Bevy collection loop

When to use

Load this when the run is about picking up objects and reaching a count.

ECS shape

• Components: a collected flag and a quota resource you define.
• Resources: run-wide tables live in a resource (bevy-data-resources), not an autoload.
• Systems: mutate those components on Update or the fixed timestep. Use .chain() when damage must land before death.
• Messages: one-shot facts (hit, pickup, quest advance) go through bevy-events-messaging. This file does not add a new event type name.

Engine counterparts

Godot idea	Bevy idiom
Pickup	A component marker. Detection waits on spatial queries.
Quota	A resource count.
Win	A state change via bevy-state-machines.

Scope

A collectible is a marker component. Overlap is a distance check you own until a physics skill supplies contacts. Mark each entity once per pass: Commands::despawn applies later, so a second collector would otherwise score the same pickup. The quota is a resource. Reaching it writes NextState, which the state schedule applies after this system.

[dependencies]
bevy = "0.20"

#[derive(Component)]
struct Collectible {
    points: u32,
}

#[derive(Component)]
struct Collector;

#[derive(Resource)]
struct CollectionScore {
    points: u32,
    quota: u32,
}

#[derive(States, Debug, Clone, Copy, PartialEq, Eq, Hash, Default)]
enum RunState {
    #[default]
    Playing,
    Won,
}