WWF No Mercy: Recompiled

WWF No Mercy: Recompiled is a project that uses N64Recomp to statically recompile the Nintendo 64 game WWF No Mercy into a native PC port, running on the N64ModernRuntime with RT64 as the rendering engine. It is the fifth project in the AKI wrestling recompilation family, after WCW vs. nWo World Tour: Recompiled, WCW/nWo Revenge: Recompiled, WWF WrestleMania 2000: Recompiled, and Virtual Pro Wrestling 64: Recompiled, sharing their runtime stack and conventions. No Mercy is WrestleMania 2000's direct sequel, so that project is this one's closest reference.

This repository and its releases do not contain game assets. The original game is required to build or run this project.

Status: beta. The game boots, renders at high resolution, plays music and sound effects, takes keyboard and gamepad input through the menus and matches, rumbles, and the cartridge flash save persists automatically across sessions. See Known Issues for what's still rough.

Table of Contents

• System Requirements
• Features
• FAQ
• Known Issues
• Lighting
• Mods and ROM Hacks
• Building
• Libraries Used and Projects Referenced
• Special Thanks

System Requirements

Currently a Windows build is targeted; other operating systems may be supported later.

A GPU supporting Direct3D 12.0 (Shader Model 6) or Vulkan 1.2 is required. A CPU supporting the SSE4.1 instruction set is also required (Intel Core 2 Penryn series or AMD Bulldozer and newer).

Features

• Plug and play — assets load directly from your ROM, no extraction step
• Hardware-accelerated high-resolution rendering through RT64 with the original N64 visual effects intact
• Widescreen support
• In-game config menus with full input rebinding for keyboard and controller
• Default mappings tailored to the AKI control scheme (d-pad movement, analog taunts)
• Flash cartridge save emulation with automatic persistence, plus rumble
• Smoother motion (Experimental): 60 and 120 fps through frame interpolation (Settings → Graphics → Framerate)
• Ray tracing (Experimental): real shadows from the arena lights, ambient occlusion, and a lighting rig for every arena, every entrance stage and the five backstage areas, which you can change yourself (see Lighting); needs D3D12 and a DirectX Raytracing 1.1 GPU
• CRT filter (Experimental): Composite, S-Video, RF or RGB signal, USA or Japan TV colors, and an optional CRT Beam Simulator (V-Sync and a 120 Hz+ display)
• HDR (Experimental): HDR Picture (Auto, Brighter, Balanced, CRT Detail, Custom) sets the brightness for your display; Auto leaves the CRT filter headroom for a full-strength phosphor mask
• Mods menu with a bundled free camera, cheats and a Quick Match testing tool (see Mods and ROM Hacks)

Planned Features

• Linux support

FAQ

What is static recompilation?

Static recompilation is the process of automatically translating an application from one platform to another — here, the game's original MIPS machine code is translated into C and compiled for modern PCs. For details, see N64Recomp. This is not an emulator and not a decompilation.

How is this related to a decompilation project?

It isn't — no public decompilation of WWF No Mercy exists. Unlike most recompilation ports, which borrow symbol names from a decomp, this project generates its own symbol metadata from scratch via a splat disassembly (see disasm/ and syms/), transferring libultra identifications from its sister project WWF WrestleMania 2000 by machine-code fingerprinting.

Which ROM does it use?

This project is only a port of WWF No Mercy, and it only accepts one specific ROM: the USA Rev 1 release (SHA1 91CEE3D096F4A76644D8B35B9AEAD6448909ABD1). The original USA release (Rev 0, which shipped the infamous save-erasure bug) and other regions are not accepted. It is not an emulator and it cannot run any arbitrary ROM.

Where is the savefile stored?

• Windows: %LOCALAPPDATA%\NoMercyRecompiled\saves\

No Mercy saves everything — game progress, unlocks ("SmackDown Mall" purchases), and created wrestlers — to the cartridge's flash memory; the port persists that flash image to disk automatically. Configuration files and the log file live one level up in the same app folder.

Can you run this project as a portable application?

Yes — place a file named portable.txt in the same folder as the executable and saves, config files, and the stored ROM will be kept next to the executable instead.

Known Issues

This is a beta. Known rough edges:

• Multi-controller sessions are still being stabilized and can crash; single controller (or keyboard) play is solid.
• First launch may pause briefly while shaders compile for your GPU.
• Only the USA Rev 1 ROM is accepted (see the FAQ) — other dumps are rejected at intake by design.
• Ray tracing at Quality or Ultra with 60/120 fps is very demanding in this game and can slow it down on mid-range GPUs. Use Performance or Balanced at 60/120 fps, or 30 fps for Quality/Ultra.
• Ray tracing, frame interpolation, the CRT filter and HDR are experimental. If something looks wrong, turn the feature off and please report it with your log file (%LOCALAPPDATA%\NoMercyRecompiled\NoMercyRecompiled.log).

Please report anything else through the issue tracker.

Lighting (Ray Tracing)

With Ray Tracing on, the lights come from assets\rt_lights.json in the game's folder (next to NoMercyRecompiled.exe; for AKI Launcher installs, the game's install folder). You can edit it with any text editor while the game runs: the game reloads it within a second, so you see each change straight away.

The file has three parts:

• "default": the rig for any scene without its own preset.
• "room": the generated fallback for small rooms without a preset (ceiling lights spread over the room).
• "venues": one preset per venue. A venue is recognized by its "match" list of texture hashes (the textures it draws); a preset only changes the fields it sets, the rest come from "default".

The main fields (distances are in game units, Y is up, and in arenas [0, 0, 0] is the middle of the ring):

Field	What it does
"lights"	Up to 8 lights: [x, y, z, weight], or [x, y, z, weight, r, g, b] for a colored one. Lower lights cast longer shadows.
"color"	Tints every light, [r, g, b] (brightness stays the same).
"size"	Width of each light: bigger = softer shadows.
"shadow", "characterShadow"	Shadow strength (0 to 1) on the world and on the wrestlers.
"radius"	How far from the center shadows land.
"glows"	Up to 4 glowing spots (screens, lamps): [x, y, z, intensity, range], optionally , r, g, b and a flicker amount.
"outsideDarkness", "outsideEdge"	Darkens everything beyond the radius (the crowd), easing in over outsideEdge units: the "house lights down" look. 0 = off.
"litAreas"	Up to 2 places, [x, z, radius, edge], kept out of that darkness (an entrance stage, for example).
"anchor": "scene"	Positions become offsets from the scene's center and floor, for rooms that sit anywhere in the world.

The top of the file documents every field.

The Lighting editor

The game has a live editor for all of this:

1. Close the game, open %LOCALAPPDATA%\NoMercyRecompiled\graphics.json (or graphics.json next to the exe in portable mode) and set "developer_mode": true.
2. Start the game and press F1 to open the RT64 inspector. Its Lighting window shows the venue the game detected and has sliders for every field, a split-screen view (ray tracing on one half only), and Save, which writes rt_lights.json.
3. To light a venue that has no preset yet, go there, type a name and press New venue from current scene: it fills in the venue's textures for you.

The bundled free camera (F6, see below) helps you look at the venue from anywhere while you work.

Releases replace assets\rt_lights.json, so keep a copy of your edits. To keep your own file somewhere else, set the environment variable WCW_RT_LIGHTS_FILE to its full path before starting the game.

Mods and ROM Hacks

This port loads mods in the .nrm format used by the N64: Recompiled projects.

Bundled mods

Three mods come with the game and are kept up to date by it. They do nothing until you use them:

• Camera: a free camera. Press F6 and fly around with WASD (Space/Ctrl up and down, Shift for speed) and the mouse; press F6 again to give the camera back to the game.
• Cheat Codes: on/off cheats for this game, plus a box for your own GameShark codes. All off by default.
• Quick Match (testing): a developer tool that skips the intro and starts a CPU-vs-CPU match in a chosen venue. Off by default; leave it off for normal play.

Their options are in Settings → Mods. To turn one off, switch it off there (deleting its file doesn't stick: the game puts it back).

Installing a mod

Copy the .nrm file into the game's mods folder, or use Install Mods in the Mods menu (or drag the file onto the window):

• Windows: %LOCALAPPDATA%\NoMercyRecompiled\mods\ (or mods\ next to the executable in portable mode)

New mods are switched on by default. Mods are applied when the game starts, so restart after changing them. To remove a mod, delete its file.

Making your own mod

A mod is a small C program compiled for the N64's MIPS CPU. The runtime links it into the recompiled game, where it can run code when a game function is called (a hook) or replace a game function (a patch).

The bundled mods are open source in AKI Mods: working examples, and a build script that does everything below for all six games at once.

You need:

• a C compiler with a MIPS backend: zig cc works out of the box (the Clang that ships with Visual Studio has no MIPS backend), plus ld.lld;
• RecompModTool, built from N64Recomp;
• modding.h and mod.ld from the MMRecompModTemplate (both work as they are; ignore its Majora's Mask headers);
• this repository's syms/dump.toml, which lists every function in the game.

There's no decompilation of this game, so functions go by their address (func_80001234). syms/dump.toml and the disassembly in disasm\ are the map; func_800012B0 runs at least once per frame, which makes it a good first hook:

#include "modding.h"

RECOMP_HOOK("func_800012B0") void my_mod_on_frame(void) {
    // runs every frame, before the game's own code
}

Compile and link (the +nooddspreg feature matters: without it floating-point code comes out wrong):

zig cc -target mips-freestanding-none -mcpu=mips2 -mabi=32 -O2 -G0 -mno-abicalls -mno-odd-spreg -Xclang -target-feature -Xclang +nooddspreg -fno-builtin -nostdinc -ffreestanding -ffunction-sections -c my_mod.c -o my_mod.o
ld.lld my_mod.o -nostdlib -T mod.ld --unresolved-symbols=ignore-all --emit-relocs -e 0 --no-nmagic -gc-sections -o mod.elf

Describe the mod in a mod.toml and pack it:

[manifest]
id = "my_mod"
version = "1.0.0"
display_name = "My Mod"
short_description = "What it does."
authors = [ "you" ]
game_id = "wwfnomercy"
minimum_recomp_version = "0.1.0"
dependencies = []
optional_dependencies = []
native_libraries = []

[inputs]
elf_path = "mod.elf"
mod_filename = "my_mod"
func_reference_syms_file = "path/to/syms/dump.toml"
data_reference_syms_files = []
additional_files = []

RecompModTool mod.toml out

That writes out\my_mod.nrm, ready to install. Options declared under [[manifest.config_options]] appear in the Mods menu; read them with the runtime's recomp_get_config_u32 / _double / _string exports (declare them with RECOMP_IMPORT("*", ...)). The game also exports keyboard and mouse input to mods (recomp_get_key_down, recomp_get_mouse_dx, ...; the full list is in src/main/main.cpp). There's no recomp_printf, and a mod that imports a function the runtime doesn't have won't load. New mods are switched on as soon as they're installed, so a mod you share should do nothing until the player turns it on.

ROM hacks as patch mods

Many ROM hacks can run as a patch mod: a mod that holds only a patch against the stock ROM. The game applies it to your own ROM when it starts, and any game code the hack changes is recompiled on the fly. It works for hacks that:

• are built on the same ROM this port uses (see the ROM's SHA1 above), and
• change code only inside the game's existing functions (data changes of any size are fine).

Hacks that add new code, rebuild or move the game's code, or are made for another revision need a full recompile and can't run as patch mods. Only one patch mod can be on at a time; each one keeps its own saves in saves\<mod id>\, apart from the stock game's.

To make one from a hack ROM you have patched yourself:

1. Get a checkout of this repository and Python 3.
2. Put your stock ROM in the repository root as nomercy.z64, and generate RecompiledFuncs\ (the recompile step in BUILDING.md). You don't need to build the game itself.
3. Make sure the hack ROM is big-endian .z64 (convert .n64 / .v64 dumps first).
4. Run:

python tools\romhack\make_patch_mod.py --base nomercy.z64 --hack my_hack.z64 --game-id wwfnomercy --id my_hack --name "My Hack" --out my_hack.nrm

The tool reports what the hack changes: data only, changed functions (fine: they're recompiled when the game starts), or code that escapes its functions or lies outside them (needs a full recompile: the tool refuses to write the mod). Without --out it only prints the report, a quick way to check a hack. Then install my_hack.nrm like any other mod. More detail in tools/romhack/README.md.

Patch mods can contain the hack's and the original game's data, so don't share patch mods you don't have the rights to: make your own from your own ROMs.

Known results for No Mercy:

• Work as patch mods: WWF No Mercy (Unlocked) (everything unlocked).
• Need a full recompile: WWF No Mercy Plus (v2.1, V3), ECW Born to be Wired, ECW House Party Mixtape, Project Outsider Extreme: all relinked or built on another base.

Building

See BUILDING.md.

Libraries Used and Projects Referenced

• N64Recomp — the static recompiler this port is built with
• N64ModernRuntime — the modern runtime (ultramodern + librecomp)
• RT64 — the rendering engine
• librashader with guest's CRT shaders, and the Blur Busters CRT Beam Simulator, for the CRT filter
• RecompFrontend — launcher, config menus, and input stack
• RmlUi for building the menus and launcher
• lunasvg for SVG rendering, used by RmlUi
• FreeType for font rendering, used by RmlUi
• SDL2 for windowing, input, and audio
• moodycamel::ConcurrentQueue for semaphores and fast, lock-free MPMC queues
• Gamepad Motion Helpers for sensor fusion and calibration algorithms
• DirectX Shader Compiler, zstd, nativefiledialog-extended, and plume via RT64
• splat / spimdisasm for the disassembly that produces this project's symbol metadata
• Inter, Noto Emoji, and PromptFont fonts (OFL; PromptFont license in assets/promptfont/)
• SDL_GameControllerDB for community controller mappings
• WCW vs. nWo World Tour: Recompiled, WCW/nWo Revenge: Recompiled, WWF WrestleMania 2000: Recompiled, Virtual Pro Wrestling 64: Recompiled, Bomberman Hero: Recompiled, and Zelda64Recomp as reference projects for structure and conventions

Special Thanks

• Wiseguy and DarioSamo for creating N64Recomp and RT64.
• Gadge64 for the frame interpolation behind the 60 and 120 fps Framerate options (#5), which the whole family of ports now uses.
• RevoSucks and the Bomberman Hero: Recompiled project, the template for this port's sister projects and therefore for this one.
• The Zelda64Recomp team for establishing the conventions the whole recomp ecosystem follows.
• ethteck and the splat/spimdisasm contributors — the disassembly tooling that made a no-decomp recompilation possible.