Add a delay to a function in SpriteKit - ios

Question

I would like to be able to only allow the player to shoot a missile every 0.7 seconds. How do I do this? Here is my code. I have tried other methods I found on this site but they do not work.
func fireTorpedo() {
if !self.player.isPaused
{
if isSoundEffect == true {
self.run(SKAction.playSoundFileNamed("Rocket", waitForCompletion: false))
}
let torpedoNode = SKSpriteNode(imageNamed: "Rocket")
torpedoNode.position = player.position
torpedoNode.position.y += 5
torpedoNode.physicsBody = SKPhysicsBody(circleOfRadius: torpedoNode.size.width / 2)
torpedoNode.physicsBody?.isDynamic = true
torpedoNode.physicsBody?.categoryBitMask = photonTorpedoCategory
torpedoNode.physicsBody?.contactTestBitMask = alienCategory
torpedoNode.physicsBody?.collisionBitMask = 0
torpedoNode.physicsBody?.usesPreciseCollisionDetection = true
self.addChild(torpedoNode)
let animationDuration:TimeInterval = 0.5
var actionArray = [SKAction]()
actionArray.append(SKAction.move(to: CGPoint(x: player.position.x, y: self.frame.size.height + 10), duration: animationDuration))
actionArray.append(SKAction.removeFromParent())
torpedoNode.run(SKAction.sequence(actionArray))
}
}

Answer 1

I like to do that like this:
class GameScene:SKScene {
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
super.touchesBegan(touches, with: event)
if action(forKey: "shooting") == nil {
let wait = SKAction.wait(forDuration: 0.7)
run(wait, withKey: "shooting")
print("shot fired")
}
}
}
While there is a key "shooting" found on a scene, you can't shoot anymore. In real game, this would be likely the part of a node (an action should be run on a node).

Answer 2

First, add a flag at class-level that indicates whether the player can fire a torpedo.
var canFireTorpedo = true
Then, at the end of the fireTorpedo method, set canFireTorpedo to false, then set it to true again after 0.7 seconds:
canFireTorpedo = false
player.run(SKAction.sequence([
SKAction.wait(forDuration: 0.7),
SKAction.run { [weak self] in self?.canFireTorpedo = true }]))
After that, check canFireTorpedo at the start of the method:
func fireTorpedo() {
if canFireTorpedo {
// put everything in the method here, including the parts I added
}
}
Hopefully this code is self-explanatory.

Answer 3

To launch every 0.7 seconds you can do:
let actionKey = "repeatLaunchMethod"
let launchMethod = SKAction.afterDelay(0.7, runBlock: {
[weak self] in
guard let strongSelf = self else { return }
strongSelf.fireTorpedo()
})
// do this if you want to repeat this action forever
self.player.run(SKAction.repeatForever(launchMethod), withKey: actionKey)
// do this if you want to repeat this action only n times
// self.player.run(SKAction.repeat(launchMethod, count: 5), withKey: actionKey)
To stop this action you can do:
if self.player.action(forKey: actionKey) != nil {
self.player.removeAction(forKey: actionKey)
}
Extension used to render the code more readable:
extension SKAction {
/**
* Performs an action after the specified delay.
*/
class func afterDelay(_ delay: TimeInterval, performAction action: SKAction) -> SKAction {
return SKAction.sequence([SKAction.wait(forDuration: delay), action])
}
/**
* Performs a block after the specified delay.
*/
class func afterDelay(_ delay: TimeInterval, runBlock block: #escaping () -> Void) -> SKAction {
return SKAction.afterDelay(delay, performAction: SKAction.run(block))
}
}