Sylpheed port agent 2135d20984 deps: bump the pin to 1a82ade -- the menu screens get their background
WHAT I WANTED FROM IT: 0ed33bc, "a RATC child's name is stated, not inferred".
A child was named by scanning backwards for the last printable run of bytes
before its magic. For `pteff05.t32` the three trailing payload bytes are
38 41 58 = `8AX`, which beat the real name, so the child registered under a name
no element declares and resolved to no sprite.

`pteff05.t32` is the full-resolution background of all five menu screens.

Every menu render this port has produced has been missing its background, and
P1 wrote that up as a fact about the disc -- "the bundle carries zero RATC
children for either, so there is no texture on the disc to export". That is
retracted in docs/DECISIONS.md rather than edited away.

The re-export is contained: six new sprites and nothing else. pteff05 on
main_menu/extras and their JP twins, pteff04 on both titles. Each gains a
`sprite` line and moves `layer_source` from "implied" to "sprite" -- the layer
key is now read from the file instead of the decoders' table of keys measured
off the running game, which is the ratchet turning the right way.

pteff05.png is 1280x720; ptbase.png, which had been carrying the background
alone, is 640x360 drawn at 200 %.

Measured against the live capture rather than the other renderer: settled
main_menu RMSE 8.05 % -> 5.92 %. The reference renderer was missing the same
element for the same reason, so no renderer-vs-renderer diff could have found
this -- the third time a capture has caught something both renderers agreed on.
2026-08-29 08:04:06 +00:00

Sylpheed Godot

A clean-room Godot 4 port of Project Sylpheed: Arc of Deception, starting with the menu shell: developer splash → intro video → title → main menu → submenus.

You need your own copy of the game. Nothing in this repository is game content. An offline exporter reads the disc you supply and writes an open, moddable asset tree; the Godot project reads only that tree and never touches a disc format.

  your disc  ──▶  crates/sylpheed-export  ──▶  export/   ──▶  port/  (Godot 4)
                  (Rust; decoders come from      JSON + PNG        reads ONLY
                   sylpheed-formats)             + OGG + OGV       open formats

Why the wall

Two reasons, and the second is the interesting one:

  1. Godot cannot read IPFB archives, RATC bundles, T8aD textures, XMA banks or WMV video, and it should not learn to.
  2. Modding is a goal of this port. If the runtime reads the original formats, modding means reverse engineering. If it reads JSON and PNG, modding means opening a file.

Where the knowledge comes from

The decoders live in sylpheed-formats, pinned by revision — a separate project, where the reverse engineering happens. Its docs/port/HANDOFF.md is the contract: what has been decoded, what was measured off the running game, and what is known to be undecodable. Read it before assuming a value is on the disc.

Layout

crates/sylpheed-export/ disc → open formats. Regenerates export/ wholesale
port/ the Godot 4 project
authored/ decisions that are not on the disc, each with its reason
export/ generated, gitignored, never hand-edited
tools/ verification harnesses that hold the port to the reference renderer
docs/ the mission, the format spec, the agent's loop prompt

Verifying

sylpheed-cli screen render -- built from the same sylpheed-formats revision the exporter is pinned to -- is the reference renderer. tools/verify-screen draws every exported screen both ways and reports the largest per-channel difference in the frame:

tools/verify-screen              # every screen in the manifest
tools/verify-screen main_menu    # one of them

Where the two disagree, one of them is wrong; docs/DECISIONS.md says which and why, rather than tuning the port until the number goes down.

Status

P1. The exporter writes GP_TITLE's twelve screen builds and their sprites, and the Godot project draws any of them statically at 1280x720 from that tree alone. main_menu matches the reference renderer to within 3/255 on every channel of every pixel. Next: P2, keyframe animation.

Description
No description provided
Readme MIT 820 MiB
Languages
Rust 57.6%
Python 27.7%
Shell 10.6%
GDScript 3.5%
Dockerfile 0.4%
Other 0.1%