1 files changed, 51 insertions, 0 deletions
diff --git a/src/pipeline/event_handler.rs b/src/pipeline/event_handler.rs
new file mode 100644
index 0000000..67e4a78
--- /dev/null
+++ b/src/pipeline/event_handler.rs
@@ -0,0 +1,51 @@
+use crate::geometry::{ContactEvent, ProximityEvent};
+use crossbeam::channel::Sender;
+
+/// Trait implemented by structures responsible for handling events generated by the physics engine.
+///
+/// Implementors of this trait will typically collect these events for future processing.
+pub trait EventHandler: Send + Sync {
+    /// Handle a proximity event.
+    ///
+    /// A proximity event is emitted when the state of proximity between two colliders changes.
+    fn handle_proximity_event(&self, event: ProximityEvent);
+    /// Handle a contact event.
+    ///
+    /// A contact event is emitted when two collider start or stop touching, independently from the
+    /// number of contact points involved.
+    fn handle_contact_event(&self, event: ContactEvent);
+}
+
+impl EventHandler for () {
+    fn handle_proximity_event(&self, _event: ProximityEvent) {}
+    fn handle_contact_event(&self, _event: ContactEvent) {}
+}
+
+/// A physics event handler that collects events into a crossbeam channel.
+pub struct ChannelEventCollector {
+    proximity_event_sender: Sender<ProximityEvent>,
+    contact_event_sender: Sender<ContactEvent>,
+}
+
+impl ChannelEventCollector {
+    /// Initialize a new physics event handler from crossbeam channel senders.
+    pub fn new(
+        proximity_event_sender: Sender<ProximityEvent>,
+        contact_event_sender: Sender<ContactEvent>,
+    ) -> Self {
+        Self {
+            proximity_event_sender,
+            contact_event_sender,
+        }
+    }
+}
+
+impl EventHandler for ChannelEventCollector {
+    fn handle_proximity_event(&self, event: ProximityEvent) {
+        let _ = self.proximity_event_sender.send(event);
+    }
+
+    fn handle_contact_event(&self, event: ContactEvent) {
+        let _ = self.contact_event_sender.send(event);
+    }
+}