So I have my SKView as an IBOutlet and a delegate that allows scenes to change the current scene as follows:
// this code is inside the view controller
func changeScene(to sceneType: GameScene.Type) {
let sceneName = NSStringFromClass(sceneType).components(separatedBy: ".").last!
let scene = sceneType.init(fileNamed: sceneName)!
scene.scaleMode = .aspectFill
scene.dialogueDelegate = self.dialogueView
scene.sceneDelegate = self
self.hudScene.hudDelegate = scene
self.actionButtonScene.actionButtonDelegate = scene
self.gameView.presentScene(scene, transition: SKTransition.fade(withDuration: 2))
}
I am calling this function once when the game starts (and it works) and once when the player falls out of the scene:
// this code is inside the scene
override func update(_ currentTime: TimeInterval) {
if self.player.position.y < -self.size.height / 2 {
self.player.removeFromParent()
self.sceneDelegate?.changeScene(to: Self.self)
}
}
But the second time it does nothing. The code gets executed, but the scene is not presented. Removing the SKTransition seems to solve the problem, but why is the transition an issue here?
Related
I have a simple (multi scene) spritekit game and would like to implement and display a settings screen using a UITableViewContoller. I am close but keep losing my reference to the games view controller when i change scene, which means i can only segue to the UITableViewController on the first scene when my game starts. I'm hoping someone can help. I setup the UITableView in the storyboard and setup a segue to the tableview from my GameViewController in there.
I have the following set up in my GameViewController file:
override func viewDidLoad() {
super.viewDidLoad()
if let view = self.view as! SKView? {
// Load the SKScene
if let scene = SKScene(fileNamed: "MenuScene") {
// Set the scale mode to scale to fit the window
scene.scaleMode = .aspectFill
//I'VE ADDED THIS
if let gameScene = scene as? MenuScene {
gameScene.viewController = self
}
// Present the scene
view.presentScene(scene)
}
view.ignoresSiblingOrder = true
}
}
func showSettings() {
performSegue(withIdentifier: "openSettings", sender: self)
}
which gives me a reference to the GameViewController from my SKScene. I then load the UITableViewController from my SKScene in spritekit when a user touches an SKLabelNode. A simpler version of my MenuScene code looks something like this:
class MenuScene: SKScene {
var viewController: GameViewController?
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?)
{
let touch:UITouch = touches.first!
let positionInScene = touch.location(in: self)
let touchedNode = self.atPoint(positionInScene)
if let name = touchedNode.name
{
let transition:SKTransition = SKTransition.fade(withDuration: 0.75)
var scene:SKScene = SKScene()
if (name == "settingsBTN"){
viewController?.showSettings()
}
else if (name == "randomBTN"){
scene = StarScene(size: self.size)
scene.backgroundColor = SKColor.black
self.view?.presentScene(scene, transition: transition)
}
}
}
}//end of MenuScene
The table view is presented fine when i tap the settingsBTN when first starting the game. however, if i visit another scene in my game (e.g. by pressing randomBTN) and return back to the menu scene i can no longer segue to the Settings view as i have lost the reference to the viewcontroller (it shows as nil) so i can't call the showSettings method in the GameViewController that performs the segue (presumably because i set up the reference to the view controller in the view controller itself).
I can't figure out how to maintain the reference to my GameViewController so i can present the settings screen at any point. Please could someone help.
There are two simple methods to call a GameViewController function from other classes: through a delegate or by making the class instance static.
// DELEGATE
//
// GameViewController.swift
protocol GameView_Delegate
{
func show_ui()
}
class GameViewController: UIViewController, GameView_Delegate
{
override func viewDidLoad()
{
// ...
if let view = self.view as! SKView?
{
if let scene = SKScene(fileNamed: "MenuScene")
{
scene.scaleMode = .aspectFill
// pass GameViewController reference
scene.gv_delegate = self
}
view.presentScene(scene)
}
// ...
}
func show_ui()
{
// show ui
// ...
}
}
// MenuScene.swift
class MenuScene: SKScene
{
var gv_delegate : GameView_Delegate!
func settings()
{
// call function show_ui from GameViewController
gv_delegate.show_ui()
}
func game_scene()
{
let transition = SKTransition.fade(with: UIColor.white, duration: 1.0)
let next_scene = GameScene()
next_scene.anchorPoint = CGPoint(x: 0.5, y: 0.5)
next_scene.scaleMode = self.scaleMode
next_scene.size = self.size
// before moving to next scene, we must pass the delegate, so we
// don't lose the connection with the GameViewController
next_scene.gv_delegate = gv_delegate
self.view?.presentScene(next_scene, transition: transition)
}
}
// GameScene.swift
class GameScene: SKScene
{
var gv_delegate : GameView_Delegate!
func settings()
{
// call function show_ui from GameViewController
gv_delegate.show_ui()
}
func main_scene()
{
let transition = SKTransition.fade(with: UIColor.white, duration: 1.0)
let next_scene = MainScene()
next_scene.anchorPoint = CGPoint(x: 0.5, y: 0.5)
next_scene.scaleMode = self.scaleMode
next_scene.size = self.size
// before moving to next scene, we must pass the delegate, so we
// don't lose the connection with the GameViewController
next_scene.gv_delegate = gv_delegate
self.view?.presentScene(next_scene, transition: transition)
}
}
When you enter a new scene, for example GameScene, the old scene MainScene in our case is deallocated (all variables emptied, all references destroyed) and a new GameScene instance is created and displayed on screen. If afterwards you want to exit that scene and enter MainScene, a new instance of that class will be created with the GameViewController reference empty. We should reference it again or pass the reference before exiting the scene (as in my example).
// STATIC
//
// GameViewController.swift
class GameViewController: UIViewController
{
static var shared : GameViewController!
override func viewDidLoad()
{
super.viewDidLoad()
GameViewController.shared = self
// ...
}
func show_ui()
{
// show ui
// ...
}
}
// MenuScene.swift
class MenuScene: SKScene
{
func settings()
{
// call function show_ui from GameViewController
GameViewController.shared.show_ui()
}
}
Read pros/cons of each method and chose the one that suits your app the best. Also, avoid using UIKit inside SpriteKit.
I want to change the initial scene being presented to be another class other than the default GameScene class. From reading other questions, I understand I must change this part from the GameViewController:
if let scene = SKScene(fileNamed: "GameScene") {
print(scene)
// Set the scale mode to scale to fit the window
scene.scaleMode = .aspectFill
// Present the scene
view.presentScene(scene)
}
So within the GameScene.swift file I am creating a new class:
class MainMenu : SKScene {
override func didMove(to view: SKView) {
print("At least it ran")
self.scene?.view?.presentScene(GameScene())
}
}
However, when I change the scene to:
if let scene = SKScene(fileNamed: "MainMenu")
When I run the project, it gets stuck, but when I run it with the string "GameScene" then it works perfectly. I am doing something wrong loading the MainMenu?
In my opinion you should separate your scenes into their own files...
Do you have an corresponding SKS file for MenuScene? You need to create one if you are trying to load it with fileNamed:
or -
Use this code to load a SKScene file that is created in code only and not in the Scene editor
if let skView = self.view as? SKView {
if skView.scene == nil {
let scene = MenuScene(size: skView.bounds.size)
scene.scaleMode = .aspectFill
skView.presentScene(scene)
}
}
and then in your MenuScene file you will need an init func
init(size: CGSize) {
super.init(size: size)
name = "menuScene"
}
I am wanting to 'reset' and 'restart' the GameScene so it is as if the GameScene was first called. I have looked at different methods for doing this, but each time I get a warning that I'm trying to add a node to a parent which already has a parent. However, in my code I delete all my existing nodes so I'm really confused as to how to reset the GameScene. This is how I do it now (this code is called when I want to restart the GameScene from scratch and it is called within the GameScene class):
let scene = GameScene(size: self.size)
scene.scaleMode = .aspectFill
let animation = SKTransition.fade(withDuration: 1.0)
self.view?.presentScene(scene, transition: animation)
self.removeAllChildren()
self.removeAllActions()
self.scene?.removeFromParent()
1.Edited: I realised that why I was getting this warning: "I'm trying to add a node to a parent which already has a parent" was because I had all the variables for the scene outside of the class and as global variables. However, now when the game restarts, the game is in the bottom left corner. Why is this the case and how do I fix this? - FIXED
2.Edited: Everything works fine now, but now my concern is that deinit{} isn't called even though every node is deleted and the fps doesn't drop over time. Here is what I have in my GameViewController for setting the scene and in my GameScene (every instance relating to the scenes so basically all that is relevant):
import UIKit
import SpriteKit
import GameplayKit
var screenSize = CGSize()
class GameViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
if let view = self.view as! SKView? {
// Load the SKScene from 'GameScene.sks'
if let scene = SKScene(fileNamed: "GameScene") {
// Set the scale mode to scale to fit the window
scene.scaleMode = .aspectFill
screenSize = scene.size
// Present the scene
view.presentScene(scene)
}
view.ignoresSiblingOrder = true
view.showsFPS = true
view.showsNodeCount = true
}
}
Then my GameScene is basically:
import SpriteKit
import GameplayKit
class GameScene: SKScene, SKPhysicsContactDelegate {
//Declare and initialise variables and enumerations here
deinit{print("GameScene deinited")}
override func didMove(to view: SKView) {
//Setup scene and nodes
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
//Do other things depending on when and where you touch
//When I want to reset the GameScene
let newScene = GameScene(size: self.size)
newScene.anchorPoint = CGPoint(x: 0.5, y: 0.5)
newScene.scaleMode = self.scaleMode
let animation = SKTransition.fade(withDuration: 1.0)
self.view?.presentScene(newScene, transition: animation)
}
Any answers would be greatly appreciated :)
How to reset the scene?
You just have to present a new, same scene again whenever you want. So, you are doing it fine.
Possible leaking problems?
Also, if you don't have leaks in your game, means no strong reference cycles, you don't even need self.removeAllChildren() and self.removeAllActions()... Of course if you explicitly want to stop actions before transition animation starts, the using this method make sense. The point is, when scene deallocates, all objects that depends on it should / will deallocate as well.
Still, if you don't know from the beginning what you are doing and how to prevent from leaks, eg. you are using strong self in block which is a part of an action sequence, which repeats forever, then you certainly have a leak, and self.removeAllActions() might help (in many cases, but it is not an ultimate solution). I would recommend to read about capture lists and ARC in general because it can be useful to know how all that work just because of these situations.
Scene is a root node
Calling removeFromParent() on a scene itself has no effect. Scene is a root node, so it can't be removed in your current context. If you check scene's parent property you will notice that it is nil. Of course it is possible to add a scene to another scene, but in that case, the scene which is added as a child, will act as an ordinary node.
And finally, how to present the new scene ? Easy, like this:
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
let newScene = GameScene(size: self.size)
newScene.scaleMode = self.scaleMode
let animation = SKTransition.fade(withDuration: 1.0)
self.view?.presentScene(newScene, transition: animation)
}
If something doesn't work for you, it is likely that you have leaks (means your scene isn't deallocated). To check this, somewhere in your GameScene override deinit method, like this:
deinit{print("GameScene deinited")}
To explain you this a bit further... What should happen is that you should present a new scene, a transition should occur, an old scene should be deallocated, and you should see a new scene with an initial state.
Also overriding deinit will just tell you if the scene is deallocated properly or not. But it will not tell you why. It is up to you to find what in your code retaining the scene.
There are 2 main ways that I can think of that do this. The main way that I go this is that if the game is over, (due to the character health falling to zero, or they collide with an object that causes the round to be over, or time is up or whatever), when that happens I like to transition to a new scene that is a summary screen of their score, how far they made it etc.
I do this by having a bool variable in the main GamePlay scene like this.
var gameOver: Bool = false
Then in the code that fires off to cause the game to end set that variable = true.
In the update function check to see if gameOver == true and transition to the GameOverScene.
override func update(_ currentTime: TimeInterval) {
// Called before each frame is rendered
// Initialize _lastUpdateTime if it has not already been
if (self.lastUpdateTime == 0) {
self.lastUpdateTime = currentTime
}
// Calculate time since last update
let dt = currentTime - self.lastUpdateTime
// Update entities
for entity in self.entities {
entity.update(deltaTime: dt)
}
self.lastUpdateTime = currentTime
if gameOver == true {
print("Game Over!")
let nextScene = GameOverScene(size: self.scene!.size)
nextScene.scaleMode = self.scaleMode
nextScene.backgroundColor = UIColor.black
self.view?.presentScene(nextScene, transition: SKTransition.fade(with: UIColor.black, duration: 1.5))
}
}
The update function will check at each frame render to see if the game is over and if it is found to be over it will perform any actions that you need it to and then present the next scene.
Then on the GameOverScene I put a button saying "Retry" and when they click that it fires off the GamePlayScene again, running the view DidLoad function and setting up the GamePlayScene from scratch the way that it should.
Here is an example of how I handle that. There are a few different ways to call a scene transtion. You can give this one a try if it isn't working quite right.
if node.name == "retryButton" {
if let scene = GameScene(fileNamed:"GameScene") {
// Configure the view.
let skView = self.view! as SKView
/* Sprite Kit applies additional optimizations to improve rendering performance */
skView.ignoresSiblingOrder = true
/* Set the scale mode to scale to fit the window */
scene.scaleMode = .aspectFill
scene.size = skView.bounds.size
skView.presentScene(scene, transition: SKTransition.fade(withDuration: 2.0))
}
}
That is my preferred method of handling the game over transitions.
The other method would be to create a function that resets all of the variables that have changed during the course of playing. Then you could use the same code from the Update function above, but instead of transitioning you could create a label on the scene. If the user clicks the label it would fire off of that function to reset all of the variables that have changed, reset the players locations, stops all actions, resets players health etc. Depending on how many things you have changing during the course of gameplay it'll probably be more practical, (as I've found), to transition to a new scene to give a summary and then reload the GamePlayScene through a button. Then everything will load up just the same as it does the first time that the user entered that main GamePlayScene.
In my SpriteKit Game i'm using:
self.scene!.removeFromParent()
let skView = self.view! as SKView
skView.ignoresSiblingOrder = true
var scene: PlayScene!
scene = PlayScene(size: skView.bounds.size)
scene.scaleMode = .AspectFill
skView.presentScene(scene, transition: SKTransition.fadeWithColor(SKColor(red: 25.0/255.0, green: 55.0/255.0, blue: 12.0/255.0, alpha: 1), duration: 1.0))
to move from one scene to another. But how can I go back to the original scene? Using the same principle of code always led to a major crash..
I made an example where global structure is used to track the info about previousScene. It can be done with a custom property as well, or by using userData which every node has. The logic is the same. Also, I've removed debugging code (debug label code etc.) because it is not important for everything to work.
Example might be better if I added a few buttons where each links to the certain scene, but I left just one button to keep everything short as possible.
What you need to know about this example (you will change this rules according to your game, but the logic is the same - set the previousScene before an actual transition):
there are three scenes, WelcomeScene (default one), MenuScene and a GameScene.
tapping on the black button takes you to the GameScene. There is an exception to this rule when current scene is a GameScene. In that case, transition will take you to the previousScene.
tapping anywhere around the black button will take you to the previous scene. There is an exception to this rule when WelcomeScene is loaded for the first time (previousScene is not set) and a transition will take you to the MenuScene in that case.
-in your GameViewController you should set up a WelcomeScene to be a default one. Otherwise, you should change a code a bit to handle situations what happening when previousScene is not set (like I did in touchesBegan of WelcomeScene).
So those are rules I've made, just in order to make all those transitions a bit more meaningful...
Here is the code (BaseScene.swift):
import SpriteKit
enum SceneType: Int {
case WelcomeScene = 0
case MenuScene //1
case GameScene //2
}
struct GlobalData
{
static var previousScene:SceneType?
//Other global data...
}
class BaseScene:SKScene {
let button = SKSpriteNode(color: SKColor.blackColor(), size: CGSize(width: 50, height: 50))
override func didMoveToView(view: SKView) {
setupButton()
}
private func setupButton(){
if (button.parent == nil){
//Just setup button properties like position, zPosition and name
button.name = "goToGameScene"
button.zPosition = 1
button.position = CGPoint(x: CGRectGetMidX(frame), y: 100)
addChild(button)
}
}
func goToScene(newScene: SceneType){
var sceneToLoad:SKScene?
switch newScene {
case SceneType.GameScene:
sceneToLoad = GameScene(fileNamed: "GameScene")
case SceneType.MenuScene:
sceneToLoad = MenuScene(fileNamed: "MenuScene")
case SceneType.WelcomeScene:
sceneToLoad = WelcomeScene(fileNamed:"WelcomeScene")
}
if let scene = sceneToLoad {
scene.size = size
scene.scaleMode = scaleMode
let transition = SKTransition.fadeWithDuration(3)
self.view?.presentScene(scene, transition: transition)
}
}
}
Every scene (WelcomeScene, MenuScene, GameScene) inherits from a BaseScene class (which is subclass of a SKScene). I guess, there is no need to explain that, but feel free to ask if something confuses you. The important method here (which is used by every subclass) is goToScene(scene:SceneType) and its parameter (of type SceneType) which tells us what type of scene a method should load.
SceneType is just an enum which holds integers...So actually we are not working with objects here, thus there is no fear of strong reference cycles.
Next, there are other scenes (WelcomeScene.swift):
import SpriteKit
class WelcomeScene:BaseScene {
override func didMoveToView(view: SKView) {
super.didMoveToView(view)
self.backgroundColor = SKColor.darkGrayColor()
}
deinit {print ("WelcomeScene deinited")}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
let touch = touches.first
if let location = touch?.locationInNode(self){
//Give a priority to a button - if button is tapped go to GameScene
let node = nodeAtPoint(location)
if node.name == "goToGameScene"{
GlobalData.previousScene = SceneType.MenuScene
goToScene(SceneType.GameScene)
}else{
//Otherwise, do a transition to the previous scene
//Get the previous scene
if let previousScene = GlobalData.previousScene {
GlobalData.previousScene = SceneType.WelcomeScene
goToScene(previousScene)
}else{
// There is no previousScene set yet? Go to MenuScene then...
GlobalData.previousScene = SceneType.WelcomeScene
goToScene(SceneType.MenuScene)
}
}
}
}
}
To keep short as possible, everything is commented. Next code (MenuScene.swift):
import SpriteKit
class MenuScene: BaseScene {
override func didMoveToView(view: SKView) {
super.didMoveToView(view)
backgroundColor = SKColor.purpleColor()
}
deinit {
print ("MenuScene deinited") //If this method isn't called, you might have problems with strong reference cycles.
}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
let touch = touches.first
if let location = touch?.locationInNode(self){
//Give a priority to a button - if button is tapped go to GameScene
let node = nodeAtPoint(location)
if node.name == "goToGameScene"{
GlobalData.previousScene = SceneType.MenuScene
goToScene(SceneType.GameScene)
}else{
//Otherwise, do a transition to the previous scene
//Get the previous scene
if let previousScene = GlobalData.previousScene {
GlobalData.previousScene = SceneType.MenuScene
goToScene(previousScene)
}
}
}
}
}
And for the end (GameScene.swift):
import SpriteKit
class GameScene: BaseScene{
override func didMoveToView(view: SKView) {
super.didMoveToView(view)
self.backgroundColor = SKColor.orangeColor()
}
deinit {print ("GameScene deinited")}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
//Here, we ignore black button because we don't want to transition to the same scene
if let previousScene = GlobalData.previousScene {
GlobalData.previousScene = SceneType.GameScene
goToScene(previousScene)
}
}
}
Preview:
Just read again the rules from the beginning and you will be fine (eg. in GameScene black button doesn't work, or on first launch previousScene is not set , so you will be transitioned to the MenuScene by default).
That would be it. Hope this helps a bit. You can copy and paste the code to test it and improve it to your needs. Still, not sure that you really need this. It looks that you just need to correctly transition between scenes.
HINT: What is important here is that every scene BaseScene, WelcomeScene... has it own .sks file. You create those from File->New->File->Resource and name it appropriately (like BaseClass.sks, WelcomeScene.sks...) Also, it is your job to maintain the state of GlobalData.previousScene variable (eg. set it before the transition is made).
You would need to create a property in your new scene that stores the previous one, something like previousScene. Then you can set it like this: scene.previousScene = self.scene. In you new scene, you can now go back to the previous scene with skView.presentScene(previousScene)
And I'd advise against naming the new scene you are going to present scene because your current scene is also named scene, so if you accidentally forget the self in self.scene then that may cause a lot of confusion. I'd name it something like newScene or sceneToPresent.
Also, your first line, self.scene!.removeFromParent(), isn't necessary. You don't need to remove the current scene before presenting a new one.
I am writing a game using SpriteKit with Swift and have run into a memory concern.
The layout of my game is such that the GameViewController (UIViewController) presents the first SKScene (levelChooserScene) in the viewDidLoad Screen. This scene does nothing more than display a bunch of buttons. When the user selects a button the scene then transitions to the correct scene using skView.presentScene, and when the level is complete, that scene then transitions back to the levelChooserScene and the game is ready for the user to select the next level.
The problem is that when the transition back to the levelChooserScene occurs the memory allocated for the game play scene is not deallocated, so after selecting only a few levels I start receiving memory errors.
Is my design correct in transitioning from SKScene to SKScene, or should I instead return to the GameViewController each time and then transition to the next SKScene from there?
I have found a few posts on here that say I should call skView.presentScene(nil) between scenes, but I am confused on how or where to implement that.
I simply want to transition from one SKScene to another and have the memory used from the outgoing scene to be returned to the system.
This is an example of how I have implemented the SKScene:
class Level3: SKScene
{
var explodingRockTimer = NSTimer()
var blowingUpTheRocks = SKAction()
override func didMoveToView(view: SKView)
{
NSTimer.scheduledTimerWithTimeInterval(5.0, target: self, selector: "dismissTheScene:", userInfo: nil, repeats: false)
var wait = SKAction.waitForDuration(0.5)
var run = SKAction.runBlock{
// your code here ...
self.explodeSomeRocks()
}
let runIt = SKAction.sequence([wait,run])
self.runAction(SKAction.repeatActionForever(runIt), withKey: "blowingUpRocks")
var dismissalWait = SKAction.waitForDuration(5.0)
var dismissalRun = SKAction.runBlock{
self.removeActionForKey("blowingUpRocks")
self.dismissTheScene()
}
self.runAction(SKAction.sequence([dismissalWait,dismissalRun]))
}
func explodeSomeRocks()
{
println("Timer fired")
}
//MARK: - Dismiss back to the level selector
func dismissTheScene()
{
let skView = self.view as SKView?
var nextScene = SKScene()
nextScene = LevelChooserScene()
nextScene.size = skView!.bounds.size
nextScene.scaleMode = .AspectFill
var sceneTransition = SKTransition.fadeWithColor(UIColor.blackColor(), duration: 1.5) //WithDuration(2.0)
//var sceneTransition = SKTransition.pushWithDirection(SKTransitionDirection.Down, duration: 0.75) //WithDuration(2.0)
//var sceneTransition = SKTransition.crossFadeWithDuration(1.0)
//var sceneTransition = SKTransition.doorwayWithDuration(1.0)
sceneTransition.pausesOutgoingScene = true
skView!.presentScene(nextScene, transition: sceneTransition)
}
}
Well the thing that was causing my trouble was inserting particle emitters every half second for 5 seconds using SKAction.repeatActionForever() to call the emitter insert function.
This repeatAction apparently was not killed by transitioning to another scene, and was causing the memory for the whole scene to be retained. I switched to SKAction.repeatAction() instead and specify how many time it should fire. The scene now returns all of its memory when I transition to the new scene.
I am not sure I understand this behavior though.
SpriteKit it's not strongly documented when it comes to create complex games. I personally had a problem like this for days until I managed to figure it out.
Some objects retain the reference, so it doesn't deinit. (SKActions, Timers, etc)
Before presenting a new scene I call a prepare_deinit() function where I manually remove the strong references which are usually not deallocated by swift.
func prepare_deinit()
{
game_timer.invalidate() // for Timer()
removeAction(forKey: "blowingUpRocks") // for SKAction in your case
// I usually add the specific actions to an object and then remove
object.removeAllActions()
// If you create your own object/class that doesn't deinit, remove all object
//actions and the object itself
custom_object.removeAllActions()
custom_object.removeFromParent()
}
deinit
{
print("GameScene deinited")
}
The last problem I encountered was that the new scene was presented much faster than my prepare_deinit() so I had to present the new scene a little later, giving the prepare_deinit() enough time to deallocate all objects.
let new_scene =
{
let transition = SKTransition.flipVertical(withDuration: 1.0)
let next_scene = FinishScene(fileNamed: "FinishScene")
next_scene?.scaleMode = self.scaleMode
next_scene?.name = "finish"
self.view?.presentScene(next_scene!, transition: transition)
}
run(SKAction.sequence([SKAction.run(prepare_deinit), SKAction.wait(forDuration: 0.25), SKAction.run(exit_to_finish)]))