Sylpheed/docs/re/f5-verified-with-full-quad-reader.md

F5 re-verified with a reader that sees every quad — the snap holds

Question: does F5's "Ⓐ snaps the whole title" survive a reader that reads every quad, not the first vertex of each draw?

What the human looks at: nothing new — this re-checks an answer already given. Pass = the snap conclusion is unchanged.

What this does NOT cover: the snap target's exact instant, F6.

Instrument: ⟨capture⟩ — same three logs, re-read by tools/re-capture/read_draws.py.

Why re-check

f6-unit11 found my reader took the first v: per draw line and dropped the rest, which killed two findings. I asserted F5 was unaffected because it compared like with like. Asserting that is the same move that produced the bug, so it is measured here instead. The new reader finds 9.7 quads/frame against ~7.5.

✅ Measured — it holds, and it is sharper than before

Count of quads mid-ramp (0 < α < 250) per frame:

	mid-ramp quads
press run, f428…f435	6 · 4 · 4 · 4 · 2 · 1 · 4 · 3
press run, f436	0
control f6b, 48 frames of build-in	never 0 (min 2)

One frame in which nothing on screen is part-way through a ramp — every element at a settled alpha at once. The control never does this anywhere in its build-in. That is the cut, on a scalar that needs no element identification.

The count rises again after (1 · 2 · 2 · 2 · 3) because the snap restarts the leaves: both sweeps then run their own ramps from their own t=0.

✅ A bonus the old reader could not show

At f436–f438 both sweeps enter, each at its declared opening alpha:

• pteff03 at x = −1.69, α255 — its leaf declares α255 at t=0;
• pteff03a at x = +1.99, α1, 2, 3, 4, 6, 11, 17 — its leaf declares α0 at t=0 ramping to 128, and x = 1721 is the right-hand start.

Both leaves' declared openings, observed directly. This is the same page's indices=8 batching that unit 11 uncovered.

Refutation attempt — the port's "clock jumps 109.4 → 236.0"

The port reports a filmed boot showing the snap landing on 236.0. I tried to contradict it and could not: at f436 the sweeps sit at α255, so the parent's declared ramp puts the title clock in [100, 238) — past t=100 and before the 238…250 exit. 236.0 sits inside that. Their figure survives, but my data cannot separate 236 from 200; it is consistent, not independently confirmed.

Not settled

• The snap target, still [100,238) from my side.
• Whether any other finding of mine rests on the truncating reader. Unit 10's decomposition and the pulse ratio are the two candidates and are not re-checked here.