f0fc4afd10
Left open earlier as do-not-fit. Closed by adding observables rather than tuning a parameter. The draw s vertex buffer carries positions and colours at the same instant, so all four quantities must agree on one t. Solving independently: quad A x gives 357.88, quad B x 357.58, quad A alpha 355.75, quad B alpha 354.09. The alphas are about 50x less precise per unit of time because alpha is a byte changing by only 0.27 to 0.33 levels per keyframe unit, so a single level of quantisation is worth 1.5 to 1.9 units, which at 4 px per unit is 6 to 8 px of sweep. The 11.5 px was that. At the position-derived t = 357.7 every observable lands: centres within 0.70 and 0.48 px, both alphas inside one level, and the parent alpha is 0 throughout. And there is no pivot correction to find -- the leaf pivot is (200,90) against a 399x180 sprite, so the pivot is the sprite centre and rotation displaces it by nothing. The methodological point is the one this exchange started with, inverted. Earlier a rule looked confirmed because it was checked against alpha, the insensitive field. Here the same insensitivity manufactured an apparent 11.5 px error. The insensitive quantity does not merely fail to falsify, it invents residuals. Solve on the fastest-moving field and check the slow one, never the reverse. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01QsEPXWVaEpyfudtR6re1Pd
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.