# RE knowledge index

Confidence: ✅ `CONFIRMED` · 🟡 `PROBABLE` · ❔ `HYPOTHESIS`. See [README](README.md).

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](structures/texture-color-k8888.md)); ~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](structures/xbg7-mesh.md)) | weapons/props: declaration-driven variable stride (36 models), GPU-confirmed. **Stage containers: 5662 sub-models across 22 stages** via content-anchored grouped pools (`stage_models`). Quantized hero bodies (DeltaSaber `f004`) still declined |
| Capital-ship part placement | 🟡 | `sylpheed-formats/src/ship.rs` (static) + [runtime capture](ship-placement-runtime-capture.md) | hull placement static-exact; external parts approximate statically. **Runtime capture** (Canary F10 → VS-constant WorldView) gives ground truth — validated on `e106` destroyer; not yet baked into the viewer |
| Weapon fields defaulted on disc | ✅/🟡 | [runtime DATA SHEET](weapon-datasheet-runtime.md) | The Arsenal Gallery-Mode panel reads the live record: `Ammo Capacity` = `LoadingCount` ✅, `Max. Lock Ons` = `TriggerShotCount` ✅. Recovers `TriggerShotCount` for `wep_05`/`wep_60` (both **4**); brackets defaulted `Power`/`MaximumRange` via the letter classes. 9 of ~61 weapons reachable at 5 % save progress |
| UI screen layout (`.rat`) | ✅/🟡 | [ui-rat-layout](structures/ui-rat-layout.md) | One pak per UI screen; each RATC = one (context × language) build; every `<name>.t32` sprite has a `<name>.rat` **layout record** (BE u32; 1280×720 design space; scale/tint/X/Y, keyframes for animated elements, `opt ` link to the focused state). **The tutorial PAUSE menu and the title main menu both rebuild pixel-accurately from the disc.** `loop1.rat` (screen-level draw order) not yet decoded |

## Functions / code paths

_None documented yet — populated during the dynamic-RE phase._

| Function | Conf. | Reimpl. | Summary |
|----------|-------|---------|---------|
| — | — | — | — |