16ab24480d
The Decoder closed it by ADDING OBSERVABLES, not by tuning. The vertex buffer carries positions and colours at the same instant, so all four quantities must agree on one t: quad A x solves to 357.88 and quad B x to 357.58, both +/-0.12 units, against 355.75 +/-1.54 and 354.09 +/-1.89 from the alphas. Alpha moves only 0.27-0.33 levels per unit, so one byte of quantisation is worth 1.5-1.9 units -- 6-8 px of sweep at 4 px/unit. That is the whole of the 11.5 px. At t=357.7 the centres land within 0.70 px and both alphas inside one level. THE LESSON IS THE EARLIER ONE INVERTED AND IT IS THE HALF WORTH KEEPING. Checking a wrong rule against alpha made it look confirmed; here the same insensitivity MANUFACTURED a residual that did not exist. An insensitive quantity does not merely fail to falsify -- it invents error. Solve on the fastest-moving field, check the slow one, never the reverse. I was already looking for a pivot rule to explain 11.5 px when they wrote; there was nothing to find. REFUTATION ATTEMPT, survived with a nuance: they state the leaf pivot is (200,90) on a 399x180 sprite, "the pivot is the centre, so rotation displaces it by nothing". Checked against my export -- pivot [200,90], sprite 399x180, true centre 199.5,90. It survives, but the sprite is ODD-WIDTH so the pivot is the centre to within half a pixel rather than exactly. No consequence against their 0.70 px agreement; worth stating because "displaces it by nothing" is the kind of sentence that later gets leaned on for a sub-pixel claim. verify-capture now poses the title at t=357.7 rather than 355: RMSE 21.07 -> 20.92, differing 1.82% -> 1.81%. Marginal, and it is the right pose for a stated reason rather than a better number. AND ptlogo_eff2 IS WITHHELD FOR A BETTER REASON THAN MINE. I had it on caution about untested generalisation; the Decoder points out it is on title_jp and MISSION section 7 scopes out "localisation beyond English", so it is not a question this port has to answer and the parked Japanese capture does not need reviving for it. authored/rendering.json now gives scope first and undecidability second. Widening scope to close a residual would have been the wrong trade. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01N7FiFFFwbvG2uxdcEh8HyF
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.