THPS2 Demo Decompilation

Note: I'm aware that at the moment this codebase is more akin to AI slop than an proper decompilation. This started out as a personal research project into the PSX animation format rather than a full-blown decompilation. The current state of this repo serves as a snapshot for interested parties, but my end-goal is to deliver something user-friendly and most importantly, readable. I intend to spend a lot more time cleaning things up in the future once fully matched, though I have started some of that already.

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Source-only work-in-progress reconstruction of the PlayStation THPS2 demo.

This minimal public snapshot contains the recovered C/C++ under src/ and the scripts needed to compile-check every translation unit. It is an unofficial research project and is not affiliated with or endorsed by Tony Hawk, Neversoft, Activision, Sony, or any other rights holder.

Status

1,635 of 1,646 functions reproduce the original object code exactly (99.33%). "Exactly" means every instruction agrees, relocations included — not merely equivalent behaviour.

The eleven remaining are StartGrind, DoInAirPhysics and DoWallRidePhysics (PHYSICS), Front_Display (FRONT), Redbook_XAPlay (REDBOOK), Bit_Display (BIT), CreateZonePacket (LEVELGEN), setData (IMAGE), ReactToCollision (CAMERA), M3dColij_LineToThisItemCached (M3DCOLIJ) and Wireframe_ProcessPolys (M3D).

The measurement itself is not reproducible from this repository: verifying it requires the target disassembly and debug symbols, which are target-derived and deliberately excluded. What is published is the source those results were produced from.

Progress reporting

build/report.json is a decomp.dev progress report in objdiff's report schema, uploaded by .github/workflows/progress.yml as the SLUS_900.86_report artifact.

It is committed rather than built in CI, because this repository deliberately cannot build: producing either the target or the base objects needs the original executable, the Sony PSY-Q SDK headers and ASPSX/PSYLINK, none of which is redistributable. The report is generated from the project's canonical measurement gate — which refuses to publish against stale or incomplete artifacts — and is refreshed in the same commit as the source it describes. CI validates its schema, internal consistency and unit totals before publishing it.

Not included

This repository intentionally excludes:

• the original executable, game assets, MAIN.SYM, and MAIN_STRUCTS.h;
• Psy-Q SDK files, ASPSX, PSYLINK, and other Sony software;
• downloaded compiler or assembler binaries;
• target disassembly, generated objects, link products, and matcher caches;
• recovered or leaked original source and development-project files; and
• private work logs, experiments, IDE state, and local paths.

Use only external inputs that you are legally authorized to possess.

Compile check

The supported environment is Linux or WSL with Bash, Python 3, GNU cpp, wget, and tar. Supply your licensed Psy-Q 4.6 (DTL-S2360) SDK headers at:

toolchain/psyq-4.6-sdk/INCLUDE/

Then run:

bash setup_toolchain.sh
bash test_all_tu.sh

setup_toolchain.sh validates the user-supplied SDK headers and downloads the separately distributed GCC compiler. It does not download Sony software or game files.

test_all_tu.sh compiles every recovered translation unit as a source-integrity check. It does not link a game executable or perform binary matching; those workflows require proprietary and target-derived inputs that are deliberately outside this repository.

build.sh is included for reference only. It drives the full assemble, link and match pipeline and depends on tooling and target data this snapshot excludes, so it will not run here.

The compiler is stock, and checked

Canonical builds use the unmodified egcs 1.1.2 cc1 and cc1plus that setup_toolchain.sh downloads. toolchain/verify_egcs_1_1_2.py checks both against their stock SHA-256 identities, and setup_toolchain.sh and test_all_tu.sh run that check and fail closed, so a modified or unknown compiler is rejected rather than quietly producing different code.

Compiler patches are out of bounds for this project by policy: a patched or hybrid compiler is a noncanonical experiment and may not publish matcher artifacts or milestone counts.

Evidence and rights

The reconstruction is based on permitted binary/debug evidence and reproducible compiler experiments. Unlicensed original source, editor/tag databases, and development-project files are not accepted as evidence.

This repository has no blanket open-source license. See LICENSE_SCOPE.md for the copyright and third-party-rights scope.