# 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 struct](structures/weapon-struct-runtime.md) · [DATA SHEET route](weapon-datasheet-runtime.md) | **Solved.** Canary maps guest RAM into `/dev/shm`, so the parsed `Weapon`/`Shell` objects are readable live; their layout is solved against disc ground truth (zero contradictions over 100+ records). All 126 weapons, exact numbers, no story progress needed — [4 393 values](captures/weapon-runtime-fields.csv) the disc does not carry. Supersedes the letter-bucket limit of the DATA SHEET route, which now serves as the independent cross-check |
| Unit (craft/vessel) fields defaulted on disc | ✅/🟡 | [runtime struct](structures/unit-struct-runtime.md) | The parsed `unit\UN_*.tbl` definition object, vtable `0x820af844`, ≥`0x380` bytes, one per unit — **discovered, not assumed** (`unit_discover.py`), and distinguished from the spawned-entity class `0x820af030` by being one-per-ID and byte-constant within a run. Across runs only pointer words move — `--crosscheck` proves **no reported field offset is run-dependent** (two words, `+0x2c8`/`+0x2d0`, are stage-dependent and remain unidentified). 27 fields ✅ (21 units, 7 runs); the `Maneuver` block is **schema declaration order, 4 bytes/field, base `0x9c` with a two-slot gap after `AA_Roll_Min`** (29 anchors, 0 conflicts), which also pins 5 fields *no* disc record ever values. Angles are **radians at runtime, degrees on disc**. Unlike weapons, unit definitions are instantiated **per stage**, so coverage (21/110) grows by visiting missions — [values](captures/unit-runtime-fields.csv) |
| 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 |

## Runtime / dynamic-capture technique

| Technique | Conf. | Spec | Notes |
|-----------|-------|------|-------|
| Live guest-memory read | ✅ | [`tools/re-capture/gmem.py`](../../tools/re-capture/gmem.py) | Canary backs the guest address space with `/dev/shm/xenia_memory_*`; guest VAs map in through Xenia's fixed table. Full-RAM search ~0.2 s (sparse, `SEEK_DATA`). No debugger, no emulator patch, game keeps running |
| IDXD object layout solver | ✅ | [`tools/re-capture/weapon_runtime.py`](../../tools/re-capture/weapon_runtime.py) | Scan RAM for a class's vtable → enumerate its objects → brute-force `(field, offset, encoding)` against the disc records. Accepts a binding only on **zero** contradictions. Generalizes to any IDXD-backed definition |
| Live entity state, anchored on the definition | ✅ | [`tools/re-capture/own_state.py`](../../tools/re-capture/own_state.py) · [autopilot](autopilot-memory-driven.md) | An undamaged craft holds its definition's own numbers, so a *solved definition field* locates the matching live field without a value scan: definition `HP` (1500) → **hull at `position+0x154`**, confirmed by a trace across a death (30/60/90 per hit, negative at 0). Reusable for any live counter whose maximum the definition carries |
| Mission / escort state, every entity's hull | ✅ | [`tools/re-capture/mission_state.py`](../../tools/re-capture/mission_state.py) · [escort state](mission-escort-state.md) | `hull = position + 0x154` is a property of the **entity class**, not of the player object: at t=0 it equals each entity's own definition `HP` across 7 classes and 5 distinct HP values (turret 100, fighter 500, destroyer 10000, cruiser 30000, **ACROPOLIS 25000**), falls under fire (780 damage events in 240 s), goes negative at death, and the object then leaves the heap. So an escort objective is scoreable live — `UN_f101_TCAF_Acropolis` measured at 25000 → 23038 over 240 s, attack starting only at t≈170 s. `REMAINING OB` counts objectives, not hostiles (012 on the HUD vs 118 live ADAN); its address is still ❔ |
| In-flight control mapping | ✅/🟡 | [`tools/re-capture/fire_probe.sh`](../../tools/re-capture/fire_probe.sh) · [controls](flight-controls-runtime.md) | Measured by holding each pad input and photographing the HUD ammo counters: **`RB` = nose gun** (6000→5956 in 4 s, ~11 rounds/s, HEAT rises), **`Y` = main mount** (missiles, 300→299), d-pad = **tactical map** overlay, nothing else moves a counter. No target-cycle input exists — the `TARGET` marker is present with nothing pressed, so targeting is automatic and a missile lock is **time-on-target**. That, not target choice or ballistics, is what caps lethality at 2 kills per 98 missiles |
| Input → dynamics calibration | ✅ | [`tools/re-capture/ctrl_probe.py`](../../tools/re-capture/ctrl_probe.py) · [`binq.py`](../../tools/re-capture/binq.py) | Hold each pad input in turn and measure the craft's speed as displacement/s of its own position triple — no speed field needed first. Settled the throttle: **`RT` accelerates, `LT` brakes, and the setting persists** (488 → 1510 → 174 units/s), overturning an earlier field-scan conclusion |

## Functions / code paths

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

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