3895f3d686
Question 1's behavioural half is answered elsewhere and measured. This is
the other half -- which function -- and it is not found. Recorded as a
bounded negative so the next attempt does not repeat four searches.
Excluded, all by exhaustive scans of the image:
integer lerp shape (divw with mullw and subf within 10 instructions):
28 sites image-wide, NONE in the UI region 0x82200000-0x823FFFFF
mulli by 40, the keyframe record stride: 31 sites, NONE in the UI region
addi rX,rX,40 in the UI region: 43 sites; the screen/bundle ones at
0x823CCA6C and 0x823CCA94 disassemble to a 40-byte container COPY loop
(CTR=10, ten-word copy), a vector reallocation, not an evaluator
fmadd-family in the UI region: 811 sites over 142 pages -- too diffuse to
select on, so float is neither excluded nor narrowed
The first two together say the evaluator does not compute its fraction with
integer multiply-and-divide and does not index records by multiplication.
With the measured steps landing on exact integers, the likeliest remaining
shape is a float lerp with a per-segment reciprocal, converted to a byte --
stated as a hypothesis, not a finding.
Names the route I would take next and did not have budget for: trace DOWN
from the quad emitter. sub_823C2AC0 has exactly 6 callers, four of them
sibling emitters, and sub_822380B0 reads its colour from this+0x04..0x10.
Whoever writes those fields is one step from the interpolator.
Reach stated: the two opcode negatives are exhaustive over the whole image
rather than sampled, but they do not exclude the interpolator living
outside the UI region, which is an assumption inherited from
ui-quad-class-foothold.md and not independently checked.
Not blocking the port: it needs whether to lerp and how, which is answered.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Jc4pciRArGHfxGGhEbwp5t
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.