bevy/examples/3d
Carter Anderson dcc03724a5 Base Sets (#7466)
# Objective

NOTE: This depends on #7267 and should not be merged until #7267 is merged. If you are reviewing this before that is merged, I highly recommend viewing the Base Sets commit instead of trying to find my changes amongst those from #7267.

"Default sets" as described by the [Stageless RFC](https://github.com/bevyengine/rfcs/pull/45) have some [unfortunate consequences](https://github.com/bevyengine/bevy/discussions/7365).

## Solution

This adds "base sets" as a variant of `SystemSet`:

A set is a "base set" if `SystemSet::is_base` returns `true`. Typically this will be opted-in to using the `SystemSet` derive:

```rust
#[derive(SystemSet, Clone, Hash, Debug, PartialEq, Eq)]
#[system_set(base)]
enum MyBaseSet {
  A,
  B,
}
``` 

**Base sets are exclusive**: a system can belong to at most one "base set". Adding a system to more than one will result in an error. When possible we fail immediately during system-config-time with a nice file + line number. For the more nested graph-ey cases, this will fail at the final schedule build. 

**Base sets cannot belong to other sets**: this is where the word "base" comes from

Systems and Sets can only be added to base sets using `in_base_set`. Calling `in_set` with a base set will fail. As will calling `in_base_set` with a normal set.

```rust
app.add_system(foo.in_base_set(MyBaseSet::A))
       // X must be a normal set ... base sets cannot be added to base sets
       .configure_set(X.in_base_set(MyBaseSet::A))
```

Base sets can still be configured like normal sets:

```rust
app.add_system(MyBaseSet::B.after(MyBaseSet::Ap))
``` 

The primary use case for base sets is enabling a "default base set":

```rust
schedule.set_default_base_set(CoreSet::Update)
  // this will belong to CoreSet::Update by default
  .add_system(foo)
  // this will override the default base set with PostUpdate
  .add_system(bar.in_base_set(CoreSet::PostUpdate))
```

This allows us to build apis that work by default in the standard Bevy style. This is a rough analog to the "default stage" model, but it use the new "stageless sets" model instead, with all of the ordering flexibility (including exclusive systems) that it provides.

---

## Changelog

- Added "base sets" and ported CoreSet to use them.

## Migration Guide

TODO
2023-02-06 03:10:08 +00:00
..
3d_scene.rs Spawn now takes a Bundle (#6054) 2022-09-23 19:55:54 +00:00
3d_shapes.rs Base Sets (#7466) 2023-02-06 03:10:08 +00:00
atmospheric_fog.rs Better cascades config defaults + builder, tweak example configs (#7456) 2023-02-05 08:06:32 +00:00
blend_modes.rs Base Sets (#7466) 2023-02-06 03:10:08 +00:00
bloom.rs Base Sets (#7466) 2023-02-06 03:10:08 +00:00
fog.rs Add Distance and Atmospheric Fog support (#6412) 2023-01-29 15:28:56 +00:00
fxaa.rs Better cascades config defaults + builder, tweak example configs (#7456) 2023-02-05 08:06:32 +00:00
lighting.rs Base Sets (#7466) 2023-02-06 03:10:08 +00:00
lines.rs Allow passing glam vector types as vertex attributes (#6442) 2022-11-04 03:45:17 +00:00
load_gltf.rs Base Sets (#7466) 2023-02-06 03:10:08 +00:00
msaa.rs Base Sets (#7466) 2023-02-06 03:10:08 +00:00
orthographic.rs Spawn now takes a Bundle (#6054) 2022-09-23 19:55:54 +00:00
parenting.rs Base Sets (#7466) 2023-02-06 03:10:08 +00:00
pbr.rs Add a more familiar hex color entry (#7060) 2023-01-04 23:40:42 +00:00
render_to_texture.rs Base Sets (#7466) 2023-02-06 03:10:08 +00:00
shadow_biases.rs Base Sets (#7466) 2023-02-06 03:10:08 +00:00
shadow_caster_receiver.rs Better cascades config defaults + builder, tweak example configs (#7456) 2023-02-05 08:06:32 +00:00
skybox.rs Make AsBindGroup unsized (#6937) 2022-12-16 01:40:15 +00:00
spherical_area_lights.rs Spawn now takes a Bundle (#6054) 2022-09-23 19:55:54 +00:00
split_screen.rs Base Sets (#7466) 2023-02-06 03:10:08 +00:00
spotlight.rs Add global time scaling (#5752) 2022-10-22 18:52:29 +00:00
texture.rs Spawn now takes a Bundle (#6054) 2022-09-23 19:55:54 +00:00
transparency_3d.rs Changed Msaa to Enum (#7292) 2023-01-20 14:25:21 +00:00
two_passes.rs Rename camera "priority" to "order" (#6908) 2022-12-25 00:39:30 +00:00
update_gltf_scene.rs Base Sets (#7466) 2023-02-06 03:10:08 +00:00
vertex_colors.rs Spawn now takes a Bundle (#6054) 2022-09-23 19:55:54 +00:00
wireframe.rs Move 'startup' Resource WgpuSettings into the RenderPlugin (#6946) 2022-12-20 16:17:11 +00:00