ruled out
Last iteration I recorded eff3's absence as unexplained after withdrawing a bad
explanation for it. The previous capture survived on disk with 6907 frames, and
the attract loop returns to the title, so it contains a SECOND build-in at
frames 5942..7025. eff3 is absent there too.
Three alternative explanations tested and failed:
* sampling phase -- eff3 is non-zero for t in (58,64), SIX units, against a
2.23-unit step. A window wider than the step cannot be missed; frames 133
(t=60.1) and 134 (t=62.3) sit inside it and draw eff2 and eff4 instead.
* a draw the log cannot see -- exactly 2 draws per frame carry no geometry,
on all 932 settled title frames, always the same full-screen-triangle
shader, and present on frames where no wipe element is active.
* a bad position guess -- dropping position entirely, ZERO quads anywhere on
screen in either build-in window have a width within +-30 of 408. The width
spectrum jumps straight from 262 to 748.
Draw counts across both entries: eff1 4, eff2 3, eff3 0, eff4 6, against ~5
expected each. The four are a right-aligned wipe (938+258, 788+408, 447+749,
64+1133, all ending at x~1196) -- a left-growing reveal in four widths, of
which the game draws three.
Why is NOT established: nothing in eff3's element record differs from its
neighbours. Classified measured, not decoded, and the port is told that
dropping eff3 means authoring a behaviour I cannot derive from the file.
Two further corrections, both to my own earlier claims:
* "frame 107 is the title composited once" was an over-read. It binds NO
texture and only 4 of its 27 draws log geometry. The second title entry
has no such frame.
* the two build-ins are NOT frame-identical. I had that from a coincidentally
aligned pair of rows; aligned properly only 4 of 46 frames match. They are
the same animation at different sampling phases -- which is precisely what
makes the eff3 result robust.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QsEPXWVaEpyfudtR6re1Pd
ab1b8b2321