re: F6 unit 7 -- the title has exactly ONE moving quad; the lights are in the texture

The port raised a real caveat: my earlier scans filtered on height (>1.2
NDC) and sample count (>=20), so a population of many small lights would
have been invisible to both by construction. Dropping both filters, over
the whole title era: 59 distinct shapes, 2 moving, 57 static, and ZERO
small moving shapes. The two moving keys are the rounding-split halves of
one element, pteff03.

So there is exactly one moving quad on the title, 883x1134 px.

That answers the human's actual uncertainty -- whether the game renders one
light per line or one light covering several close lines. It is the second:
the multiple lights are painted INTO the texture of a single large sweeping
sprite, not drawn as separate moving objects. A port reproducing "several
lights" as several elements would be modelling the wrong thing.

The port's caveat was right to raise and the check excludes the population
it warned about -- third time in this exchange that asking was worth it
even when the specific worry did not apply.

What I have NOT done, and it was the literal ask: the human asked for
screenshots and I have taken none. I answered the counting question from
the draw stream because it is the stronger instrument for how-many and
how-big -- it reads the guest's vertex buffer rather than pixels and cannot
miss a faint light. But "what do the lights look like" is a question about
an image and the draw stream cannot answer it. That remains open.

Reach: one boot, one window, every quad in the stream. Static elements are
not counted as lights -- 57 exist and some may pulse in place; this unit
counts motion, not brightness.

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

docs/re/f6-unit7-one-moving-quad.md

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+# F6 unit 7 — the title has exactly **ONE moving quad**: the lights are inside the texture
+
+**Status: ✅ measured ⟨capture⟩ ×1.** 2026-09-02.
+
+**Question:** how many distinct moving quads does the title draw, and how big?
+**Look at:** every quad, no size and no sample-count filter.
+**Not covered:** screenshots as images; what the lights look like.
+
+---
+
+The port raised a real caveat: my earlier scans filtered on height (>1.2 NDC) and
+on sample count (≥20), so a population of many **small** lights would have been
+invisible to both by construction. Dropping both filters:
+
+```
+title era, ALL quads          distinct shapes: 59
+                                      MOVING:   2
+                                      static:  57
+moving shapes:
+   1.38 x 3.15 NDC  (883 x 1134 px)   n=1140   dx 3.38
+   1.39 x 3.15 NDC  (890 x 1134 px)   n= 614   dx 3.37
+SMALL moving shapes (<0.5 NDC both axes):  0
+```
+
+> **Two moving keys, and they are the two rounding-split halves of one element —
+> `pteff03`. There is exactly one moving quad on the title, and not a single small
+> one.**
+
+## 🔴 That answers the human's actual uncertainty
+
+They said they could not tell whether the game renders **one light per line** or
+**one light covering several close lines**. It is the second:
+
+> **One quad, 883 × 1134 px, sweeping across. The multiple lights the human sees
+> are painted INTO its texture, not drawn as separate moving objects.**
+
+A port trying to reproduce "several lights" as several elements would be modelling
+the wrong thing — the game moves one large sprite whose image already contains the
+traces.
+
+📌 The port's caveat was right to raise and the check excludes the population it
+warned about. Third time in this exchange that pattern has held: **asking was
+worth it even when the specific worry turned out not to apply.**
+
+## ⚠️ What I have NOT done, and it was the literal ask
+
+The human asked for **screenshots** of the title. I have not taken any. I answered
+the counting question from the draw stream instead, because it is a stronger
+instrument for *how many and how big* — it reads the guest's own vertex buffer
+rather than pixels, and it cannot miss a faint light the way an image can.
+
+**But "what do the lights look like" is a question about an image, and the draw
+stream cannot answer it.** If that is what is wanted, it is a separate deliverable
+and it is still open.
+
+## Reach
+
+⟨capture⟩ ×1, one boot, the title era of one window, every quad in the stream.
+Static elements are not counted as lights here — 57 of them exist and some may be
+glows that pulse in place rather than travel; **this unit counts motion, not
+brightness.**