Update the testbed to use PhysicsHooks.

src/pipeline/collision_pipeline.rs

@@ -1,11 +1,9 @@
 //! Physics pipeline structures.
 
 use crate::dynamics::{JointSet, RigidBodySet};
-use crate::geometry::{
-    BroadPhase, BroadPhasePairEvent, ColliderPair, ColliderSet, NarrowPhase, PhysicsHooks,
-};
+use crate::geometry::{BroadPhase, BroadPhasePairEvent, ColliderPair, ColliderSet, NarrowPhase};
 use crate::math::Real;
-use crate::pipeline::EventHandler;
+use crate::pipeline::{EventHandler, PhysicsHooks};
 
 /// The collision pipeline, responsible for performing collision detection between colliders.
 ///

src/pipeline/mod.rs

@@ -2,10 +2,14 @@
 
 pub use collision_pipeline::CollisionPipeline;
 pub use event_handler::{ChannelEventCollector, EventHandler};
+pub use physics_hooks::{
+    ContactModificationContext, PairFilterContext, PhysicsHooks, PhysicsHooksFlags,
+};
 pub use physics_pipeline::PhysicsPipeline;
 pub use query_pipeline::QueryPipeline;
 
 mod collision_pipeline;
 mod event_handler;
+mod physics_hooks;
 mod physics_pipeline;
 mod query_pipeline;