fix(thinker): stop using the child/parent system for toplevel thinkers

src/lib.rs

@@ -194,6 +194,7 @@ impl Plugin for BigBrainPlugin {
         app.add_system(thinker::thinker_system.system());
         app.add_system(thinker::thinker_component_attach_system.system());
         app.add_system(thinker::thinker_component_detach_system.system());
+        app.add_system(thinker::actor_gone_cleanup.system());
         app.add_system(actions::steps_system.system());
         app.add_system(scorers::fixed_score_system.system());
         app.add_system(scorers::all_or_nothing_system.system());

src/thinker.rs

@@ -147,9 +147,7 @@ pub fn thinker_component_attach_system(
 ) {
     for (entity, thinker_builder) in q.iter() {
         let thinker = thinker_builder.attach(&mut cmd, entity);
-        cmd.entity(entity)
-            .insert(HasThinker(thinker))
-            .push_children(&[thinker]);
+        cmd.entity(entity).insert(HasThinker(thinker));
     }
 }
 
@@ -163,6 +161,19 @@ pub fn thinker_component_detach_system(
     }
 }
 
+pub fn actor_gone_cleanup(
+    mut cmd: Commands,
+    actors: Query<&ThinkerBuilder>,
+    q: Query<(Entity, &Actor)>,
+) {
+    for (child, Actor(actor)) in q.iter() {
+        if actors.get(*actor).is_err() {
+            // Actor is gone. Let's clean up.
+            cmd.entity(child).despawn_recursive();
+        }
+    }
+}
+
 #[derive(Debug)]
 pub struct HasThinker(Entity);