Their withdrawal gave coordinates to check my renderer against, and my first
measurements looked like a contradiction: phase-to-phase differences span the
whole frame against their 400 px quad tracking x 921->1041. Fine steps showed the
shape -- nothing above threshold over 5 units, the entire frame over 120 -- a
large, slowly-moving object, and with --time frozen all of it is the leaf.
Reading the leaf record from my own export resolves it. ptloop01: leaf pteff03,
span 600, x track -639..1521, scale (100,600). ptloop02: span 720, scale (100,800).
Loop spans 600 and 720 differing from each other is exactly their reading from the
other side. Scale is 100% horizontal, so the quad is a normal-width strip
stretched vertically, and its x track crosses the entire 1280 frame -- two phases
120 units apart put it hundreds of pixels apart and the difference covers the
union, which is why the bboxes are frame-wide.
Their 921->1041 is a segment of that track, not its extent. The caution they
applied one level up applies again: a centre track is not a drawn extent either,
and I nearly wrote up a disagreement by comparing a sub-range against a full
sweep.
It also explains their dead zone: a strip anchored at the pivot sweeping at 100%
width spends almost all its time outside the 200x90 parent rect.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N7FiFFFwbvG2uxdcEh8HyF
bb1e4c4195