Schedule-First: the new and improved add_systems

benches/benches/bevy_ecs/components/archetype_updates.rs

@@ -9,7 +9,7 @@ fn setup(system_count: usize) -> (World, Schedule) {
     fn empty() {}
     let mut schedule = Schedule::new();
     for _ in 0..system_count {
-        schedule.add_system(empty);
+        schedule.add_systems(empty);
     }
     schedule.run(&mut world);
     (world, schedule)

benches/benches/bevy_ecs/empty_archetypes.rs

@@ -154,7 +154,7 @@ fn empty_archetypes(criterion: &mut Criterion) {
     let mut group = criterion.benchmark_group("empty_archetypes");
     for archetype_count in [10, 100, 500, 1000, 2000, 5000, 10000] {
         let (mut world, mut schedule) = setup(true, |schedule| {
-            schedule.add_system(iter);
+            schedule.add_systems(iter);
         });
         add_archetypes(&mut world, archetype_count);
         world.clear_entities();
@@ -185,7 +185,7 @@ fn empty_archetypes(criterion: &mut Criterion) {
     }
     for archetype_count in [10, 100, 500, 1000, 2000, 5000, 10000] {
         let (mut world, mut schedule) = setup(true, |schedule| {
-            schedule.add_system(for_each);
+            schedule.add_systems(for_each);
         });
         add_archetypes(&mut world, archetype_count);
         world.clear_entities();
@@ -216,7 +216,7 @@ fn empty_archetypes(criterion: &mut Criterion) {
     }
     for archetype_count in [10, 100, 500, 1000, 2000, 5000, 10000] {
         let (mut world, mut schedule) = setup(true, |schedule| {
-            schedule.add_system(par_for_each);
+            schedule.add_systems(par_for_each);
         });
         add_archetypes(&mut world, archetype_count);
         world.clear_entities();

benches/benches/bevy_ecs/scheduling/run_condition.rs

@@ -19,7 +19,7 @@ pub fn run_condition_yes(criterion: &mut Criterion) {
     fn empty() {}
     for amount in 0..21 {
         let mut schedule = Schedule::new();
-        schedule.add_system(empty.run_if(yes));
+        schedule.add_systems(empty.run_if(yes));
         for _ in 0..amount {
             schedule.add_systems((empty, empty, empty, empty, empty).distributive_run_if(yes));
         }
@@ -42,7 +42,7 @@ pub fn run_condition_no(criterion: &mut Criterion) {
     fn empty() {}
     for amount in 0..21 {
         let mut schedule = Schedule::new();
-        schedule.add_system(empty.run_if(no));
+        schedule.add_systems(empty.run_if(no));
         for _ in 0..amount {
             schedule.add_systems((empty, empty, empty, empty, empty).distributive_run_if(no));
         }
@@ -72,7 +72,7 @@ pub fn run_condition_yes_with_query(criterion: &mut Criterion) {
     }
     for amount in 0..21 {
         let mut schedule = Schedule::new();
-        schedule.add_system(empty.run_if(yes_with_query));
+        schedule.add_systems(empty.run_if(yes_with_query));
         for _ in 0..amount {
             schedule.add_systems(
                 (empty, empty, empty, empty, empty).distributive_run_if(yes_with_query),
@@ -101,7 +101,7 @@ pub fn run_condition_yes_with_resource(criterion: &mut Criterion) {
     }
     for amount in 0..21 {
         let mut schedule = Schedule::new();
-        schedule.add_system(empty.run_if(yes_with_resource));
+        schedule.add_systems(empty.run_if(yes_with_resource));
         for _ in 0..amount {
             schedule.add_systems(
                 (empty, empty, empty, empty, empty).distributive_run_if(yes_with_resource),

benches/benches/bevy_ecs/scheduling/running_systems.rs

@@ -23,7 +23,7 @@ pub fn empty_systems(criterion: &mut Criterion) {
     for amount in 0..5 {
         let mut schedule = Schedule::new();
         for _ in 0..amount {
-            schedule.add_system(empty);
+            schedule.add_systems(empty);
         }
         schedule.run(&mut world);
         group.bench_function(&format!("{:03}_systems", amount), |bencher| {

benches/benches/bevy_ecs/scheduling/schedule.rs

@@ -1,4 +1,4 @@
-use bevy_app::App;
+use bevy_app::{App, Update};
 use bevy_ecs::prelude::*;
 use criterion::Criterion;
 
@@ -72,7 +72,7 @@ pub fn build_schedule(criterion: &mut Criterion) {
     group.measurement_time(std::time::Duration::from_secs(15));
 
     // Method: generate a set of `graph_size` systems which have a One True Ordering.
-    // Add system to the schedule with full constraints. Hopefully this should be maximimally
+    // Add system to the schedule with full constraints. Hopefully this should be maximally
     // difficult for bevy to figure out.
     let labels: Vec<_> = (0..1000).map(|i| NumSet(i)).collect();
 
@@ -83,7 +83,7 @@ pub fn build_schedule(criterion: &mut Criterion) {
             bencher.iter(|| {
                 let mut app = App::new();
                 for _ in 0..graph_size {
-                    app.add_system(empty_system);
+                    app.add_systems(Update, empty_system);
                 }
                 app.update();
             });
@@ -93,7 +93,7 @@ pub fn build_schedule(criterion: &mut Criterion) {
         group.bench_function(format!("{graph_size}_schedule"), |bencher| {
             bencher.iter(|| {
                 let mut app = App::new();
-                app.add_system(empty_system.in_set(DummySet));
+                app.add_systems(Update, empty_system.in_set(DummySet));
 
                 // Build a fully-connected dependency graph describing the One True Ordering.
                 // Not particularly realistic but this can be refined later.
@@ -105,7 +105,7 @@ pub fn build_schedule(criterion: &mut Criterion) {
                     for label in &labels[i + 1..graph_size] {
                         sys = sys.before(*label);
                     }
-                    app.add_system(sys);
+                    app.add_systems(Update, sys);
                 }
                 // Run the app for a single frame.
                 // This is necessary since dependency resolution does not occur until the game runs.

crates/bevy_animation/src/lib.rs

@@ -5,7 +5,7 @@
 use std::ops::Deref;
 use std::time::Duration;
 
-use bevy_app::{App, CoreSet, Plugin};
+use bevy_app::{App, Plugin, PostUpdate};
 use bevy_asset::{AddAsset, Assets, Handle};
 use bevy_core::Name;
 use bevy_ecs::prelude::*;
@@ -550,10 +550,9 @@ impl Plugin for AnimationPlugin {
         app.add_asset::<AnimationClip>()
             .register_asset_reflect::<AnimationClip>()
             .register_type::<AnimationPlayer>()
-            .add_system(
-                animation_player
-                    .in_base_set(CoreSet::PostUpdate)
-                    .before(TransformSystem::TransformPropagate),
+            .add_systems(
+                PostUpdate,
+                animation_player.before(TransformSystem::TransformPropagate),
             );
     }
 }