I struggled with some sprite sheet animation which was like drifting from right to left.
This PR documents the current behaviour that the padding which is used on slicing a texture into a texture atlas, is assumed to be only between tiles. In my case I had some padding also on the right side of the texture.
OK, here's my attempt at sprite flipping. There are a couple of points that I need review/help on, but I think the UX is about ideal:
```rust
.spawn(SpriteBundle {
material: materials.add(texture_handle.into()),
sprite: Sprite {
// Flip the sprite along the x axis
flip: SpriteFlip { x: true, y: false },
..Default::default()
},
..Default::default()
});
```
Now for the issues. The big issue is that for some reason, when flipping the UVs on the sprite, there is a light "bleeding" or whatever you call it where the UV tries to sample past the texture boundry and ends up clipping. This is only noticed when resizing the window, though. You can see a screenshot below.

I am quite baffled why the texture sampling is overrunning like it is and could use some guidance if anybody knows what might be wrong.
The other issue, which I just worked around, is that I had to remove the `#[render_resources(from_self)]` annotation from the Spritesheet because the `SpriteFlip` render resource wasn't being picked up properly in the shader when using it. I'm not sure what the cause of that was, but by removing the annotation and re-organizing the shader inputs accordingly the problem was fixed.
I'm not sure if this is the most efficient way to do this or if there is a better way, but I wanted to try it out if only for the learning experience. Let me know what you think!
* Remove cfg!(feature = "metal-auto-capture")
This cfg! has existed since the initial commit, but the corresponding
feature has never been part of Cargo.toml
* Remove unnecessary handle_create_window_events call
* Remove EventLoopProxyPtr wrapper
* Remove unnecessary statics
* Fix unrelated deprecation warning to fix CI