Revert "Rapier context as a Component (dimforge#545)"

This reverts commit bab3431.

CHANGELOG.md

@@ -21,19 +21,6 @@ which was its hardcoded behaviour.
   `RapierDebugColliderPlugin` and `DebugRenderContext`, as well as individual collider setup via
   a `ColliderDebug` component.
 
-### Modified
-
-- `RapierContext`, `RapierConfiguration` and `RenderToSimulationTime` are now a `Component` instead of resources.
-  - Rapier now supports multiple independent physics worlds, see example `multi_world3` for usage details.
-  - Migration guide:
-    - `ResMut<mut RapierContext>` -> `WriteDefaultRapierContext`
-    - `Res<RapierContext>` -> `ReadDefaultRapierContext`
-    - Access to `RapierConfiguration` and `RenderToSimulationTime` should query for it
-on the responsible entity owning the `RenderContext`.
-  - If you are building a library on top of `bevy_rapier` and would want to support multiple independent physics worlds too,
-you can check out the details of [#545](https://github.com/dimforge/bevy_rapier/pull/545)
-to get more context and information.
-
 ## v0.27.0 (07 July 2024)
 
 **This is an update from rapier 0.19 to Rapier 0.21 which includes several stability improvements

bevy_rapier2d/Cargo.toml

@@ -60,7 +60,6 @@ serde = { version = "1", features = ["derive"], optional = true }
 bevy = { version = "0.14", default-features = false, features = [
     "x11",
     "bevy_state",
-    "bevy_debug_stepping",
 ] }
 oorandom = "11"
 approx = "0.5.1"

bevy_rapier2d/examples/player_movement2.rs

@@ -24,8 +24,7 @@ fn main() {
 #[derive(Component)]
 pub struct Player(f32);
 
-pub fn spawn_player(mut commands: Commands, mut rapier_config: Query<&mut RapierConfiguration>) {
-    let mut rapier_config = rapier_config.single_mut();
+pub fn spawn_player(mut commands: Commands, mut rapier_config: ResMut<RapierConfiguration>) {
     // Set gravity to 0.0 and spawn camera.
     rapier_config.gravity = Vec2::ZERO;
     commands.spawn(Camera2dBundle::default());

bevy_rapier2d/examples/testbed2.rs

@@ -204,9 +204,7 @@ fn main() {
             OnExit(Examples::PlayerMovement2),
             (
                 cleanup,
-                |mut rapier_config: Query<&mut RapierConfiguration>,
-                 ctxt: ReadDefaultRapierContext| {
-                    let mut rapier_config = rapier_config.single_mut();
+                |mut rapier_config: ResMut<RapierConfiguration>, ctxt: Res<RapierContext>| {
                     rapier_config.gravity =
                         RapierConfiguration::new(ctxt.integration_parameters.length_unit).gravity;
                 },

bevy_rapier3d/Cargo.toml

@@ -62,7 +62,6 @@ bevy = { version = "0.14", default-features = false, features = [
     "x11",
     "tonemapping_luts",
     "bevy_state",
-    "bevy_debug_stepping",
 ] }
 approx = "0.5.1"
 glam = { version = "0.27", features = ["approx"] }

bevy_rapier3d/examples/joints3.rs

@@ -284,7 +284,7 @@ pub fn setup_physics(mut commands: Commands) {
 }
 
 pub fn print_impulse_revolute_joints(
-    context: ReadDefaultRapierContext,
+    context: Res<RapierContext>,
     joints: Query<(Entity, &ImpulseJoint)>,
 ) {
     for (entity, impulse_joint) in joints.iter() {

bevy_rapier3d/examples/ray_casting3.rs

@@ -76,7 +76,7 @@ pub fn setup_physics(mut commands: Commands) {
 pub fn cast_ray(
     mut commands: Commands,
     windows: Query<&Window, With<PrimaryWindow>>,
-    rapier_context: ReadDefaultRapierContext,
+    rapier_context: Res<RapierContext>,
     cameras: Query<(&Camera, &GlobalTransform)>,
 ) {
     let window = windows.single();

bevy_rapier_benches3d/src/lib.rs

@@ -26,10 +26,7 @@ pub fn custom_bencher(steps: usize, setup: impl Fn(&mut App)) {
         app.update();
         timer_full_update.pause();
         let elapsed_time = timer_full_update.time() as f32;
-        let rc = app
-            .world_mut()
-            .query::<&RapierContext>()
-            .single(app.world());
+        let rc = app.world().resource::<RapierContext>();
         rapier_step_times.push(rc.pipeline.counters.step_time.time() as f32);
         total_update_times.push(elapsed_time);
     }

src/pipeline/events.rs

@@ -1,5 +1,5 @@
 use crate::math::{Real, Vect};
-use bevy::prelude::{Entity, Event};
+use bevy::prelude::{Entity, Event, EventWriter};
 use rapier::dynamics::RigidBodySet;
 use rapier::geometry::{
     ColliderHandle, ColliderSet, CollisionEvent as RapierCollisionEvent, CollisionEventFlags,
@@ -58,8 +58,8 @@ pub(crate) struct EventQueue<'a> {
     // Used to retrieve the entity of colliders that have been removed from the simulation
     // since the last physics step.
     pub deleted_colliders: &'a HashMap<ColliderHandle, Entity>,
-    pub collision_events: RwLock<Vec<CollisionEvent>>,
-    pub contact_force_events: RwLock<Vec<ContactForceEvent>>,
+    pub collision_events: RwLock<EventWriter<'a, CollisionEvent>>,
+    pub contact_force_events: RwLock<EventWriter<'a, ContactForceEvent>>,
 }
 
 impl<'a> EventQueue<'a> {
@@ -94,7 +94,7 @@ impl<'a> EventHandler for EventQueue<'a> {
         };
 
         if let Ok(mut events) = self.collision_events.write() {
-            events.push(event);
+            events.send(event);
         }
     }
 
@@ -118,7 +118,7 @@ impl<'a> EventHandler for EventQueue<'a> {
         };
 
         if let Ok(mut events) = self.contact_force_events.write() {
-            events.push(event);
+            events.send(event);
         }
     }
 }
@@ -155,13 +155,15 @@ mod test {
         pub struct EventsSaver<E: Event> {
             pub events: Vec<E>,
         }
+
         impl<E: Event> Default for EventsSaver<E> {
             fn default() -> Self {
                 Self {
                     events: Default::default(),
                 }
             }
         }
+
         pub fn save_events<E: Event + Clone>(
             mut events: EventReader<E>,
             mut saver: ResMut<EventsSaver<E>>,
@@ -170,6 +172,7 @@ mod test {
                 saver.events.push(event.clone());
             }
         }
+
         fn run_test(app: &mut App) {
             app.add_systems(PostUpdate, save_events::<CollisionEvent>)
                 .add_systems(PostUpdate, save_events::<ContactForceEvent>)
@@ -189,12 +192,12 @@ mod test {
                 .world()
                 .get_resource::<EventsSaver<CollisionEvent>>()
                 .unwrap();
-            assert!(saved_collisions.events.len() > 0);
+            assert_eq!(saved_collisions.events.len(), 3);
             let saved_contact_forces = app
                 .world()
-                .get_resource::<EventsSaver<CollisionEvent>>()
+                .get_resource::<EventsSaver<ContactForceEvent>>()
                 .unwrap();
-            assert!(saved_contact_forces.events.len() > 0);
+            assert_eq!(saved_contact_forces.events.len(), 1);
         }
 
         /// Adapted from events example
@@ -229,7 +232,7 @@ mod test {
                 TransformBundle::from(Transform::from_xyz(0.0, 13.0, 0.0)),
                 RigidBody::Dynamic,
                 cuboid(0.5, 0.5, 0.5),
-                ActiveEvents::COLLISION_EVENTS,
+                ActiveEvents::COLLISION_EVENTS | ActiveEvents::CONTACT_FORCE_EVENTS,
                 ContactForceEventThreshold(30.0),
             ));
         }
@@ -244,10 +247,13 @@ mod test {
             TransformPlugin,
             RapierPhysicsPlugin::<NoUserData>::default(),
         ))
-        .insert_resource(TimestepMode::Interpolated {
-            dt: 1.0 / 30.0,
-            time_scale: 1.0,
-            substeps: 2,
+        .insert_resource(RapierConfiguration {
+            timestep_mode: TimestepMode::Interpolated {
+                dt: 1.0 / 30.0,
+                time_scale: 1.0,
+                substeps: 2,
+            },
+            ..RapierConfiguration::new(1f32)
         })
         .add_systems(Startup, setup_physics)
         .add_systems(Update, remove_collider);

src/plugin/configuration.rs

@@ -1,22 +1,20 @@
-use bevy::{
-    prelude::{Component, Resource},
-    reflect::Reflect,
-};
+use bevy::prelude::{FromWorld, Resource, World};
 
 use crate::math::{Real, Vect};
+use crate::plugin::RapierContext;
 
 #[cfg(doc)]
 use {crate::prelude::TransformInterpolation, rapier::dynamics::IntegrationParameters};
 
 /// Difference between simulation and rendering time
-#[derive(Component, Default, Reflect)]
+#[derive(Resource, Default)]
 pub struct SimulationToRenderTime {
     /// Difference between simulation and rendering time
     pub diff: f32,
 }
 
-/// The different ways of adjusting the timestep length each frame.
-#[derive(Copy, Clone, Debug, PartialEq, Resource)]
+/// The different ways of adjusting the timestep length.
+#[derive(Copy, Clone, Debug, PartialEq)]
 pub enum TimestepMode {
     /// Use a fixed timestep: the physics simulation will be advanced by the fixed value
     /// `dt` seconds at each Bevy tick by performing `substeps` of length `dt / substeps`.
@@ -55,25 +53,17 @@ pub enum TimestepMode {
     },
 }
 
-impl Default for TimestepMode {
-    fn default() -> Self {
-        TimestepMode::Variable {
-            max_dt: 1.0 / 60.0,
-            time_scale: 1.0,
-            substeps: 1,
-        }
-    }
-}
-
-#[derive(Component, Copy, Clone, Debug, Reflect)]
-/// A component for specifying configuration information for the physics simulation
+#[derive(Resource, Copy, Clone, Debug)]
+/// A resource for specifying configuration information for the physics simulation
 pub struct RapierConfiguration {
     /// Specifying the gravity of the physics simulation.
     pub gravity: Vect,
     /// Specifies if the physics simulation is active and update the physics world.
     pub physics_pipeline_active: bool,
     /// Specifies if the query pipeline is active and update the query pipeline.
     pub query_pipeline_active: bool,
+    /// Specifies the way the timestep length should be adjusted at each frame.
+    pub timestep_mode: TimestepMode,
     /// Specifies the number of subdivisions along each axes a shape should be subdivided
     /// if its scaled representation cannot be represented with the same shape type.
     ///
@@ -86,6 +76,16 @@ pub struct RapierConfiguration {
     pub force_update_from_transform_changes: bool,
 }
 
+impl FromWorld for RapierConfiguration {
+    fn from_world(world: &mut World) -> Self {
+        let length_unit = world
+            .get_resource::<RapierContext>()
+            .map(|ctxt| ctxt.integration_parameters.length_unit)
+            .unwrap_or(1.0);
+        Self::new(length_unit)
+    }
+}
+
 impl RapierConfiguration {
     /// Configures rapier with the specified length unit.
     ///
@@ -98,6 +98,11 @@ impl RapierConfiguration {
             gravity: Vect::Y * -9.81 * length_unit,
             physics_pipeline_active: true,
             query_pipeline_active: true,
+            timestep_mode: TimestepMode::Variable {
+                max_dt: 1.0 / 60.0,
+                time_scale: 1.0,
+                substeps: 1,
+            },
             scaled_shape_subdivision: 10,
             force_update_from_transform_changes: false,
         }