README

Akuji the Demon — source reconstruction

Rebuilding the source of Akuji the Demon, a Japanese doujin action-platformer for Windows, written in Borland Delphi and released around 2001. Its source was never published; this repository reconstructs it from akuji.exe, in Object Pascal.

The output is the source: it compiles with Free Pascal and Lazarus, and it is cross-platform because Free Pascal is — not through a porting layer. There is no SDL layer and no C.

Where it stands

The game is completable from start to finish. "149 / 149" means every game-layer function has code rather than a description of code; it does not mean every one has been verified. notes/audited.md carries one row per function saying exactly what evidence exists for it, and 47 of those rows say "none yet".

Layout

akuji-re/
????????? CLAUDE.md          the working rules - read before changing anything
????????? src/               the reconstruction (Object Pascal, builds to akuji.exe)
???   ????????? akuji.lpr          entry point
???   ????????? screens/           main form, menus, dialogue, opening, ending
???   ????????? gameplay/          state, session, player, entities, camera, stages
???   ????????? events/            event data, command decoding, script execution
???   ????????? render/            fonts, surfaces, sprites, tile maps, backgrounds
???   ????????? media/             archives, sound effects, PCM output, MIDI
???   ????????? components/        replacements for the third-party DirectX suite
???   ????????? selftests/         the executable's self-test modes
├── tools/             verification and analysis; check.sh is the gate
├── notes/             the decoded formats, the audit ledger, the findings
├── ghidra_scripts/    Ghidra scripts, incl. the differential emulator
├── ghidra/            the Ghidra project database (Git LFS)
└── tests/fixtures/    a real shipped save file, tracked on purpose

Building

Requires Lazarus 4.8 with Free Pascal 3.2.2 and the LCL package.

lazbuild src/akuji.lpi          # produces src/akuji.exe

The game data is not in this repository — you need your own copy of the game. Point the tools at its directory (the one containing data/).

Verifying

One command runs the build, the self-tests and every static check:

tools/check.sh "/path/to/game directory"

It is a commit gate on purpose: a single command, so a broken build cannot slip through a shell chain. It covers 14 self-test modes, the reference decoders, the audit ledger, the divergence register, record layouts, table extents, the frame loop's shape, and a negative control that must fail.

The differential suite is separate because it drives Ghidra headless for minutes:

python tools/emudiff.py          # all case sets
python tools/emudiff.py handler_live

It executes the original's own machine code under Ghidra's emulator and requires the reconstruction to agree, case by case. Ghidra 12.0.4 is the version in use.

Reading order

CLAUDE.md first — it is rules, not reference, and it is short. Then:

Open items

• The v1.0 binary baseline is stale. tools/samebinary.py fails and check.sh is red because of it. Splitting the self-tests out of akuji.lpr moved .text; no game function changed length and the differential suite gives identical results before and after, but the baseline is deliberately not re-recorded until the game has been played. See notes/status.md.
• 47 game functions are unverified. Not suspect — unproven.

Data files

Flat data\ directory: tk###.dat tile maps and ev###.dat event scripts (66 each), surf##.dat and spr##.dat (10 each), plus system.dat, stage.dat and save.dat. Sound effects are .wav under data\wav\, music is .mid, and bitmaps come from the bmp.qda archive.

src/gameplay/PlayerState.pas maps directly onto save.dat; changing its packed record breaks existing saves.

License

A reverse-engineering project for preservation and study. Akuji the Demon is copyright its respective owners. No game data or original binary is distributed here.