starfall-core

The pure game core of STARFALL — a roguelite shmup. Logic and a renderer that writes to any surface offering four methods. No dependencies, no terminal, no DOM, no I/O.

The same code runs the SSH arcade at ssh -p 2222 invaders.m2-webvision.de and the browser easter egg on m2-webvision.de.

Usage

import { createGame, newGame, update, draw, type Surface } from "starfall-core"

const game = createGame(46, 30)   // columns, rows — at least 44x22
newGame(game)

update(game, 1 / 60, { left: false, right: true, fire: true, choose: 0 })
draw(game, surface)

update() is pure apart from mutating the state you hand it, takes an injectable random source, and never touches the clock — so a run is reproducible from a seed.

The surface

interface Surface {
  clear(bg?: Color): void
  drawText(text: string, x: number, y: number, fg: Color, bg?: Color): void
  fillRect(x: number, y: number, width: number, height: number, bg: Color): void
  drawTextSub?(text: string, x: number, y: number, fg: Color, fx: number, fy: number): void
}

A Color is a hex string. Coordinates are cells, not pixels.

drawTextSub is optional and carries the fractional part of a position. A canvas can use it to move things smoothly between cells; a terminal, which only has whole cells, leaves the method out and the renderer rounds instead.

Shipping format

TypeScript source, no build step. Bundlers need to be told to transpile it — for Next.js that means transpilePackages: ["starfall-core"] plus allowImportingTsExtensions in tsconfig.json.

MIT