ReaperOfVeriod
e27c40e738
The texcoords are 12-bit fixed on 82.5% of vertices, not 100%, and the residual had no explanation. Grouped by the vertex's i16[3] slot across 95,612 vertices on levels 0-2, the buckets separate completely: i16[3] n % / 4096 % / 256 negative 333 1.2% 1.2% == 0 5,851 29.2% 60.7% 1..63 28,884 92.7% 94.3% 64..255 54,606 92.3% 93.8% 256..511 8 0.0% 0.0% 512..1023 5,391 0.0% 0.0% >= 1024 539 0.2% 0.2% The residual is fully accounted for. 87.3% of vertices sit in 1..255 at about 92.5% fixedness, contributing 0.873 * 0.925 = 80.8 points; the 5,851 at i16[3] == 0 contribute 1.8 more. That is the 82.5% measured, to the point. The remaining ~6% are not 12-bit fixed at all. i16[3] >= 256, and negatives, score 0% at BOTH 4096 and 256 -- 6,271 vertices in an encoding this reading does not see. And i16[3] == 0 scores 29.2% at 4096 but 60.7% at 256, which is a third distribution rather than a weaker version of the same one. What this establishes: i16[3] is a per-vertex packed attribute whose value SELECTS HOW the texcoord pair is stored, rather than an independent field sitting beside the texcoords. 1-255 is the ordinary case, 0 is special, 256-and-up and negatives are a different encoding. What those three cases MEAN is still open -- texture index, normal index, flag or a combination -- but it is now a field whose role is known, which is more than "packed word". Worth noting the shape of the claim this replaces: "the texcoords are 12-bit fixed at i16[4]/i16[5], 73.6% of the time, unexplained". The field position was right; the 73.6% was a population average over three encodings. Partitioning by the one variable that separates them turns a mystery into a lookup -- rule 3a again, and the third time this session that partitioning a mystery produced the answer rather than merely bounding it.
Going Commando
A native PC reimplementation of Ratchet & Clank: Going Commando (PlayStation 2, 2003), written in Rust.
The game is reimplemented, not emulated. There is no MIPS interpreter here and no CPU emulator: the systems are ported to Rust so they run as ordinary native code.
Status: initial scaffold. The disc is identified and verified, the
workspace builds, and nothing else is implemented yet. See
docs/roadmap.md for where things stand and what comes next.
The target
| Game | Ratchet & Clank: Going Commando |
| Platform | PlayStation 2 |
| Disc | SCUS_972.68 v1.01, USA Black Label |
| Video | NTSC, 60 Hz |
| Boot ELF SHA-1 | bacda860cbd6723142e86db56f197e47e728970f |
Verified against a real disc — see docs/disc-identification.md.
This is the build the reference projects pin; Greatest Hits v2.00 is a
different binary and is not the target.
No game content
This repository contains no game assets, no disc images, no BIOS dumps and no proprietary toolchains. You supply your own legally obtained copy of the disc as an input, the way the upstream reference projects do.
A pre-commit hook enforces this, blocking disc images, asset directories, container signatures and files over 50 MiB. If you clone elsewhere, enable it:
git config core.hooksPath .githooks
Layout
crates/
gc-formats/ asset format parsers (pure, no I/O beyond the caller's buffer)
gc-extract/ disc pipeline: identify, unpack, verify
gc-game/ game logic: hero, weapons, moby classes, progression, saves
gc-video/ IPU / MPEG-2 decode
gc-engine/ Bevy app: Graphics Synthesizer, VU0/VU1, renderer, frame loop
docs/
disc-identification.md which disc we build against, verified
roadmap.md phases, gates, current status
plan/ one file per subsystem, written as work proceeds
formats/ format specs, written as formats are reversed
tools/
identify-disc.py identify any Going Commando disc image
vendor/
rerac/ pinned upstream reference checkout (not tracked)
Building
Requires a Rust toolchain via rustup.
cargo check --workspace
cargo test --workspace
The host audio backend is disabled in Cargo.toml (see the comment there) so
that the workspace builds without system ALSA development headers. Audio decode
is the last phase of the port and lives in gc-video; re-enable it and install
alsa-lib-devel when that work starts.
Identifying a disc
python3 tools/identify-disc.py <your-disc.iso>
Reports the serial, version and video mode from SYSTEM.CNF, hashes the boot
executable, and warns when the disc is not the supported build. Reads only a
few megabytes, so it is near-instant.
How it will be verified
Visual and behavioural comparison against PCSX2, replaying recorded input and
comparing frames, level by level. The PS2 float model is reproduced rather than
approximated — see AGENTS.md.
PCSX2 is installed and working on this machine; the comparison loop that reads
the game's own memory over its debug protocol is up, and level 0's and level
1's tfrag lighting are verified byte-exact against it. See
docs/plan/pcsx2-verification.md for the
setup and how to run it.
Credits and licensing
This project learns from and is built on the work of others. Licences are
recorded in PROVENANCE.md and notices must travel with any
code derived from them.
- ReRAC — a native Rust/Bevy port of Ratchet & Clank (2002), the first game. ISC. The architecture this project follows.
- OpenRAC / rac2-gc-decomp — matching decompilation research for this game. MIT. Source of verified struct layouts and engine documentation.
- Wrench — community documentation of Insomniac's container formats. GPL, used as a specification reference only; no code is copied.
Ratchet & Clank is a trademark of Sony Interactive Entertainment. This is an unofficial fan project, not affiliated with or endorsed by Sony Interactive Entertainment or Insomniac Games.