Swift Spritekit Contact Bitmask and Score Label

Question

I am a fairly new programmer, attempting to make it so that during a bricked breaker like game, when the ball hits the paddle, I would like to add one point to the score. I think I am partway there, but cannot figure it out.

    let BallCategory   : UInt32 = 0x1 << 0 // 
    let BottomCategory : UInt32 = 0x1 << 1 //
    let BlockCategory  : UInt32 = 0x1 << 2 //
    let PaddleCategory : UInt32 = 0x1 << 3 //

    bottom.physicsBody?.categoryBitMask = BottomCategory
    bottom.physicsBody?.contactTestBitMask = BallCategory
    paddle.physicsBody?.categoryBitMask = PaddleCategory
    paddle.physicsBody?.contactTestBitMask = BallCategory
    paddle.physicsBody?.collisionBitMask = BallCategory
    ball.physicsBody?.categoryBitMask = BallCategory
    ball.physicsBody?.contactTestBitMask = BottomCategory | PaddleCategory
    ball.physicsBody?.contactTestBitMask = PaddleCategory

    var score = 0
            func didBeginContact(contact: SKPhysicsContact) {
                score = +1
            }

    let label = SKLabelNode(fontNamed: "Chalkduster")
            label.text = String(score)
            label.fontSize = 50
            label.fontColor = SKColor.whiteColor()
            label.position = CGPoint (x: 568, y: 600)
            addChild(label)

These are three sections of my code I believe I need to change in order to have the score work in my game and if you could help me, I would appreciate it.

Answer 1

You have to test if the colliding bodies have the correct bitmasks before increasing the score inside didBeginContact. You can use the following code to increase score on collision between paddle and ball.

func addScore() {
    score += 1
    scoreLabel.text = "\(score)"
}

func didBeginContact(contact: SKPhysicsContact) {

    var body1 : SKPhysicsBody!
    var body2 : SKPhysicsBody!

    if contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask {
        body1 = contact.bodyA
        body2 = contact.bodyB
    }
    else  {
        body1 = contact.bodyB
        body2 = contact.bodyA
    }

    if body1.categoryBitMask == BallCategory && body2.categoryBitMask == PaddleCategory {
        addScore()
    }
}