01fc4cd133
The Decoder found it and it is not geometry: my leaf path pairs each pose with the NEXT pose's time. Fed my pairing into its own interpolation it reproduces -324 to the digit; corrected, t=355 gives centre 980.5 against 992.0 measured. So there was no 1300 px pivot mystery, and saying both numbers rather than hunting one is what surfaced it. CORRECTING BLOCKED: this was never gated on a branch landing. The row said the change "cannot be taken yet ... reaches the port only when that branch lands on main". Wrong -- ui_layout.rs in this checkout carries the corrected association behind SYLPHEED_KF_TIME_SHIFT=1 and has all along. I read that file twice this session, once for rotation_deg and once for the leaf note, without noticing the switch. Ran the experiment. Re-exported under the shift and asked the oracle: publisher_logo 1.00% -> 0.75% better developer_logos 0.39% -> 0.33% better title RMSE 21.07 -> 20.41 better (area 1.82 -> 1.86, worse) main_menu 0.06% -> 0.10% worse extras 0.20% -> 0.24% worse NOT DECISIVE, and the reason is the point: under the shift the untimed keyframe moves from LAST to FIRST, while `pose_at` is written around "the final keyframe carries no t, so it is given a synthetic time exit_ramp_units after the last timed frame". The numbers measure a renderer/association mismatch, not the association. Adopting it means re-deriving exit_ramp_units, settle_units, spin_period_units and the plate against a layout where the untimed frame is first. Export reverted to the default; doing that work hastily is how a 1.8% gap becomes five wrong ones. THE METHODOLOGICAL POINT IS THE DECODER'S AND IS THE BEST THING HERE: its rule matched because alpha at t=355 sits inside a long segment where a one-keyframe shift barely moves it, while x sweeps 1560 px over the same span. It confirmed on the insensitive quantity, I was wrong on the sensitive one, and neither of us saw it until they were compared. CHECK A NEW INTERPRETATION AGAINST THE FASTEST-MOVING FIELD YOU HAVE, NOT THE ONE THAT HAPPENS TO AGREE. That is a control chosen where it could not fail, which is a different failure from the uncontrolled instruments this session has collected. An 11.5 px residual is left and is not to be fitted. 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.