fix background simulation with split components

Cargo.toml

@@ -9,6 +9,10 @@ resolver = "2"
 [profile.release]
 codegen-units = 1
 
+[profile.tracing]
+inherits = "release"
+debug = 1
+
 [patch.crates-io]
 #nalgebra = { path = "../nalgebra" }
 #parry2d = { path = "../parry/crates/parry2d" }

bevy_rapier2d/Cargo.toml

@@ -50,8 +50,7 @@ serde-serialize = ["rapier2d/serde-serialize", "bevy/serialize", "serde"]
 enhanced-determinism = ["rapier2d/enhanced-determinism"]
 headless = []
 async-collider = ["bevy/bevy_asset", "bevy/bevy_scene"]
-background_simulation = []
-profiling = ["rapier2d/profiler"]
+background_simulation = ["bevy/multi_threaded"]
 
 [dependencies]
 bevy = { version = "0.15", default-features = false }
@@ -64,7 +63,7 @@ bitflags = "2.4"
 log = "0.4"
 serde = { version = "1", features = ["derive"], optional = true }
 crossbeam-channel = "0.5"
-async-std = "*"
+async-std = "1.13"
 
 [dev-dependencies]
 bevy = { version = "0.15", default-features = false, features = [

src/plugin/context/mod.rs

@@ -657,7 +657,7 @@ impl RapierQueryPipeline {
 ///
 /// This should be attached on an entity with a [`RapierContextSimulation`]
 #[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
-#[derive(Component, Default, Clone)]
+#[derive(Component, Default, Debug, Clone)]
 pub struct RapierRigidBodySet {
     /// The set of rigid-bodies part of the simulation.
     pub bodies: RigidBodySet,

src/plugin/systems/rigid_body.rs

@@ -428,10 +428,10 @@ pub fn writeback_rigid_bodies(
         }
         let handle = handle.0;
 
-        let rigid_body_set = rigid_body_sets
-            .get_mut(link.0)
-            .expect(RAPIER_CONTEXT_EXPECT_ERROR)
-            .into_inner();
+        let Ok(rigid_body_set) = rigid_body_sets.get_mut(link.0) else {
+            continue;
+        };
+        let rigid_body_set = rigid_body_set.into_inner();
         let sim_to_render_time = sim_to_render_time
             .get(link.0)
             .expect("Could not get `SimulationToRenderTime`");

src/plugin/systems/task.rs

@@ -28,6 +28,10 @@ use std::time::Duration;
 use crate::{
     pipeline::{CollisionEvent, ContactForceEvent},
     plugin::context,
+    prelude::{
+        RapierContextColliders, RapierContextJoints, RapierContextSimulation, RapierQueryPipeline,
+        RapierRigidBodySet,
+    },
 };
 use crate::{
     plugin::{RapierConfiguration, RapierContext, SimulationToRenderTime, TimestepMode},
@@ -37,6 +41,14 @@ use crossbeam_channel::{Receiver, Sender, TryRecvError, TrySendError};
 
 use super::BevyPhysicsHooksAdapter;
 
+pub struct SimulationTaskResult {
+    pub context: RapierContextSimulation,
+    pub bodies: RapierRigidBodySet,
+    pub colliders: RapierContextColliders,
+    pub joints: RapierContextJoints,
+    pub query_pipeline: RapierQueryPipeline,
+}
+
 /// A component that holds a Rapier simulation task.
 ///
 /// The task inside this component is polled by the system [`handle_tasks`].
@@ -46,7 +58,7 @@ use super::BevyPhysicsHooksAdapter;
 /// This component is removed when it's safe to access the [`RapierContext`] again.
 #[derive(Component)]
 pub struct SimulationTask {
-    pub recv: Receiver<RapierContext>,
+    pub recv: Receiver<SimulationTaskResult>,
 }
 
 /// This system queries for [`RapierContext`] that have our `Task<RapierSimulation>` component. It polls the
@@ -55,7 +67,10 @@ pub struct SimulationTask {
 pub(crate) fn handle_tasks(
     mut commands: Commands,
     mut q_context: Query<(
-        &mut RapierContext,
+        &mut RapierContextSimulation,
+        &mut RapierRigidBodySet,
+        &mut RapierContextColliders,
+        &mut RapierQueryPipeline,
         &RapierConfiguration,
         &mut SimulationToRenderTime,
     )>,
@@ -66,9 +81,19 @@ pub(crate) fn handle_tasks(
     for (entity, mut task) in &mut transform_tasks {
         //if let Some(mut result) = block_on(future::poll_once(&mut task.0)) {
         if let Some(mut result) = task.recv.try_recv().ok() {
-            let (mut context, config, mut sim_to_render_time) = q_context.get_mut(entity).unwrap();
-            // mem::forget(mem::replace(&mut *context, result));
-            mem::swap(&mut *context, &mut result);
+            let (
+                mut context,
+                mut bodies,
+                mut colliders,
+                mut query_pipeline,
+                config,
+                mut sim_to_render_time,
+            ) = q_context.get_mut(entity).unwrap();
+            // TODO: mem swap with a buffer
+            *context = result.context;
+            *bodies = result.bodies;
+            *colliders = result.colliders;
+            *query_pipeline = result.query_pipeline;
             context.send_bevy_events(&mut collision_events, &mut contact_force_events);
             commands.entity(entity).remove::<SimulationTask>();
         }
@@ -84,7 +109,11 @@ pub(crate) fn spawn_simulation_task<Hooks>(
     mut q_context: Query<
         (
             Entity,
-            &mut RapierContext,
+            &mut RapierContextSimulation,
+            &RapierContextColliders,
+            &RapierRigidBodySet,
+            &RapierContextJoints,
+            &RapierQueryPipeline,
             &RapierConfiguration,
             &mut SimulationToRenderTime,
         ),
@@ -100,10 +129,25 @@ pub(crate) fn spawn_simulation_task<Hooks>(
     //let hooks_adapter = BevyPhysicsHooksAdapter::new(hooks.into_inner());
     //let hooks_adapter = BevyPhysicsHooksAdapter::new(());
 
-    for (entity, mut context_ecs, config, sim_to_render_time) in q_context.iter_mut() {
+    for (
+        entity,
+        mut context_ecs,
+        colliders,
+        bodies,
+        joints,
+        query_pipeline,
+        config,
+        sim_to_render_time,
+    ) in q_context.iter_mut()
+    {
         // FIXME: Clone this properly?
-        let mut context = RapierContext::default();
+        let mut context = RapierContextSimulation::default();
         mem::swap(&mut context, &mut *context_ecs);
+        // TODO: use a double buffering system to avoid this more expensive (to verify) cloning.
+        let mut colliders = colliders.clone();
+        let mut bodies = bodies.clone();
+        let mut joints = joints.clone();
+        let mut query_pipeline = query_pipeline.clone();
         // let mut context: RapierContext =
         //    unsafe { mem::transmute_copy::<RapierContext, RapierContext>(&*context_ecs) };
         let config = config.clone();
@@ -120,6 +164,9 @@ pub(crate) fn spawn_simulation_task<Hooks>(
                 if config.physics_pipeline_active {
                     profiling::scope!("Rapier physics simulation");
                     context.step_simulation(
+                        &mut colliders,
+                        &mut joints,
+                        &mut bodies,
                         config.gravity,
                         timestep_mode,
                         true,
@@ -129,14 +176,20 @@ pub(crate) fn spawn_simulation_task<Hooks>(
                         None,
                     );
                 } else {
-                    context.propagate_modified_body_positions_to_colliders();
+                    bodies.propagate_modified_body_positions_to_colliders(&mut colliders);
                 }
 
                 if config.query_pipeline_active {
-                    context.update_query_pipeline();
+                    query_pipeline.update_query_pipeline(&colliders);
                 }
-
-                sender.send(context);
+                let result = SimulationTaskResult {
+                    context,
+                    bodies,
+                    joints,
+                    colliders,
+                    query_pipeline,
+                };
+                sender.send(result);
             })
             .detach();