Open Fantasy

A JRPG written in raw x86_64 assembly for Linux.

Why

I've been playing the original Final Fantasy on NES, which, like most games from that era, was written in assembly by hand. These days AI can write most of your code for you, so as a personal flex and a bit of catharsis, I'm building a JRPG entirely in x86_64 assembly instead. No engine, no scripting layer, just syscalls, registers, and stack frames.

Rules I'm setting for myself

• The game logic, rendering, sprites, audio playback, everything that makes this a game, is written by me, by hand, in assembly.
• I'm allowing myself a small set of C libraries for the stuff that isn't worth reinventing (windowing, graphics context, OS differences):
  • GLFW — window/context/input handling
  • miniaudio — audio playback (planned, not wired up yet)
• Everything else (sprite rendering, tile/map rendering, animation, input, entities, whatever a JRPG needs) is hand-rolled assembly.

Platform

Currently Linux only (System V x86_64, raw syscalls for I/O/exit). Windows support is a maybe-later.

Building

Requires nasm and ld (from binutils), plus GLFW and OpenGL development libraries installed on the system.

Debian/Ubuntu/Mint:

sudo apt install nasm binutils libglfw3-dev libgl1-mesa-dev

Fedora:

sudo dnf install nasm binutils glfw-devel mesa-libGL-devel

Arch:

sudo pacman -S nasm binutils glfw mesa

Then:

make        # build bin/fantasy
make run    # build and run
make clean  # remove build/ and bin/

Layout

src/                     game source (assembly)
  fantasy.asm              entry point, GL/GLFW setup, and main loop
  constants.inc             shared constants (key codes, speeds, etc.)
  input.asm                 keyboard input handling
  playerOverworld.asm       player state machine and overworld movement
  renderer.asm               framebuffer/texture rendering
  spriteAnimation.asm       fixed-point sprite animation frame stepping
  sprites.asm                packed 2bpp character sprites and palettes
  tileset.asm                 packed 2bpp tile sprites and palettes
  maps.asm                    map/tilemap data
  utils.asm                   string, syscall, and misc helpers
build/                   object files (gitignored)
bin/                     final binary (gitignored)