EntityComponentSystem

Install using this command:

$ npm install @luminate_d/ecs

Importing in browser

Use script tag to import browser build:

<script src="node_modules/@luminate_d/ecs/build/browser.js"></script>

Use by accessing ECS globals variable:

const ecs = new ECS.EntityComponentSystem();
// ...

Usage example

const ECS = require('@luminate_d/ecs'); // Import library

// Create custom component
class MyComponent extends ECS.Component {
    constructor() {
        this.something = true;
    }
}

// Create custom system
class MySystem extends ECS.System {
    filter(entity) { // filter what entities system will handle
        if(entity.hasComponent(MyComponent)) return true;
        return false;
    }
    
    update(deltaTime, entities) {
        entities.forEach(entity => {
            console.log('Updating entity', entity);
        });
    }
}
const ecs = new ECS.EntityComponentSystem(); // create ecs instance
const system = new MySystem(); // create system instance

ecs.addSystem(system); // add system to ecs

let idCounter = 0;
const entity = new ECS.Entity(idCounter++); // create entity
entity.addComponent(new MyComponent()); // add component to entity
system.addEntity(entity); // add entity to the system

// update system
let lastUpdate = Date.now();
setInterval(() => {
    let delta = lastUpdate - Date.now();
    lastUpdate = Date.now();
    
    ecs.update(delta);
}, 1000 / 60);

Documentation

Entity

entity.id - Id of the entity entity.components - Components attached to the entity

entity.addComponent(component: Component) - Attach component instance to the entity entity.removeComponent(component: Component) - Remove component from entity entity.hasComponent(component: Type<Component>): boolean - Does entity contain this component entity.getComponent(component: Type<Component>): Component - Returns component attached to the entity if it is present

System

system.filter(entity: Entity): boolean - Returns true when system will handle this entity system.update(deltaTime: number, entities: Set<Entity> | Array<Entity>) - Updates each entity

EntityComponentSystem

ecs.entities - Set of entities added to ECS ecs.systems - Set of systems added to ECS

ecs.update(deltaTime: number) - Update each system with only entities they can handle ecs.getEntities(filter: () => boolean): Array<Entity> - Returns filtered entities ecs.addEntity(entity: Entity) - Add entity to the ECS ecs.removeEntity(entity: Entity) - Remove entity from the ECS ecs.getEntity(id: number): Entity | null - Returns entity by id if its present ecs.hasEntity(entity: Entity): boolean - Does ECS contain entity

ecs.addSystem(system: System) - Add system to ECS ecs.removeSystem(system: System) - Remove system from ECS ecs.hasSystem(system: System): boolean - Does ECS contain system ecs.getSystem(system: Type<System>): System | null - Returns system if its present inside ecs