SpriteKit - didBegin contact is called 30 times instead of 1 time - swift

Question

I am making a little FlappyBird clone and have got everything working as it should until I changed the physics body of the bird to be exact to the texture. Now what it does is when it flies through the gap in the pipes it counts 30 points instead of just 1 point.
This only happens when I use the texture exact physics body which I need because the bird isn't round nor rectangular.
How would I go about making the collision so it only collides once with each gap node. I have tried setting the categoryBitBask to 0 after the contact but then all the gaps after don't add to the point count anymore at all.
Here is the full game code:
var score = 0
class GameScene: SKScene, SKPhysicsContactDelegate {
var bird = SKSpriteNode()
var bg = SKSpriteNode()
var ground = SKSpriteNode()
var scoreLabel = SKLabelNode(fontNamed: "Candice")
var gameOverLabel = SKLabelNode(fontNamed: "Candice")
var countbg = SKSpriteNode()
var timer = Timer()
enum ColliderType: UInt32 {
case Bird = 1
case Object = 2
case Gap = 4
}
var gameOver = false
let swooshSound = SKAction.playSoundFileNamed("sfx_swooshing.wav", waitForCompletion: false)
let pointSound = SKAction.playSoundFileNamed("sfx_point.wav", waitForCompletion: false)
let hitSound = SKAction.playSoundFileNamed("sfx_hit.wav", waitForCompletion: false)
#objc func makePipes() {
let movePipes = SKAction.move(by: CGVector(dx: -2 * self.frame.width, dy: 0), duration: TimeInterval(self.frame.width / 150))
let removePipes = SKAction.removeFromParent()
let moveAndRemovePipes = SKAction.sequence([movePipes, removePipes])
let gapHeight = bird.size.height * 2.8
let movementAmount = arc4random() % UInt32(self.frame.height) / 2
let pipeOffset = CGFloat(movementAmount) - self.frame.height / 4
let pipeTexture = SKTexture(imageNamed: "pipe1.png")
let pipe1 = SKSpriteNode(texture: pipeTexture)
pipe1.position = CGPoint(x: self.frame.midX + self.frame.width, y: self.frame.midY + pipeTexture.size().height / 2 + gapHeight / 2 + pipeOffset)
pipe1.zPosition = 2
pipe1.run(moveAndRemovePipes)
pipe1.physicsBody = SKPhysicsBody(rectangleOf: pipeTexture.size())
pipe1.physicsBody!.isDynamic = false
pipe1.physicsBody!.contactTestBitMask = ColliderType.Object.rawValue
pipe1.physicsBody!.categoryBitMask = ColliderType.Object.rawValue
pipe1.physicsBody!.collisionBitMask = ColliderType.Object.rawValue
self.addChild(pipe1)
let pipe2Texture = SKTexture(imageNamed: "pipe2.png")
let pipe2 = SKSpriteNode(texture: pipe2Texture)
pipe2.position = CGPoint(x: self.frame.midX + self.frame.width, y: self.frame.midY - pipeTexture.size().height / 2 - gapHeight / 2 + pipeOffset)
pipe2.zPosition = 2
pipe2.run(moveAndRemovePipes)
pipe2.physicsBody = SKPhysicsBody(rectangleOf: pipe2Texture.size())
pipe2.physicsBody!.isDynamic = false
pipe2.physicsBody!.contactTestBitMask = ColliderType.Object.rawValue
pipe2.physicsBody!.categoryBitMask = ColliderType.Object.rawValue
pipe2.physicsBody!.collisionBitMask = ColliderType.Object.rawValue
self.addChild(pipe2)
let gap = SKNode()
gap.position = CGPoint(x: self.frame.midX + self.frame.width, y: self.frame.midY + pipeOffset)
gap.physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: 1, height: gapHeight))
gap.physicsBody!.isDynamic = false
gap.run(moveAndRemovePipes)
gap.physicsBody!.contactTestBitMask = ColliderType.Bird.rawValue
gap.physicsBody!.categoryBitMask = ColliderType.Gap.rawValue
gap.physicsBody!.collisionBitMask = ColliderType.Gap.rawValue
self.addChild(gap)
}
func didBegin(_ contact: SKPhysicsContact) {
if gameOver == false {
if contact.bodyA.categoryBitMask == ColliderType.Gap.rawValue || contact.bodyB.categoryBitMask == ColliderType.Gap.rawValue {
score += 1
scoreLabel.text = String(format: "%05d", score)
run(pointSound)
} else {
self.speed = 0
run(hitSound)
gameOver = true
timer.invalidate()
bird.removeFromParent()
let changeSceneAction = SKAction.run(changeScene)
self.run(changeSceneAction)
}
}
}
//MARK: Change to Game Over Scene
func changeScene(){
let sceneToMoveTo = GameOverScene(size: self.size)
sceneToMoveTo.scaleMode = self.scaleMode
let myTransition = SKTransition.fade(withDuration: 0.5)
self.view!.presentScene(sceneToMoveTo, transition: myTransition)
}
override func didMove(to view: SKView) {
self.physicsWorld.contactDelegate = self
setupGame()
}
func setupGame() {
timer = Timer.scheduledTimer(timeInterval: 3, target: self, selector: #selector(self.makePipes), userInfo: nil, repeats: true)
let groundTexture = SKTexture(imageNamed: "ground.png")
let moveGroundAnimation = SKAction.move(by: CGVector(dx: -groundTexture.size().width, dy: 0), duration: 7)
let shiftGroundAnimation = SKAction.move(by: CGVector(dx: groundTexture.size().width, dy: 0), duration: 0)
let moveGroundForever = SKAction.repeatForever(SKAction.sequence([moveGroundAnimation, shiftGroundAnimation]))
var i: CGFloat = 0
while i < 3 {
ground = SKSpriteNode(texture: groundTexture)
ground.position = CGPoint(x: self.size.width * i, y: self.size.height / 7.65)
ground.zPosition = 3
ground.run(moveGroundForever)
self.addChild(ground)
i += 1
}
let bottom = SKNode()
bottom.position = CGPoint(x: self.frame.midX, y: self.size.height / 7)
bottom.physicsBody = SKPhysicsBody(rectangleOf: CGSize(width: self.frame.width, height: 1))
bottom.physicsBody!.isDynamic = false
bottom.physicsBody!.contactTestBitMask = ColliderType.Object.rawValue
bottom.physicsBody!.categoryBitMask = ColliderType.Object.rawValue
bottom.physicsBody!.collisionBitMask = ColliderType.Object.rawValue
self.addChild(bottom)
let bgTexture = SKTexture(imageNamed: "bg.png")
bg = SKSpriteNode(texture: bgTexture)
bg.position = CGPoint(x: self.frame.midX, y: self.frame.midY)
bg.size = self.frame.size
bg.zPosition = 1
self.addChild(bg)
let birdTexture = SKTexture(imageNamed: "flappy1.png")
let bird2Texture = SKTexture(imageNamed: "flappy2.png")
let bird3Texture = SKTexture(imageNamed: "flappy3.png")
let bird4Texture = SKTexture(imageNamed: "flappy4.png")
let bird5Texture = SKTexture(imageNamed: "flappy5.png")
let bird6Texture = SKTexture(imageNamed: "flappy6.png")
let animation = SKAction.animate(with: [birdTexture, bird2Texture, bird3Texture, bird4Texture, bird5Texture, bird6Texture], timePerFrame: 0.1)
let makeBirdFlap = SKAction.repeatForever(animation)
bird = SKSpriteNode(texture: birdTexture)
bird.position = CGPoint(x: self.frame.midX, y: self.frame.midY)
bird.setScale(1)
bird.zPosition = 6
bird.run(makeBirdFlap)
self.addChild(bird)
bird.physicsBody = SKPhysicsBody.init(circleOfRadius: birdTexture.size().height / 2)
//bird.physicsBody = SKPhysicsBody(texture: birdTexture, size: birdTexture.size())
bird.physicsBody!.isDynamic = false
bird.physicsBody!.contactTestBitMask = ColliderType.Object.rawValue
bird.physicsBody!.categoryBitMask = ColliderType.Bird.rawValue
bird.physicsBody!.collisionBitMask = ColliderType.Bird.rawValue
let countbg = SKSpriteNode(imageNamed: "count_bg.png")
countbg.position = CGPoint(x: self.size.width / 4.8, y: self.size.height * 0.94)
countbg.setScale(0.8)
countbg.zPosition = 4
addChild(countbg)
scoreLabel.fontSize = 80
scoreLabel.text = String(format: "%05d", score)
scoreLabel.fontColor = SKColor(red: 218/255, green: 115/255, blue: 76/255, alpha: 1)
scoreLabel.position = CGPoint(x: self.size.width / 4, y: self.size.height * 0.94)
scoreLabel.zPosition = 5
addChild(scoreLabel)
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
if gameOver == false {
bird.physicsBody!.isDynamic = true
bird.physicsBody!.velocity = CGVector(dx: 0, dy: 0)
bird.physicsBody!.applyImpulse(CGVector(dx: 0, dy: 280))
//run(swooshSound)
} else {
gameOver = false
score = 0
self.speed = 1
self.removeAllChildren()
setupGame()
}
}
override func update(_ currentTime: TimeInterval) {
// Called before each frame is rendered
}
}

Answer 1

If you would be using RxSwift, you would be able to easily get rid of those extra events easily by using debounce() or throttle() or distinctUntilChanged(). If you are willing to try this approach, give RxSpriteKit framework a go. Otherwise, store a timestamp of the last contact and ignore the following contacts until some time period elapses.