The human chose Option A: teach sylpheed-formats own renderer to draw rotation_deg so it and the port stay comparable and verify-screen keeps meaning someone is wrong. Three pieces, because rotation alone does nothing on the title. blit gains a rotated path that draws by inverse mapping over the rotated bounding box, turning about the pivot, whose absolute position is invariant under scale; zero rotation keeps the original forward-mapped path byte for byte so non-rotating screens cannot regress. compose draws a nested .rat leaf when the leaf carries geometry the parent does not, which is the sweeps case, but not as a blanket rule since a button s leaf duplicates its parent. And --at poses leaves at a keyframe time, because the sweeps hold off-screen at x=1521 so a resting composite omits them. A trap found the hard way: posing EVERYTHING at one global time is wrong, because a top-level group s final keyframes are its exit ramp and rest() deliberately stops before them. Posing the title at t=358 walked every parent into its exit and drove the disagreement from 10.92 to 61.74. So at poses leaves only. Controls: 0 and 360 degrees byte-identical to the unrotated path, 90 degrees swaps a 10x4 to 4x10, area conserved within 15 percent, centroid stays on the pivot. 116 lib tests pass, main_menu unchanged at 9.26. And the verification did not show what it was meant to, which is reported rather than buried: scanning the pose time against the title capture gives 10.73 to 11.17 against a 10.92 baseline -- flat, no minimum, best 1.7 percent. The whole-frame mean is dominated by the tone curve, and the renderer still does not draw ptlogo1/ptlogo2 at all, which is a far larger spatial gap than two translucent sweeps. So rotation is correct in isolation and no screen regressed, but whether it closes the port s 1.81 percent is not established here. 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.