notnull games

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

building

You do not install tinygo - 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-go:latest mygame

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

Go notes

• The API is CamelCase here, wrapping the raw //go:wasmimport declarations.
• There is no working directory - os.ReadFile("/main.lua") works, os.ReadFile("main.lua") does not.

a cart, in Go

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

package main

import null0 "null0"

//export load
func load() {
	null0.Clear(null0.BLUE)
	null0.DrawCircle(100, 100, 50, null0.RED)
	null0.DrawText(null0.FONT_DEFAULT, "hello from Go", 170, 92, null0.WHITE)
}

// tinygo needs a main, even though null0 never calls it
func main() {}

// callbacks (optional - implement as needed)
//
//	//export update
//	func update() {}

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

callbacks

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

//export load
func load() {}

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