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Reverse-engineer the single-stream XBG7 geometry layout (clean-room: hex
inspection + geometric validation of the retail disc's
hidden/resource3d/*.xpr, no game code copied) and present models as
textured 3D meshes in the explorer.
Format (docs/re/structures/xbg7-mesh.md): XBG7 geometry resources sit
inside XPR2 containers alongside TX2D textures. For ~25 single-stream
models (weapons, simple props) the data section is a sequence of
sub-meshes, each an u16-BE triangle-list index buffer followed (after a
fixed 12-byte header) by a stride-24 vertex buffer whose declaration is
in the descriptor: POSITION f32x3 @0x00, NORMAL f16x4 @0x0C, TEXCOORD
f16x2 @0x14. Sub-mesh (vtx,idx) counts come from descriptor tuples.
The +12 vertex offset is pinned by the recovered normals being exactly
unit-length (align16 lands 4 bytes early and silently corrupts every
field). A safety gate rejects any model whose indices are out of range
or whose mean |normal| is not ~1, declining garbage (Stage_S*
placeholders, the complex multi-stream hero-ship body) rather than
mis-decoding it.
- mesh.rs: Xbg7Model::from_xpr2 -> GameMesh { positions, normals, uvs,
indices }; standalone f16->f32; unit + real-disc tests (weapon decodes
to 215v/364t with unit normals + in-range UVs; DeltaSaber body
declined).
- texture.rs: from_xpr2_index / texture_names so the viewer can pick a
model's _col albedo map.
- viewer: loose .xpr with decodable XBG7 spawns Bevy meshes (real normals,
double-sided) textured with the albedo, framed by the orbit camera; the
central egui panel goes transparent so the 3D scene shows through.
Complex multi-stream body meshes (DeltaSaber f004, other vertex layouts)
remain undecoded and are cleanly declined — next target is dynamic RE.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2.0 KiB
2.0 KiB
RE knowledge index
Confidence: ✅ CONFIRMED · 🟡 PROBABLE · ❔ HYPOTHESIS. See README.
Formats we've already reversed are, for now, documented by their parser + disc round-trip
tests (the executable spec) rather than a prose file — the "Spec" column points there.
Promote to a prose structures/…md file when a format needs behavioural notes beyond layout.
Data structures / formats
| Format | Conf. | Spec (parser + tests) | Notes |
|---|---|---|---|
IPFB .pak archive |
✅ | sylpheed-formats/src/pak.rs + tests/pak_idxd_disc.rs |
header + 12-byte TOC, Z1/zlib payloads |
| name-hash (TOC keys) | ✅ | sylpheed-formats/src/hash.rs |
Barrett-reduction hash; recovers original paths |
| IDXD object/table | ✅ | sylpheed-formats/src/idxd.rs |
self-describing; ship/weapon stats verified vs known values |
| XPR2 texture + cubemap | 🟡 | sylpheed-formats/src/texture.rs |
de-tile + A8R8G8B8; colours unverified (dynamic item) |
| T8aD 2D texture | 🟡 | sylpheed-formats/src/t8ad.rs |
~85% decode; colours ✅ CONFIRMED (k8888); ~15% variants deferred |
| RATC bundle | 🟡 | sylpheed-formats/src/ratc.rs |
child listing confirmed; one level deep |
| LSTA sprite list | 🟡 | sylpheed-formats/src/lsta.rs |
inline T8aD frames |
| IXUD subtitle | 🟡 | sylpheed-formats/src/ixud.rs |
timed cues; movie↔track link unknown (dynamic item) |
| Fonts (ttf/otf/ttc) | ✅ | sylpheed-formats/src/font.rs |
standard OpenType, parsed via ttf-parser |
| XBG7 mesh | 🟡/❔ | sylpheed-formats/src/mesh.rs + tests/mesh_disc.rs (xbg7) |
single-stream layout decoded (~25 models, pos+normal+UV via vertex declaration); complex body layout + other vertex layouts declined |
Functions / code paths
None documented yet — populated during the dynamic-RE phase.
| Function | Conf. | Reimpl. | Summary |
|---|---|---|---|
| — | — | — | — |