notnull games

• Template: cart_zig - press "Use this template" and you have a working game.
• Docker image: ghcr.io/notnullgames/null0-cart-zig:latest
• Your code: cart/main.zig, compiled with zig, wasm32-wasi
• Bindings: carts/zig/null0.zig (baked into the docker image for you)
• WASI is available, so ordinary file and stdio calls work.
• See carts made with Zig
• API docs for Zig

building

You do not install zig, wasm32-wasi - the docker image has it, and the current null0 bindings, baked in. There is nothing in your project to keep in sync with the engine.

docker run --rm --user $(id -u):$(id -g) \
  -v ./cart:/src -v ./webroot:/out \
  ghcr.io/notnullgames/null0-cart-zig:latest mygame

The template wraps that in npm start, which also serves the result and rebuilds when you save.

Zig notes

• wasm32-wasi executables need a main, even though null0 never uses it. Keep it empty.

a cart, in Zig

This is carts/zig/simple/main.zig in the engine repo - the same file CI builds into the cart below, so it always compiles.

const null0 = @import("null0.zig");

// zig needs an entry-point for wasm32-wasi executables
pub fn main() void {}

export fn load() void {
    null0.clear(null0.BLUE);
    null0.draw_circle(100, 100, 50, null0.RED);
    null0.draw_text(null0.FONT_DEFAULT, "hello from Zig", 170, 92, null0.WHITE);
}

// callbacks (optional - implement as needed)

// export fn update() void {}
// export fn unload() void {}

This toolchain needs an entry point to exist even though null0 never uses it for gameplay. Leave it empty: pub fn main() void {}

callbacks

A cart implements the callbacks it cares about. In Zig they look like this:

export fn load() void {}

See anatomy of a cart for the full list and what each one is passed.