Move the ship & bullet systems into the object mod

src/objects.rs

@@ -5,23 +5,26 @@
 use bevy::{
     ecs::{
         component::Component,
+        entity::Entity,
         event::{EventReader, EventWriter},
-        system::{Commands, Query, Res},
+        query::With,
+        system::{Commands, Query, Res, ResMut, Single},
     },
-    math::{Vec2, Vec3Swizzles},
+    math::{Vec2, Vec3, Vec3Swizzles},
     prelude::{Deref, DerefMut},
     render::mesh::Mesh2d,
     sprite::MeshMaterial2d,
+    state::state::NextState,
     time::{Timer, TimerMode},
     transform::components::Transform,
 };
-use bevy_rapier2d::prelude::{Collider, Sensor};
+use bevy_rapier2d::prelude::{ActiveCollisionTypes, ActiveEvents, Collider, Sensor};
 
 use crate::{
-    GameAssets, Lifetime,
+    AngularVelocity, GameAssets, GameState, Lifetime, Lives,
     config::ASTEROID_LIFETIME,
-    events::{AsteroidDestroy, SpawnAsteroid},
-    physics::Velocity,
+    events::{AsteroidDestroy, BulletDestroy, ShipDestroy, SpawnAsteroid},
+    physics::{Velocity, Wrapping},
 };
 
 #[derive(Component, Deref, DerefMut)]
@@ -121,3 +124,70 @@ pub fn split_asteroids(
         }
     }
 }
+
+pub fn spawn_player(mut commands: Commands, game_assets: Res<GameAssets>) {
+    commands
+        .spawn((
+            Collider::ball(0.7),
+            Sensor,
+            ActiveEvents::COLLISION_EVENTS,
+            ActiveCollisionTypes::STATIC_STATIC,
+            Ship,
+            Wrapping,
+            Velocity(Vec2::ZERO),
+            AngularVelocity(0.0),
+            Mesh2d(game_assets.ship().0),
+            MeshMaterial2d(game_assets.ship().1),
+            Transform::default().with_scale(Vec3::new(20.0, 20.0, 20.0)),
+        ))
+        .with_child((
+            Mesh2d(game_assets.thruster_mesh()),
+            MeshMaterial2d(game_assets.thruster_mat_inactive()),
+            Transform::default()
+                .with_scale(Vec3::splat(0.5))
+                .with_translation(Vec3::new(-0.5, 0.0, -0.1)),
+        ));
+}
+
+/// Watch for [`BulletDestroy`] events and despawn
+/// the associated bullet.
+pub fn bullet_impact_listener(mut commands: Commands, mut events: EventReader<BulletDestroy>) {
+    for event in events.read() {
+        commands.entity(event.0).despawn();
+    }
+}
+
+/// Watch for [`ShipDestroy`] events and update game state accordingly.
+///
+/// - Subtract a life
+/// - Check life count. If 0, go to game-over state
+/// - Clear all asteroids
+/// - Respawn player
+pub fn ship_impact_listener(
+    mut events: EventReader<ShipDestroy>,
+    mut commands: Commands,
+    mut lives: ResMut<Lives>,
+    rocks: Query<Entity, With<Asteroid>>,
+    mut player: Single<(&mut Transform, &mut Velocity), With<Ship>>,
+    mut next_state: ResMut<NextState<GameState>>,
+) {
+    for _ in events.read() {
+        // STEP 1: Decrement lives (and maybe go to game over)
+        if lives.0 == 0 {
+            // If already at 0, game is over.
+            next_state.set(GameState::GameOver);
+        } else {
+            // Decrease life count.
+            lives.0 -= 1;
+        }
+
+        // STEP 2: Clear asteroids
+        for rock in rocks {
+            commands.entity(rock).despawn();
+        }
+
+        // STEP 3: Respawn player (teleport them to the origin)
+        player.0.translation = Vec3::ZERO;
+        player.1.0 = Vec2::ZERO;
+    }
+}