 dc3f801239
			
		
	
	
		dc3f801239
		
	
	
	
	
		
			
			# Objective The [Stageless RFC](https://github.com/bevyengine/rfcs/pull/45) involves allowing exclusive systems to be referenced and ordered relative to parallel systems. We've agreed that unifying systems under `System` is the right move. This is an alternative to #4166 (see rationale in the comments I left there). Note that this builds on the learnings established there (and borrows some patterns). ## Solution This unifies parallel and exclusive systems under the shared `System` trait, removing the old `ExclusiveSystem` trait / impls. This is accomplished by adding a new `ExclusiveFunctionSystem` impl similar to `FunctionSystem`. It is backed by `ExclusiveSystemParam`, which is similar to `SystemParam`. There is a new flattened out SystemContainer api (which cuts out a lot of trait and type complexity). This means you can remove all cases of `exclusive_system()`: ```rust // before commands.add_system(some_system.exclusive_system()); // after commands.add_system(some_system); ``` I've also implemented `ExclusiveSystemParam` for `&mut QueryState` and `&mut SystemState`, which makes this possible in exclusive systems: ```rust fn some_exclusive_system( world: &mut World, transforms: &mut QueryState<&Transform>, state: &mut SystemState<(Res<Time>, Query<&Player>)>, ) { for transform in transforms.iter(world) { println!("{transform:?}"); } let (time, players) = state.get(world); for player in players.iter() { println!("{player:?}"); } } ``` Note that "exclusive function systems" assume `&mut World` is present (and the first param). I think this is a fair assumption, given that the presence of `&mut World` is what defines the need for an exclusive system. I added some targeted SystemParam `static` constraints, which removed the need for this: ``` rust fn some_exclusive_system(state: &mut SystemState<(Res<'static, Time>, Query<&'static Player>)>) {} ``` ## Related - #2923 - #3001 - #3946 ## Changelog - `ExclusiveSystem` trait (and implementations) has been removed in favor of sharing the `System` trait. - `ExclusiveFunctionSystem` and `ExclusiveSystemParam` were added, enabling flexible exclusive function systems - `&mut SystemState` and `&mut QueryState` now implement `ExclusiveSystemParam` - Exclusive and parallel System configuration is now done via a unified `SystemDescriptor`, `IntoSystemDescriptor`, and `SystemContainer` api. ## Migration Guide Calling `.exclusive_system()` is no longer required (or supported) for converting exclusive system functions to exclusive systems: ```rust // Old (0.8) app.add_system(some_exclusive_system.exclusive_system()); // New (0.9) app.add_system(some_exclusive_system); ``` Converting "normal" parallel systems to exclusive systems is done by calling the exclusive ordering apis: ```rust // Old (0.8) app.add_system(some_system.exclusive_system().at_end()); // New (0.9) app.add_system(some_system.at_end()); ``` Query state in exclusive systems can now be cached via ExclusiveSystemParams, which should be preferred for clarity and performance reasons: ```rust // Old (0.8) fn some_system(world: &mut World) { let mut transforms = world.query::<&Transform>(); for transform in transforms.iter(world) { } } // New (0.9) fn some_system(world: &mut World, transforms: &mut QueryState<&Transform>) { for transform in transforms.iter(world) { } } ```
		
			
				
	
	
		
			267 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			267 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
| pub mod wireframe;
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| 
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| mod alpha;
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| mod bundle;
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| mod light;
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| mod material;
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| mod pbr_material;
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| mod render;
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| 
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| pub use alpha::*;
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| pub use bundle::*;
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| pub use light::*;
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| pub use material::*;
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| pub use pbr_material::*;
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| pub use render::*;
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| 
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| use bevy_window::ModifiesWindows;
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| 
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| pub mod prelude {
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|     #[doc(hidden)]
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|     pub use crate::{
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|         alpha::AlphaMode,
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|         bundle::{
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|             DirectionalLightBundle, MaterialMeshBundle, PbrBundle, PointLightBundle,
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|             SpotLightBundle,
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|         },
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|         light::{AmbientLight, DirectionalLight, PointLight, SpotLight},
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|         material::{Material, MaterialPlugin},
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|         pbr_material::StandardMaterial,
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|     };
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| }
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| 
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| pub mod draw_3d_graph {
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|     pub mod node {
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|         /// Label for the shadow pass node.
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|         pub const SHADOW_PASS: &str = "shadow_pass";
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|     }
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| }
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| 
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| use bevy_app::prelude::*;
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| use bevy_asset::{load_internal_asset, Assets, Handle, HandleUntyped};
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| use bevy_ecs::prelude::*;
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| use bevy_reflect::TypeUuid;
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| use bevy_render::{
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|     camera::CameraUpdateSystem,
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|     extract_resource::ExtractResourcePlugin,
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|     prelude::Color,
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|     render_graph::RenderGraph,
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|     render_phase::{sort_phase_system, AddRenderCommand, DrawFunctions},
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|     render_resource::{Shader, SpecializedMeshPipelines},
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|     view::VisibilitySystems,
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|     RenderApp, RenderStage,
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| };
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| use bevy_transform::TransformSystem;
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| 
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| pub const PBR_TYPES_SHADER_HANDLE: HandleUntyped =
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|     HandleUntyped::weak_from_u64(Shader::TYPE_UUID, 1708015359337029744);
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| pub const PBR_BINDINGS_SHADER_HANDLE: HandleUntyped =
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|     HandleUntyped::weak_from_u64(Shader::TYPE_UUID, 5635987986427308186);
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| pub const UTILS_HANDLE: HandleUntyped =
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|     HandleUntyped::weak_from_u64(Shader::TYPE_UUID, 1900548483293416725);
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| pub const CLUSTERED_FORWARD_HANDLE: HandleUntyped =
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|     HandleUntyped::weak_from_u64(Shader::TYPE_UUID, 166852093121196815);
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| pub const PBR_LIGHTING_HANDLE: HandleUntyped =
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|     HandleUntyped::weak_from_u64(Shader::TYPE_UUID, 14170772752254856967);
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| pub const SHADOWS_HANDLE: HandleUntyped =
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|     HandleUntyped::weak_from_u64(Shader::TYPE_UUID, 11350275143789590502);
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| pub const PBR_SHADER_HANDLE: HandleUntyped =
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|     HandleUntyped::weak_from_u64(Shader::TYPE_UUID, 4805239651767701046);
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| pub const PBR_FUNCTIONS_HANDLE: HandleUntyped =
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|     HandleUntyped::weak_from_u64(Shader::TYPE_UUID, 16550102964439850292);
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| pub const SHADOW_SHADER_HANDLE: HandleUntyped =
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|     HandleUntyped::weak_from_u64(Shader::TYPE_UUID, 1836745567947005696);
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| 
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| /// Sets up the entire PBR infrastructure of bevy.
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| #[derive(Default)]
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| pub struct PbrPlugin;
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| 
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| impl Plugin for PbrPlugin {
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|     fn build(&self, app: &mut App) {
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|         load_internal_asset!(
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|             app,
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|             PBR_TYPES_SHADER_HANDLE,
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|             "render/pbr_types.wgsl",
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|             Shader::from_wgsl
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|         );
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|         load_internal_asset!(
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|             app,
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|             PBR_BINDINGS_SHADER_HANDLE,
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|             "render/pbr_bindings.wgsl",
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|             Shader::from_wgsl
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|         );
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|         load_internal_asset!(app, UTILS_HANDLE, "render/utils.wgsl", Shader::from_wgsl);
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|         load_internal_asset!(
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|             app,
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|             CLUSTERED_FORWARD_HANDLE,
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|             "render/clustered_forward.wgsl",
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|             Shader::from_wgsl
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|         );
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|         load_internal_asset!(
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|             app,
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|             PBR_LIGHTING_HANDLE,
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|             "render/pbr_lighting.wgsl",
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|             Shader::from_wgsl
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|         );
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|         load_internal_asset!(
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|             app,
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|             SHADOWS_HANDLE,
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|             "render/shadows.wgsl",
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|             Shader::from_wgsl
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|         );
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|         load_internal_asset!(
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|             app,
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|             PBR_FUNCTIONS_HANDLE,
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|             "render/pbr_functions.wgsl",
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|             Shader::from_wgsl
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|         );
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|         load_internal_asset!(app, PBR_SHADER_HANDLE, "render/pbr.wgsl", Shader::from_wgsl);
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|         load_internal_asset!(
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|             app,
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|             SHADOW_SHADER_HANDLE,
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|             "render/depth.wgsl",
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|             Shader::from_wgsl
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|         );
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| 
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|         app.register_type::<CubemapVisibleEntities>()
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|             .register_type::<DirectionalLight>()
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|             .register_type::<PointLight>()
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|             .register_type::<SpotLight>()
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|             .add_plugin(MeshRenderPlugin)
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|             .add_plugin(MaterialPlugin::<StandardMaterial>::default())
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|             .register_type::<AmbientLight>()
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|             .register_type::<DirectionalLightShadowMap>()
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|             .register_type::<PointLightShadowMap>()
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|             .init_resource::<AmbientLight>()
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|             .init_resource::<GlobalVisiblePointLights>()
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|             .init_resource::<DirectionalLightShadowMap>()
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|             .init_resource::<PointLightShadowMap>()
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|             .add_plugin(ExtractResourcePlugin::<AmbientLight>::default())
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|             .add_system_to_stage(
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|                 CoreStage::PostUpdate,
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|                 // NOTE: Clusters need to have been added before update_clusters is run so
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|                 // add as an exclusive system
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|                 add_clusters
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|                     .at_start()
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|                     .label(SimulationLightSystems::AddClusters),
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|             )
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|             .add_system_to_stage(
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|                 CoreStage::PostUpdate,
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|                 assign_lights_to_clusters
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|                     .label(SimulationLightSystems::AssignLightsToClusters)
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|                     .after(TransformSystem::TransformPropagate)
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|                     .after(VisibilitySystems::CheckVisibility)
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|                     .after(CameraUpdateSystem)
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|                     .after(ModifiesWindows),
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|             )
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|             .add_system_to_stage(
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|                 CoreStage::PostUpdate,
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|                 update_directional_light_frusta
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|                     .label(SimulationLightSystems::UpdateLightFrusta)
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|                     // This must run after CheckVisibility because it relies on ComputedVisibility::is_visible()
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|                     .after(VisibilitySystems::CheckVisibility)
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|                     .after(TransformSystem::TransformPropagate),
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|             )
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|             .add_system_to_stage(
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|                 CoreStage::PostUpdate,
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|                 update_point_light_frusta
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|                     .label(SimulationLightSystems::UpdateLightFrusta)
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|                     .after(TransformSystem::TransformPropagate)
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|                     .after(SimulationLightSystems::AssignLightsToClusters),
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|             )
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|             .add_system_to_stage(
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|                 CoreStage::PostUpdate,
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|                 update_spot_light_frusta
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|                     .label(SimulationLightSystems::UpdateLightFrusta)
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|                     .after(TransformSystem::TransformPropagate)
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|                     .after(SimulationLightSystems::AssignLightsToClusters),
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|             )
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|             .add_system_to_stage(
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|                 CoreStage::PostUpdate,
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|                 check_light_mesh_visibility
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|                     .label(SimulationLightSystems::CheckLightVisibility)
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|                     .after(TransformSystem::TransformPropagate)
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|                     .after(VisibilitySystems::CalculateBounds)
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|                     .after(SimulationLightSystems::UpdateLightFrusta)
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|                     // NOTE: This MUST be scheduled AFTER the core renderer visibility check
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|                     // because that resets entity ComputedVisibility for the first view
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|                     // which would override any results from this otherwise
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|                     .after(VisibilitySystems::CheckVisibility),
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|             );
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| 
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|         app.world
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|             .resource_mut::<Assets<StandardMaterial>>()
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|             .set_untracked(
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|                 Handle::<StandardMaterial>::default(),
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|                 StandardMaterial {
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|                     base_color: Color::rgb(1.0, 0.0, 0.5),
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|                     unlit: true,
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|                     ..Default::default()
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|                 },
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|             );
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| 
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|         let render_app = match app.get_sub_app_mut(RenderApp) {
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|             Ok(render_app) => render_app,
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|             Err(_) => return,
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|         };
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| 
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|         render_app
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|             .add_system_to_stage(
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|                 RenderStage::Extract,
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|                 render::extract_clusters.label(RenderLightSystems::ExtractClusters),
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|             )
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|             .add_system_to_stage(
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|                 RenderStage::Extract,
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|                 render::extract_lights.label(RenderLightSystems::ExtractLights),
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|             )
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|             .add_system_to_stage(
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|                 RenderStage::Prepare,
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|                 // this is added as an exclusive system because it contributes new views. it must run (and have Commands applied)
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|                 // _before_ the `prepare_views()` system is run. ideally this becomes a normal system when "stageless" features come out
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|                 render::prepare_lights
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|                     .at_start()
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|                     .label(RenderLightSystems::PrepareLights),
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|             )
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|             .add_system_to_stage(
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|                 RenderStage::Prepare,
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|                 // NOTE: This needs to run after prepare_lights. As prepare_lights is an exclusive system,
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|                 // just adding it to the non-exclusive systems in the Prepare stage means it runs after
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|                 // prepare_lights.
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|                 render::prepare_clusters.label(RenderLightSystems::PrepareClusters),
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|             )
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|             .add_system_to_stage(
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|                 RenderStage::Queue,
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|                 render::queue_shadows.label(RenderLightSystems::QueueShadows),
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|             )
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|             .add_system_to_stage(RenderStage::Queue, render::queue_shadow_view_bind_group)
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|             .add_system_to_stage(RenderStage::PhaseSort, sort_phase_system::<Shadow>)
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|             .init_resource::<ShadowPipeline>()
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|             .init_resource::<DrawFunctions<Shadow>>()
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|             .init_resource::<LightMeta>()
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|             .init_resource::<GlobalLightMeta>()
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|             .init_resource::<SpecializedMeshPipelines<ShadowPipeline>>();
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| 
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|         let shadow_pass_node = ShadowPassNode::new(&mut render_app.world);
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|         render_app.add_render_command::<Shadow, DrawShadowMesh>();
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|         let mut graph = render_app.world.resource_mut::<RenderGraph>();
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|         let draw_3d_graph = graph
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|             .get_sub_graph_mut(bevy_core_pipeline::core_3d::graph::NAME)
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|             .unwrap();
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|         draw_3d_graph.add_node(draw_3d_graph::node::SHADOW_PASS, shadow_pass_node);
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|         draw_3d_graph
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|             .add_node_edge(
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|                 draw_3d_graph::node::SHADOW_PASS,
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|                 bevy_core_pipeline::core_3d::graph::node::MAIN_PASS,
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|             )
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|             .unwrap();
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|         draw_3d_graph
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|             .add_slot_edge(
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|                 draw_3d_graph.input_node().unwrap().id,
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|                 bevy_core_pipeline::core_3d::graph::input::VIEW_ENTITY,
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|                 draw_3d_graph::node::SHADOW_PASS,
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|                 ShadowPassNode::IN_VIEW,
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|             )
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|             .unwrap();
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|     }
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| }
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