Use the lifetime limiters on Bullets & Asteroids

Closes #14

Despawn bullets to limit range.

Despawn asteroids to limit random garbage floating around the scene.

src/asteroids.rs

@@ -7,7 +7,7 @@ use std::time::Duration;
 
 use bevy::prelude::*;
 
-use crate::{GameAssets, WorldSize, physics::Velocity};
+use crate::{GameAssets, Lifetime, WorldSize, config::ASTEROID_LIFETIME, physics::Velocity};
 
 #[derive(Component, Deref, DerefMut)]
 pub struct Asteroid(AsteroidSize);
@@ -124,6 +124,7 @@ pub fn spawn_asteroid(
             Velocity(spawn.vel),
             Mesh2d(mesh),
             MeshMaterial2d(material),
+            Lifetime(Timer::from_seconds(ASTEROID_LIFETIME, TimerMode::Once)),
         ));
     }
 }

src/config.rs

@@ -17,5 +17,8 @@ pub(crate) const SHIP_THRUST: f32 = 1.0;
 pub(crate) const SHIP_ROTATION: f32 = 4.0; // +/- rotation speed in... radians per frame
 
 pub(crate) const BULLET_SPEED: f32 = 150.0;
+pub(crate) const BULLET_LIFETIME: f32 = 2.0;
+
+pub(crate) const ASTEROID_LIFETIME: f32 = 40.0;
 
 pub const RNG_SEED: [u8; 32] = *b"12345678909876543210123456789098";

src/lib.rs

@@ -8,12 +8,12 @@ mod title_screen;
 
 use crate::asteroids::{Asteroid, AsteroidSpawner};
 use crate::config::{
-    ASTEROID_SMALL_COLOR, BACKGROUND_COLOR, BULLET_COLOR, BULLET_SPEED, PLAYER_SHIP_COLOR,
-    SHIP_ROTATION, SHIP_THRUST, SHIP_THRUSTER_COLOR_ACTIVE, SHIP_THRUSTER_COLOR_INACTIVE,
-    WINDOW_SIZE,
+    ASTEROID_SMALL_COLOR, BACKGROUND_COLOR, BULLET_COLOR, BULLET_LIFETIME, BULLET_SPEED,
+    PLAYER_SHIP_COLOR, SHIP_ROTATION, SHIP_THRUST, SHIP_THRUSTER_COLOR_ACTIVE,
+    SHIP_THRUSTER_COLOR_INACTIVE, WINDOW_SIZE,
 };
 use crate::physics::AngularVelocity;
-use crate::ship::Ship;
+use crate::ship::{Bullet, Ship};
 
 use bevy::prelude::*;
 use bevy_inspector_egui::InspectorOptions;
@@ -58,6 +58,7 @@ impl Plugin for AsteroidPlugin {
                 collision_listener,
                 // TODO: Remove debug printing
                 debug_collision_event_printer,
+                tick_lifetimes,
             )
                 .run_if(in_state(GameState::Playing)),
         )
@@ -71,7 +72,8 @@ impl Plugin for AsteroidPlugin {
         )
         .add_event::<asteroids::SpawnAsteroid>()
         .add_event::<event::AsteroidDestroy>()
-        .add_event::<event::ShipDestroy>();
+        .add_event::<event::ShipDestroy>()
+        .add_event::<event::BulletDestroy>();
         app.insert_state(GameState::Playing);
     }
 }
@@ -98,7 +100,9 @@ fn collision_listener(
     mut collisions: EventReader<CollisionEvent>,
     mut ship_writer: EventWriter<event::ShipDestroy>,
     mut asteroid_writer: EventWriter<event::AsteroidDestroy>,
+    mut bullet_writer: EventWriter<event::BulletDestroy>,
     player: Single<Entity, With<Ship>>,
+    bullets: Query<&Bullet>,
     rocks: Query<&Asteroid>,
 ) {
     for event in collisions.read() {
@@ -125,7 +129,20 @@ fn collision_listener(
                 }
             }
 
-            // TODO: Bullet-asteroid collisions
+            // Option 2: Bullet & Asteroid
+            if bullets.contains(*one) {
+                if rocks.contains(*two) {
+                    dbg!("Writing AsteroidDestroy & BulletDestroy events");
+                    asteroid_writer.write(event::AsteroidDestroy(*two));
+                    bullet_writer.write(event::BulletDestroy(*one));
+                }
+            } else if rocks.contains(*one) {
+                if bullets.contains(*two) {
+                    dbg!("Writing AsteroidDestroy & BulletDestroy events");
+                    asteroid_writer.write(event::AsteroidDestroy(*one));
+                    bullet_writer.write(event::BulletDestroy(*two));
+                }
+            }
         }
     }
 }
@@ -147,6 +164,9 @@ impl From<Score> for String {
     }
 }
 
+#[derive(Component)]
+struct Lifetime(Timer);
+
 #[derive(InspectorOptions, Reflect, Resource, Debug, Deref, Clone, Copy)]
 #[reflect(Resource, InspectorOptions)]
 struct Lives(i32);
@@ -320,6 +340,7 @@ fn input_ship_shoot(
             Mesh2d(game_assets.bullet().0),
             MeshMaterial2d(game_assets.bullet().1),
             ship_pos.clone(), // clone ship transform
+            Lifetime(Timer::from_seconds(BULLET_LIFETIME, TimerMode::Once)),
         ));
     }
 }
@@ -330,3 +351,12 @@ fn spawn_ui(mut commands: Commands, score: Res<Score>, lives: Res<Lives>) {
         TextFont::from_font_size(25.0),
     ));
 }
+
+fn tick_lifetimes(mut commands: Commands, time: Res<Time>, query: Query<(Entity, &mut Lifetime)>) {
+    for (e, mut life) in query {
+        life.0.tick(time.delta());
+        if life.0.just_finished() {
+            commands.entity(e).despawn();
+        }
+    }
+}