)){
            println("Collision")
        }
    }

}

也许使用 CGRectIntersectsRect 是一种错误的方法，但我可以代替它使用？

Answer 1

框架属性

The frame property is a rectangle in the parent’s coordinate system that contains the node’s content, ignoring the node’s children.

也来自文档：

The frame is non-empty if the node’s class draws content.

而且因为SKNode class不执行任何自己的绘图，你的平台可能是SKNode的子class，播放器是SKNode的框架属性总是 (0,0,0,0).

您可以通过以下几种方式获取框架的实际大小：

您可以将播放器和平台设为 SKSpriteNode 的子class。
您可以保持原样并访问其中的子 SKSpriteNode。
您可以保持原样并使用calcualteAccumulatedFrame()方法。

关于文档中的 calcualteAccumulatedFrame()：

A node’s accumulated frame, retrieved by calling the calculateAccumulatedFrame method, is the largest rectangle that includes the frame of the node and the frames of all its descendants.

如何在没有物理学的情况下检测碰撞

How to detect collision without physics

game-physics

sprite-kit

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cgrectintersectsrect