dcc03724a5
# 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
49 lines
1.1 KiB
Rust
49 lines
1.1 KiB
Rust
mod bundle;
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mod dynamic_scene;
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mod dynamic_scene_builder;
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mod scene;
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mod scene_loader;
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mod scene_spawner;
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#[cfg(feature = "serialize")]
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pub mod serde;
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pub use bundle::*;
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pub use dynamic_scene::*;
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pub use dynamic_scene_builder::*;
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pub use scene::*;
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pub use scene_loader::*;
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pub use scene_spawner::*;
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pub mod prelude {
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#[doc(hidden)]
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pub use crate::{
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DynamicScene, DynamicSceneBuilder, DynamicSceneBundle, Scene, SceneBundle, SceneSpawner,
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};
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}
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use bevy_app::prelude::*;
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use bevy_asset::AddAsset;
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use bevy_ecs::prelude::*;
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#[derive(Default)]
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pub struct ScenePlugin;
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#[cfg(feature = "serialize")]
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impl Plugin for ScenePlugin {
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fn build(&self, app: &mut App) {
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app.add_asset::<DynamicScene>()
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.add_asset::<Scene>()
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.init_asset_loader::<SceneLoader>()
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.init_resource::<SceneSpawner>()
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.add_system(scene_spawner_system)
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// Systems `*_bundle_spawner` must run before `scene_spawner_system`
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.add_system(scene_spawner.in_base_set(CoreSet::PreUpdate));
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}
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}
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#[cfg(not(feature = "serialize"))]
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impl Plugin for ScenePlugin {
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fn build(&self, _: &mut App) {}
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}
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