Repeat function while touchesBegan in Swift 4 - ios

Question

I am trying to make my Bullet fire continuously while touching the screen. This is what I got so far, but it's not really working.
func fireBullet() {
let bullet = SKSpriteNode(imageNamed: "bullet")
bullet.name = "Bullet"
bullet.setScale(1.5) // Bullet Size
bullet.position = player.position
bullet.zPosition = 1
bullet.physicsBody = SKPhysicsBody(rectangleOf: bullet.size)
bullet.physicsBody!.affectedByGravity = false
bullet.physicsBody!.categoryBitMask = PhysicsCategories.Bullet
bullet.physicsBody!.collisionBitMask = PhysicsCategories.None
bullet.physicsBody!.contactTestBitMask = PhysicsCategories.Enemy
self.addChild(bullet)
let moveBullet = SKAction.moveTo(y: self.size.height + bullet.size.height, duration: 1)
let deleteBullet = SKAction.removeFromParent()
let bulletSequence = SKAction.sequence([bulletSound, moveBullet, deleteBullet])
let bulletRepeat = SKAction.repeatForever(bulletSequence)
bullet.run(bulletRepeat)
}

Answer 1

what you need is someway of turning on the fire when you press down on the screen and turning it off when you lift your finger. You can use the touches began to set a variable to true the says you should be firing isFiring = true and then catch that variable in the update. When you lift your finger the touches ended will turn the variable off.
Another nice touch is that you can adjust the firingInterval variable in real time to adjust the rate of fire.
private var updateTime: Double = 0
private var isFiring = false
//rate of fire, 1 means fire once a second
private var firingInterval: Double = 1
override func update(_ currentTime: TimeInterval) {
//check if we should be firing if not get outta here
guard isFiring else { return }
if updateTime == 0 {
updateTime = currentTime
}
if currentTime - updateTime > firingInterval {
self.fireBullet()
updateTime = currentTime
}
}
override touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
isFiring = true
}
override touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
isFiring = false
}
func fireBullet() {
let bullet = SKSpriteNode(imageNamed: "bullet")
bullet.name = "Bullet"
bullet.setScale(1.5) // Bullet Size
bullet.position = player.position
bullet.zPosition = 1
bullet.physicsBody = SKPhysicsBody(rectangleOf: bullet.size)
bullet.physicsBody!.affectedByGravity = false
bullet.physicsBody!.categoryBitMask = PhysicsCategories.Bullet
bullet.physicsBody!.collisionBitMask = PhysicsCategories.None
bullet.physicsBody!.contactTestBitMask = PhysicsCategories.Enemy
self.addChild(bullet)
let moveBullet = SKAction.moveTo(y: self.size.height + bullet.size.height, duration: 1)
let deleteBullet = SKAction.removeFromParent()
let bulletSequence = SKAction.sequence([bulletSound, moveBullet, deleteBullet])
//let bulletRepeat = SKAction.repeatForever(bulletSequence)
bullet.run(bulletSequence )
}

Answer 2

You could use a Timer object, started in the touchesBegan and cancel it in the touchesEnded method.
For timers, I use the following class that I've written :
class MyTimerHandlerObject: NSObject {
var timerCounter: CGFloat = 0
var myTimer = Timer()
override init() {super.init()}
#objc func myTimerHandler(_ theTimer: Timer) {
timerCounter += 0.1
// Do what needs do be done here ...
}
func startMyTimer() {
timerCounter = 0
self.myTimer = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(MyTimerHandlerObject.myTimerHandler(_:)), userInfo: nil, repeats: true)
}
func stopMyTimer() {
self.myTimer.invalidate()
timerCounter = 0
}
}
You can then easily start the timer and stop it, by declaring a variable of type MyTimerHandlerObject and use the methods 'StartMyTimer' and 'StopMyTimer'