Update for bevy ecs v2

[rparrett]

A work in progress.

Things seem to work, but I ran out of time and only fixed one of the examples for now.

Should be able to finish this up later tonight.

This should be good to go.

[rparrett]

Unfortunately, there seems to be an issue and some of the examples aren't working properly at the moment. I tested all the others and they seem fine.

sprite - not ok, nothing displayed
breakout - not ok, only score displayed
font_atlas_debug - panics

[rparrett]

Won't be able to work on this today, but I tried rebasing against the dev branch (locally) and this didn't seem to help the situation.

But the rebase was very painless.

Should this be pointed at that branch?

[rparrett]

Didn't get anywhere this morning, but observed that the reflected layout info! isn't happening in this PR (but that's true in the examples that do work as well)

[rparrett]

It looks like I had just falsely remembered the sprite flipping PR getting merged after ecs v2. Ignoring that would certainly cause issues with sprites showing up. Investigating.

edit: yup, that's the issue. Will fully implement sprite flipping in a bit.

[rparrett]

This is now rebased against/pointing at the dev branch.

[rparrett]

@mrk-its

Pinging you to let you know that I will likely need to abandon this work for now due to time constraints.

I've pushed my current efforts to get this working with bevy's new PBR stuff.

This puts this PR in a state where 2d stuff seems to work, but basically everything 3d is broken. It's broken in a way that shaders compile, there are no error messages or warnings, but we just get a grey screen.

I suspect that there's something flying over my head related to texture samplers, or perhaps the camera bindings.

[rparrett]

The issue seems related to camera bindings, or bindings in general.

I accidentally found that a simple change in utils.rs / reflect_layout seems to at least make some stuff show up in 3d_scene. I discovered this while attempting to add a BindingDescriptor to the CameraViewProj BindGroupDescriptor in the same function. (Which got me nothing but webgl errors)

if name == "CameraPosition" {
    continue;
}

[rparrett]

This is now working (thanks mockersf) but relies on bevyengine/bevy#1798

[rparrett]

There are some lingering questions about whether the manual BindingDescriptor overrides in utils.rs are actually needed, and a few comments about a couple specific changes here: https://github.com/rparrett/bevy_webgl2/pull/1