Correct way of deleting a Display Object

[Fricken Hamster]

Hey, I couldn't find any good references for this, but what is the correct way of deleting a display object?

It seems the destroy function only unsets all the fields in a Display object, so currently I am doing

1. removing from parent display object

2. running destroy

3. removing references to the display object.

This seems to function without any errors, and shouldn't leave any references left. 

[ivan.popelyshev]

Nice nickname, I like it

Do you know how Javascript Garbage Collector works? Object is removed when there is no path of references from root context to it. If you have some array that contains all your displayObjects, and you dont remove it from there, it wont be freed, you'll need 3). In most cases, you dont need to think about that, just use 1). I doubt you can make memory leak with a plain PIXI.Container or PIXI.DisplayObject.

If object is a Text or Mesh , then we have a problem: that objects have links to WebGL stuff which is not managed by javascript and eats videomemory. That's why we have "destroy()" method. For Texts and Meshes do 2).

Sprites:

If you loaded texture with standart way, like fromImage or with PIXI.loader, you dont have to destroy() it, because its texture is cached and will be reused for other sprites you create from the same file. In that case destroy() will affect your performance in a bad way.

If you created Sprite with texture that was created from canvas which you obtained dynamically, call destroy(), you wont need that texture anymore. 

[Fricken Hamster]

Thanks for the response

For clarification,
1,2 and 3 are not separate.
I am doing all 3 in that order.

Not removing children and running destroy seems to give me errors. I don't believe destroy makes any changes on the parent container unless, the container checks to see if it's children have been destroyed when it is trying to render, which I don't believe it does because of the errors I get running destroy without first removing the display object from the container.

[ivan.popelyshev]

Its all about parameters. As you see, if you call destroy(true) you wont be able to use that texture anymore, and if you loaded it from atlas, that will be a big problem. If you call destroy(true, true) then it will purge the image from videomemory. Be careful of what are you doing.

Sprite.prototype.destroy = function (destroyTexture, destroyBaseTexture)
{
    Container.prototype.destroy.call(this);

    this.anchor = null;

    if (destroyTexture)
    {
        this._texture.destroy(destroyBaseTexture);
    }

    this._texture = null;
    this.shader = null;
};

 

[Fricken Hamster]

As per the documentation, I am not adding any parameters to the destroy method, to not destroy the textures.

However, I guess what I am really wondering is if all 3 steps are necessary for just deleting a Sprite, though I guess it is only steps 1 and 2 that could maybe make sense to be combined in some fashion. It might have been this way in flash, but thats too long ago for me to remember