Hi,

I've been playing about with Spritekit recently and have come across a somewhat novel issue. I've created a scene with three sprites, and can move them about happily. I then save, reset and reload, and that's where the funkiness starts - there is nothing amiss with the saving and loading functions, and everything else appears to be working well. I hope the following screenshots and explanation outline well enough what I'm talking about.

1) I generate three objects and their position is set at 0.0...

2) I move them to the following positions...

3) I then save and reload, there is an almost imperceptible shifting of the sprites...

4) I then move the top sprite back to the middle of the screen...

5) I then save and reload...and it jumps down to the bottom of the screen..!

If I save and load without moving any of the sprites they stay in the same position.

Here is the code that I'm using:

import Foundation
import SpriteKit

class SpriteKitManager: ObservableObject {
    static let shared = SpriteKitManager()
    // Create a scene with a default size
    let scene = GameScene(size: CGSize(width: 640, height: 480))

    init(){
        // Set the scale mode to resize fill
        scene.scaleMode = .resizeFill
        scene.anchorPoint = CGPoint(x: 0.5, y: 0.5)
    }
}

class GameScene: SKScene {
    override func didMove(to view: SKView) {
        refreshAnimalSprites()
    }

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

    }

    func refreshAnimalSprites(){
        for child in children {
            child.removeFromParent()
        }

        for animal in animalManager.animals {
            let animalSprite = AnimalSprite(id: animal.id, animalType: animal.type)
            animalSprite.position = animal.position
            addChild(animalSprite)
        }
    }
}

class AnimalSprite : SKNode {
    var id : Int
    private var currentNode: SKNode?

    override var isUserInteractionEnabled: Bool {
        set {
            // ignore
        }
        get {
            return true
        }
    }

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first {
            let location = touch.location(in: self)

            let touchedNodes = self.nodes(at: location)
            for node in touchedNodes.reversed() {
                self.currentNode = node
            }
        }

    }

    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first, let node = self.currentNode {
            let touchLocation = touch.location(in: self)
            // Convert the touch location to the coordinate system of the parent node
            let nodeLocation = self.convert(touchLocation, to: node.parent!)
            node.position = nodeLocation
        }
    }

    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        if self.currentNode != nil {
            if let animal = animalManager.animals.first(where: { $0.id == id }) {
                if let touch = touches.first, let node = self.currentNode {
                    let touchLocation = touch.location(in: self)
                    // Convert the touch location to the coordinate system of the parent node
                    let nodeLocation = self.convert(touchLocation, to: node.parent!)
                    animal.position = nodeLocation
                }
            }

            self.currentNode = nil
        }
    }

    init(id: Int, animalType: AnimalType){
        var sprite : SKNode

        switch(animalType) {
        case .dog:
            sprite = SKSpriteNode(imageNamed: "Dog" )
        case .cat:
            sprite = SKSpriteNode(imageNamed: "Cat" )
        case .owl:
            sprite = SKSpriteNode(imageNamed: "Owl" )
        case .penguin:
            sprite = SKSpriteNode(imageNamed: "Penguin" )
        case .human:
            sprite = SKSpriteNode(imageNamed: "Person" )
        default:
            sprite = SKSpriteNode(color: .red, size: CGSize(width: 50, height: 50))
        }
        self.id = id
        super.init()

        addChild(sprite)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

I am confident with the rest of the code, I just can't track down what I am getting wrong with my positioning. There is no scaling going on beyond the resizeFill. Whenever I move a sprite and save/reload it's almost like there's a move along the same vector, if that makes sense, and then it stays where it is.

If anyone could shed any light, I'd be grateful.

Many thanks,

Jes

Thanks for the response.

The save and load functions work exactly as expected, it's just that occaisionally it looks like the touchesEnded method doesn't fire correctly, or at least that how it appears.

I've got things mostly working now apart from that occasional glitch, so I'll just pursue that avenue.