f3d3594c9c
Last iteration left an unidentified full-screen untextured quad decaying 255->15 during a menu->title transition, which build 5's declaration does not account for. Hypothesis: it is the INCOMING screen's own pteff00, which opens at a255 and clears. 8 frames matching build 4's declared 16 units is a FIT, so the test was a transition whose incoming screen declares something else: title->menu brings in build 5, 0->12 = 12 units = 6 frames. Prediction recorded before the run. Measured: menu->title decay 8 frames (incoming build 4, declared 8), title->menu decay 5 frames (incoming build 5, declared 6). Different incoming screen, different decay, in the predicted direction. The second is one frame short of prediction, inside the documented +-1. The tell that clinches it: a screen contributes TWO primitives, pteff00 at 255 and pteff02 at 64. The settled menu's untextured set is [64]; at frame 34 it becomes [64, 255, 64] -- build 4's opening pair, which no single element explains. Bonus, and it closes the alpha puzzle: in capture 2 the outgoing quad ramps with no other untextured quad present -- 63, 127, 191, 255, steps of exactly 64, four frames, against build 4's declared 261->269 = 8 units = 4 frames. Exact and exactly linear. Capture 1's 102/127/255 was a composite of two overlapping quads, as sylpheed-port proposed. The thing neither of us predicted: the two directions are not the same shape. (A) title->menu is SEQUENTIAL with a real black interval of 5 frames (~10 units, against the port's authored 9). (B) menu->title is a CROSS-FADE with no black interval at all -- the incoming title starts drawing at frame 34, before the outgoing menu's quad begins ramping at 40. Authoring one hold for both directions inserts black that (B) does not have. Also fixed: fade_pair.py's automatic rising/decaying classifier worked on capture 1 and produced nonsense on capture 2, where the title has no full-screen primitive at rest and the heuristic latched onto a transient. It now prints and does not decide. Refutation attempted: sylpheed-port's structural prediction of a 6-frame decay for an incoming menu. Measured 5. Survives as direction, one frame short as duration; recorded as both. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Wuu56cE8vJGTBtn1ppsk8v
Sylpheed
A clean-room reverse engineering and port project for Project Sylpheed: Arc of Deception (Xbox 360, 2007).
Three things live here, in one repository so that a change spanning them lands as one commit:
| The decoders | crates/sylpheed-formats — the disc's formats, read and verified disc-wide |
| The port | port/ — a Godot 4 project, plus crates/sylpheed-export which converts a disc into the open asset tree it reads |
| The corpus | docs/re/ — what has been reverse engineered, with its evidence, its retractions and its dead ends |
You need your own copy of the game. No game content is in this repository and none ever will be. The exporter reads the disc you supply.
The oracle is the real game
sylpheed-cliand the Explorer are tools for verifying our decoding. They are hypotheses under test and they have been wrong. When something must be checked against the truth, the truth is the game running in Xenia Canary, captured — not any renderer of ours.
This is stated first because getting it backwards is the most expensive mistake this project has made.
Layout
crates/
sylpheed-formats/ the decoders. Disc-wide verified; the corpus is its spec
sylpheed-cli/ headless tools -- render a screen, dump a table, probe audio
sylpheed-viewer/ the Explorer: a human's window onto the disc. STATIC data only
sylpheed-export/ disc -> the open, moddable asset tree
port/ the Godot 4 project. Reads open formats ONLY
authored/ decisions that are NOT on the disc, each with its reason
data/
base/ generated by the exporter. Gitignored, never hand-edited
mods/ drop-in overrides. Yours
docs/
re/ the corpus: findings, refutations, method traps
game/ how the game is navigated -- menus, modals, flight
port/ the port's mission, its handoff contract, modding rules
agents/ how the agent team works together
tools/ capture harnesses, probes, the share tool
exchange/ transient inter-agent files. NOT in git
docker/ the agent containers
Where to start
docs/re/INDEX.md— what is decodeddocs/re/REFUTED.md— what has been tested and dieddocs/re/METHOD.md— traps this project has already paid fordocs/game/navigation.md— how the game is navigateddocs/port/MODDING.md— why the asset tree looks the way it does
Xenia Canary is a separate repository: it is a fork tracking upstream, and it carries our instrumentation.
Conventions
Confidence is per claim, never per document: ✅ CONFIRMED · 🟡 PROBABLE ·
❔ HYPOTHESIS · ❌ REFUTED. A withdrawn result is kept with its reasoning
rather than deleted — that is why the numbers here can be trusted.