l2eme/uecs

Micro ECS

μECS is an ECS library.

It is:

• 🏋️ Lightweight, ~3kb unpacked
• 💻 Easy to use
• ⚡ Extremely fast

μECS is available on NPM and the unpkg CDN, for use in both browsers and Node.

What is ECS?

Entity Component System is an architectural pattern. It it used to decouple a game's state from its logic, which makes reasoning about your game much easier. Instead of a complex game object hierarchy, you're left with components, composed into entities, all living in a shared world, manipulated by systems. It has the additional benefit of performing well on modern CPUs, due to being data oriented.

For a proper introduction to what ECS is, what it's aiming to fix and how it works, I recommend reading this series of articles.

Usage

Visit the this page to see a full walk-through of the entire API, auto-generated documentation (which contains more examples and API explanations), as well as a simple demo!

import { World } from 'uecs';

class Position { x = 0; y = 0; }
class Velocity { x = 10; y = 10; }

const world = new World;
for (let i = 0; i < 100; ++i) {
    world.create(new Position, new Velocity);
}

function physics(world, dt) {
    world.view(Position, Velocity).each((entity, position, velocity) => {
        position.x += velocity.x * dt;
        position.y += velocity.y * dt;
    });
}

Benchmark

This library focuses on being small and simple, but without compromising on performance. μECS is one of the fastest ECS libraries available, according to this benchmark.

Notes

Even though the library's version is currently below 1.0, the API should be considered stable, because the library is feature-complete. The only thing that may change are the internals, in hopes of increasing performance or decreasing built size.

This is because μECS has been in the works for many months, but it was only made public recently. Now that it is, I'd like to see what people have to say about it- maybe there are some huge flaws which can be addressed before commiting to 1.0.