ReaperOfVeriod
4ab30e1f4d
Picked the tie flat encoding to close, sincee5cd3dfleft it as the largest unidentified field. What came out was a retraction of my own earlier claim. The texcoord slot was recorded at i16[4]/i16[5] on a 73.6% "both multiples of 4096" score. Two problems, either of which would be enough. First, that 73.6% was computed on the 16-byte element reading thate5cd3dfretracted. Half the records are VIF packets and half are flat, so the figure describes neither population cleanly. Second, and decisive on its own: measured on the FLAT records only -- levels 0-2, 930 records, 47,909 vertices -- the question that separates a 12.4 fixed-point texcoord from anything else is how many of a slot's distinct values are multiples of 4096 at all. For a texcoord it is all of them. slot distinct of which are multiples of 4096 i16[4] 1,488 16 i16[5] 1,261 16 i16[6] 966 4 i16[7] 489 5 One percent. The dominant PAIRS do look like UV corners -- (0,0) 5,773, (0,4096) 5,500, (4096,4096) 5,059, (4096,0) 4,521 -- and that is precisely why the claim was persuasive. But it is a statement about the most frequent values, not about the field: 1,472 of the 1,488 values in i16[4] are not multiples of 4096 at all. This is the moby class-ID artifact one level down. A small set of dominant values that happen to satisfy the test, scored as though the whole population did. The arithmetic was right about the popular values and the conclusion was wrong about the field. The retraction commit itself warned about exactly this shape, which makes the repeat more useful than the original claim was. So the texcoord slot of a flat tie record is NOT identified. What survives is the boundary work -- vert_ofs + vert_size + scissor_size is the region length -- and the LOD1/LOD2 sharing result, which is stride-insensitive and survives the stride retraction. Both docs updated: the roadmap's two [x] claims about the texcoord field and about i16[3] selecting its encoding are now [~] with the evidence, and the format file has a retraction section giving the table above. I did not find a replacement reading for i16[4..7]. Three discriminators were tried -- LOD sharing, multiple-of-4096 rate, value-set size -- and each came back ambiguous or negative. That is worth recording as the state rather than generating a fourth hypothesis. 258 tests.
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.