Re-Spawn Items That Fall Out-of-bounds

Author: zicklag

src/map.rs

@@ -31,7 +31,10 @@ impl Plugin for MapPlugin {
                     .register_rollback_type::<Handle<MapElementMeta>>()
             })
             .extend_rollback_schedule(|schedule| {
-                schedule.add_system_to_stage(RollbackStage::Last, despawn_out_of_bounds);
+                schedule.add_system_to_stage(
+                    RollbackStage::Last,
+                    handle_out_of_bounds_players_and_items,
+                );
             })
             .add_plugin(elements::MapElementsPlugin);
     }
@@ -43,6 +46,12 @@ impl Plugin for MapPlugin {
 #[reflect(Component, Default)]
 pub struct MapElementHydrated;
 
+/// If this component and a [`Transform`] component is added to any entity, it will be moved back to
+/// given position if the entity ever ends up outside the map bounds.
+#[derive(Deref, DerefMut, Component, Reflect, Default, Debug)]
+#[reflect(Default, Component)]
+pub struct MapRespawnPoint(pub Vec3);
+
 // /// Contains the scripts that have been added for the currently loaded map
 // #[derive(Deref, DerefMut, Default)]
 // pub struct MapScripts(pub HashSet<Handle<JsScript>>);
@@ -260,10 +269,11 @@ pub fn hydrate_map(
     session_manager.start_session();
 }
 
-fn despawn_out_of_bounds(
+fn handle_out_of_bounds_players_and_items(
     mut commands: Commands,
     map: Query<&MapMeta>,
     players: Query<(Entity, &Transform), With<PlayerIdx>>,
+    mut items: Query<(&mut Transform, &MapRespawnPoint), Without<PlayerIdx>>,
 ) {
     const KILL_ZONE_BORDER: f32 = 500.0;
     let Ok(map) = map.get_single() else {
@@ -275,11 +285,21 @@ fn despawn_out_of_bounds(
     let right_kill_zone = map_width + KILL_ZONE_BORDER;
     let bottom_kill_zone = -KILL_ZONE_BORDER;
 
+    // Kill out of bounds players
     for (player_ent, transform) in &players {
         let pos = transform.translation;
 
         if pos.x < left_kill_zone || pos.x > right_kill_zone || pos.y < bottom_kill_zone {
             commands.add(PlayerKillCommand::new(player_ent));
         }
     }
+
+    // Reset out of bound item positions
+    for (mut transform, respawn_point) in &mut items {
+        let pos = transform.translation;
+
+        if pos.x < left_kill_zone || pos.x > right_kill_zone || pos.y < bottom_kill_zone {
+            transform.translation = respawn_point.0;
+        }
+    }
 }

src/map/elements.rs

@@ -3,7 +3,7 @@ use crate::{
     damage::{DamageRegion, DamageRegionOwner},
     item::{Item, ItemDropped, ItemUsed},
     lifetime::Lifetime,
-    map::MapElementHydrated,
+    map::{MapElementHydrated, MapRespawnPoint},
     metadata::{BuiltinElementKind, MapElementMeta},
     name::EntityName,
     physics::{collisions::CollisionWorld, KinematicBody},

src/map/elements/grenade.rs

@@ -98,6 +98,7 @@ fn pre_update_in_game(
                 })
                 .insert(map_element_handle.clone_weak())
                 .insert_bundle(VisibilityBundle::default())
+                .insert(MapRespawnPoint(transform.translation))
                 .insert_bundle(TransformBundle {
                     local: *transform,
                     ..default()

src/map/elements/sword.rs

@@ -63,6 +63,7 @@ fn pre_update_in_game(
                     ..default()
                 })
                 .insert_bundle(VisibilityBundle::default())
+                .insert(MapRespawnPoint(transform.translation))
                 .insert_bundle(TransformBundle {
                     local: *transform,
                     ..default()