Stunt Race FX - DECOMP

Stunt Race FX - DECOMP

A native PC port of Stunt Race FX (SNES, Super FX) aimed at a smooth, responsive, high-resolution experience - while keeping the original game's logic exactly as it was.

This is a fork of the byte-exact, cycle-exact decompilation by Jeffrey Wilbur / Strut B, LLC: jeff-strutb/stuntracefx. All the hard work of decompiling the game is theirs; this fork builds on their native port and adds the presentation features below. Their original README is kept in docs/UPSTREAM-README.md.

Current build: 60 fps picture, 3D redrawn at 3× resolution with anti-aliasing.

No game data is included. You need your own ROM of Stunt Race FX (USA) (Rev 1) (SHA-1 781e376ff453a83c7bcf72339abe6b842efd9c86).

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What this fork adds

The original game runs its races at roughly 10-20 frames per second on the console. This fork keeps the game's own logic untouched (the race plays out identically, verified tick for tick) and rebuilds what you see around it:

Feature	What it does
Smooth 60 fps	The game's own logic runs at its steady pace with no slowdown ("natural 10"); in-between frames are drawn by re-running the Super FX's own 3D programs with the camera and every object interpolated.
Low input lag (look-ahead)	The next game ticks are run ahead on a copy of the game, so the picture answers your steering within about 1-2 frames (the original console takes around 20). Predictions are checked against the real game and are exact.
High-resolution 3D	Every polygon and sprite is captured with its exact, unrounded position and redrawn at 2×, 3× or 4× resolution, with 2×2 anti-aliasing (3× default). Course seams and flicker from the original's rounding are fixed.
Far cars in 3D	Opponents stay full 3D models up to 4× farther out instead of turning into flat sprites, with wheels, colours and smoothed movement - without changing the race.
HUD in step	The HUD (countdown lights, rank badges, timer) is taken from the same look-ahead moment as the 3D, so it stays in sync with the picture.
Wide view - EXPERIMENTAL	Removes the bezel and draws the 3D across the whole screen, corner to corner, with more of the course visible - no stretching. The background panorama, sky and HUD are rebuilt around it. Still rough in places and heavier to run; off by default.
Launcher	SDL3 launcher: choose and verify your ROM, set resolution, look-ahead, far cars, wide view, speed, fullscreen and vsync.

Everything is optional: each feature can be turned off (in the launcher or with the keys below) to get back to the original's look.

Status

• ✅ Speed Trax races (Novice courses tested most), pause, results.
• 🟡 Wide view (experimental): sprite assets at the edges, some courses not yet checked.
• 🟡 Other courses (e.g. Big Ravine, Night Owl) need a pass each.
• ✅ Car selection (Speed, Stunt, Battle Trax): the turning vehicle in high resolution.
• ✅ Windows: the same as Linux (look-ahead, wide view, hi-res, launcher), portable (everything stays in its folder).
• 🟡 Some stages may still show artifacts at tunnel entrances.
• ⬜ Other menus and 2-player battle races are shown at the original resolution, without in-between frames.
• ✅ Packaged builds: beta 0.2 for Linux (AppImage) and Windows (zip).

Running

From source (Linux)

Requirements: clang, python3, SDL3 development files (sdl3 via pkg-config), and your ROM.

# the game, built WITHOUT the ROM inside (reads your ROM at start)
HOST=sdl3 ROM_EXTERNAL=1 OUT=build/stuntracefx/port/sdl3 \
  CC="clang -D_GNU_SOURCE -O2" SRFX_ROM="/path/to/Stunt Race FX (USA) (Rev 1).sfc" \
  sh ports/stuntracefx/link.sh
./build/stuntracefx/port/sdl3/stuntracefx --rom "/path/to/Stunt Race FX (USA) (Rev 1).sfc"

The build reads the ROM once to generate a table of routine addresses (no ROM data ends up in the program). The launcher and AppImage are built with sh ports/stuntracefx/launcher/build-appimage.sh.

Windows (cross-built on Linux)

Requirements: MinGW-w64 (x86_64-w64-mingw32-gcc), SDL3's MinGW development package from libsdl-org/SDL's releases (its x86_64-w64-mingw32 folder in SDL3_MINGW, a path without spaces), and your ROM for the build step above.

SDL3_MINGW=/path/to/SDL3-x.y.z/x86_64-w64-mingw32 SRFX_ROM="/path/to/rom.sfc" \
  sh ports/stuntracefx/launcher/build-windows.sh

This makes a portable folder and zip in ../dist. Windows has no fork(), so the look-ahead's copies there come from a snapshot of the running game in a second process (runtime/la_win.c); the game and its pictures are the same as on Linux.

Controls

SNES	Keyboard	Controller
D-pad	Arrows	D-pad / left stick
B / A	Z / X	A / B
Y / X	A / S	X / Y
L / R	Q / W	Shoulders
Start / Select	Return / Tab	Menu / View

In game: F3 speed mode · F4 look-ahead (3/2/1/off) · F5 3D resolution · F7 far cars in 3D · F8 wide view · Alt+Enter fullscreen · hold Esc (or View + Menu on a controller) for one second to quit.

Credits and license

• Decompilation and native port: Jeffrey Wilbur / Strut B, LLC - jeff-strutb/stuntracefx, released under CC0 1.0 (see LICENSE).
• This fork (smooth frames, look-ahead, high-resolution 3D, wide view, launcher): Mabec Games. Offered under the same CC0 terms.
• Stunt Race FX is © Nintendo / Argonaut. This project contains no game data and is not affiliated with or endorsed by Nintendo.