Virtua Fighter 2 Recomp

Virtua Fighter 2 Recomp

Virtua Fighter 2 (SEGA, arcade, Model 2, 1994) as a native PC game. The game's own program, for the board's Intel i960 CPU, is recompiled to native code (ARM64 or x86-64) from your ROM each time it starts, and checked instruction for instruction, cycle for cycle against MAME's i960 interpreter; the rest of the Model 2A board (the TGP geometry processor, the geometrizer and polygon renderer, the System 24 tile layers, and the sound board's 68000 and SCSP) runs on code from MAME, inside an SDL 3 host. Render scales up to 6x, widescreen and ultrawide, smooth motion at your screen's refresh rate, a menu and gamepads, and the arcade's frames and sound as MAME makes them at 1x (pixel for pixel on Apple silicon; on x86-64 a few texels a frame round differently, the renderer's multiply-adds not fused). Mac, Windows and Linux / Steam Deck.

Downloads and more: https://vf2-recomp.pages.dev/

An unofficial fan project, not made, approved or supported by SEGA, and not affiliated with it.

Bring your own MAME vf2 set

Nothing from the game is in this repository: no ROMs and nothing made from them. You need your own dump of the game as MAME's vf2 set (vf2.zip, Version 2.1). The game asks for it the first time it starts.

Build

Needs a C++20 compiler, zlib, SDL 3 and FreeType (Mac: brew install sdl3 freetype).

make                    # build/bin/vf2, and the headless tools
build/bin/vf2 path/to/vf2.zip

The release packages: tools/mac/package.sh (Mac), tools/win/build.sh (Windows, cross-compiled with MinGW-w64), tools/deck/build.sh (Linux / Steam Deck: x86-64, in Valve's Steam Runtime "sniper" SDK container). tools/release/licenses.sh gathers the third-party notices they carry.

build/bin/vf2run runs the board headless (pictures, RAM dumps, raw sound, an input script such as tools/scripts/start_game.txt); tools/compare.py and tools/sound_compare.py compare its output with MAME's.

The recompiler (src/rec) finds the program's code with an address map (src/rec/vf2_map.cpp: where the functions start and where the indirect jumps lead, no bytes from the ROM), made from coverage runs (vf2run --cov, then make map). make rec also recompiles it to C++ (into build/, from your roms/vf2.zip: never committed) for build/bin/vf2lock, which runs the interpreter and the recompiled code side by side and compares the CPU's whole state, the clocks, the RAMs and the pictures as they go. vf2 --interp and vf2run --interp run the interpreter.

Layout

Path	What
src/core	the Fujitsu MB86233 (TGP) core, from MAME, and the shim MAME's CPU cores compile against
src/rec	the i960 recompiler: code discovery, native code (SLJIT) at start-up, the C++ build's, the runtime
src/machine	Model 2A: memory map, interrupts and timers, the TGP glue, geometrizer and renderer, the tile chip, the sound board, smooth motion
src/host	the SDL 3 host: window, input, pacing, scene sync, the GPU compositing, the RmlUi menu (assets/ui)
third_party	MAME's i960 and 68000 cores, SLJIT, RmlUi, stb_image
tools	the headless runner, disassembler, comparisons, the packaging scripts

How it's made

Made with the help of AI coding tools. Every build is checked against the arcade: the recompiled i960 program runs side by side with MAME's interpreter, and the pictures, RAM and sound are compared frame by frame with MAME's.

Credits

Built on MAME's work on the Model 2: the i960 core and disassembler (Farfetch'd, R. Belmont), the 68000 core and the TGP (Olivier Galibert), the Model 2 driver and video (R. Belmont, Olivier Galibert, ElSemi, Angelo Salese, Matthew Daniels), the System 24 tile chip (Olivier Galibert), the SCSP and its DSP (ElSemi, R. Belmont), the polygon scan converter (Ville Linde, Aaron Giles) and more (third_party/mame/README.md lists every file and its authors), all BSD-3-Clause. Also RmlUi (MIT), stb_image (Sean Barrett, public domain / MIT), SDL 3 (zlib), FreeType (FreeType License), zlib, and the Barlow Condensed font (SIL Open Font License).

Virtua Fighter 2 is SEGA's. This project is not affiliated with or endorsed by SEGA.

Licence

MIT for this project's own code: see LICENSE. Code from MAME keeps its BSD-3-Clause licence and notices; the rest of third_party/ keeps its own, and the Barlow Condensed font the SIL Open Font License. The art, the player select's painted sides (assets/backgrounds/select.png) and the app icon (assets/icon/, drawn by tools/release/make_icon.py), is by Mr Finster under CC BY 4.0.