checs

An Entity-Component-System library.

Example

This is a very basic example of how to use checs.

You can find this example at examples/basic.rs. Run it with:

sh cargo run --example basic

Define some components and a World to store them in.

Note: Components are just plain old Rust types.

```rust struct Position { x: u32, y: u32, } struct Health(i32); struct Visible;

checs::impl_storage!( struct Storage { positions: Position, healths: Health, visibles: Visible, } );

let mut world = checs::world::World::::new(); ```

Create entities with initial components.

```rust // Either manually... let player = world.spawn(); world.put(player, Position { x: 0, y: 0 }); world.put(player, Visible); world.put(player, Health(80));

// ...or by using the spawn macro. let obstacle = checs::spawn!(world, Position { x: 1, y: 1 }, Visible); let trap = checs::spawn!(world, Position { x: 2, y: 1 }); let enemy = checs::spawn!(world, Position { x: 1, y: 4 }, Visible, Health(100)); ```

Find the entities that have some components.

```rust use checs::iter::LendingIterator; use checs::query::IntoQuery;

let ps = &world.storage.positions; let hs = &mut world.storage.healths; let vs = &world.storage.visibles;

let query = (ps, hs, vs).into_query();

query.for_each(|(e, (p, h, _v))| { h.0 = h.0 - 17; println!("{e:?} at ({}, {}) has {} HP.", p.x, p.y, h.0); });

// Entity(0) is Visible at (0, 0) with 63 HP. // Entity(3) is Visible at (1, 4) with 83 HP. ```