Trying to pass UIImage from one ViewController to my GameScene in spriteKit - ios

Question

I thought it would be interesting to learn how to pass an image from an imagePicker to my GameScene to use as a SKSpriteNode(texture: SKTexture(image: UIImage)) but i keep getting an error after selecting my image and pressing a button to go into my gameScene
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if (segue.identifier == "startSegue") {
var gameViewController = segue.destinationViewController as GameScene
gameViewController.imageToPass = pickedImage.image
}
anyone know what im doing wrong?
keep getting exc_breakpoint (code=exc_i386_bpt, subcode 0x0)
when initializing gameViewController as GameScene
I am trying to pass imageToPass to the GameScene.swift that is created when i create a new game project in Xcode
class GameScene: SKScene {
var imageToPass = UIImage()
var bird = SKSpriteNode()
override func didMoveToView(view: SKView) {
/* Setup your scene here */
var birdTexture = SKTexture(image: imageToPass)
bird = SKSpriteNode(texture: birdTexture)
bird.position = CGPoint(x: CGRectGetMidX(self.frame), y: CGRectGetMidY(self.frame))
self.addChild(bird)
}

Answer 1

The destination view controller is a UIViewController or its subclass. Not an SKScene. So I don't think it can be converted to GameScene. GameScene is usually a property of a UIViewController that holds it. In my project the UIViewController is called GameViewController. GameViewController has a property called gameScene
So the code should be
if let gameViewController = segue.destinationViewController as? GameViewController
{
gameViewController.imageToPass = pickedImage.image
}
create a property in GameViewController called imageToPass. Set the imageToPass to GameScene.imageToPass in viewDidLoad.
class GameViewController: UIViewController {
var pickedImage : UIImage!
override func viewDidLoad() {
super.viewDidLoad()
if let scene = GameScene.unarchiveFromFile("GameScene") as? GameScene {
let skView = self.view as SKView
skView.showsFPS = true
skView.showsNodeCount = true
skView.ignoresSiblingOrder = true
scene.scaleMode = .AspectFill
scene.imageToPass = pickedImage
skView.presentScene(scene)
}
}
}
You can create a property observer on imageToPass to change it dynamically.
var bird : SKSpriteNode!
var imageToPass : UIImage!
{
didSet
{
createBird()
}
}
func createBird()
{
var birdTexture = SKTexture(image: imageToPass)
bird?.removeFromParent()
bird = SKSpriteNode(texture: birdTexture)
bird.position = CGPoint(x: CGRectGetMidX(self.frame), y: CGRectGetMidY(self.frame))
self.addChild(bird)
}

Answer 2

In the default SpriteKit implementation, the View Controller created is a GameViewController. In Interface Builder, it has for its view an SKView. In viewDidLoad, the key lines are
if let scene = GameScene.unarchiveFromFile("GameScene") as? GameScene {
// Configure the view.
let skView = self.view as SKView
/* more setup */
skView.presentScene(scene)
}
It looks like you've edited your question to reflect this. I'm not a SpriteKit expert, but if you get imageToPass to the GameViewController, then you should be able to pass it to your GameScene in viewDidLoad before it's presented. Good luck.
Note "GameScene.swift" is just the name of the text file that contains the code, so you wouldn't pass anything to it, the class is created in class GameScene: SKScene { /* class properties and methods */
Original Answer:
Are you sure the destinationViewController is a GameScene? Really sure? Because you're using as, you're force downcasting the segue view controller as a "GameScene".
Take advantage of Swift's safety features:
if var gameViewController = segue.destinationViewController as? GameScene {
gameViewController.imageToPass = pickedImage.image
}
or using optional chaining:
var gameViewController = segue.destinationViewController as? GameScene
gameViewController?.imageToPass = pickedImage.image
The pickedImage won't get through if not a GameScene, regardless, but you won't get a crash.
EDIT: By the way, it really should be GameSceneViewController so its clear everywhere it's a View Controller. If it's not a View Controller, that's a problem and has no chance to work.