ReaperOfVeriod
b3b4d47d97
The 16-byte reading was retracted without a replacement. This searches for one --
every tie vertex region, strides 4, 8, ... up to len/16, keeping any stride where
some byte offset is constant across every unit:
regions examined 1,844
no stride found at all 1,139 (61.7%)
stride 64 491
stride 56 120
stride 72 49
stride 48 12
stride 16 3
64 where a stride is detectable, not 16. And for 1,139 regions there is no stride
in range producing a single constant byte -- those are genuinely variable, or the
element is larger than region/16, which is the same statement.
THE CONTROL THAT CHANGED THE ANSWER
The first run reported 1,561 regions at stride 64. Wrong, and wrong in a way worth
recording: a large stride divides a region into fewer units, and fewer units makes
an accidental constant more likely. Region length is fixed across candidates, so
the widest stride always has the fewest units and the best chance of constancy by
luck alone. The search was reporting its own sampling.
Requiring every candidate stride to cover the SAME minimum of 16 units, and
preferring the SMALLER stride on ties, drops it to 491 and promotes 56 and 72 into
view, which were invisible before.
This is rule 3a's sampling failure in its purest form -- an aggregate over
candidates with different denominators, where the largest denominator wins for a
reason unconnected to the data. The first number was not imprecise; it WAS the
artefact. Worth noting that without the control I would have reported "64" with
confidence and been right by accident, three times the observed figure.
What this does not settle: 64 is the stride where one is detectable, which is not
the same as the stride. The 1,139 regions with no constant byte at any tested
stride leave the element genuinely unknown. But 16 is now excluded quantitatively
-- 3 of 1,844 regions show a constant byte there -- which is the retraction's
content, as a measurement, and a third independent check now agreeing with 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.