Rule out GS packet framing in tie, with a control that nearly fooled me

Range measured: level 0, the 73 tie span bodies (bytes +0x40 onward), 2585856 bytes pooled. Per-position distinct counts, an autocorrelation scan against a shuffled control, and a GS GIF tag test. Result 1: the bodies are dense. Every one of the 16 slot positions takes 245 to 256 distinct values, byte 15 zero on 81.3% and byte 7 zero on 78.8%. The best stride peak is 48 at +0.097, barely above 16 at +0.095 -- no period. Result 2: no GS GIF framing at 16-byte alignment. Testing whether byte 15's low three bits fall in 0..4, the GS tag range, gives 97.0%. That looked like a strong hit until the control was done properly. A uniform shuffle gives 62.6%, exactly 5/8, what a random byte predicts -- so the naive comparison reads as a 34-point excess. The distribution-matched null is 97.0%, identical to the observation. The whole excess was that byte 15 is 81% zero and (0 & 7) <= 4 is always true. Recomputed per alignment the null tracks the observation everywhere: align 0 97.0% align 4 75.7% align 8 96.7% align 2 75.5% align 12 89.3% This is the control rule earning its place a second time. A uniform shuffle is not a matched control when the data is skewed, and AGENTS.md already says so; the near-miss was reading 62.6% as a baseline without checking what the data's own distribution predicts. The tie bytes concentrate on 0, 1, 2, 3 and 63 -- suggestive in isolation -- and still carry no framing. What this rules out: the tie bodies are not GS GIF packet streams at 16-byte alignment and carry no measurable periodicity. With every slot position taking ~256 distinct values they are dense data -- fat vertices, as the roadmap expects -- and locating the vertex layout needs a reference for this game's instanced geometry format, not another stride scan.
2026-10-12 02:56:58 +02:00
parent 86ff2e6052
commit 72bbd5da38
1 changed files with 41 additions and 0 deletions
@@ -1445,3 +1445,44 @@ and the value set is quantised. The bounding-box reading does not survive.
 **Not decoded:** what the three floats are, what `0x100` at `+0x00` counts,
 and what the 83 values at `+0x0c` are.
 ## Tie geometry: no GS packet framing, and a control that nearly fooled me
 **Range measured:** level 0, the 73 tie span bodies (bytes `+0x40` onward),
 **2,585,856 bytes** pooled. Per-position distinct counts, an autocorrelation
 scan against a shuffled control, and a GS GIF tag test.
 **Result 1 -- the bodies are dense.** Every one of the 16 slot positions takes
 245 to 256 distinct values, with byte 15 zero on 81.3% and byte 7 zero on 78.8%.
 The best stride peak is 48 at +0.097, barely above 16 at +0.095 -- no period.
 **Result 2 -- no GS GIF framing at 16-byte alignment.** Testing whether byte 15's
 low three bits fall in 0..4, the GS tag range, gives **97.0%**.
 That looked like a strong hit until the control was done properly. A uniform
 shuffle gives **62.6%** -- which is exactly 5/8, what a random byte predicts --
 so the naive comparison reads as a 34-point excess.
 **The distribution-matched null is 97.0%, identical to the observation.** The
 whole "excess" was that byte 15 is 81% zero, and `(0 & 7) <= 4` is always true.
 Recomputed per alignment, the null tracks the observation everywhere:
 | align | matched null |
 |---|---|
 | 0 | 97.0% |
 | 2 | 75.5% |
 | 4 | 75.7% |
 | 8 | 96.7% |
 | 12 | 89.3% |
 **This is the control rule earning its place a second time.** A uniform shuffle
 is not a matched control when the data is skewed, and `AGENTS.md` already says
 so; the near-miss here was reading the 62.6% as a baseline without checking
 what the data's own distribution predicts. The tie bytes are concentrated on
 0, 1, 2, 3 and 63 -- suggestive in isolation -- and still carry no framing.
 **What this rules out.** The tie bodies are not GS GIF packet streams at 16-byte
 alignment, and they carry no measurable periodicity. With every slot position
 taking ~256 distinct values they are dense data -- fat vertices, as the roadmap
 expects -- and locating the vertex layout inside them needs a reference for this
 game's instanced-geometry format, not another stride scan.