extras sits at 0.19% differing against main_menu's 0.06%, on two screens of the
same family. The signed difference explains it: both are uniformly +9 to +12
brighter in the dark outer columns, in nearly identical patterns (+12.13/+12.29
against +11.63/+11.03 at x=0; +10.60/+9.05 against +10.24/+8.84 at x=960). That
is the transfer curve -- gamma > 1 in the darks -- with no dipole, no
displacement and no missing element.
So the 0.06/0.19 gap is not a difference in fidelity. The thresholded count only
sees pixels differing by more than 64 levels, which are text and sprite EDGES,
and the two screens have different amounts of high-contrast edge. The level
disagreement, which is what a tone term produces, is the same on both. I had
taken the ratio of two counts as meaningful -- the bounding-box lesson in a
different costume.
A DIAGNOSTIC TRAP OF MY OWN: the first pass reported 10 of 18 elements
"transparent at rest" on extras -- the buttons, the title, the frames -- and
looked exactly like a missing-element bug. `--screen=NAME` without `--time`
renders at t=0, and pose_at clamps t to minf(t, settle_units), so t=0 stays t=0.
With --time=2.0 it draws 18 of 18. The tool was right and my invocation was
wrong, and it reported a WORSE problem than existed, which wastes an iteration
rather than hiding one.
REFUTATION ATTEMPT, SURVIVED: the Decoder's 239.8 units for palogo_sqex's alpha
>= 1 span, which is the denominator of the units-per-frame conversion behind the
9-unit black hold I just authored. Computed independently from my export under
the linear ramp the port already uses: alpha first reaches 1 at t=15.0588 and
last exceeds it at t=254.8750, giving 239.816 units. Agrees to four significant
figures, from different sides of the same record -- which is what makes that
constant safe to hold.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N7FiFFFwbvG2uxdcEh8HyF
e4775f64cc