re: three angle fields found in the keyframe -- and they are not the

title's rotation

Looking for where the rotated quads come from, the obvious candidates
were the three keyframe words at +4, +8 and +12 that ui_layout.rs
documents as zero.

They are not zero. Across 72287 keyframe blocks disc-wide they are
non-zero in 4.81, 4.56 and 15.82 percent of blocks, and read as signed
values clustering on 180, -180, 90, -90, 120 and 22 -- degrees. Three of
them, so plausibly rotation about three axes. I have marked that amber
because it is the shape of the numbers and nothing more; no observed
rotation has been tied to a value. The doc comment is corrected
regardless: "0 on every frame seen" was an artefact of the sample.

And they do not explain the screen I was chasing. Every element of
GP_TITLE build 4 has all three at zero, element by element, while the
game demonstrably submits rotated parallelograms there. So the title's
rotation comes from outside the keyframe data and is still unidentified.

One correction to my own last write-up, flagged rather than left: I
stated that the skewed draw IS the swoosh. It is the only skewed geometry
in the capture and the swoosh is the only diagonal element on the screen,
so the inference is reasonable -- but I never confirmed it by matching
the draw's texture or screen position to that element, and I should have
said so the first time.
This commit is contained in:
Sylpheed RE agent
2026-08-28 22:17:14 +00:00
parent 0ecb20bdbc
commit 5115b4894a
3 changed files with 54 additions and 4 deletions

View File

@@ -35,6 +35,12 @@ neighbourhood, not just the line.
## Screens, classes and RTTI
* "the keyframe words at `+4`/`+8`/`+12` are always zero" → they are non-zero in
4.81 %, 4.56 % and 15.82 % of 72 287 blocks disc-wide, reading as **degrees**
(±180, ±90, 120). The original note was a sample artefact.
* "those angle fields are where the title's rotated quads come from" → **no** —
every `GP_TITLE` build 4 element has all three at zero.
[`ui-title-build-map.md`](ui-title-build-map.md)
* "the game passes a pink per-vertex colour for the title swoosh" → **refuted by
draw capture.** Every vertex colour in the capture is `<alpha>FFFFFF`, white RGB.
* "the swoosh discrepancy is undecodable" → **solved**: the game submits it as two