Running a function when the game becomes active iOS - SpriteKit - ios

In my game in swift / SpriteKit, I have a problem when the user quits the app and opens it up again. If the game is on the pause menu and everything is paused, when the game is reloaded the game is unpaused but the labels on the pause menu do not disappear. How do I keep the game paused when I reopen it? I have tried
func applicationWillEnterForeground(application: UIApplication) {
// Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
let scene = GameScene(size: CGSize(width: 2048, height: 1356))
scene.view?.paused = true
}
But this is not doing anything. I have also tried pause() but that messes things up. Any help is appreciated.

You want to use the applicationWillResignActive function to pause your scene, by doing something like scene.speed = 0 which will properly pause your scene (don't know why, but it doesn't quite work just using pause). Here you can also display your pause menus (which you appear to be doing).
Then you want to use the applicationDidBecomeActive function to continue your game. Here you do your checks to see if (guessing here) your "resume" button is pressed, and in the response method for that, set the scene.speed = 1. Here your response method, do anything that requires starting back up (animations, actions, hiding your pause menu(s), or music).
I will say, these are the two functions that I use, you are free to use whichever two functions you would like that have a on/off kind of thing. I've found these to be very reliable.

Related

'Play on' feature is an in-app purchase? SpriteKit/Swift

I'm near the end of developing a game, and long story short, the game will be over when an object crashes into one of the obstacles. I've got that part down and the game runs really well by itself, but there is one more step I am looking to add in.
I would like to add in an in-app purchase of a 'play on' feature, that is, starting where the user's game originally ended so they can continue on. I'm okay with in-app purchases on the whole, but I guess what I want to know is how does one make it possible to 'play on' following the in app purchase? I'm just looking for something basic I can build on.
I'm a Stack newbie, as I've only created an account today (but I've been programming for a little while and this site has helped me so many times), so I'm sorry if there has been a duplicate thread made elsewhere. I did look around for an hour or so before deciding to post (and Google was no help).
As a general stack overflow rule you should always post some of your own code or what code you have played around with.
I am actually also looking to integrate a playOn button in my game. Now I haven't actually found the perfect solution for this yet but hopefully this helps you get on the right track.
Step 1:
How have you programmed your game over scenario?
Are you just pausing the scene, are you pausing nodes or are you removing all children from your scene?
The way I pause my scene is by creating a worldNode and than adding all objects that I need paused to the worldNode.
You can read my two answered questions for more detail
Keeping the game paused after app become active?
Sprite moves two places after being paused and then unpaused
This way when I pause my game I dont actually pause the scene which gives me more flexibility adding pauseMenus etc. Furthermore its seems smoother than pausing the skView.
I also call pause when the player died, which means I could resume the enemies/obstacles from where they left of if I call resume.
So my game over method looks like this
func gameOver() {
pause() // call pause method to pause worldNode etc
//show game over screen including playOn button
}
Step 2:
Now in regards to respawning the player, it depends on how he is positioned, how far he can move etc.
If your player is mostly in the same area than you can probably just respawn you player manually once "PlayOn" is pressed and than resume the game as if it was just paused.
So once your playOn button is pressed you can call a method like so
func playOnPressed() {
// Remove current player
// Doesnt have to be called, you could just change the position
player.removeFromParent()
// Add player manually again to scene or just reposition him
...
// Remove obstacle that killed player
// haven't found a great solution for this yet
// You could make the player not receive damage for 5 seconds to make sure you dont die immediately after playOn is pressed
// Call resume method, maybe with delay if needed
resume()
}
If your player position could be all over the screen, as in my game, I have been playing around with a few things so far.
I created a position property to track the player position
playerPosition = CGPoint!
and than in my scene update method I constantly update this method to the
actual position of the player.
override func update(currentTime: CFTimeInterval) {
if gameOver = false {
playerPosition = player.position
}
}
I than have been playing around with the "playOnPressed" method,
func playOnPressed() {
// Remove current player
//Doesnt have to be called, you could just change the positioon
player.removeFromParent()
// Add player manually again to scene or just reposition him
...
player = SKSpriteNode(...
player.position.x = playerPosition.x - 40 // adjust this so it doesnt spawn where he died but maybe a bit further back
player.position.y = playerPosition.y // adjust if needed
// Remove obstacle that killed player
// haven't found a great solution for this yet
// You could make the player not receive damage for 5 seconds to make sure you dont die immediately after playOn is pressed
// Call resume method, with delay if needed
resume()
}
I hope this helps you playing around with your playOn button, if someone has a better way I would also appreciate it immensely.

iOS Swift - How do I respond to a banner notification?

My Sprite Kit game has trouble reacting to banner notifications. When the user gets an alert notification, the game pauses as intended thanks to applicationWillResignActive, which isn't called with banner notifications. When there is a banner notification, the projectiles in the game go straight through walls instead of being removed from their parent after making contact with the (thick) wall.
I've searched, but I can't find any function that I can use to pause the game when the user gets a banner notification. Anyone know of a function I can use?
You have 2 options basically
Pause the SKView in your ViewController
self.view?.paused = true
The problem here is that it will pause everything which makes it a bit trickier to add pauseMenus or other nodes after.
The better way is to create a worldNode (global)
let worldNode = SKNode()
add it to the scene
addChild(worldNode)
than add all your sprites that you need paused to that node
worldNode.addChild(yourSprite)
and than finally when you want to pause the game you call
worldNode.paused = true
self.physicsWorld.speed = 0 // call this as well when paused and reset to 1 when resuming
This way you can still add pauseMenu nodes/sprites, labels and so on while your game is paused.
To do this when a notification is received I believe you need to use the delegates methods in a your app delegate such as this one
application:didReceiveLocalNotification
You can read more here
https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIApplicationDelegate_Protocol/index.html#//apple_ref/occ/intfm/UIApplicationDelegate/application:didReceiveLocalNotification:

How to ensure SKScene is paused when app resumed from background?

I am developing an iOS game; I am using several SKScenes and a single View Controller and my menu navigates between the different SKScenes. I'm having a problem with pausing (my game is using SKActions):
Problem: Suppose my game is in a 'paused' state (all SKActions of objects in my game are paused). When I click the 'home' button and send my app to the background, everything remains paused as it should. However, when I click my app to resume it, the scene that should be paused automatically 'resumes' itself, and all the SKActions resume to completion, and then the game pauses after this. (Please let me know if I can provide any additional details).
'Evidence': I know this because in the 'update' loop called every frame I have an NSLog statement that prints when the SKNode nodeGamePlay is paused, and it prints several times (half a second) when I click my game on the simulator's background.
What I want: When the app is clicked and opens, I want my pause-game-menu to appear, and I want my game (children of nodeGamePlay) to be paused.
What I have: In my SKScenePlay, I have a method that loads a 'pause menu' (not a child of nodeGamePlay) and pauses nodeGamePlay, which displays when a user clicks the pause button. Currently, when the user sends my app to the background and then reopens it, this method is called and the pause menu is added and the nodeGamePlay SHOULD GET paused (I call it with the following in my only viewController). However, although the pause menu displays, the nodeGamePlay does not get paused. How can I fix this?
- (void)appDidBecomeActive:(NSNotification *)notification {
[[NSNotificationCenter defaultCenter] postNotificationName:#"loadPauseGameMenu" object:scene];
}
EDIT: Update, when I set self.paused=true (for the SKScene), everything pauses correctly. When I do a for-in loop for each child in self and set each child.paused=true, SKActions are not paused correctly.

How to effectively pause a game in spritekit?

This seems like such a basic concept but there is really no good answer.
I currently have a pretty basic setup, in my game's scene, I have an enum gameState which is currently either inGame or gamePaused.
I have my button set up, and I have it so pressing simply toggles gameState.
Then, to make it work, I have two separate update methods: One for when gamePaused, one for when inGame.
This works for 95% of my game, as the updates in my game can be pretty readily started and stopped without any issues. There are some issues I cannot tackle though.
First and foremost are actions. I use SKActions for a bit of my project (some movement, scaling, fading...) and this method does NOT pause them. This can be catastrophic in certain points. Secondly, this doesn't handle particles, physics, and a few other things that are not directly associated to my update methods.
The only clue I have is self.view.paused = YES, but that isn't going to work either.
First off, this DOES fix my actions, particles, and physics problem... kinda. But This question suggests that SKActions aren't actually PAUSED by this, but actually STOPPED completely. Is this true? If it is, then it won't work smoothly either because my actions are thrown out of whack.
Also, pausing the view seems to do what it says: stop everything. EVERYTHING. Newbie question here, but how am I supposed to get any code to run at that point? It's all cut off. Is this where I need subViews? I have never used a subView yet, but it sounds like its what I want in this case.
Simply put, there are a lot of unanswered questions for me, and I don't know how to proceed. I'm hoping there's some 'standard procedure' for pausing in Sprite Kit, but with pausing the view halting actions I truly have no idea where to proceed.
Should I move away from using actions? Is my idea of a pause subView sound?
I don't want to babble, all I want to know is how you go about pausing in your average Sprite Kit project. Additional info provided upon request.
Pausing a node will pause (not stop) the node's actions, and i suppose pause will also be applied to all children of the paused node in the same way. All other unpaused nodes will continue to run their actions to completion.
You should have a "game layer" node with all game nodes in them that you want to pause, and then just pause that "game layer" node. Then have a "pause game menu" node where you add all the pause menu stuff you need which will continue to function normally even if the game layer is paused.
Be very sure you do not use performSelector or NSTimer or GCD or any other scheduling methods besides actions or the scene's update: method because those will not adhere to a node's paused state.
Pausing the view effectively freezes everything in it, pausing the scene according to some will not pause the update: calls - but I have not verified this myself. If this were the case you can always check inside the update method whether a given node that you send a message to is paused and if so, decide not to send certain messages to that node.
I just called a map function on all children of the scene and set the paused property to true
self.children.map{($0 as SKNode).paused = false}
By setting it to true you can easily undo the freeze.
EDIT:
Better use a for-loop to iterate over the children.
for node in self.children as [SKNode] {
node.paused = false
}
I can tell you what I did in my game:
Pause the SKView on -applicationWillResignActive: (or equivalent, using NSNotifications),
Un-pause the SKView on -applicationDidBecomeActive: (or equivalent, using NSNotifications),
For the actual game scene only, I set a boolean flag _isPaused when resigning active, and if it is true I just skip the -update: method (frame updates). (I also show the "paused" menu when the user resumes the app).
...But my game is a simple puzzle game, and there's no long actions that should continue past the pause/resume. I can not confirm right now that all actions are aborted, but I think it's not the case.
I also used self.children.map{($0 as SKNode).paused = false} and it does work if you create a var layer of type SKSpriteNode and add it on top of the scene. But I also have an NSTimer I'm using to spawn sprites on the scene. Everything currently on the scene is paused, but sprites keep appearing and moving across the screen. It is not pausing the spawning.
I tried pausing the NSTimer when I call the above code by setting repeats to false, then setting it to true when I remove the layer but it doesn't work. I also tried self.scene?.view?.paused = true but that freezes everything and the layer I create does not even appear onscreen.
You need to set the delegate for the View!
func PauseGame(){
self.scene.view.paused = true
}
fun playGame(){
self.scene.pause = false
}
This function is work perfectly if you are not using the NSTimer to call a function. If you use NSTimer your view will pause perfectly but when you play the game again by play game functionality you see that all the functions that use the NSTimer function that runs in the back end and your screen full with your sprite-kits. So when you use NSTimer in the function you have to first pause the NSTimer functions also after that this function work perfectly.
//For Pause
func pauseGame() {
scene?.view?.paused = true
}
//For play.
func playGame() {
scene?.view?.paused = false
}

iOS correctly resume after application becomes active

I'm building a game for iOS using Cocos2D. In my game I have a pause menu that can be pulled up when playing the game. A simple tap will return from the pause menu to the game. What I would like to implement is a clean way to resume the game on the pause menu if the method applicationDidBecomeActive is called. The problem is that only the appDelegate receives the call to applicationDidBecomeActive, and my pause menu is many layers deeper than that. Right now I'm essentially passing the applicationDidBecomeActive call through about 4 different layers to get it down to the pause menu. There must be a cleaner way?
Sure is. Just add an observer for the UIApplicationDidBecomeActiveNotification from anywhere that's convenient. Application state changes can be hooked that way as well as via the app's delegate.
(Docs here.)
Read about the NSNotificationCenter
here and at Apple or just receive the UIApplicationDidBecomeActiveNotification anywhere.
take a BOOL variable in appdelegate.h with property and synthesised it then when pause button pressed from any scene set this variable to yes.
in applicationDidBecomeActive method of appdelegate check if(self.pause == YES) then don't resume ccdirector else resume it
i used this in my game and it work fine when i press pause and then press home button and when come back the app is still pause. try this

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