0265da31a1
Two corrections from one experiment.
A keyframe group is entry -> hold -> exit, and the exit ends invisible:
on the five port screens the final keyframe is invisible for 21/24
(title), 8/16 (main menu), 12/18 (EXTRAS), 2/3 and 6/7 (splashes). So the
screen as seen is the HOLD, which is why rest_plateau is the right
primary rule and why "rest = last keyframe" would empty every screen.
That suggested a fix: an element with no hold has no representative pose,
so draw nothing rather than guess an endpoint. Tested through compose's
visible mask and correlated against the live captures:
title +0.9500 -> +0.6839 -0.2661
main menu +0.9460 -> +0.9037 -0.0423
EXTRAS +0.9440 -> +0.9094 -0.0346
Refuted on all three, and the reason invalidates a number I published. An
element with a SINGLE keyframe has no adjacent pair, so the plateau test
marks it plateau-less -- but its one pose is unambiguously its rest.
Suppressing those removes backgrounds and full-screen layers, which is
the title's -0.27.
no plateau (as published) 3 807 (24.57 %)
... single-keyframe 1 502 trivially at rest, not a guess
genuinely ambiguous 2 305 (14.88 %)
So rest() guesses for 2 305 elements, not 3 807 -- the figure I gave the
port overstated the defect by 65%. Corrected in HANDOFF and the page.
METHOD: a predicate over adjacent PAIRS silently misclassifies a
one-element list; and acting on a claim is a better test of it than
re-reading it -- this flaw survived a census, a write-up and a handoff
row, and died the moment the rule was used to change a rendering.