feat: Redeploy enemies when too far away from player

src/enemy/archer/spawn.rs

@@ -6,12 +6,13 @@ use bevy::prelude::*;
 use bevy_rapier2d::prelude::*;
 use bevy_trickfilm::prelude::*;
 
-use crate::{player::Player, utils::quat_from_vec2, world::camera::YSort, GameAssets, GameState};
+use crate::{
+    enemy::spawn::SPAWN_OFFSET, player::Player, utils::quat_from_vec2, world::camera::YSort,
+    GameAssets, GameState,
+};
 
 use super::{ArcherState, Enemy, EnemyArcher};
 
-const OFFSET: f32 = 1000.0;
-
 #[derive(Resource)]
 struct EnemySpawnCooldown {
     timer: Timer,
@@ -40,7 +41,7 @@ fn spawn_enemies(
         .repeat();
 
     let pos = player_transform.translation
-        + Quat::from_rotation_z(rng.gen_range(0.0..TAU)).mul_vec3(Vec3::X) * OFFSET;
+        + Quat::from_rotation_z(rng.gen_range(0.0..TAU)).mul_vec3(Vec3::X) * SPAWN_OFFSET;
 
     let collider = commands
         .spawn((

src/enemy/bat/spawn.rs

@@ -6,12 +6,12 @@ use bevy::prelude::*;
 use bevy_rapier2d::prelude::*;
 use bevy_trickfilm::prelude::*;
 
-use crate::{player::Player, world::camera::YSort, GameAssets, GameState};
+use crate::{
+    enemy::spawn::SPAWN_OFFSET, player::Player, world::camera::YSort, GameAssets, GameState,
+};
 
 use super::{Enemy, EnemyBat};
 
-const OFFSET: f32 = 500.0;
-
 #[derive(Resource)]
 struct EnemySpawnCooldown {
     timer: Timer,
@@ -40,7 +40,7 @@ fn spawn_enemies(
         .repeat();
 
     let pos = player_transform.translation
-        + Quat::from_rotation_z(rng.gen_range(0.0..TAU)).mul_vec3(Vec3::X) * OFFSET;
+        + Quat::from_rotation_z(rng.gen_range(0.0..TAU)).mul_vec3(Vec3::X) * SPAWN_OFFSET;
 
     let collider = commands
         .spawn((

src/enemy/spawn.rs

@@ -4,6 +4,9 @@ use crate::{player::Player, GameState};
 
 use super::{Enemy, EnemyProjectile};
 
+pub const SPAWN_OFFSET: f32 = 900.0;
+const MAX_PLAYER_DISTANCE: f32 = 1200.0;
+
 #[derive(Event)]
 pub struct DespawnEnemy {
     pub pos: Vec2,
@@ -58,14 +61,39 @@ fn adjust_sprite_flip(
     }
 }
 
+fn redeploy_enemies(
+    q_player: Query<&Transform, With<Player>>,
+    mut q_enemies: Query<&mut Transform, (With<Enemy>, Without<Player>)>,
+) {
+    let player_transform = match q_player.get_single() {
+        Ok(r) => r,
+        Err(_) => return,
+    };
+
+    for mut enemy_transform in &mut q_enemies {
+        if enemy_transform
+            .translation
+            .truncate()
+            .distance_squared(player_transform.translation.truncate())
+            >= MAX_PLAYER_DISTANCE.powi(2)
+        {
+            let dir = (player_transform.translation - enemy_transform.translation)
+                .truncate()
+                .normalize_or_zero();
+            enemy_transform.translation =
+                player_transform.translation + dir.extend(0.0) * SPAWN_OFFSET;
+        }
+    }
+}
+
 pub struct EnemySpawnPlugin;
 
 impl Plugin for EnemySpawnPlugin {
     fn build(&self, app: &mut App) {
         app.add_event::<DespawnEnemy>()
             .add_systems(
                 Update,
-                (adjust_sprite_flip,).run_if(in_state(GameState::Gaming)),
+                (adjust_sprite_flip, redeploy_enemies).run_if(in_state(GameState::Gaming)),
             )
             .add_systems(Update, (despawn_enemies, despawn_projectiles))
             .add_systems(