Initial commit

src/main.rs

@@ -0,0 +1,95 @@
+use bevy::prelude::*;
+
+#[derive(Component)]
+struct EntityPhysics {
+    x: f32,
+    y: f32,
+    speed: f32,
+    heading: f32,
+}
+
+fn main() {
+    let mut app = App::new();
+
+    app.add_plugins(DefaultPlugins)
+        .add_systems(Startup, (hello_world, camera_setup, sprite_setup).chain())
+        .add_systems(Update, (handle_keys, player_physics).chain());
+
+    app.run();
+}
+
+fn hello_world() {
+    println!("Hello, world!");
+}
+
+fn camera_setup(mut clear_color: ResMut<ClearColor>, mut commands: Commands) {
+    *clear_color = ClearColor(Color::WHITE);
+
+    commands.spawn(Camera2d);
+}
+
+fn sprite_setup(assets: Res<AssetServer>, mut commands: Commands) {
+    let sprite_handle = assets.load("sprite-0001.png");
+
+    commands.spawn((
+        Sprite {
+            image: sprite_handle,
+            ..default()
+        },
+        EntityPhysics {
+            x: 0.,
+            y: 0.,
+            speed: 0.,
+            heading: 0.,
+        },
+    ));
+}
+
+fn handle_keys(mut q_player: Query<&mut EntityPhysics>, keys: Res<ButtonInput<KeyCode>>) {
+    if keys.just_pressed(KeyCode::KeyQ) {
+        info!("Quit.");
+    }
+
+    let Ok(mut player) = q_player.single_mut() else {
+        return;
+    };
+
+    if keys.just_pressed(KeyCode::ArrowUp) {
+        player.speed += 0.1;
+    }
+
+    if keys.just_pressed(KeyCode::ArrowRight) {
+        player.heading += 0.1;
+    }
+
+    if keys.just_pressed(KeyCode::ArrowLeft) {
+        player.heading -= 0.1;
+    }
+}
+
+fn player_physics(mut q_player: Query<(&mut EntityPhysics, &mut Transform)>) {
+    let Ok((mut physics, mut transform)) = q_player.single_mut() else {
+        return;
+    };
+
+    let x_speed = physics.heading.sin() * physics.speed;
+    let y_speed = physics.heading.cos() * physics.speed;
+
+    physics.x += x_speed;
+    physics.y += y_speed;
+
+    transform.translation = Vec3 {
+        x: physics.x as f32,
+        y: physics.y as f32,
+        z: 0.,
+    };
+
+    transform.rotation = Quat::from_axis_angle(
+        Vec3 {
+            x: 0.,
+            y: 0.,
+            z: -1.,
+        },
+        physics.heading,
+    );
+}