Event Rearchitecture

Cargo.toml

@@ -632,6 +632,7 @@ serde_json = "1.0.140"
 bytemuck = "1"
 bevy_render = { path = "crates/bevy_render", version = "0.17.0-dev", default-features = false }
 # The following explicit dependencies are needed for proc macros to work inside of examples as they are part of the bevy crate itself.
+bevy_animation = { path = "crates/bevy_animation", version = "0.17.0-dev", default-features = false }
 bevy_ecs = { path = "crates/bevy_ecs", version = "0.17.0-dev", default-features = false }
 bevy_state = { path = "crates/bevy_state", version = "0.17.0-dev", default-features = false }
 bevy_asset = { path = "crates/bevy_asset", version = "0.17.0-dev", default-features = false }

benches/benches/bevy_ecs/observers/propagation.rs

@@ -62,14 +62,16 @@ pub fn event_propagation(criterion: &mut Criterion) {
 }
 
 #[derive(EntityEvent, Clone, Component)]
-#[entity_event(traversal = &'static ChildOf, auto_propagate)]
-struct TestEvent<const N: usize> {}
+#[entity_event(propagate, auto_propagate)]
+struct TestEvent<const N: usize> {
+    entity: Entity,
+}
 
 fn send_events<const N: usize, const N_EVENTS: usize>(world: &mut World, leaves: &[Entity]) {
-    let target = leaves.iter().choose(&mut rand::rng()).unwrap();
+    let target = *leaves.iter().choose(&mut rand::rng()).unwrap();
 
     (0..N_EVENTS).for_each(|_| {
-        world.trigger_targets(TestEvent::<N> {}, *target);
+        world.trigger(TestEvent::<N> { entity });
     });
 }
 

benches/benches/bevy_ecs/observers/simple.rs

@@ -1,8 +1,9 @@
 use core::hint::black_box;
 
 use bevy_ecs::{
-    event::EntityEvent,
-    observer::{On, TriggerTargets},
+    entity::Entity,
+    event::{EntityEvent, Event},
+    observer::{EventTargets, On},
     world::World,
 };
 
@@ -13,8 +14,13 @@ fn deterministic_rand() -> ChaCha8Rng {
     ChaCha8Rng::seed_from_u64(42)
 }
 
+#[derive(Clone, Event)]
+struct SimpleEvent;
+
 #[derive(Clone, EntityEvent)]
-struct EventBase;
+struct SimpleEntityEvent {
+    entity: Entity,
+}
 
 pub fn observe_simple(criterion: &mut Criterion) {
     let mut group = criterion.benchmark_group("observe");
@@ -23,10 +29,10 @@ pub fn observe_simple(criterion: &mut Criterion) {
 
     group.bench_function("trigger_simple", |bencher| {
         let mut world = World::new();
-        world.add_observer(empty_listener_base);
+        world.add_observer(on_simple_event);
         bencher.iter(|| {
             for _ in 0..10000 {
-                world.trigger(EventBase);
+                world.trigger(SimpleEvent);
             }
         });
     });
@@ -35,21 +41,23 @@ pub fn observe_simple(criterion: &mut Criterion) {
         let mut world = World::new();
         let mut entities = vec![];
         for _ in 0..10000 {
-            entities.push(world.spawn_empty().observe(empty_listener_base).id());
+            entities.push(world.spawn_empty().observe(on_simple_entity_event).id());
         }
         entities.shuffle(&mut deterministic_rand());
         bencher.iter(|| {
-            send_base_event(&mut world, &entities);
+            for entity in entities {
+                world.trigger(SimpleEntityEvent { entity });
+            }
         });
     });
 
     group.finish();
 }
 
-fn empty_listener_base(event: On<EventBase>) {
+fn on_simple_event(event: On<SimpleEvent>) {
     black_box(event);
 }
 
-fn send_base_event(world: &mut World, entities: impl TriggerTargets) {
-    world.trigger_targets(EventBase, entities);
+fn on_simple_entity_event(event: On<SimpleEntityEvent>) {
+    black_box(event);
 }

crates/bevy_animation/Cargo.toml

@@ -10,6 +10,7 @@ keywords = ["bevy"]
 
 [dependencies]
 # bevy
+bevy_animation_macros = { path = "macros", version = "0.17.0-dev" }
 bevy_app = { path = "../bevy_app", version = "0.17.0-dev" }
 bevy_asset = { path = "../bevy_asset", version = "0.17.0-dev" }
 bevy_color = { path = "../bevy_color", version = "0.17.0-dev" }

crates/bevy_animation/macros/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "bevy_animation_macros"
+version = "0.17.0-dev"
+description = "Macros for bevy_animation"
+edition = "2024"
+license = "MIT OR Apache-2.0"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+bevy_macro_utils = { path = "../../bevy_macro_utils", version = "0.17.0-dev" }
+
+syn = { version = "2.0", features = ["full"] }
+quote = "1.0"
+
+[lints]
+workspace = true
+
+[package.metadata.docs.rs]
+rustdoc-args = ["-Zunstable-options"]
+all-features = true

crates/bevy_animation/macros/LICENSE-APACHE

@@ -0,0 +1,176 @@
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crates/bevy_animation/macros/LICENSE-MIT

@@ -0,0 +1,19 @@
+MIT License
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
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+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

crates/bevy_animation/macros/src/animation_event.rs

@@ -0,0 +1,26 @@
+use bevy_macro_utils::BevyManifest;
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{parse_macro_input, DeriveInput};
+
+pub fn derive_animation_event(input: TokenStream) -> TokenStream {
+    let ast = parse_macro_input!(input as DeriveInput);
+    let manifest = BevyManifest::shared();
+    let bevy_ecs = manifest.get_path("bevy_ecs");
+    let bevy_animation = manifest.get_path("bevy_animation");
+
+    let generics = ast.generics;
+    let (impl_generics, type_generics, where_clause) = generics.split_for_impl();
+
+    let struct_name = &ast.ident;
+
+    quote! {
+        impl #impl_generics #bevy_ecs::event::Event for #struct_name #type_generics #where_clause {
+            type Trigger<'a> = #bevy_animation::AnimationEventTrigger;
+        }
+
+        impl #impl_generics #bevy_animation::AnimationEvent for #struct_name #type_generics #where_clause {
+        }
+    }
+    .into()
+}

crates/bevy_animation/macros/src/lib.rs

@@ -0,0 +1,16 @@
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+
+//! Macros for deriving animation behaviors.
+
+extern crate proc_macro;
+
+mod animation_event;
+
+use proc_macro::TokenStream;
+
+/// Implements the `AnimationEvent` trait for a type - see the trait
+/// docs for an example usage.
+#[proc_macro_derive(AnimationEvent)]
+pub fn derive_animation_event(input: TokenStream) -> TokenStream {
+    animation_event::derive_animation_event(input)
+}