I recently asked a question on how to use a protocol delegate pattern here: How do you use the Delegate Protocol Pattern with SpriteKit?
And while I got an answer that got me a long way, I don't get it working all the way, and I think it has to do with the fact that I don't (and can't I think) use the same instance when changing SKViews. Let me explain.
I have one UIViewController and two SKScenes. The UIViewController present the two scenes by rotating the device; landscape load SKScene 1 and portrait load SKScene 2 like this:
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
print("TRIGGERED")
if UIDevice.current.orientation.isLandscape {
print("Landscape")
presentView(name: "GameScene")
} else {
print("Portrait")
presentView(name: "GameScene2")
}
super.viewWillTransition(to: size, with: coordinator)
}
func presentView(name: String) {
if let view = self.view as! SKView? {
if let scene = SKScene(fileNamed: name) {
scene.scaleMode = .aspectFill
view.presentScene(scene)
}
view.ignoresSiblingOrder = true
view.showsFPS = true
view.showsNodeCount = true
}
}
and in SKScene 1:
protocol MyProtocol {
func myProtocolFunc(someString: String)
}
class GameScene: SKScene{
var myDelegate: MyProtocol!
and in SKScene 2:
class GameScene2: MyProtocol {
private var label: SKLabelNode?
func myProtocolFunc(someString: String) {
label = SKLabelNode(fontNamed: "Chalkduster")
label!.text = someString
label!.position = CGPoint(x: 0, y: 0)
addChild(label!)
}
The SKlabel isn't updated with the delegate value however. An like I said I think this is because I create a new instance of scene when loading SKScene 2. And that instance don't have the delegate. I'm not sure how to work around this though since I need to have a new instance of SKScene to load the other scene.
It might be worth for you to read into the coordinator pattern https://www.hackingwithswift.com/articles/71/how-to-use-the-coordinator-pattern-in-ios-apps
Related
I'm trying to learn how to make a GameManager type class, and making individual classes for each of my GameScenes... probably the wrong thing to do, but for the sake of this question, please accept this as the way to do things.
My GameManager looks like this, having a reference to each of the scenes, that's static:
import SpriteKit
class GM {
static let scene2 = SecondScene()
static let scene3 = ThirdScene()
static let home = SKScene(fileNamed: "GameScene")
}
How do I create a SKScene programmatically, without size info, since they're in a subclass of SKScene and don't have any idea what the view size is, and I don't want them to need worry about this:
I'm doing this, but getting a EXC_BAD_Access at convenience override init()
class SecondScene: SKScene {
override init(size: CGSize){
super.init(size: size)
}
convenience override init(){
self.init()
self.backgroundColor = SKColor.red
self.anchorPoint = CGPoint(x: 0.5, y: 0.5)
}
}
As I mentioned your question is a bit vague but lets do some examples of what a GameManager class can be.
Before I start lets differentiate between calling this
let scene = StartScene(size: ...)
and this
let scene = SKScene(fileNamed: "StartScene")
The 1st method, with size, is when you create your scenes all in code and you are not using the xCode visual level editor.
The 2nd method is when you are using the Xcode level editor, so you would need to create a StartScene.sks file. Its that .sks file that it looks for in fileNamed.
Now for some game manager example, lets first imagine we have 3 SKScenes.
class StartScene: SKScene {
override func didMove(to view: SKView) { ... }
}
class GameScene: SKScene {
override func didMove(to view: SKView) { ... }
}
class GameOverScene: SKScene {
override func didMove(to view: SKView) { ... }
}
Lets say you want to transition from StartScene to GameScene, you would add this code in your StartScene at the correct spot e.g when the play button is pressed. Thats the simplest way to move from one SKScene to the next, directly from the SKScene itself.
// Code only, no xCode level editor
let gameScene = GameScene(size: CGSize(...))
let transition = SKTransition...
gameScene.scaleMode = .aspectFill
view?.presentScene(gameScene, transition: transition)
// With xCode level editor (returns an optional so needs if let
// This will need the GameScene.sks file with the correct custom class set up in the inspector
// Returns optional
if let gameScene = SKScene(fileNamed: "GameScene") {
let transition = SKTransition...
gameScene.scaleMode = .aspectFill
view?.presentScene(gameScene, transition: transition)
}
Now for some actual examples of GameManagers, Im sure you know about some of them already.
EXAMPLE 1
Lets say we want a scene loading manager. You approach with static methods will not work because a new instance of SKScene needs be created when you transition to one, otherwise stuff like enemies etc will not reset. Your approach with static methods means you would use the same instance every time and that is no good.
I personally use a protocol extension for this.
Create a new .swift file and call it SceneLoaderManager or something and add this code
enum SceneIdentifier: String {
case start = "StartScene"
case game = "GameScene"
case gameOver = "GameOverScene"
}
private let sceneSize = CGSize(width: ..., height: ...)
protocol SceneManager { }
extension SceneManager where Self: SKScene {
// No xCode level editor
func loadScene(withIdentifier identifier: SceneIdentifier) {
let scene: SKScene
switch identifier {
case .start:
scene = StartScene(size: sceneSize)
case .game:
scene = GameScene(size: sceneSize)
case .gameOver:
scene = GameOverScene(size: sceneSize)
}
let transition = SKTransition...\
scene.scaleMode = .aspectFill
view?.presentScene(scene, transition: transition)
}
// With xCode level editor
func loadScene(withIdentifier identifier: SceneIdentifier) {
guard let scene = SKScene(fileNamed: identifier.rawValue) else { return }
scene.scaleMode = .aspectFill
let transition = SKTransition...
view?.presentScene(scene, transition: transition)
}
}
Now in the 3 scenes conform to the protocol
class StartScene: SKScene, SceneManager { ... }
and call the load method like so, using 1 of the 3 enum cases as the scene identifier.
loadScene(withIdentifier: .game)
EXAMPLE 2
Lets make a game manager class for game data using the Singleton approach.
class GameData {
static let shared = GameData()
private init() { } // Private singleton init
var highscore = 0
func updateHighscore(forScore score: Int) {
guard score > highscore else { return }
highscore = score
save()
}
func save() {
// Some code to save the highscore property e.g UserDefaults or by archiving the whole GameData class
}
}
Now anywhere in your project you can say
GameData.shared.updateHighscore(forScore: SOMESCORE)
You tend to use Singleton for things where you only need 1 instance of the class. A good usage example for Singleton classes would be things such as helper classes for Game Center, InAppPurchases, GameData etc
EXAMPLE 3
Generic helper for storing some values you might need across all scenes. This uses static method approach similar to what you were trying to do. I like to use this for things such as game settings, to have them in a nice centralised spot.
class GameHelper {
static let enemySpawnTime: TimeInterval = 5
static let enemyBossHealth = 5
static let playerSpeed = ...
}
Use them like so in your scenes
... = GameHelper.playerSpeed
EXAMPLE 4
A class to manage SKSpriteNodes e.g enemies
class Enemy: SKSpriteNode {
var health = 5
init(imageNamed: String) {
let texture = SKTexture(imageNamed: imageNamed)
super.init(texture: texture, color: SKColor.clear, size: texture.size())
}
func reduceHealth(by amount: Int) {
health -= amount
}
}
Than in your scene you can create enemies using this helper class and call the methods and properties on it. This way you can add 10 enemies easily and individually manage their health etc. e.g
let enemy1 = Enemy(imageNamed: "Enemy1")
let enemy2 = Enemy(imageNamed: "Enemy2")
enemy1.reduceHealth(by: 3)
enemy2.reduceHealth(by: 1)
Its a massive answer but I hope this helps.
I need some help setting up delegation in SpriteKit. the function in second scene is not called.
But I just cannot figure out what I am doing wrong.
Many thanks in advance
protocol receivingStringDelegate:class {
func didReceiveString(message:String)
}
class GameScene: SKScene {
weak var gamescene_transmissiondelegate: receivingStringDelegate?
private func sendString(message:String){
gamescene_transmissiondelegate?. didReceiveString(message)
}
}
class SecondScene: SKScene, receivingStringDelegate {
// here I get stuck, what to do?
var gameScene : GameScene = GameScene()
override func didMove(to view: SKView) {
gameScene.gamescene_transmissiondelegate = self
}
func didReceiveString(message:String) {
print ("hi there", message)
}
}
I woudld do it with scene properties vs a global class
class ConnectionScene: SKScene {
private var player1pos: CGPoint = CGPoint.zero
private var player2pos: CGPoint = CGPoint.zero
///some code in this scene sets player positions
func startMultiplayerGame() {
//this assumes your scene is setup in the editor not programmatically
if let gameScene = GameScene(fileNamed: "GameScene") {
gameScene.scaleMode = .aspectFill
gameScene.player1pos = player1pos
gameScene.player2pos = player2pos
self.view?.presentScene(multiplayerScene, transition: SKTransition.reveal(with: .down, duration: 1.0))
}
}
}
class GameScene: SKScene {
var player1pos: CGPoint = CGPoint.zero
var player2pos: CGPoint = CGPoint.zero
override func sceneDidLoad() {
//sceneDidLoad happens first
super.sceneDidLoad()
//do setup that doesn't require passed in variables in here
//this isn't set from connectScene yet so won't have the values
print("player1pos \(player1pos)")
print("player2pos \(player2pos)")
}
override func didMove(to view: SKView) {
//didMove happens last and already has the variables assigned
//now do setup that requires these variables
//this now has value from connectScene
print("player1pos \(player1pos)")
print("player2pos \(player2pos)")
}
}
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"
}
Normally in a sprite kit game, when a new scene presented, all the nodes in the old scene and their content removed automatically. Now what is, if a node like "HUD" should be not removed? Is there any way in sprite kit to create a node only once and use it in all scenes without removing and creating it again and again every time in every new scene? There must be a technique that makes it possible. that's a serious sprite kit design problem, if it is not possible. But I don't think so. The singleton technique is working great with an audio player, that created only once and used in all scenes. There is surley a way to create a node only once and use it in all scenes. Thanks for any idea.
You can't create a node that persists between scenes. Once you present a new scene, you would need to add the nodes to this new scene.
For this reason, I do not use SKScenes the way Apple describes in the documentation because of this issue. Not only is it cumbersome to have to add the nodes to the new scene each time but also extremely inefficient for nodes like background nodes that should always be present.
So what I did is create 2 scenes, one for the game scene and one for the menu (GUI).
For the menu scene I subclass SKNodes for my interface and then use SKActions on these nodes to present and dismiss them on the screen so it feels like the user is transitioning between scenes. This gives you total customization because you can present multiple nodes, you can keep nodes on the screen permanently etc.
By subclassing the SKNodes you can organize your code just as you did for the scenes. Each node will represent a "scene" in your App. Then you just need to write a method to present and dismiss these nodes.
I've added some sample code below to show one implementation of using SKNodes as "Scenes." The sample code has a base class called SceneNode which we subclass (just as you would subclass an SKScene). In this implementation, I use the GameScene to handle all transitions between scene nodes*. I also keep track of the current scene node so that I can update its layout in case the scene changes size (such as rotation or window resize on OS X**). Your game might not need this, but it's a great way to dynamically layout your nodes. Anything that you want to add to the background or keep around, simply add it to the GameScene. Anything that you want to add to a scene, simply subclass a SceneNode, transition to it and your good to go.
*You could easily present scene nodes directly from other scene nodes instead of going through the GameScene. However I have found that using the GameScene to handle transitions between nodes works very well, especially when you have many scenes with complex transitions.
**There is a bug on OS X, resizing the window does not call the scene's didChangeSize. You need to manually call it.
class GameViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let scene = GameScene(size:self.view.bounds.size)
scene.scaleMode = .ResizeFill
(self.view as! SKView).presentScene(scene)
}
}
class GameScene: SKScene {
var currentSceneNode: SceneNode!
override func didMoveToView(view: SKView) {
self.backgroundColor = SKColor.whiteColor()
transitionToScene(.Menu)
}
override func didChangeSize(oldSize: CGSize) {
currentSceneNode?.layout()
}
func transitionToScene(sceneType: SceneTransition) {
switch sceneType {
case .Menu:
currentSceneNode?.dismissWithAnimation(.Right)
currentSceneNode = MenuSceneNode(gameScene: self)
currentSceneNode.presentWithAnimation(.Right)
case .Scores:
currentSceneNode?.dismissWithAnimation(.Left)
currentSceneNode = ScoresSceneNode(gameScene: self)
currentSceneNode.presentWithAnimation(.Left)
default: fatalError("Unknown scene transition.")
}
}
}
class SceneNode: SKNode {
weak var gameScene: GameScene!
init(gameScene: GameScene) {
self.gameScene = gameScene
super.init()
}
func layout() {}
func presentWithAnimation(animation:Animation) {
layout()
let invert: CGFloat = animation == .Left ? 1 : -1
self.position = CGPoint(x: invert*gameScene.size.width, y: 0)
gameScene.addChild(self)
let action = SKAction.moveTo(CGPoint(x: 0, y: 0), duration: 0.3)
action.timingMode = SKActionTimingMode.EaseInEaseOut
self.runAction(action)
}
func dismissWithAnimation(animation:Animation) {
let invert: CGFloat = animation == .Left ? 1 : -1
self.position = CGPoint(x: 0, y: 0)
let action = SKAction.moveTo(CGPoint(x: invert*(-gameScene.size.width), y: 0), duration: 0.3)
action.timingMode = SKActionTimingMode.EaseInEaseOut
self.runAction(action, completion: {self.removeFromParent()})
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
class MenuSceneNode: SceneNode {
var label: SKLabelNode
var container: SKSpriteNode
override func layout() {
container.position = CGPoint(x: gameScene.size.width/2.0, y: gameScene.size.height/2.0)
}
override init(gameScene: GameScene) {
label = SKLabelNode(text: "Menu Scene")
label.horizontalAlignmentMode = .Center
label.verticalAlignmentMode = .Center
container = SKSpriteNode(color: UIColor.blackColor(), size: CGSize(width: 200, height: 200))
container.addChild(label)
super.init(gameScene: gameScene)
self.addChild(container)
self.userInteractionEnabled = true
}
override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
self.gameScene.transitionToScene(.Scores)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
class ScoresSceneNode: SceneNode {
var label: SKLabelNode
var container: SKSpriteNode
override func layout() {
container.position = CGPoint(x: gameScene.size.width/2.0, y: gameScene.size.height/2.0)
}
override init(gameScene: GameScene) {
label = SKLabelNode(text: "Scores Scene")
label.horizontalAlignmentMode = .Center
label.verticalAlignmentMode = .Center
container = SKSpriteNode(color: UIColor.blackColor(), size: CGSize(width: 200, height: 200))
container.addChild(label)
super.init(gameScene: gameScene)
self.addChild(container)
self.userInteractionEnabled = true
}
override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
self.gameScene.transitionToScene(.Menu)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
enum SceneTransition{
case Menu, Scores
}
enum Animation {
case Left, Right, None
}