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>
Resolved the "colours look odd" channel-order/sRGB question for k_8_8_8_8
(T8aD 2D UI textures) with no emulator run:
- sRGB: Canary's Vulkan host-format table maps plain k_8_8_8_8 to
R8G8B8A8_UNORM and contains no R8G8B8A8_SRGB anywhere — gamma is a
separate explicit EDRAM path. So these are raw linear bytes; apply no
sRGB/gamma decode.
- Channel order: measured 789 real disc textures — byte0 is the opaque
alpha (==0xFF-dominant) in 97% — so on-disk is ARGB. Cross-checked
against xenia-rs decode_k8888_tiled, the Canary-validated M1/M2 path,
which nets the same [A,R,G,B]->[R,G,B,A]. sylpheed-formats is correct.
Promotes the k8888 entry HYPOTHESIS -> CONFIRMED; INDEX updated. XPR2
skybox tiling + viewer display-gamma remain separate open items.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Establish docs/re/ as the spec-side of the clean-room:
- README: confidence tiers (HYPOTHESIS/PROBABLE/CONFIRMED), promotion
requires NEW independent evidence, append-only evidence logs,
demote-on-contradiction, and a clean-room firewall (describe behaviour +
cite addresses; never paste decompiled code). Documents the toolchain
(sylpheed.db + zq.py, xenia-rs probes, Wine-Canary oracle) and the
join-by-guest-PC method with the VA-equality caveat.
- Function/structure templates + a seeded INDEX (9 already-reversed formats).
- First entry: texture-color-k8888 — CONFIRMED plain k_8_8_8_8 is linear
UNORM (no sRGB), channel order still to be measured.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
