Cannot present scene with SpriteKit - ios

I have two SKScene SceneA,SceneB.
I have implemented two methods(willMoveFromView,didMoveToView) in each scene.
Assume, I am currently in SceneA and i want to present SceneB via this code block:
SceneB *sceneB = [SceneB sceneWithSize:self.view.bounds.size];
sceneB.scaleMode = SKSceneScaleModeAspectFill;
[self.view presentScene:sceneB];
When I present this scene, I can see this:
sceneA willMoveFromView
sceneB didMoveToView
sceneA init
sceneB willMoveFromView
sceneA didMoveToView
And finally I return to first SceneA ! There is no other code that pushes SceneA from SceneB . I don't know what to do, please help
UPDATE:
As #LearnCocos2D says, viewWillLayoutSubviews is forced every time I present scene
And I present sceneA in viewWillLayoutSubviews with following code
-(void)viewWillLayoutSubviews{
[super viewWillLayoutSubviews];
SKView* skView = (SKView*)self.view;
SceneA *sceneA = [SceneA sceneWithSize:self.view.bounds.size];
sceneA.scaleMode = SKSceneScaleModeAspectFill;
[skView presentScene:sceneA];
}

As #LearnCocos2D says, viewWillLayoutSubviews is forced repeatedly , And I used to create new scene everytime it has been called. So I need to check if SKView.scene property is not nil. Here is the code:
-(void)viewWillLayoutSubviews{
[super viewWillLayoutSubviews];
SKView* skView = (SKView*)self.view;
if(!skView.scene){
SceneA *sceneA = [SceneA sceneWithSize:self.view.bounds.size];
sceneA.scaleMode = SKSceneScaleModeAspectFill;
[skView presentScene:sceneA];
}
}

Related

How to deallocate unused SKScene

I have a SKScene object setup in GameViewController. I implemented dealloc into the SKScene subclass as follow:
- (void)dealloc {
NSLog(#"Dealloc: %#", self);
}
Now I want to present another view controller on top of GameViewController. I used storyboard segue to do this. But after the new view controller is presented, I never received the SKScene dealloc. It got stuck in the memory. My app starts to freeze after a few minute due to low memory. How can I dealloc the scene after presenting the new view controller.
In order to deallocate you SKScene instance -> you Should Eliminate every pointer that retains it -> then ARC will automagically release it.
Simply call the [skView presentScene:nil]; method which also will remove the SCScene and deallocate it by setting SKView.scene property to nil.
SKView *skView = (SKView *)self.view;
GameScene *scene = (GameScene *)skView.scene;
for(SKNode * child in scene.children)
{
[child removeAllActions];
}
[scene removeAllChildren];
[scene removeAllActions];
[skView presentScene:nil];
Note Normally you don't have to remove everything from the SKScene if your memory is managed right just call [skView presentScene:nil]; method and ARC will take care of it.
Apparently you had something inside the SKScene that retained it.
So by removing everything from it, we eliminated the retain cycle.
This solution will not always work, it will work only if one of the SKActions or SKNodes are retaining the SKScene which were the issue in your case, However your SKScene could be retained from somewhere else and this answer wouldn't really help you

How to set view of programatically created view controller to SKView?

I am developing a game and would like to have one sprite-kit scene have its own view controller (a conclusion I've reached after much debate), and would like to avoid using storyboard (I can accomplish what I want with storyboard, but would like to learn how to do it without storyboard).
In my main view controller, after clicking a button, I have the following code
MyViewController2 *test = [[MyViewController2 alloc] init];
test.view = [[SKView alloc] init];
[self presentViewController: test animated:YES completion:nil];
However, this just transitions a grey screen with nothing on it (did not overwrite "-(id)init" yet). The following code gets called if I overwrite the "-(id)init" method in MyViewController2:
-(id)init
{
NSLog(#"init overwrite works");
SKView * skView = (SKView *)self.view;
SKScene2 *scene = [SKScene2 sceneWithSize:skView.bounds.size];
scene.scaleMode = SKSceneScaleModeFill;
[skView presentScene:scene];
return self;
}
but it won't display because I get this error:
-[UIView presentScene:]: unrecognized selector sent to instance
I know what this error means (the presentScene can only be executed by skView and can't be executed by UIView), but even though when I create the ViewController and in its init I set views to be only SKView, I still get this error. How can I fix this? Thanks for your time and help.
The view property is managed by the UIViewController and represents the root view. You cannot simply assign your own view at any point.
Option 1
If you wish to replace the view property with your own view you can override UIViewController's loadView method and assign the view there. It is documented in the class reference for this method:
The view controller calls this method when its view property is
requested but is currently nil. This method loads or creates a view and assigns it to the view property
...
You can override this method in order to create your views manually.
If you choose to do so, assign the root view of your view hierarchy to
the view property
So it will look something like this:
- (void)loadView
{
self.view = [[SKView alloc] init];
}
Option 2
You can add your SKView as a subview.
Add a property to your view controller so you can access it when necessary:
#property (strong, nonatomic) SKView *skView;
Initialize and add it as a subview when the view is loaded:
- (void)viewDidLoad
{
[super viewDidLoad];
self.skView = [[SKView alloc] init];
[self.view addSubview:self.skView];
SKScene2 *scene = [SKScene2 sceneWithSize:self.skView.bounds.size];
scene.scaleMode = SKSceneScaleModeFill;
[self.skView presentScene:scene];
}

iPhone- Spritekit Programming: Loading Scene from Button

I am new to the spritekit system. However, I have some questions. I have an app that has a menu screen, instructions page, etc..., none of which recquire me loading a skcene. However, I want to be able to load my "Game" scene on the press of a button. How would I do that regarding code?
FIXED:
I just did not check the IB settings for one of my views: my view type should be SKView.
Create new SKView in your view controller's -viewDidLoad: method
SKView *spriteView = (SKView *) self.view;
Then create new SKScene class in a separate file
#interface GameScene : SKScene
#end
Return to your previous view controller and place this code in your
button's event handler
GameScene* scene = [[GameScene alloc] initWithSize:CGSizeMake(768,1024)];
SKView *spriteView = (SKView *) self.view;
[spriteView presentScene: scene];
More info in Apple's documentation.

Go back to view controller from SKScene

So when you create a project using the SpriteKit template. You have your View controller and your SKScene.
From my view controller I start my game with the code given by default and present the scene.
In my TCAViewcontroller.m
- (IBAction)startGame:(id)sender {
NSLog(#"Start Game triggered");
mainPageImage.hidden = 1;
// Configure the view.
// Configure the view after it has been sized for the correct orientation.
SKView *skView = (SKView *)self.view;
if (!skView.scene) {
skView.showsFPS = YES;
skView.showsNodeCount = YES;
// Create and configure the scene.
TCAMyScene *theScene = [TCAMyScene sceneWithSize:skView.bounds.size];
theScene.scaleMode = SKSceneScaleModeAspectFill;
// Present the scene.
[skView presentScene:theScene];
}
}
When the user loses in the game I would like to dismiss the scene and go back to my view controller I have. I can't seem to find anything with my searches to going back to the original view controller, just pushing to a game over scene. But I don't want to push to another scene, just dismiss the current scene and go back to my TCAViewController. Please answer using code for clarification Thanks
Your scene needs to offer a line of communication to your controller to indicate that is finished. You could, for example, create a delegate protocol and corresponding property in your scene. An example:
#protocol TCAMySceneDelegate;
#interface TCAMyScene : SKScene
#property (nonatomic, weak> id<TCAMySceneDelegate> delegate;
#end
#protocol TCAMySceneDelegate <NSObject>
- (void)mySceneDidFinish:(TCAMyScene *)gameScene;
#end
Then, in the .m of your TCAMyScene
- (void)endTheGame {
// Other game-ending code
[self.delegate mySceneDidFinish:self];
}
In your view controller, set itself as the delegate for your scene and implement the method:
- (IBAction)startGame:(id)sender {
// Other code
TCAMyScene *theScene = [TCAMyScene sceneWithSize:skView.bounds.size];
theScene.scaleMode = SKSceneScaleModeAspectFill;
theScene.delegate = self;
// Other code
}
- (void)mySceneDidFinish:(TCAMyScene *)myScene {
// logic for dismissing the view controller
}

How to dismiss SKScene?

When Im finished with my SKScene is there a way to dismiss the SKScene from within my SKScene class?
If not back in my Viewcontroller where I present my SKScene [skView presentScene:theScene]; is there a way to restart the scene or remove in from my SKView?
The SKScene Class Reference and SKView Class Reference are no help.
Update:
The following code removes my scene from my SKView [yourSKView presentScene:nil]; but when Im back in my view controller the scene is still running in the background. I can always pause it when the game is over and I'm sent back to my view controller(menu) but I'm wondering is there another method other then pausing it like completely removing it?
-(void)endTheGame {
[highscoreLabel removeFromSuperview];
NSLog(#"Game Over");
//would like to end here before calling the below method in my view controller
[self.delegate mySceneDidFinish:self];
}
Having met a similar issue I stumbled around your question, and since nobody gave a decent answer here's how I solved it:
in my scene I called both lines
[self removeFromParent];
[self.view presentScene:nil];
in my controller (the controller that displays the SKScene) I changed the template code from Apple, which was creating and presenting my scene from viewDidLoad in order to create and present my scene in viewWillAppear, only if the view's scene is nil
here's my Swift code, even if you're using Objective C you'll understand what it does; the key line being the "if skView.scene == nil" test :
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
let skView = self.view as SKView
if skView.scene == nil {
let scene = GameScene(size:skView.bounds.size)
scene.controller = self
skView.ignoresSiblingOrder = true
scene.scaleMode = .AspectFill
skView.presentScene(scene)
}
}
You can use:
[yourSKView presentScene:nil];
to remove the scene.
"You can't go "Back to the View Controller" from a scene. The scene is a View, the view controller controls and displays views. Use the view controller to change views. Remember the view controller itself is not a view." -Wharbio
Best solution here is to create another View Controller. This view controller will be my menu. Then the other viewcontroller will act as a host for the skscene.
In my situation I then use my menu viewcontroller to dismiss the viewcontroller displaying in the skview.
From within your SKScene, you can simply do [self.view presentScene:aNewScene] to present another scene
I completely remove scenes by using this block in my view controller:
Obviously you will need to declare your Size, and "newSKview"
SKView * skView = (SKView *)self.view;
SKScene *newScene = [[newSKView alloc]initWithSize:size];
newScene.scaleMode = SKSceneScaleModeAspectFill;
SKScene *oldScene=(skView.scene);
[oldScene removeFromParent];
[skView presentScene:newScene];
This works fine for me. None of my Scenes are retained or strong.
I prefer to use an additional UIViewController for SKView and Notification Center in where the UIViewController made SkScene.
The callback function is
#objc func cb_dismissingVC(_ notificaiton: Notification) {
self.dismiss(animated: true, completion: nil)
}
Maybe my variant will be helpful:
[[self.scene childNodeWithName:#"YourChildNodeName"] removeFromParent];

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