game stage and image persistence

[casey]

I am trying to test out persistence of objects--at the moment an image, but eventually a group that will be a UI component.

Right now, my image that I want to persist ("persist") goes from State1 to State2 just fine, but when I go back to State1, it disappears and I get an error ("uncaught typeError: cannot read property 'compressionAlgorithm of null in Phaser.js" and then points to a bunch of pixi.webgl render locations)

Why is the item disappearing if it's been added to the stage, and how do I overcome this problem?

 

Here is the code for State1:

var state1 = {
	
preload: function () {
		
		this.load.image('persist', 'persist.png');
		this.load.image('btn', 'btn.png');
	},
    
    create: function () {

		this.persist = game.add.image(this.world.centerX, this.world.centerY, 'persist');
		this.game.stage.addChild(this.persist);
		
		this.btn = this.add.image(200, 200, 'btn');
		this.btn.inputEnabled = true;
		this.btn.events.onInputDown.add(this.changeState, this); 		  
	},
	
	changeState: function() {
	 this.state.start("state2");
	}

 

And then State 2 is just taking us back to state1 on clicking the button

var state2 ={

	preload: function(){
			
		this.load.image('btn', 'inventory/btn.png');
		
	},

create: function(){
    	
		this.btn = this.add.image(200, 200, 'btn');
		this.btn.inputEnabled = true;
		this.btn.events.onInputDown.add(this.changeState, this); 
    
},
	
	changeState: function(){
		this.state.start("state1");
	}
   
    
};

Thanks in advance

[samme]

Use distinct keys for the two button images.

Either use checkImageKey in the preload calls or move all the preloading to a boot state (run only once), e.g., 

var boot = {

  preload: function () {
    this.load.image('persist', 'persist.png');
    this.load.image('btn', 'btn.png');
    this.load.image('btn-inventory', 'inventory/btn.png');
  },

  create: function () {
    this.state.start('state1');
  }

};

 

[casey]

Brilliant. Wasted all day on that  (well, that and trying to get a function statement to work inside a switch statement. grrrr.