re: F6 unit 5 -- pteff03a is never drawn; the game shows ONE sweep, not two

Every quad taller than 1.2 NDC in the whole capture, frames 1..2499:
h=3.15 travelling left-to-right over 1754 samples (pteff03), and h=2.00
static for 54 frames (not a sweep). Nothing in pteff03a's expected band
above 3.4, and only one travelling quad in the capture at all.

pteff03a declares 800% scale against pteff03's 600%, so its AABB is ~1303
px ~ 3.62 NDC, travelling right-to-left. It is absent.

Not a windowing artefact: ptloop02's leaf reaches alpha 128 at its t=150,
which at the unit-3 leaf rate is ~324 frames after its start, well inside
the 1754 frames captured.

For the port: their renderer draws pteff03a, confirmed on their side at
three instants. An extra light streak the game never shows, appearing
partway through the build-in, looks exactly like "the sweep starts too
early" -- and unlike the alpha question it does not depend on unit 2.

One capture, one boot, one window. The scan was over every tall quad in the
whole stream rather than a filtered subset, so the absence is strong, but
it is still absence in one observation. The five-second human check the
port is arranging (one streak or two) settles it faster than another
capture and should come before anyone deletes an element.

The disc declares ptloop02.rat as element 12 beside ptloop01.rat as 11,
identical pivots and keyframe times, so why one is submitted and not the
other moves to my side. Untested candidates: its leaf alpha starts at 0
where pteff03's starts at 255; or a focus/variant link means only one of
the pair is ever active.

Refutation: the port's own challenge to my by-size identification -- that
both sprites are byte-identical in size -- they withdrew themselves and
correctly. The sprites are both 399x180 but the LEAVES declare different
scales, so the drawn quads differ by a third in height. Second time in this
exchange a challenge was right to raise and wrong in its stated reason, and
both times the check still found something real. The value was in asking.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Jc4pciRArGHfxGGhEbwp5t

docs/re/f6-unit5-pteff03a-never-drawn.md

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+# F6 unit 5 — `pteff03a` is **never drawn**: the game shows ONE sweep, not two
+
+**Status: ✅ measured ⟨capture⟩ ×1.** 2026-09-02.
+
+**Question:** does `pteff03a` appear anywhere in the capture?
+**Look at:** any quad travelling right-to-left at the larger scale. Pass = found;
+fail = absent throughout.
+**Not covered:** why the disc declares it if it is absent; other screens.
+
+---
+
+## The measurement
+
+Every quad taller than 1.2 NDC in the whole capture — frames 1…2499, the title's
+build-in and settle:
+
+```
+h=3.15   n=1754   frames 746..2499   x drift +2.19   LEFT->RIGHT     <- pteff03
+h=2.00   n=  54   frames 729.. 782   x drift  0.00   static          <- not a sweep
+
+quads in pteff03a's expected height band (>3.4): NONE
+```
+
+`pteff03a` declares **800 % scale** against `pteff03`'s 600 %, so its AABB is
+≈ 1303 px ≈ **3.62 NDC**, and it travels **right-to-left**. There is no quad of
+that height anywhere, and only **one** travelling quad in the capture at all.
+
+> **The game draws one sweep during the title. The second is declared and not
+> submitted.**
+
+📌 **Not a windowing artefact.** `ptloop02`'s leaf reaches α = 128 at its `t = 150`;
+at the leaf rate measured in unit 3 that is ≈ 324 frames after its start, well
+inside the 1 754 frames captured. If it shared `pteff03`'s clock it had ample room
+to appear.
+
+## What it hands to the port
+
+Their renderer **draws** `pteff03a` — confirmed on their side at three instants.
+**An extra light streak the game never shows, appearing partway through the
+build-in, looks exactly like "the sweep starts too early."** That is a better
+candidate for the human's report than any clock offset, and it does not depend on
+unit 2's unresolved alpha question at all.
+
+⚠️ **One capture, one boot, one window.** Absence here is strong — the scan was
+over every tall quad in the whole stream, not a filtered subset — but it is still
+absence in one observation. The five-second human check the port is asking for
+(*one streak or two?*) would settle it faster than another capture, and I would
+wait for that before anyone deletes an element.
+
+## 🔴 The disc declares it, so the question moves to my side
+
+`GP_TITLE` build 4 declares `ptloop02.rat` as element 12, beside `ptloop01.rat` as
+element 11 — identical pivots, identical keyframe times. **Why the game submits one
+and not the other is not answered here.** Candidates, none tested: its leaf alpha
+starts at 0 where `pteff03`'s starts at 255, so a zero-alpha skip would suppress
+its first frames but not the whole run; or a focus/variant link means only one of
+the pair is ever active.
+
+## Refutation attempt
+
+**Target:** the port's refutation of my by-size identification — *"both sweep
+sprites are byte-identical in size, so size cannot separate them"*.
+
+**Result: they refuted it themselves first, and correctly.** The two *sprites* are
+399×180, but the two *leaves* declare different scales, so the drawn quads differ
+in height by a third. Size separates them fine. Recorded because it is the second
+time in this exchange that a challenge was right to be raised and wrong in its
+stated reason — and both times the check still found something real. **The value
+was in asking, not in the diagnosis.**