sylph-decoder 7b5a4aa041 re: the paint-order tie-break costs one pixel, on one screen we do not ship
Closes the open half of Q3. `ui-paint-order-derived-check.md` bounded WHERE a
wrong tie-break could show -- overlapping same-key pairs -- and said outright
that nobody had measured how many change a pixel.

At the instant the player sees, the answer is: at most 1 px at max channel
difference 1, on the JAPANESE title only (`ptlogo2` x `ptlogo_tm`, 5 px of
shared ink). Exactly 0 px on all five port screens.

The earlier 24-pair bound was counted at `rest()`, and 10 of the title's 11
overlapping tied pairs are between `ptlogo_back2eff1`..`eff5` -- the five
transient flashes from the settle-time finding, transparent on the settled
screen. A tie between two invisible elements cannot cost a pixel.

Not a knife-edge. Sweeping every keyframe time and every midpoint between
keyframe times, the live-pair count is flat across the ENTIRE settle window:
1 on the EN title, 2 on the JP title, 0 on all four loading bundles -- whose
tie is live only at t17..t33, during the build-in, which matters because
their settle windows are narrow enough to deserve little trust otherwise.

Controls: every entry reporting zero also swaps an overlapping DIFFERENT-key
pair, which must and does move pixels (25 310 / 268 698 / ~765 000 px). Zeros
are explained by shared-ink counts rather than asserted -- the `ptframe` pairs
overlap by bounding box and share 0 px of ink. Entries 0/1/12/15 have NO live
control and their zeros rest on keyframe data rather than a render; recorded
as the weaker claim it is.

Refutation attempt on the corpus's "24 overlapping pairs": it SURVIVES as a
rest-pose count -- an independent recount reproduces entry 7's 16 exactly.
What is overturned is its interpretation as the risk surface.

`tie_break_pixel_cost` gains a settle-time case and an alpha/scale filter on
its rect test; `tie_cost_over_time` is new. Also strips 611 bytes of captured
cargo warnings from the head of the committed tie census.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QsEPXWVaEpyfudtR6re1Pd
2026-08-29 19:35:29 +00:00

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-cli and 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

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.

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