`ratc::parse` named each child by scanning backwards for the last printable run
of bytes before its magic. The format states the name explicitly instead, in an
`opt ` block: `"opt " | BE32 len | name | NUL | 3 bytes | magic` -- the same
block `ui_layout::opt_link` already read for a button's focus link.
The scan agrees with it 17 918 times out of 17 942 and is wrong 24 times, every
one the same failure: the 3 trailing payload bytes are themselves printable and
beat the real name. For `pteff05.t32` those bytes are `38 41 58` = `8AX`, so the
full-resolution background of all five menu screens registered under a name no
element declares, resolved to no sprite, and `compose` dropped it through an
early `continue` that -- unlike the two arms above it -- records nothing. The
screen lost its background and `screen render` still reported "all resolved".
`8AX` was never a name. Docs that treated it as one are corrected here.
Disc-wide, and the control is the 17 918 the scan already got right: the `opt `
reading reproduces every one of them. Effect on the five screens is the
signature of the same art at twice the resolution -- mean brightness unmoved,
high-frequency detail x1.15..x1.30 -- which is what the separately-measured
`ui-8ax-fullres-background` result said the game draws.
Also closes a long-standing dangling reference: `pmbase.t32`, recorded as "on
the disc nowhere", is the `GP_STAGE_CLEAR` child the scan called `8AX`. RATC
sibling references now resolve 10 148 of 10 148.
Verified: 114/114 sylpheed-formats unit tests (including two new ones pinning
the `8AX` case byte for byte and the no-block fallback), and every disc-gated
integration suite in sylpheed-formats/sylpheed-cli.
I had parked this as "needs a per-draw capture recording texture base
addresses". It did not. 8AX (1280x720) and ptbase (640x360 at 200%) are
the SAME artwork at two resolutions, which is exactly why comparing
either against a capture is inconclusive -- and why comparing their
DIFFERENCE is not. Compute 8AX - upscale(ptbase), the detail only 8AX
has, and ask whether the capture contains it.
Both candidates are first mapped into the capture's tone domain with the
measured gamma; without that the residual is dominated by the tone
difference and the test is blind.
main menu corr +0.0475 controls +0.0032 shift, -0.0075 flip 68% of ceiling
title corr +0.0634 controls +0.0095 shift, +0.0086 flip 68% of ceiling
Two independent screens, both at 68% of the theoretical ceiling
(sd of the 8AX-only detail over sd of the capture residual), 7-15x their
matched controls. The controls preserve spatial correlation and destroy
only alignment, so they are what "no signal" looks like.
So the recommendation changes: resolve the name and draw 8AX at 1:1.
Upscaling ptbase 2x is wrong, not merely softer. Still do not draw both --
an opaque layer over an identical one costs fill and hides later changes,
and ptbase's element is the one carrying the keyframes, so a consumer
needs its timing with 8AX's pixels.
Also recorded and withdrawn: a cruder pixel-pair test gave 0.00-0.72 for
upscales, 0.98 native and 1.01 for the capture -- apparently decisive.
Additive noise raises both terms of that ratio equally and drives any
value toward 1; fitting a noise term, both "native + noise" and "bilinear
+ noise" reproduce the observed numbers. The conclusion is right, that
test does not establish it, and it is in REFUTED because the number looks
conclusive and is not.
Not shown: whether ptbase is also drawn underneath. 8AX is ~86% opaque
and carries the same art, so it would hide it either way.
Audited what `screen render` silently omits on the port's five screens,
since an element the game draws but we skip is the one defect class the
port agent has actually hit. Everything is accounted for -- kind & 0x4
ghost instances, .prm primitives, loop* animations -- except pteff04.t32
on the title and pteff05.t32 on both menus. Those are kind 0x0, one
keyframe, rest a=255, pivot (640,360): full-screen and opaque.
Cause: the element declares pteff05.t32, but the T8aD behind its `opt `
link is registered under the name 8AX, so build.sprites.get() misses and
compose hits a silent continue. Bytes at 0x0e2035 of GP_TITLE entry 5:
opt ... 70 74 65 66 66 30 35 2e 74 33 32 00 38 41 58 54 38 61 44
p t e f f 0 5 . t 3 2 \0 8 A X T 8 a D
8AX is 1280x720 and present in all six title-family bundles; it is a
sprite in builds 4/5/6 and never an element.
It does not currently show, and that is the useful half. ptbase.t32 is
640x360 drawn at 200% and carries THE SAME ARTWORK: its 2x upscale
differs from 8AX by mean abs diff 2.05 (max 80), and our rendered
background is pixel-identical to 8AX in every patch sampled. So resolving
the name and drawing it in addition would double-draw an opaque
full-screen layer -- invisible as a doubling, which is worse than a
visible bug. Written into HANDOFF as a do-not-do.
The free win, offered and not taken: use 8AX at 1:1 and drop ptbase
instead of upscaling a half-res copy. That is a rendering choice and
ptbase's element carries the keyframes, so it is the port's call.
Not established: which of the two the game actually draws. Both carry the
same art, so pixels cannot separate them; it needs a per-draw capture
recording texture base addresses, since the two differ in size.
