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 aPlayer
, the corresponding id isId<Player>
. - You only need one
Store
for all of your types. Withthunderdome
you'd need to create a separateArena<T>
for every typeT
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);
Plushy is free and open source and dual licensed under MIT and Apache 2.0 licenses.