README

essem.js - Javascript ECS game engine

essem.js is a Javascript library that allows you to build games and animations in a entity component system style manner.

essem.js is still very much a work in progress but it can render using WebGL fine right now.

Setup

If using for the browser:

Add a script tag to the header (you can swap 0.0.0 for any version):

<head>
    <script src="https://cdn.jsdelivr.net/npm/essem.js@0.0.1/build/essem.js"></script>
</head>

If using as a module:

Run npm install essem.js to install essem.js module. Then import essem.js (supports typescript):

import * as ESSEM from "essem.js";

Basic Example

Texture drawing example:

const app = new ESSEM.Application();

app.registerSystem(ESSEM.CameraSystem, ESSEM.SpriteRendererSystem):
app.loader.add(ESSEM.Texture, "fish.png");

document.body.appendChild(app.canvas.element);

app.eventManager.addListener(ESSEM.ApplicationInitEvent, () => {
    const scene = app.createScene();
    const entity = scene.createEntity();
    entity.addComponent(new ESSEM.TransformComponent());
    entity.addComponent(new ESSEM.SpriteComponent(app.loader.resources["fish.png"]));

    const camera = scene.createEntity();
    camera.addComponent(new ESSEM.TransformComponent());
    camera.addComponent(new ESSEM.CameraComponent());
    camera.addTag("MainCamera");
});

Documentation

The documentation is here You can also build the documentation from the sources by doing yarn run docs and viewing the docs/ directory.

Contributing

We're using yarn for this project so make sure it's installed with npm install -g yarn and use yarn for every command.

First, run yarn to install the dependencies.

Then, to develop the library you should use yarn run dev which will setup a development server and automatically compiles all the typescript files.

After you made some changes, you should use yarn run lint:fix to lint the code and run yarn run build && yarn run test to test the code. This will be automatically ran with github actions on every push.

To build the documentation from jsdoc: yarn run docs

Usage no npm install needed!