bevy-ecs-expertlisted

# Bevy ECS Expert ## Overview A guide to building high-performance game logic using Bevy's data-oriented ECS architecture. Learn how to structure systems, optimize queries, manage resources, and leverage parallel execution. ## When to Use This Skill - Use when developing games with the Bevy engine in Rust. - Use when designing game systems that need to run in parallel. - Use when optimizing game performance by minimizing cache misses. - Use when refactoring object-oriented logic into data-oriented ECS patterns. ## Step-by-Step Guide ### 1. Defining Components Use simple structs for data. Derive `Component` and `Reflect`. ```rust #[derive(Component, Reflect, Default)] #[reflect(Component)] struct Velocity { x: f32, y: f32, } #[derive(Component)] struct Player; ``` ### 2. Writing Systems Systems are regular Rust functions that query components. ```rust fn movement_system( time: Res<Time>, mut query: Query<(&mut Transform, &Velocity), With<Player>>, ) { for (mut transform, velocity) in &mut query { transform.translation.x += velocity.x * time.delta_seconds(); transform.translation.y += velocity.y * time.delta_seconds(); } } ``` ### 3. Managing Resources Use `Resource` for global data (score, game state). ```rust #[derive(Resource)] struct GameState { score: u32, } fn score_system(mut game_state: ResMut<GameState>) { game_state.score += 10; } ``` ### 4. Scheduling Systems Add systems to the `App` builder, defining