Road Rash — Native Port

Native C++20 / SDL3 port of the 1996 Windows rerelease of Road Rash. Runs the game directly on modern systems: no Wine, no x86 emulation at runtime.

Primary target is macOS ARM64, second is Android ARM64. Linux and Windows are planned (see docs/plans/33-linux-windows-ports.md). The port is incomplete; see Status below.

Reference for reverse engineering is the unmodified disc binary at ../cdrom/ROADRASH/ROADRASH.EXE. Oracle captures run it under Wine to produce comparison traces. It is never executed by the game itself.

Status

Playable today via rr-game: full menu / career / shop / save flow leads into races on all five courses (Napa, City, Highway, Canyon, Medley) with the original bike physics, AI field, combat, traffic, pedestrians, engine / effect audio, soundtrack, and cutscene playback.

What matches the original on receipted captures:

• Napa level 1, full 14-rider offline field: 2400/2400 ticks identical.
• Napa level 1, recorded human-input run: 1431/1431 ticks identical.
• Full native suite: 105/105 CTests, zero skips; sanitizer suites clean.

Still open (see docs/CURRENT_STATUS.md and docs/PROGRESS.md):

• Simulation parity outside those captures: other courses/levels, human paths beyond the receipted run, isolated fight/steal/traffic cases.
• Gameplay: live police (periodic 4096-tick and DZHR spawns, chase, siren, arrest, BUSTED flow) is implemented, native-tested, and matches the original tick-for-tick: parked (635 pursuit ticks, RNG/field to 4730, arrest 4552), crashed (935 ticks, field to 5030, no arrest either side), on-foot ×2 (605 ticks each, full parity to 4700, arrests 4616/4544), and City (456 ticks, field to 4551; original arrests at 4552, not asserted while City AI RNG stays open past 954). Walls (0x0043a610), crash entry/motion/recovery (0x00403d60 family) and rider/car/pedestrian contact branches are ported; pedestrian pairs never contact in the original (0x004368f0 & 3 gate), and the traffic draw order approximation is visual-only. Race MIDI (SBKGRNG1..5 + KLOWN via RaceMusicPlayer, hooked at race start/stop), sirens (slots 30/31, event 19) and car engines (slots 4/6, Engcar11, 0x00435090 Doppler route) play; the player engine switches to the tunnel variant (slot 2, EngTunne) on terrain type 3 (0x00434a80, Race::player_in_tunnel, pinned). Exact AWE/MIDI timbre remains open.
• Frontend: jukebox, sound mix and controls are implemented; mano-a-mano stays disabled — online multiplayer (plan 34) is in scope per the owner's October 26 decision and is not yet implemented. Seeded original-writer saves round-trip byte-identical and driven-career saves round-trip (win + purchase + save + reload pinned in career-test --corpus, plus an original-driven save that round-trips byte-identical with its dumped game state (career-test --save-corpus). Menu layout acceptance covers all 223 original items plus native screens (2 scrollable, 28 hidden placeholders) with main-menu 1x/2x/4x checks; masked pixel checks pass for main menu (menu-09 and fe-main goldens: 60% masked, 98% exact, 0% large-diff) and the Big Game street screen (fe-career-start golden, item-driven mask: 67% masked, 96% exact, 0% large-diff). Characters/restroom/jukebox/graphics still diverge in background/portrait art (measured ~1% exact unmasked on restroom-class screens); full unmasked pixel equality remains open on GDI-hinting text shapes and that art mapping.
• Android builds and packages but hardware validation (render, input, import, lifecycle, performance) is pending.
• Linux and Windows build and pass their tests (Linux in Docker; Windows x64/ARM64 on GitHub runners, including the zip and installer packages), but neither has been played on real hardware yet (plans 33a/33b).

Browser build

The same game now runs as WebAssembly. Run tools/build_web.sh, then serve build-agent-browser/dist/ with a local HTTP server. Import your original PC disc ISO or ROADRASH folder; files stay in private browser storage. Choose Quick race for immediate play or Start game for the original frontend. See docs/WEB.md for deployment, tests and current limitations.

Requirements

• Your own 1997 Windows rerelease disc (ISO or extracted ROADRASH folder, 341 files, SHA-256 verified on import). No game data is included or redistributed.
• CMake 3.22+, a C++20 compiler, SDL3 3.2+ (brew install cmake sdl3).
• Android builds additionally need JDK 21, Android SDK 35 / NDK 28, Gradle wrapper in android/.

Quick start (macOS)

./run-macos.sh                       # Release build in build-play/, launch game
./run-macos.sh --debug               # Debug build in build/ (slower renderer)

Or with CMake directly:

cmake -S . -B build -DCMAKE_BUILD_TYPE=Debug
cmake --build build --parallel
ctest --test-dir build --output-on-failure
build/rr-game --assets ../cdrom/ROADRASH

Options:

build/rr-game --assets ../cdrom/ROADRASH --course 0 --level 1 --bike 0
build/rr-game --assets ../cdrom/ROADRASH --video VIDEO/INTRO.AVI

--course 0-4 (Napa, City, Highway, Canyon, Medley), --level 1-5, --bike 0-14, --character 1-8 (Axle .. Teflon Mike). An interactive quick race is a Thrash race in the original front end: it ends on the original results and standings screens, then the Thrash menus. Omitting race flags enters the menu/career flow. --ticks N --screenshot out.bmp runs a headless verification slice; tool runs (--ticks, --autopilot, captures, benchmarks, --opponents) keep the standalone race.

Controls

Action	Keyboard	Gamepad	Touch
Accelerate	Up / W	South / RT	Free zones (auto-throttle)
Brake	Down / S	East / LT	Bottom-middle zone
Steer	Left/Right, A/D	D-pad / left stick	Left/right thirds
Punch / Kick / Backhand	Z / X / C	West / North / RB	Top third
Pause	P / Esc	Start	System Back / pause tap
Restart after finish	Enter	South	Tap
Quit (desktop)	Q	—	—

P/Esc/Start opens the pause menu (Resume, Sound, Display, Controls, Quit Race with confirmation). Backgrounding, focus loss, or disconnecting the active gamepad also pauses; resume is always explicit. Keys are rebindable in Graphics Options → Configure Input; gamepad mapping is fixed except punch/kick swap and stick dead zone.

Disc import

First launch without --assets shows the import screen: pick the ISO or an extracted folder. The importer verifies all 341 files by SHA-256 and commits only a complete match; failures leave any existing install untouched.

Command-line equivalent:

build/rr-import "/path/to/Road Rash.iso" "/path/to/imported/ROADRASH"
build/rr-game --assets "/path/to/imported/ROADRASH"

Default destination is the SDL pref dir RoadRashNative/RoadRash/game/ROADRASH. RR_PREF_OVERRIDE redirects it for isolated test runs.

Tools

Binary / script	Purpose
build/rr-game	The game (menus, career, races, video playback)
build/rr-viewer (./run-viewer.sh)	Asset research viewer, not the game: screens, course drive-through
build/rr-import	CLI disc import with hash verification
build/rr-inspect FILE.RSC	Dump a resource container directory
build/rr-course --exe ../cdrom/ROADRASH/ROADRASH.EXE DATA/COURSES/*.CRS	Course graph / projection sweep
python3 tools/check_corpus.py <assets>	Validate all resource containers
python3 tools/render_demo.py	Render a 2-minute 5-course demo MP4 from the engine
tools/bench_game.sh user original enhanced	Race frame-time benchmark (docs/PERFORMANCE.md)
tools/ci.sh	Local verification gate (native build, tests, APK assembly)

Video playback uses native Cinepak / IMA-ADPCM decoders. FFmpeg appears only in tests as a decode oracle; runtime needs neither FFmpeg nor Wine.

Android

export JAVA_HOME=/opt/homebrew/opt/openjdk@21/libexec/openjdk.jdk/Contents/Home
android/gradlew -p android assembleDebug

Output: android/app/build/outputs/apk/debug/app-debug.apk. Normal APKs ship no game data; on first launch pick your own ISO and it is verified the same way as desktop. SDK location lives in the ignored android/local.properties. Optimized local build: assembleRelease -PreleaseDebugSigning=true. Owner signing and versioning are documented in docs/USER_GUIDE.md. Device behavior is unverified.

macOS packaging

tools/build_macos_app.sh

Produces build-release/Road Rash Native.app and a ZIP with pinned static SDL3, ARM64 / macOS 13 baseline, bundled licences, ad-hoc signature, and no game data. Pushing a v* tag builds and attaches the same package via GitHub Actions.

Windows packaging

From an MSVC developer prompt (windows-msvc-arm64 for ARM64):

cmake --preset windows-msvc
cmake --build build-windows-msvc --config Release
python tools/build_windows_package.py --build-dir build-windows-msvc --arch x64
python tools/verify_windows_package.py build-windows-msvc\package\RoadRashNative-<version>-windows-x64.zip --arch x64 --run

Produces a portable zip (portable.txt keeps data beside the exe) and, with Inno Setup 6.3+, a per-user installer, both with a static CRT and SDL, so they need no DLLs beyond Windows' own, and no game data. tools/sign_windows.ps1 signs them when the owner sets RR_SIGN_*; otherwise they are unsigned and SmartScreen warns. The verifier needs pip install pefile. CI builds and install-tests both architectures.

Docs map

• docs/CURRENT_STATUS.md — evidence matrix and latest gate receipts.
• docs/PROGRESS.md — what is ported, approximations, next steps.
• docs/VERIFICATION.md — commands run, outcomes, skips, evidence paths.
• docs/REVERSE_ENGINEERING.md — recovered structures and addresses.
• docs/USER_GUIDE.md — install, import, settings, controls reference.
• docs/plans/00-INDEX.md — plan dependency order to completion.
• docs/AGENT_TOOLING.md — agent workflow, gates, capture rules.

Commercial assets, disc dumps, and upscaled artwork stay local and out of the source tree, APKs, and app bundles. Third-party licence texts are in third_party/. No redistribution licence for the game is implied.