p5js_gleam

A simple game library providing p5js bindings for Gleam in a functional style to make basic games and animations. Heavily inspired by the Racket library 2htdp/universe.

This project is primarily made up of

A bun script that is used to generate bindings for p5js class methods
- Script is based on script created for glare
A wrapper game engine that provides a functional interface to p5js

Using the library

Add the library to your project by running the following command

gleam add p5js_gleam

Then add a call to the start_sketch function in your main function.

import p5js_gleam.{type P5, SketchConfig}
import p5js_gleam/bindings as p5
import gleam/option

fn setup(p: P5) -> String {
  p5.create_canvas(p, 800.0, 600.0)
  "Hello, world!"
}

fn draw(p: P5, state: String) {
  p5.background(p, "#ffffff")
  p5.fill(p, "#000000")
  p5.text(p, state, 400.0, 300.0)
}

pub fn main() {
  p5.start_sketch(SketchConfig(
    init: setup,
    draw: draw,
    on_tick: option.None,
    on_key: option.None,
    on_mouse: option.None,
  ))
}

Afterwards you will need to build your project and include it in an html file. The html file must import p5js as a module before the generated javascript file. The easiest way to do this is to load the p5js library from a CDN.

<!doctype html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Ball Spawner</title>
    <script src="https://cdn.jsdelivr.net/npm/p5@1.9.2/lib/p5.js"></script>
    <script type="module">
      import { main } from "./ball_spawner.js";
      main();
    </script>
  </head>
  <body></body>
</html>

To see the library in action you can serve one of the examples in the examples directory.

Generating FFI Bindings

To generate the FFI bindings you will need bun installed. Once you have bun installed run

bun run ./scripts/generate_p5.ts