ReaperOfVeriod
7b6de36958
The stride retraction (e5cd3df) disowned the 16-byte element reading and the
95,612-vertex population that came with it. Two committed tests still compute
exactly those figures and still pass:
tie_vertex_element_is_16_bytes_with_fixed_texcoords
tie_vertex_layout_is_selected_by_i16_3_high_byte
They pass because the arithmetic is self-consistent about a WITHDRAWN population --
the same shape as the chunk uniformity claim, one level up. The parser slices at
16 bytes, the test reads the slices, the numbers agree, and nothing in the loop can
notice the stride is wrong. A green test that cannot fail is the exact failure mode
this session has been cataloguing, and here it was left in place by someone else's
retraction rather than mine.
Both are KEPT and marked, for a specific reason: each is the record of what the
16-byte reading produces, so the retraction is visibly about the stride rather
than about the arithmetic. Deleting or renaming them would erase the thing the
retraction is a retraction OF, and there would be no way to check later that the
numbers moved because the layout changed rather than because someone edited a
constant.
The marking says, at the top of both:
Do not quote the 82.5% figure as a property of tie vertices. It is a property
of one reading of the vertex region, on a population the retraction disowned.
TWO DENOMINATORS, BOTH CORRECT, 92.9% APART
The layout test reports (4,5) as 12-bit fixed on 92.9% OF VERTICES. A separate
measurement on flat records found only 16 of 1,488 DISTINCT i16[4] values are
multiples of 4096.
Both are right. Most vertices use the handful of UV-corner values -- (0,0),
(0,4096), (4096,4096), (4096,0) -- which are all multiples of 4096, so the
per-vertex rate is high. The other 1,472 are not, so the per-distinct-value rate is
1%.
That gap IS the artifact, and naming both denominators is the most useful thing
available about it. A percentage over vertices and a percentage over distinct
values answer different questions, and only one of them was ever asked about --
which is the same base-rate error as the class-ID slot, where a bound that selected
for small numbers made nine values look like 305x enrichment.
268 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.