How to spawn images forever? Sprite-Kit - ios

Question

Im trying to create a dodgeball feature in my game and I need to repeatedly spawn a dodgeball and the current code I used (shown below) results in Thread 1: Exception: "Attemped to add a SKNode which already has a parent: name:'(null)' texture:[ 'dodgeball5' (500 x 500)] position:{-140.00019836425781, -55.124687194824219} scale:{1.00, 1.00} size:{30, 30} anchor:{0.5, 0.5} rotation:0.00". What am I doing incorrect?
class ClassicLevelScene: SKScene {
// Right Pointing Cannons
var rightPointingCannon: [SKReferenceNode] = []
// Dodgeball 5 Constants
var dodgeball5 = SKSpriteNode(imageNamed: "dodgeball5")
// Dodgeball SKActions
var dodgeballRepeat = SKAction()
let dodgeballMoveLeft = SKAction.moveBy(x: -400, y: 0, duration: 0.5)
let dodgeballMoveRight = SKAction.moveBy(x: 400, y: 0, duration: 0.5)
let dodgeballMoveDone = SKAction.removeFromParent()
let dodgeballWait = SKAction.wait(forDuration: 1)
var dodgeballLeftSequence = SKAction()
var dodgeballRightSequence = SKAction()
override func didMove(to view: SKView) {
// Cannon Setup
for child in self.children {
if child.name == "rightPointingCannon" {
if let child = child as? SKReferenceNode {
rightPointingCannon.append(child)
dodgeball5.position = child.position
run(SKAction.repeatForever(
SKAction.sequence([
SKAction.run(spawnDodgeball),
SKAction.wait(forDuration: 1.0)
])
))
}
}
}
// Dodgeball Right Sequence
dodgeballRightSequence = SKAction.sequence([dodgeballMoveRight, dodgeballMoveDone, dodgeballWait])
}
func spawnDodgeball() {
dodgeball5.zPosition = -1
dodgeball5.size = CGSize(width: 30, height: 30)
addChild(dodgeball5)
dodgeball5.run(dodgeballRightSequence)
}
}

Answer 1

Assuming single ball and ball can go off screen:
I would actually recommend against cloning the sprite.
Simply reuse it.
Once it's off the screen, you can reset it's position and speed and display it again. No need to create lots of objects, if you only need one.

Answer 2

One SKNode only can have 1 parent at time.
You need to create a new SKSpriteNode or clone the dodgeball5 before to add again on spawnDodgeball()
You can use
addChild(dodgeball5.copy())
instead of
addChild(dodgeball5)
But be make sure dodgeball5 have no parent before.

Answer 3

Your code seems to be unnecessarily complex.
all you need to do is copy() you ball and add it to your scene
Also all of your SKActions don't need to be declared at a class level
And it's not clear why you are creating an array of cannons when only one is instantiated
class ClassicLevelScene: SKScene {
// Dodgeball 5 Constants
var dodgeball5 = SKSpriteNode(imageNamed: "dodgeball5")
override func didMove(to view: SKView) {
setupCannonAndBall()
let dodgeballMoveRight = SKAction.moveBy(x: 400, y: 0, duration: 0.5)
let dodgeballMoveDone = SKAction.removeFromParent()
let dodgeballWait = SKAction.wait(forDuration: 1)
dodgeballRightSequence = SKAction.sequence([dodgeballMoveRight, dodgeballMoveDone, dodgeballWait])
//setup sequences ^ before spawning ball
let spawn = SKAction.run(spawnDodgeball)
let wait = SKAction.wait(forDuration: 1.0)
run(SKAction.repeatForever(SKAction.sequence([spawn, wait])))
}
func setupCannonAndBall() {
if let cannonRef = SKReferenceNode(fileNamed: "rightPointingCannon") {
dodgeball5.position = cannonRef.position
dodgeball5.isHidden = true
dodgeball5.size = CGSize(width: 30, height: 30)
dodgeball5.zPosition = -1
}
}
func spawnDodgeball() {
let dodgeball = dodgeball.copy()
dodgeball.isHidden = false
addChild(dodgeball)
dodgeball.run(dodgeballRightSequence)
}
}