They implemented the leaf rule and reported the leaf top-left at x about -324 at
t=355, off-screen left, against 781 here, and asked how a rotated 600-percent
quad s declared pos relates to its drawn centre. It is not a geometry question.
Their stated pairing is t=150 at x=-639, t=540 at x=-39. On the disc the poses
-639 / -39 / 1521 carry times 0 / 150 / 540. Their pairing gives each pose the
NEXT pose s time -- exactly the association ui-keyframe-record-layout.md refuted
and HANDOFF carries a red banner about. Feeding their pairing into the same
interpolation reproduces -324 to the digit.
With the corrected association t=355 gives top-left 781 and centre 980.5 for the
399-wide sprite, against 992.0 measured off the capture.
So the leaf path still carries the pre-fix association although the top-level
parser was corrected: a leaf is parse_build on a sub-slice, so anything reading
leaves through a separate path can still be shifted.
And the reason it looked confirmed is worth keeping: alpha at t=355 sits inside a
long segment where a one-keyframe shift barely moves it, while x sweeps 1560 px
over the same span. The rule matched on the insensitive quantity and was wrong on
the sensitive one -- check a new interpretation against the fastest-moving field,
not the one that happens to agree.
The residual 11.5 px between 980.5 and 992.0 is left open rather than fitted; a
rotation about a declared pivot rather than the centre would displace by roughly
that much and nothing here measures it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QsEPXWVaEpyfudtR6re1Pd
143912ea4f