Retaker

Retaker is an ECS(very wip) that aims for simplicity and just enough performance to use ECS.

Example :

use retaker::{
    entity::EntityIdGenerator, system::Scheduler, world::World
};

#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub enum SystemGroups {
    SomeSystemGroup,
}

pub struct State {
    world: World,
    generator: EntityIdGenerator
}

pub struct MyComponent(String);
pub struct Exclude;

fn system(state: &mut State) {
    let entity1 = state.generator.generate();
    state.world.insert_component(&entity1, MyComponent(String::from("hi!!!")));

    let entity2 = state.generator.generate();
    state.world.insert_component(&entity2, MyComponent(String::from("bye!!!")));

    let entity3 = state.generator.generate();
    state.world.insert_component(&entity3, MyComponent(String::from("excluded!!!")));
    state.world.insert_component(&entity3, Exclude);

    {
        let mut query = state.world.query::<MyComponent>();
        query.filter_without::<Exclude>(&mut state.world);
        for entity in query {
            let mut string = state.world.mut_component::<MyComponent>(&entity).unwrap();

            string.0 = string.0.to_uppercase();
    
            println!("{}", string.0);
        }
    }
}

fn main() {
    let mut state = State {
        world: World::new(),
        generator: EntityIdGenerator::new()
    };
    let mut scheduler: Scheduler<SystemGroups, State> = Scheduler::new();

    scheduler.add_system(system, SystemGroups::SomeSystemGroup);

    scheduler.run_group(&mut state, SystemGroups::SomeSystemGroup);
}