This is a rather simple but wide change, and it involves adding a new `bevy_app_macros` crate. Let me know if there is a better way to do any of this!
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# Objective
- Allow adding and accessing sub-apps by using a label instead of an index
## Solution
- Migrate the bevy label implementation and derive code to the `bevy_utils` and `bevy_macro_utils` crates and then add a new `SubAppLabel` trait to the `bevy_app` crate that is used when adding or getting a sub-app from an app.
# Objective
- Prevent the need to specify a sprite size when using the pipelined sprite renderer
## Solution
- Re-introduce the sprite auto resize system from the old renderer
# Objective
- Allow you to compile Bevy with the `bevy_sprite2` feature, but without the `bevy_pbr2` feature.
- This currently fails because the `bevy_sprite2` crate does not require the `derive` feature of the `bytemuck` crate in its `Cargo.toml`, even though it is required to compile.
## Solution
- Add the `derive` feature of `bytemuck` to the `bevy_sprite2` crate
# Objective
Restore the functionality of sprite atlases in the new renderer.
### **Note:** This PR relies on #2555
## Solution
Mostly just a copy paste of the existing sprite atlas implementation, however I unified the rendering between sprites and atlases.
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
This decouples the opinionated "core pipeline" from the new (less opinionated) bevy_render crate. The "core pipeline" is intended to be used by crates like bevy_sprites, bevy_pbr, bevy_ui, and 3rd party crates that extends core rendering functionality.
