Commit Graph
153 Commits
Author SHA1 Message Date
ReaperOfVeriod a9e43e39c1 Parse the level container header, naming each level's four extents
The first typed structure read from real data. Every one of the 27 level
containers begins with the same 0x60-byte header, which turns the generic pair
table into named assets: data, sound_bank, gameplay and occlusion, plus three
chunk descriptors.

Two things about this header are worth stating because both are silent failures
rather than errors.

Sizes here are sector counts, not byte counts. The generic G/ pair table on the
same disc uses byte counts, so both readings type-check and the wrong one is off
by a factor of 2048. The tiling check settles it: read as sectors, the four
extents tile every one of the 27 containers exactly; read as bytes they overlap
each other.

Level id is not container order. LEVEL21.WAD reports id 30, so a level was cut
from the disc and its number left a gap. Anything keying off file order -- a
save slot, the planet select screen -- would mislabel that planet. There is also
a second trap in the same area: the ISO filesystem sorts names alphabetically, so
LEVEL10 precedes LEVEL2, and any tool needing order has to sort numerically.

The header's field at 0x04 is zero on all 27 levels. It is not the container
size despite looking like one, so the code reads it as a runtime field and takes
the container length from the ISO entry instead.

Measured across all 27 levels, three invariants now hold in tests: extents tile
in file order; extent coverage plus chunks reaches at least the end of the
container (21 levels land exactly on its length, 6 leave 134 to 689 sectors of
trailing data); and exactly one level's id differs from its container index. The
coverage assertion is >= rather than == on purpose -- 21 levels end one sector
past the file end because the header occupies sector 0, and asserting equality
would truncate a level's tail.

gameplay is left unparsed and that is recorded rather than hidden. It begins
"WAD" plus a per-level byte and does not decode with the WAD LZ77 decoder: all
27 levels produce plausible output for the first packet and then fail on a rule
the format's own encoder never breaks, which means the input is wrong rather
than the decoder. docs/plan/level-assets.md records what is ruled out and what
to try next.

66 unit tests, plus 7 integration tests against the real disc. The unpack hash
table is unchanged, so this adds parsing without altering the pipeline.
2026-10-09 16:20:25 +02:00
ReaperOfVeriod 027373e65b Add the disc pipeline: identify, unpack and verify
Phase 1 of the roadmap. The disc is now turned into verified asset files, and
the result is checked against a committed hash table rather than against
whatever happens to be on disk.

  gc-extract identify disc.iso        SCUS_972.68 v1.01 NTSC, ELF SHA-1 matches
  gc-extract unpack   disc.iso out/   5135 files, 4,500,106,960 bytes, 10.8s
  gc-extract verify   out/ table.tsv  OK: 5135 files match

All 92 G/*.WAD containers parse. MPEG1 and MPEG2 are raw video and pass
through whole; the other 90 are indexed containers whose extents are extracted
individually.

Formats recovered and written up in docs/formats/:

- iso9660.rs. R&C2 lists its assets in the filesystem, unlike R&C1, so a
  directory walk is the primary asset index. Three details that all fail
  quietly rather than loudly: directory records store every 32-bit field twice
  (little-endian then big-endian), the CD001 signature is at sector offset 1
  rather than 0x8001, and the directory flag at record offset 25 is
  authoritative where the identifier's trailing slash is not.

- global_wad.rs. Container headers hold a table of extents. All 92 indexed
  containers use {offset in sectors, size in bytes}. Measured, not assumed: the
  sector-count reading places every entry of all 27 LEVEL<n> and all 27
  AUDIO<n> containers out of range, while the byte reading places all of them
  correctly. SCENE<n> is the one exception, a flat sector list whose extents
  are sized by the next value.

- wad.rs. Insomniac's LZ77 stream: four flag-selected packet classes, with 0-3
  trailing literal bytes per packet carried in unused low bits. This is not a
  bit stream, which is why it resists the usual LZ77 reading.

- buf.rs. A bounds-checked reader, so untrusted 2003 disc data produces typed
  errors rather than panics.

gc-extract carries the three stages and a SHA-1 implementation with FIPS 180-4
test vectors, so identification works without pulling in a crypto dependency.

Verification: 54 unit tests, plus four integration tests that run only when
GC_DISC names a disc. Those four check identification against the recorded
values, cross-check the Rust identifier against tools/identify-disc.py, parse
all 92 containers, and confirm a full unpack matches the committed table. The
committed table is 316 KB of sizes and SHA-1s for all 5,135 files: hashes only,
no game content, so it is safe to version and it turns "matches retail" into
something a test can assert.

docs/plan/disc-pipeline.md records two wrong turns, because both are easy to
repeat and both failed by producing plausible wrong output rather than an
error: the container table was read backwards, and the LZ77 stream was modelled
as a bit stream. The first survived because it happened to be correct on the
one container used for manual checking.
2026-10-09 16:08:30 +02:00
ReaperOfVeriod a02f79a6d1 Initialise native Rust port of Ratchet & Clank: Going Commando
Sets up the foundation for reimplementing the PS2 game in Rust rather than
emulating it. Nothing is implemented yet; this is the scaffold, the verified
target and the working agreements that keep a long project coherent.

Target disc, verified against a real image:

  SCUS_972.68 v1.01, USA Black Label, NTSC 60 Hz
  boot ELF 2,618,684 bytes, SHA-1 bacda860...d098a77, entry 0x00131AE8

The entry point independently matches the value recorded by the rac2-gc-decomp
community reference, which cross-confirms the identification. This is the exact
build the upstream research pins; Greatest Hits v2.00 is a different binary and
is not the target. NTSC matters beyond label compatibility: PAL discs run 50 Hz,
which would make chargeboots and other speed-sensitive movement run at 5/6
speed. Verifying the disc before writing movement code avoids discovering that
in Phase 5.

Contents:

- Five-crate workspace (formats, extract, game, video, engine) on Bevy 0.19.1,
  matching the version ReRAC uses so its Graphics Synthesizer and VU work stays
  portable. `cargo check --workspace` is clean.

- tools/identify-disc.py, which reproduces the identification against any
  disc image and distinguishes a truncated dump from a non-PS2 image.

- .githooks/pre-commit, refusing game data from entering git history: disc
  image extensions, asset directories, container signatures at offset 0, and
  files over 50 MiB. Verified against seven cases including a disc image
  renamed to look like source. Now that this pushes to a remote, this matters
  more than it would have locally.

- AGENTS.md, the operating agreements: no game data ever, reproduce the PS2
  float model rather than approximating it, bound every read, verify against
  the real disc.

- PROVENANCE.md, recording that this follows ReRAC (ISC) and learns from
  rac2-gc-decomp (MIT). Wrench is used as a written specification only and no
  GPLv3 code is copied, since that would relicense everything derived from it.
  RAC2Decomp is explicitly not used: its provenance is disputed in the upstream
  community reference, and it targets the wrong region.

- docs/roadmap.md, phased so the riskiest unknowns are retired early. The two
  that matter: overlay relocation transfers from ReRAC and makes 27 level
  overlays tractable, while VU1 microcode is binary and is the hardest single
  item. Phase 5 is a deliberately scoped Veldin vertical slice as the go/no-go.
2026-10-09 15:42:10 +02:00