The dword-swap that fixes DXT1 is a property of the BC1 COLOUR block, not of
BCn in general. RE on a DXT5A (BC4) mask showed the alpha block is byte-indexed
and wants the endian swap ALONE — dword-swapping it makes it worse. The blanket
swap from the previous commit was therefore breaking the (common) DXT5A/DXN
alpha & normal masks.
Now targeted by format:
- DXT1 : swap dwords of each 8-byte colour block (verified).
- DXT2_3 / DXT4_5 : swap only the colour half (bytes 8..16) of each 16-byte
block; alpha half endian-only. TENTATIVE — these formats
are near-absent in the game assets, so unvalidated against
a clear image.
- DXT5A / DXN : no dword swap (endian only).
DXT1 export re-verified clean (weapon skins); 16 formats tests pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
DXT1 (108/137 textures in Base.xpr — the bulk of picture assets) decoded to
noise. Root cause found by RE: Xbox 360 BCn blocks store the two 32-bit words
of each 64-bit sub-block in the opposite order to the PC/DDS layout — colour
endpoints live in the HIGH dword, indices in the low one. The endian field
(k8in16) only fixes byte order within the 16-bit words; it does not reorder the
dwords, so without this every DXT texture transposed endpoints/indices → noise.
Isolation that led here:
- de-tile proven correct for bpb=8 (coherent per-block signature map; the
linear read is scrambled) — same faithful Xenos Tiled2D as the verified
bpb=4 ARGB path (green Acheron backdrop).
- inspecting a smooth region, coherent colour endpoints appeared only in
bytes[4..8], with the high-entropy indices in bytes[0..4].
Fix: swap_bc_block_dwords() swaps the two dwords within each 64-bit unit after
the byte-level endian swap, for every BCn format. Verified in the real Rust CLI:
weapon skins (rou_f001_wep_*) now decode to clean, recognisable images.
Viewer: DXT1 is fixed transparently (from_xpr2 feeds tex.data straight to the
GPU as Bc1). Also corrected the uncompressed path — post-swap k_8_8_8_8 is
[A,R,G,B]; reorder to [R,G,B,A] and upload as Rgba8UnormSrgb (was Bgra8, wrong).
Knob: XPR_NO_BC_DWORD_SWAP disables the swap for A/B validation.
KNOWN REMAINING: 16-byte blocks (BC2/DXT3, BC3/DXT5) and BC4/BC5 (DXT5A/DXN)
still need their alpha+colour half layout worked out — they decode to noise for
now. DXT1 + uncompressed + cubemaps are correct.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Reworks the XPR2 texture path after RE against the retail disc (viewer
previews were scrambled/failed).
- de-tile: replace the naive Morton-over-32×32 approximation with the
faithful Xenos Tiled2D bank/pipe/macro-tile address formula (ported
from xenia texture_address.h). Verified correct: the Acheron backdrop
decodes to a sharp planet with its spiral storm.
- endian: undo the X360 word byte-swap per the fetch-constant endianness
field (k8in16/k8in32/k16in32) — without it BCn/ARGB data is noise.
- cubemaps: parse TXCM resources (skybox/backdrops), decoding face 0,
instead of erroring "No TX2D found".
- A8R8G8B8: correct channel order after the k8in32 swap ([A,R,G,B]→RGBA)
— the Acheron backdrop is now correctly green, not red.
- XPR files are texture PACKS; add XPR_RES_INDEX to select a resource.
- CLI `texture export` now writes real PNGs (texpresso BCn decode +
image), replacing the stub. Adds texpresso + image deps.
- tests/texture_disc.rs: integration test running the pipeline over real
disc .xpr files (28/28 parse). RE debug knobs: XPR_NO_DETILE /
XPR_NO_ENDIAN / XPR_FORCE_ENDIAN.
KNOWN ISSUE: mipmapped DXT1 textures still decode to noise — mip 0 is
not at base_address in the multi-resource packs (localized to a mip
storage-offset quirk; uncompressed + de-tile + endian are all verified).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Add hash::recover_toc_name + TOC_NAME_SCHEMES (confirmed path schemes:
unit\<ID>.tbl, weapon\<ID>.tbl, message\<ID>.tbl, effect\<ID>.tbl,
<name>.tbl) that reproduce an entry's original backslash path from its
internal identity string via the recovered name-hash.
`pak list` now extracts identifier candidates from each IDXD entry
(ID/Name/Model + pool tokens) and prints the resolved path when a scheme
matches — e.g. unit\UN_f001_TCAF_DeltaSaber_T.tbl,
weapon\Weapon_…_Missile.tbl, message\CharacterCARL.tbl — plus a
name-resolved count. 308/1004 resolved on GP_MAIN_GAME_E; the remainder
use deeper cross-referenced paths (deferred).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The pak TOC key was previously an unknown hash (crc32/fnv/djb2/… ruled
out), forcing content-only lookup. Recovered it by static RE of the
retail title:
sub_824609C8 (pak lookup-by-name) dups the requested path, lowercases
it (sub_825F4F90), hashes with sub_82455C78, then binary-searches the
sorted TOC. sub_82455C78 is a per-byte Barrett-reduced polynomial hash
(modulus 0x00FFF9D7, reciprocal 0x80031493): the low 24 bits are the
modular hash, the top byte an 8-bit additive checksum of the bytes.
New `hash` module reproduces it exactly (faithful op sequence, no
textbook %). Verified against the real disc: name_hash("files.tbl") ==
0x83421153 and name_hash("eng\\weapon.tbl") == 0x900C8DCD, both present
in retail TOCs. Add PakArchive::find_by_name / read_by_name and a disc
integration test resolving eng\weapon.tbl by path (→ valid IDXD).
Note: retail paths use backslash separators (eng\weapon.tbl).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Add readers for Project Sylpheed's on-disc data format so the
reimplementation can load exact ship/weapon constants straight from
the game files.
- pak.rs: PakArchive — parse the IPFB `.pak` index + concatenated
`.pNN` segments, binary-search the TOC by name-hash, and transparently
inflate the per-entry "Z1" (zlib) container. Adds flate2.
- idxd.rs: IdxdObject — parse the IDXD reflective object serialization.
The string pool stores properties value-before-key with defaulted
fields omitted; typed getters (get_f32/get_i64/get_str/get_bool) read
explicit values reliably, get_raw exposes identifier fields, and
resolved_fields() enumerates every explicit (key,value). Defaulted
fields correctly return None rather than a neighbouring key.
- sylpheed-cli: `pak list` (inventory entries + identity) and
`pak dump <hash>` (full stat sheet for one object).
Verified against the real disc (auto-skipped without it): DeltaSaber
craft (HP=1000, Acceleration=600, velocity curve 100/700/1200, Turn=100,
RadarRange=500000) and the DSaber missile (LoadingCount=144, Interval=3.00,
Mass=0.77). 10 unit + 3 integration tests pass.
Not yet decoded: defaulted fields (many ratios, the *Count family) whose
values come from schema defaults or the hash-keyed binary node region.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
