RUST

rust bevy query option

fn check_zero_health(
    // access entities that have `Health` and `Transform` components
    // get read-only access to `Health` and mutable access to `Transform`
    // optional component: get access to `Player` if it exists
    mut query: Query<(&Health, &mut Transform, Option<&Player>)>,
) {
    // get all matching entities
    for (health, mut transform, player) in query.iter_mut() {
        eprintln!("Entity at {} has {} HP.", transform.translation, health.hp);

        // center if hp is zero
        if health.hp <= 0.0 {
            transform.translation = Vec3::ZERO;
        }

        if let Some(player) = player {
            // the current entity is the player!
            // do something special!
        }
    }
}