Projectile damage

src/damagable.rs

@@ -0,0 +1,17 @@
+use bevy::prelude::*;
+
+#[derive(Component)]
+pub struct Damagable {
+    hp: u32,
+    max_hp: u32,
+}
+
+impl Damagable {
+    pub fn new(max_hp: u32) -> Damagable {
+        Damagable { max_hp, hp: max_hp }
+    }
+
+    pub fn damage(&mut self, amount: u32) {
+        self.hp = u32::clamp(self.hp - amount, 0, self.max_hp)
+    }
+}

src/main.rs

@@ -5,7 +5,9 @@ use crate::movable::MovablePlugin;
 use crate::ships::ShipsPlugin;
 
 mod collision;
+mod damagable;
 mod movable;
+mod projectile;
 mod ships;
 
 fn main() {

src/projectile.rs

@@ -0,0 +1,44 @@
+use bevy::prelude::*;
+
+use crate::{
+    collision::{Collided, Collider},
+    damagable::Damagable,
+};
+
+#[derive(Component)]
+pub struct Projectile {
+    damage: u32,
+}
+
+impl Projectile {
+    pub fn new(damage: u32) -> Projectile {
+        Projectile { damage }
+    }
+}
+
+pub fn spawn_projectile(commands: &mut Commands, sprite: Handle<Image>, damage: u32) {
+    commands
+        .spawn((
+            Projectile::new(damage),
+            Sprite::from(sprite),
+            Collider::new(8.),
+            Transform::from_xyz(0., 0., 0.),
+        ))
+        .observe(observe_collision);
+}
+pub fn observe_collision(
+    collision: On<Collided>,
+    mut commands: Commands,
+    projectile_query: Query<&Projectile>,
+    mut collision_query: Query<&mut Damagable>,
+) {
+    let Ok(projectile) = projectile_query.get(collision.entity) else {
+        return;
+    };
+    let Ok(mut collided) = collision_query.get_mut(collision.with) else {
+        return;
+    };
+
+    collided.damage(projectile.damage);
+    commands.get_entity(collision.entity).unwrap().despawn();
+}

src/ships/enemy.rs

@@ -1,6 +1,6 @@
 use bevy::prelude::*;
 
-use crate::{collision::Collider, movable::Movable};
+use crate::{collision::Collider, damagable::Damagable, movable::Movable};
 
 #[derive(Component)]
 pub struct Enemy;
@@ -12,5 +12,6 @@ pub fn spawn_enemy(commands: &mut Commands, sprite: Handle<Image>, at: Vec2) {
         Movable::new(500., f32::to_radians(360.)),
         Sprite::from(sprite),
         Transform::from_xyz(at.x, at.y, 0.),
+        Damagable::new(10),
     ));
 }

src/ships/mod.rs

@@ -1,5 +1,7 @@
 use bevy::prelude::*;
 
+use crate::projectile::spawn_projectile;
+
 pub mod enemy;
 pub mod player;
 
@@ -16,9 +18,11 @@ impl Plugin for ShipsPlugin {
 fn startup(mut commands: Commands, asset_server: Res<AssetServer>) {
     let player_sprite: Handle<Image> = asset_server.load("player.png");
     let enemy_sprite: Handle<Image> = asset_server.load("enemy.png");
+    let projectile: Handle<Image> = asset_server.load("projectile.png");
 
     commands.spawn(Camera2d);
 
     player::spawn_player(&mut commands, player_sprite, Vec2::new(0., 0.));
     enemy::spawn_enemy(&mut commands, enemy_sprite.clone(), Vec2::new(100., 100.));
+    spawn_projectile(&mut commands, projectile, 1);
 }

src/ships/player.rs

@@ -1,4 +1,4 @@
-use crate::{collision::Collider, movable::Movable};
+use crate::{collision::Collider, damagable::Damagable, movable::Movable};
 use bevy::prelude::*;
 
 #[derive(Component)]
@@ -13,6 +13,7 @@ pub fn spawn_player(commands: &mut Commands, sprite: Handle<Image>, at: Vec2) {
         Movable::new(500., f32::to_radians(360.)),
         Sprite::from(sprite),
         Transform::from_xyz(at.x, at.y, 0.),
+        Damagable::new(10),
     ));
 }