Retaker

Retaker is an ECS with a lot of work to be done.

The World struct can create entities then insert components in them, it can also create resources.

To query components, first a component list is locked, then you can query the entities of that list from the list.

Components can be read/written when locking a component list and getting them from the list with an entity id.

Because the World has to be locked by every system that creates an entity, it is a bit inneficient. The optimal solution would be a queue that can delete and create entities, then push to that queue instead of blocking a whole World.

Queuing is a bit verbose as well as making a system and locking a World. Macros or a better structural design could alleviate this.

Having the world locked dynamically for each system is inneficient, if i could get metadata of a function like in Zig, a scheduler that permits a lot more systems run parallel and reduce systems locking the world to almost none.

All this said, this ecs is good enough for me and not very much complex.

World Example :

    let mut world = World::new();

    struct Person {
        name: String,
    }
    struct Dead;

    let mathias = world.create_entity();
    world.insert(
        &mathias,
        Person {
            name: "Mathias".to_string(),
        },
    );
    world.insert(&mathias, Dead);

    let thomas = world.create_entity();
    world.insert(
        &thomas,
        Person {
            name: "Thomas".to_string(),
        },
    );

    let dead_components = world.components::<Dead>().unwrap();
    let person_components = world.components::<Person>().unwrap();

    for dead_person_id in person_components.with(dead_components.query()) {
        let person = person_components.get(&dead_person_id).unwrap();
        println!("{} is dead", person.name);
    }

    for alive_person_id in dead_components.without(person_components.query()) {
        let person = person_components.get(&alive_person_id).unwrap();
        println!("{} is alive", person.name);
    }

Three more examples that also feature systems are found in the examples folder