🎉 Source available in celebration of 10k unique players! 🎉

bulletz.io is a real time multiplayer 2D shooter. The backend is written in the functional programming language Elixir. The game runs on a custom game engine that was written with fault tolerance in mind. Fault tolerance is achieved by leveraging erlang's OTP library to create error boundaries around each individual player, bullet, and powerup. All engine code, logic, networking code, frontend, and backend code are custom written for bulletz.io.

🎮 Play now! 🎮
Development
Infrastructure
Architecture
License
Acknowledgements

Infrastructure

The system consists of a few pieces

Hugo web client
Elixir Game Servers
a server lister (currently disabled as I'm only running one server)

Game servers can run anywhere; the current live one runs on a Kubernetes cluster that I run on Google Kubernetes Engine.

As a cost cutting mechanism Tthe servers are currently pre-emptible, so there is some down time.

Architecture

The game consists of a Hugo backend under client/ and an Elixir backend hosted under game_server/.

Frontend Architecture

Hugo is pretty bad in terms of JavaScript and TypeScript interop, so I have a client/js_src/ directory containing the TypeScript source, and the Hugo build relies on the transpiled output which is output to client/assets/js.app.

The client is a PWA, written entirely using a custom routing framework.

Quite possibly the worst decision I made in writing bulletz.io is to write the entire frontend based on RxJS. I did this primarily as a learning exercise because the product I worked on at Google at the time heavily used RxJS. Really regret it.

Truth be told, I want to refactor the frontend to be a React/TypeScript/NextJS app.

Backend Architecture

The backend server is a stripped down custom Phoenix server. Each entity has its own OTP entity (excluding food), module, and unique game logic.

All config is held under game_server/game_config/.

Every entity exists under game_server/entities/.

Services all exist under game_server/services/.

Finally, the server itself is under game_server/socket_server.

Development

This section provides an overview of how to setup a local development environment for bulletz.io.

If you can't get the environment setup, please file an issue at https://github.com/LukeWood/bulletz.io/issues so we can improve the instructions.

Setup/Installs

First, you'll need to install the following packages:

NPM & NodeJS
GNU make
hugo
Elixir
tmux

and run the following commands:

npm install -g postcss-cli
npm install -g autoprefixer
mix local.rebar

Next, you'll need to get the frontend dependencies:

cd client/js_src
yarn

Next, install backend dependencies:

cd game_server/socket_server
mix deps.get

Development Server

Running a dev server should be as easy as: make dev-server

That's all! Read below the line to see exactly what this command does:

make dev-server does the following for you:

Create a hugo server instance cd client && hugo server -D

Create a webpack watcher instance cd client/js_src && npm run watch

Run the backend: cd game_server/socket_server && MIX_ENV=dev iex -S mix phx.server

Make Some Changes!

Once you have a development server running, try changing the game a bit! My recommendation is to go into game_server/game_config/ and change a few values.

See what you can come up with

Contributing

Any filed issue is open for contribution.

Have an idea? Want to clean the code up?

Open a GitHub issue or send a PR!
Tag @lukewood for a review.

License

I made bulletz.io source available so that passionate users can shape the direction of bulletz.io. Luke Wood is still the sole owner of bulletz.io.

More formal license:

You may not use the code for bulletz.io for anything without express written consent from Luke Wood. All code contributed to bulletz.io is sole property of Luke Wood. By contributing to this repo you acknowledge that the code you contribute is the sole property of Luke Wood.

Acknowledgements

Special thanks to Dave Thomas for teaching me Elixir, advising me on OTP structuring, and reviewing the code.

A final thank you to all of the players of bulletz.io, and to all of my wonderful friends who have playtested bulletz.io along the way.

Servers, Finances and Sponsorship

While historically I have run special event servers (i.e. the Halloween server), I currently only run the main server. This is primarily due to a lack of financing for bulletz.io.

Have an idea for a server? Want a server with custom powerups? Sponsor a server!

I do not pay to run more than one server at this time.

Want to sponsor bulletz.io?

Contact Luke!

Some benefits of sponsorship:

a special thanks in Acknowledgements
a special thanks on the homepage of that server
strong input into the powerups that will be hosted on your server

Please send me a message via any contact option on lukewood.xyz

LukeWood / bulletz.io

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