darthdeus / plushy

Plushy is a comfy generational arena for arbitrary types

Plushy

Plushy is a comfy generational arena for arbitrary types. You can think of it as thunderdome for all types at once, or as an ECS where you can only have one component at a time.

Plushy is a relatively simple crate that builds on top of thunderdome, but adds a few nice things, specificaly:

• Strongly typed wrappers around Index, meaning you can't accidentally mix up your entity ids. If you insert a Player, the corresponding id is Id<Player>.
• You only need one Store for all of your types. With thunderdome you'd need to create a separate Arena<T> for every type T you want to store.

let mut store = Store::new();

struct Enemy {
    pub x: i32,
}

struct Player {
    pub health: f32,
}

// New entities can just be spawned, we don't need to register
// the types anywhere.
store.spawn(Enemy { x: 1 });
store.spawn(Enemy { x: 2 });

// Store the player's ID for later
let player = store.spawn(Player { health: 100.0 });

assert_eq!(
    &[1, 2],
    store
        .iter::<Enemy>()
        .map(|t| t.1.x)
        .collect::<Vec<_>>()
        .as_slice()
);

// Fetch the player based on the ID. Note we don't need to write
// `store.get::<Player>(player)`, the type is inferred from the
// strongly typed ID.
assert_eq!(100.0, store.get(player).unwrap().health);

// Change player health
store.get_mut(player).unwrap().health = 200.0;

// Fetch it again and verify the change. Note we can also just directly
// index. This will panic if the `Id` is invalid.
assert_eq!(200.0, store[player].health);

License

Plushy is free and open source and dual licensed under MIT and Apache 2.0 licenses.