# PROVENANCE

This project is built on the work of other people. Their licences apply to their
code, and those notices travel with anything derived from it.

## Summary

| Project | Role | Licence | Code copied into this repo? |
|---|---|---|---|
| [OpenRAC/rac2-gc-decomp](https://github.com/OpenRAC/rac2-gc-decomp) | Byte-exact reconstruction research for the same disc (SHA-256 verified identical) -- supplied `$gp`, the `.lit` load base, the seven-section program layout, the `lvl.vtbl`/`lvl.camvtbl`/`lvl.sndvtbl` dispatch record shapes, and the 256-byte `MobyInstance` field map transcribed into `gc_formats::moby` | GPL-3.0-or-later | Not yet; vendored read-only at `vendor/rac2-gc-decomp`. Note: its *function addresses* did not transfer (they land in NOBITS memory); its *struct layouts* are used as layout claims, not verified against disc bytes |
| [ReRAC](https://github.com/re-rac/rerac) | Native Rust/Bevy port of Ratchet & Clank (2002) — the architecture this follows | ISC | Not yet; derived from, attribute when used |
| [OpenRAC / rac2-gc-decomp](https://github.com/OpenRAC/rac2-gc-decomp) | Matching decompilation research for this game | MIT | No — consulted for documentation |
| [rac2-gc-decomp community reference](https://github.com/OpenRAC/rac2-gc-decomp/blob/RAC2/docs/COMMUNITY-ENGINE-REFERENCE.md) | Engine architecture notes, moby struct layout | MIT | Documentation only |
| [Wrench](https://github.com/chaoticgd/wrench) | Insomniac container format documentation | GPLv3 | **No.** Specification reference only |
| [RAC2Decomp](https://github.com/platypet2217-star/RAC2Decomp) | Functional decompilation, PAL | MIT | **Not used** — see below |

## Game content: none

No game assets, disc images, extracted data, BIOS dumps or proprietary
toolchains are or may be committed to this repository. The build takes the
user's own legally obtained disc as input. This is enforced by
`.githooks/pre-commit`.

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.

---

## ReRAC — ISC

The direct model for this project. ReRAC re-implements the *first* Ratchet &
Clank as a native Rust application on Bevy, reading assets from the player's own
disc. This project follows the same architecture for the second game.

What we take from ReRAC:

- **The architecture.** Crate split (`formats` / `extract` / `game` / `engine` /
  `video`), Bevy 0.19.1, the PS2 float-model discipline, and the milestone
  gating style.
- **Overlay relocation.** `rc-formats::level_overlay` implements
  relocation-tolerant code-identity matching so one level's function can be
  found on every other level. R&C2's 27 overlays have the same seven-section
  layout (`.lit`, `.bss`, `.data`, `lvl.vtbl`, `lvl.camvtbl`, `lvl.sndvtbl`,
  `.text`), so this machinery transfers directly. It is the single most
  valuable thing we inherit.
- **Verified format specs.** `docs/formats/disc_layout.md` documents all four
  R&C games' container layouts, derived from behavioural analysis.
- **Discipline worth copying.** Golden tests against committed snapshot hashes;
  bit-exact CPU/GPU identity checks; documenting negative results.

ISC permits use, modification and redistribution with the notice intact. When
code is derived from ReRAC it must carry:

```
Copyright (c) 2026 ReRAC contributors
Licensed under the ISC License.
```

Pinned checkout: `vendor/rerac` at commit
`d00cb00ad4018f776556e72640dcba438d098a77` (2026-10-09). Not tracked by git —
clone it yourself; the commit is recorded so everyone uses the same one.

Note that ReRAC targets a *different game*. Its per-level documentation is a
useful hint about Insomniac's engine in general, but R&C2's spherical worlds
changed roughly 50,000 lines of gameplay code, so nothing about R&C1's
movement, camera or level geometry should be treated as directly applicable.

## OpenRAC / rac2-gc-decomp — MIT

Matching decompilation research for **this** game, targeting exactly our disc
(`SCUS_972.68` v1.01). It reconstructs the boot ELF and all 27 level overlays
byte-for-byte, and publishes verified struct layouts, symbol names and engine
documentation.

We use it as a **reference**, not as source. Its value is that it tells us what
the structures *are*, which saves a great deal of guessing.

Its matching progress is low (~1.6% of code in C) and byte-matching is not a
prerequisite for this port anyway — it is a verification technique. We are not
pursuing a byte-identical rebuild.

## Wrench — GPLv3, specification reference only

Community documentation and tooling for Insomniac's container formats. We use
the written format *specifications* as a reference for how the data is laid
out.

**No Wrench code is copied into this repository.** That is deliberate and
load-bearing: copying GPLv3 code would impose GPLv3 terms on everything derived
from it. Clean-room reimplementation from a written specification does not. If
this boundary is ever crossed, the licensing of this project changes and
`AGENTS.md` must be updated to say so.

## RAC2Decomp — not used

A functional (non-byte-matching) decompilation of the PAL release. It is
recorded here only so its absence is a decision rather than an oversight.

The `rac2-gc-decomp` community reference explicitly flags it as *"criticized by
community for questionable provenance and non-clean-room C code. Avoid
copying."* Given that we are building a reimplementation and its provenance is
disputed, we do not use it. It is also the wrong region: PAL, 50 Hz.

## Third-party libraries

Rust dependencies keep their own licences; see `Cargo.lock` and each crate's
`LICENSE` file. Notable ones:

- **Bevy** (MIT / Apache-2.0) — application framework and wgpu renderer.
- **wgpu / wgpu-hal / wgpu-types** (MIT / Apache-2.0) — GPU abstraction used for
  the Graphics Synthesizer reimplementation.
- **bytemuck** (Zlib OR Apache-2.0 OR MIT) — zero-copy casts over asset
  structures.
- **thiserror**, **anyhow** (MIT OR Apache-2.0) — error handling.

## When you add a dependency or port code

1. Record it in this file, with its licence and what you took.
2. Keep the upstream notice intact in any file containing derived code.
3. If it would change this project's licensing terms, stop and say so first.

## Update 2026-10-15: decomp advanced to 8a174cb

Vendored checkout moved from `aca4f59` to **`8a174cb`**, 18 commits ahead
(`origin/master`). All 18 are `src/game` function-matching work; **no header,
doc, config or `config/levels/functions.tsv` changes**, so the function extents and
level catalogue this project uses are unaffected.

What is new and usable: **14 of the newly matched functions fall inside the
overlay `.text`** (`0x2a3b80`-`0x447900`), so they are decomp addresses verified
against the same code this project runs:

    002A7750 002AA800 002B3868 002B6120 002B7E28 002C7748 002CD8C0
    002D5E98 002DDEC8 002DF1B8 002E7018 002F5220 002FC8D0 00300618

None of them is camera, frustum or GS code -- the bodies are game logic and
toolchain-status material. Recorded because matched-in-overlay addresses are the
thing `PROVENANCE.md` says is reliable here, and `20655c7` needs exactly that kind
of anchor to follow `UpdateCamera_6` from `lvl.camvtbl`.