Sylpheed/docs/re/ui-title-build-map.md

# Which `GP_TITLE` build is which screen — measured against the running game

**Status:** ✅ `CONFIRMED` for the four screens the boot path actually shows
(title art, `PRESS Ⓐ BUTTON`, main menu, `EXTRAS`); 🟡 `PROBABLE` for their
Japanese twins; ❔ open for the two `DELTASABER` plates.

Answers [MISSION Q2](../port/MISSION.md). The previous statement — *"build 4
title, 5 main menu, 6/8/9 submenus"* — is **partly wrong** and is withdrawn:
build 8 is the **Japanese main menu**, not a submenu, and `GP_TITLE` holds
exactly **one** submenu (`EXTRAS`), in two languages.

## The archive is eight screens, each shipped twice

`GP_TITLE.pak` has 16 entries; `sylpheed-cli screen list` calls 12 of them
composable builds. The 16 fall into **eight pairs**, and each pair's two members
have near-identical sizes and name hashes that differ by a constant — one
character of the name apart:

| entry | hash | bytes | build idx | pair |
|---|---|---|---|---|
| 0 | `01a2db9c` | 483 958 | 0 | A |
| 1 | `0ff0b8a8` | 483 958 | 1 | A |
| 2 | `285d8849` | 267 014 | 2 | B |
| 3 | `369773cb` | 267 014 | 3 | B |
| 4 | `a60fcb85` | 12 278 666 | 4 | C |
| 7 | `b483e6e6` | 13 363 328 | 7 | C |
| 5 | `a715f485` | 6 977 437 | 5 | D |
| 8 | `b58a0fe6` | 6 931 653 | 8 | D |
| 6 | `a81c1d85` | 6 549 126 | 6 | E |
| 9 | `b69038e6` | 6 548 438 | 9 | E |
| 10 | `cdba806e` | 426 473 | — | F |
| 13 | `db2ea1f8` | 423 333 | — | F |
| 11 | `cec0a96e` | 999 643 | — | G |
| 14 | `dc34caf8` | 999 643 | — | G |
| 12 | `cf2a8ccd` | 1 774 639 | 10 | H |
| 15 | `dd56d99b` | 1 774 639 | 11 | H |

For the three pairs whose members differ visibly — C, D, E — **the difference is
English versus Japanese**: build 7 is the title art with the katakana subtitle
プロジェクト シルフィード, build 8 the main menu reading 新規 / ロード /
チュートリアル / オプション / エクストラ, build 9 the `EXTRAS` submenu as
エクストラ. That is the whole of the language split we can see. In pairs A, B and
H the two members render **byte-identical PNGs** — the archive still carries two
copies, but the artwork does not change with the language.

Pairs F and G are the four entries `screen list` does *not* classify as builds by
default. **They are the developer splash**, and they render — see below.

## The map

Contact sheet of every render:
[`captures/title-builds/title-build-contact-sheet.png`](captures/title-builds/title-build-contact-sheet.png).

| build | what it is | confirmed how |
|---|---|---|
| 0, 1 | a `DELTASABER / SYLPHEED A.I.` plate low-left on black, no background | ❔ **not observed running.** Never seen in the boot path, the main menu, `EXTRAS` or `MISSION SELECT` |
| **2**, 3 | the `PRESS Ⓐ BUTTON` plate — **an overlay build of its own**, not a state of build 4 | ✅ seen composited over build 4 on the live title, at the same rect our render puts it |
| **4** | title art, English (`PROJECT SYLPHEED`, ™, `(C)2006,2007 SQUARE ENIX`) | ✅ [`live-title-press-a.png`](captures/title-builds/live-title-press-a.png) |
| 7 | the same, Japanese | 🟡 renders as the JP twin of build 4; the container runs an English locale, so it was not seen |
| **5** | main menu, English: NEW GAME / LOAD GAME / TUTORIAL / OPTIONS / EXTRAS, footer `Ⓐ : OK` | ✅ [`live-main-menu.png`](captures/title-builds/live-main-menu.png) — element for element |
| 8 | the same, Japanese | 🟡 as above |
| **6** | the `EXTRAS` submenu, English: MISSION SELECT / MOVIE THEATER / BACK, footer `Ⓐ : OK  Ⓑ : Back` | ✅ [`live-extras.png`](captures/title-builds/live-extras.png) |
| 9 | the same, Japanese | 🟡 as above |
| 10, 11 | the same `DELTASABER` plate as build 0, over a dark circuit-line background | ❔ **not observed running** |

## ✅ The splash — the four "non-build" entries, rendered

`screen list --all` widens the enumeration to every composable bundle and shows
all **16** entries. The four that the default listing drops are the two halves of
the developer splash, each shipped twice:

| entry | elements / sprites | what it is |
|---|---|---|
| **10, 13** | 3 / 2 | the white **`SQUARE ENIX`** publisher logo |
| **11, 14** | 7 / 6 | **`GAME ARTS` / `SETA` / `studio anima`** — the developer logos |

[`splash-entries-rendered.png`](captures/title-builds/splash-entries-rendered.png).
Rendered with `screen render --all --primitives --black`. Entry 11's seven
elements are the three logos, their three `_eff` glows and the
`palogo_eff0.prm` black backdrop — exactly the composition
[`structures/ui-paint-order-key.md`](structures/ui-paint-order-key.md) measured
for the splash.

### ✅ Confirmed against the running game — 2026-08-28

The 🟡 above ("no framebuffer capture to diff against") is closed. Recording the
boot from the moment the window appears, at 2 fps, catches the splash before the
movie:
[`live-splash-publisher.png`](captures/title-builds/live-splash-publisher.png),
[`live-splash-developer.png`](captures/title-builds/live-splash-developer.png).

Edge-correlated against the renders, **with the other half as a negative
control**:

| capture | vs entry 10 | vs entry 11 |
|---|---|---|
| publisher frame (t ≈ 2.0 s) | **0.9146** @ (0,0) | 0.027 ✗ |
| developer frame (t ≈ 6.0 s) | −0.033 ✗ | **0.9792** @ (0,0) |

Both halves match their own render at zero shift and are firmly rejected by the
other. The `13`/`14` twins score 0.876 / 0.966 — near-identical artwork, so this
test cannot tell a pair apart, only a screen from a different screen.

### ✅ The splash's timing is DECODED, and the capture confirms it

Re-recorded at **10 fps** (the 2 fps pass below was ±0.5 s and could not see
ramps at all). The splash **fades, both ways** — it does not cut — and the
bundle's own keyframes say so:

```
$ sylpheed-cli screen info --all --build 10 GP_TITLE.pak
1  palogo_sqex.t32       7 kf  [15  30  235 239 251 255  -]
2  palogo_sqex_eff.t32   4 kf  [15  30  45  -]              (the glow, child of 1)

$ ... --build 11
1  palogo_gamearts.t32   7 kf  [15  30  190 194 206 210  -]   (seta, anima identical)
2  palogo_gamearts_eff   4 kf  [15  30  45  -]
```

Under Q1's `1 unit = 1/60 s`:

| | declared | measured at 10 fps |
|---|---|---|
| `SQUARE ENIX` ramp in | `15 → 30` = 0.25 s | rise 0.4 → 0.8 s |
| `SQUARE ENIX` hold | `30 → 235` = **3.42 s** | ≈ 3.5 s (0.8 → 4.3 s) |
| `SQUARE ENIX` fade out | `235 → 255` = **0.33 s** | **≈ 0.3 s** (4.4 → 4.7 s) |
| developer hold | `30 → 190` = **2.67 s** | ≈ 2.4 s (5.6 → 8.0 s) |
| developer fade out | `190 → 210` = **0.33 s** | **≈ 0.3 s** (8.1 → 8.4 s) |

The offset between declared and measured start is ≈ 0.35 s, which is simply that
the recording's `t = 0` is when the *window* appears, not when the guest starts
drawing. Everything downstream of that lines up.

**The overshoot is the glow.** The measured rise peaks (6.21) at 0.8 s and settles
back (5.39) by 1.1 s, which looks like a bloom. It is the `_eff` child element:
its keyframes are `15 → 30 → 45`, so it ramps in *after* the logo and then back
down, while the logo itself holds. Decoded, not a rendering artifact.

So the port can **read** the splash's timing off the disc rather than author it —
the first screen's animation is not a measurement it has to trust.

### The wall-clock sequence, for orientation

| | |
|---|---|
| `SQUARE ENIX` on screen | **≈ 0.5 → 4.0 s** after the window appears |
| black | ≈ 4.5 s |
| `GAME ARTS` / `SETA` / `studio anima` | **≈ 5.0 → 7.5 s** |
| black | ≈ 9.0 s |
| `ADV.wmv` begins | **≈ 9.5 s** |

⚠️ The frames at ≈ 9.5–12.5 s show `SQUARE ENIX` again in **cyan**. That is not a
third splash — it is the intro movie's own opening, which the milestone-2 notes
describe as "white SQUARE ENIX + cyan glow + red diamonds". A capture-only reading
would have recorded a third logo screen that does not exist.

**So the first of the five screens now has a reference composite, a framebuffer
capture, and its on-screen durations.**

**Reach of the two negatives.** Builds 0/1 and 10/11 were looked for in: the whole
boot sequence (a 5 s-cadence filmstrip from launch to the title, ~190 s), the
title, the main menu, the `EXTRAS` submenu, the `LOAD GAME` slot list, the
transition into `MISSION SELECT` (a 40-frame burst), and the attract cycle. They
appear in none of them. The obvious remaining candidate is a *long* load — a
mission launch — which is out of this objective's scope; they are most likely a
loading/AI-chatter plate. That is a hypothesis, not a result.

## Three things the captures settle beyond the map

**The live title is two builds composited.** Build 4 draws the art; build 2 draws
`PRESS Ⓐ BUTTON` on top, and it **fades in a beat later** — a screenshot taken
2.5 s after arriving at the title has the art and no plate, one taken ~1 s later
has both. The port must treat the plate as its own timed element.

**The attract-loop title carries the plate too.** After ~8–10 s idle the title
fades to black, a full-motion video plays for ~85 s, and the title comes back —
*with* `PRESS Ⓐ BUTTON`
([`live-attract-title-press-a-band.png`](captures/title-builds/live-attract-title-press-a-band.png)).
This is consistent with, and adds nothing to, the draw-quad comparison in
[`canary-scripted-input-traps.md`](canary-scripted-input-traps.md): the plate is
not the tell that distinguishes the boot title from the attract title.

**`EXTRAS` is the only main-menu destination inside `GP_TITLE`.** Ⓐ on `EXTRAS`
opens build 6 — measured. The other four destinations leave the archive: Ⓐ on
`LOAD GAME` opened a `LOAD GAME` slot list, and Ⓐ on `MISSION SELECT` inside
`EXTRAS` opened a `MISSION SELECT` screen, neither of which is a `GP_TITLE`
build. `dat/` carries `GP_SAVE_LOAD.pak`, `GP_TUTORIAL.pak`, `GP_OPTIONS.pak`,
`GP_MISSION_SELECT.pak` and `GP_MOVIE_THEATER.pak`; **that those are the archives
behind the other four buttons is an inference from the names, not a measurement.**

## How to reproduce

```bash
sylpheed-cli screen list  "$SYLPHEED_DISC/dat/GP_TITLE.pak"
sylpheed-cli screen render --build 6 "$SYLPHEED_DISC/dat/GP_TITLE.pak" /tmp/b6.png
tools/re-capture/boot_menu.sh q2      # boots to the main menu, cursor on NEW GAME
tools/re-capture/pad.py dpad down 0.35 # x4 -> EXTRAS
tools/re-capture/pad.py tap A 0.30
```

Mind the d-pad hold — see [`METHOD.md`](METHOD.md).

## ✅ The title is not a still image — it loops, ≈ 2.2 s

Recording the title at 10 fps for 22 s shows the screen **never settles**. After
the build-in it oscillates by about ±0.5 in mean luminance, continuously:

```
peaks at   5.6  7.8  10.0  12.7  15.2  17.1  19.2  21.3 s
intervals  2.2  2.2   2.7   2.5   1.9   2.1   2.1
                                       mean 2.24 s
```

**measured**, n = 7 intervals, spread 1.9–2.7 s — peak-picking a low-amplitude
signal is coarse, so read it as **≈ 2.2 s ± 0.4**, not a precise period.

The mechanism is already decoded: build 4 declares **`ptloop01.rat` /
`ptloop02.rat`**, and `loop*.rat` is a **looping sprite animation** rather than a
composition ([`INDEX.md`](INDEX.md), UI screen layout row). So the title carries a
looping element by construction; what is new is that it runs at ≈ 2.2 s and never
stops.

### ✅ The loop records ARE decoded — and they are not what I measured

`ptloop01.rat` is an **`opt `-linked leaf record**: in build 4 the chunk `opt `
(size `0x0c`) carries the name, immediately followed by a `RATC` blob at
**`0xbb5966`** (`ptloop02.rat` the same at `0xbb5a82`). Its pivot fields read
`200`/`90`, matching `screen info`'s `pivot (200,90)` — the right blob.

**The keyframes use the ordinary 40-byte block layout**, starting at `+0x68`:

| | `ptloop01` → `pteff03.t32` | `ptloop02` → `pteff03a.t32` |
|---|---|---|
| kf0 | `t=150` x=**−639** α=`ff` | `t=150` x=**1721** α=`00` |
| kf1 | `t=540` x=−39 α=`80` | `t=630` x=1111 α=`80` |
| kf2 | `t=600` x=**1521** α=`ff` | `t=720` x=**−839** α=`ff` |
| scale | 100 × 600 | 100 × 800 |
| span | 150 → 600 = **450 units = 7.5 s** | 150 → 720 = **570 units = 9.5 s** |

Y is constant at 270 and X runs off one edge to the other, so these are
**horizontal light sweeps** — `loop01` left → right, `loop02` right → left.

### 🔴 Two things I wrote last iteration are wrong

**1. "A leaf record's keyframes are not in the build's 40-byte layout."**
Withdrawn — they are, exactly. The scan that "found nothing" demanded **29**
strictly-increasing times because I read the word at `+0x004` (`0x001e0000`) as a
keyframe count. These records hold **three** keyframes. A filter that hard-codes
the expected count rejects the right structure; whatever the `30` is, it is not
the number of keyframes here.

**2. "The ≈ 2.2 s oscillation is the `ptloop` elements."** Withdrawn — I asserted
the link because build 4 declares those elements, not because anything showed it.
The decoded sweeps run **7.5 s and 9.5 s**. A 22 s capture would show ~3 peaks
from a 7.5 s cycle; it showed **8**. So the loops are *not* what the oscillation
measured.

### ✅ Identified: it is the `PRESS Ⓐ BUTTON` plate pulsing

A per-tile amplitude map over the capture (8 × 6 grid, 18 s after build-in)
localises the 2.3 s period precisely:

| region | sd | dominant lag |
|---|---|---|
| band x ≈ 318–954, y ≈ 560–672 | **7.65** | **2.3 s** |
| wordmark centre | 0.06 | — |
| bottom-right corner | 0.003 | — |

That band is the `PRESS Ⓐ BUTTON` plate's rest position (`ptbtn00.rat`, rest
`(383,550)`, pivot `(256,25)`). It is **build 2**, composited over the title — not
build 4.

Decoding `ptbtn00f.rat`, the plate's highlight variant, gives the pulse directly:

| kf | t | alpha |
|---|---|---|
| 0 | 6 | `0x00` |
| 1 | 29 | `0x06` |
| 2 | 35 | `0x4a` |
| 3 | 50 | `0x50` |
| 4 | 58 | `0x50` (hold) |
| 5 | 97 | `0x4a` |
| 6 | 105 | `0x06` |

A glow that fades in to `0x50` and back out — exactly a "press start" pulse.

There is an **eighth** keyframe: fade `0x00ffffff` at the same position — the glow
returns to **fully transparent**, so this is a closed cycle, not a one-shot ramp.

🟡 **The cycle length is still not readable — and now that is an observation.**
The eighth block's time slot contains the four bytes `end `, the record's ASCII
terminator: the record simply stops there and the value does not exist. So the
corpus's "a group's last block has no time of its own" rule holds here in a second
form — not the next group's index, but the chunk terminator.

Declared span is **≥ 105 units = 1.75 s**; measured **≈ 2.3 s** (≈ 138 units),
which would need a final step of ≈ 33 units. **That 33 is fitted to the
measurement, not read from the file**, and is recorded only so nobody re-derives
it as if it were a decode.

❔ **The word at `+0x004` is not a keyframe count.** It reads `0x003c0000` (60)
here with 8 keyframes, and `0x001e0000` (30) in the loop records with 3. Whatever
it is, it is not the count, and it is not decoded.

### ❔ The declared 4.08 s build-in was not tested

That was the intent of this recording and it did not work. The title was reached
by **skipping the movie with Ⓐ**, which cuts to black and brings the title up on a
path that may not be the normal one; and the visible rise (≈ 2.7 s, from t ≈ 0.8
to 3.5) is a *luminance* curve, which
[`screen-transitions.md`](screen-transitions.md) already establishes is **not**
the fade quad's ramp. So ≈ 2.7 s neither confirms nor contradicts build 4's
declared `16 → 261` (4.08 s); the two are not measuring the same thing.

Testing it properly needs the title reached **without** a skip, and a way to
separate the quad from the elements — neither of which this recording had.


## ✅ For the port: build 4 alone, and groups HOLD rather than loop

Both answers the port agent asked for, in one recording.

### The capture — the title with no `PRESS Ⓐ` plate over it

Ⓑ from the main menu returns to the title and the plate fades in **a beat later**,
which opens a clean window. Recorded at 20 fps from the press:

| | |
|---|---|
| title art appears | t ≈ 1.10 s |
| builds in | 1.10 → 3.70 s (mean 41.8 → 63.2) |
| **settled, still no plate** | **3.70 → 5.00 s** |
| plate arrives | t ≈ 5.10 s (band jumps 282 → 3 755 bright px) |

[`live-title-build4-no-plate.png`](captures/title-builds/live-title-build4-no-plate.png)
is t = 4.0 s — build 4, settled, unobstructed. That is the reference for the
washed-out cyan glow slab the port reports drawing and the game not having.

### ✅ A keyframe group HOLDS at its last keyframe — it does not loop

This follows from the decoded sweeps plus a measurement, and the two agree:

* `ptloop01.rat`'s final keyframe puts `pteff03.t32` at **x = 1521** and
  `ptloop02.rat`'s puts `pteff03a.t32` at **x = −839** — both **off-screen** on a
  1280-wide design. A group that holds therefore parks both sweep sprites out of
  view and nothing moves after the build-in.
* Measured: over 18 s of settled title the centre tiles sit at **sd ≤ 0.01**
  (per-tile map above). A looping group would recross the screen every **7.5 s**
  and be unmissable.

So the name `loop*.rat` is misleading — in this build the records animate **once**
during the build-in and then rest off-screen. 🟡 This is about *these* groups on
*this* screen; nothing here says no group anywhere loops.

## ✅ The title's settled pose is `rest`, and the "washed-out slab" is a MISSING dim

The port agent could not decide whether `rest` or its played-out timeline is the
title's arrived pose (they disagree by 142–247/255), and separately reported a
*"washed-out cyan glow slab over the title logo that the running game doesn't
have"*. The plate-free capture settles both.

`sylpheed-cli screen render --build 4 --black`, edge-correlated against
[`live-title-build4-no-plate.png`](captures/title-builds/live-title-build4-no-plate.png)
— a capture of the real screen, so this is an independent oracle and not one
renderer checking another:

> **0.9163 at shift (0,0)**, and per band 0.92 / 0.78 / 0.93.

**Geometry is right**, so `rest` is the arrived pose for the title.

### The slab is the 25 % dim, absent — not a glow, present

`rest` alone is **uniformly too bright**, and the excess leans cyan:

| render | mean (render − capture) | R | G | B |
|---|---|---|---|---|
| `--black` | **+13.14** | +12.35 | +13.58 | +13.48 |
| `--black --primitives` | **+0.55** | +1.30 | +0.89 | −0.54 |

Drawing the `.prm` primitives collapses the excess to nothing. The element is
**`pteff02.prm`**, the 25 % dim quad (build 4, rest at `t=46`, fade `0x40` = 64 =
25 %) — and `--primitives` is **off by default**.

So the "washed-out cyan slab" is not something being drawn that shouldn't be. It
is the **dim that should be drawn and isn't**: without it every pixel sits ~13
high, and because the title art is blue-dominant the shortfall reads as a cyan
wash. ⚠️ Any consumer of `screen render` that omits `--primitives` on this screen
gets it.

### 🟡 The residual: right on average, not right per pixel

With primitives the *mean* is essentially exact (+0.55) but pixel agreement is
slightly **worse** — edge-correlation 0.9163 → **0.9066**, and pixels differing by
> 20 rise 108 051 → 162 636. So the dim's average contribution is right while its
application is not exactly the game's (blend mode or per-region alpha). Not
diagnosed.

### 🔴 The real defect: the logo swoosh is drawn white and thick

With the dim in place, the residual is **not uniform** — it is a dark patch beside
a bright one in one band:

```
row1 (y 112-225):  -2.0  +3.0  -8.8  -38.6  -17.6  +16.2  +33.8  +24.4
```

Cropping that band from capture and render
([`title-swoosh-capture-vs-render.png`](captures/title-builds/title-swoosh-capture-vs-render.png))
shows it plainly: the game draws the logo's `Z` **swoosh thin, with a
pink/magenta edge**; our render draws it **thick and solid white**. Too bright to
its right, too dark where the game's thin stroke actually falls.

**This — not the missing dim — is the port agent's "washed-out slab over the title
logo".** The dim explains a *uniform* +13; the slab is this.

The elements are `ptlogo_back2.t32` (rest `(71,126)`, pivot `(500,117)` — a
1000 × 234 diagonal), its glow `ptlogo_back2eff.t32`, and the five
`ptlogo_back2eff1…5` segments at y ≈ 117–194 — exactly the band that disagrees.

🟡 **A connection worth chasing, not a diagnosis.** Those five segments are the
group whose **paint-order tie-break is the known unsolved residual**
([`structures/ui-paint-order-key.md`](structures/ui-paint-order-key.md)): they
share key `0x8083`, the game paints them `14,15,18,16,17`, the stable sort paints
`14,15,16,17,18`, and the measured cost is "`ptlogo_back2eff5` against `eff3`
(22 568 px) and against `eff4` (32 395 px)". **Same screen, same elements.**

❔ But a blend-order swap is a poor explanation for *white instead of pink* — that
looks like a tint or blend-mode problem, so I would expect a second cause.

### 🟡 A quantified cause for the GEOMETRY: the pivot belongs to the other language

The fade and tint fields are **not** the culprit — every keyframe of every swoosh
element carries `0x??ffffff`, white RGB with only alpha varying, and no tint is
anything but `0xffffffff`. Nor is the texture pink: `ptlogo_back2.t32` decodes
**blue**-leaning (175, 174, 198) and its glow warm (255, 253, 234).

What *is* wrong is the **pivot**. Checking every `GP_TITLE` element whose texture
we decode (109 of 178) against the rule *pivot = texture ÷ 2*:

| | |
|---|---|
| exact | 17 |
| off by ≤ 1 px (rounding) | 54 |
| off by ≤ 8 px | 14 |
| **off by > 8 px** | **24** |

and the gross ones are **concentrated on the title's logo elements**:

```
a60fcb85 ptlogo_back2.t32     pivot (500,117)  texture 1118x262 -> implies (559,131)   off 59.0
a60fcb85 ptlogo_back2eff.t32  pivot (507,126)  texture 1133x280 -> implies (566,140)   off 59.5
a60fcb85 ptlogo2.t32          pivot (449, 46)  texture  992x104 -> implies (496, 52)   off 47.0
b483e6e6 ptlogo1.t32          pivot (451, 50)  texture  822x100 -> implies (411, 50)   off 40.0
```

**Why:** build 4's `ptlogo_back2` pivot `(500,117)` is *exactly* half of the
**Japanese** texture (1000 × 234), not its own English one (1118 × 262). The
layout record is authored once and shared while the `.t32` sprites are swapped per
language — the effect
[`structures/ui-rat-layout.md`](structures/ui-rat-layout.md) warns about in
general, here measured on the screen where the render disagrees with the game.
Note it cuts **both ways**: the Japanese build's `ptlogo1` is off by 40 px too.

A 59 px offset on a 1118 px sprite is the right order to produce "too thick and
extending too far right", which is what the crop shows.

### 🔴 …and that candidate is refuted

Checked, as promised. `ui_layout`'s `blit` takes the drawn size from the
**texture** (`img.width`/`img.height`), and uses the pivot only for the
scale anchor:

```rust
let ox = kf.x - (pivot_x as i32 * (sx_pct as i32 - 100)) / 100;
```

At `sx_pct == 100` that term is **zero**. And **every one of the seven swoosh
elements is scale `(100,100)` at every keyframe** — `ptlogo_back2`,
`ptlogo_back2eff` and `ptlogo_back2eff1…5` all report a single scale. So the
pivot mismatch, real as it is in the data, **cannot** move or resize the swoosh in
our render.

⚠️ It is not harmless everywhere: `ptlogo1`/`ptlogo2` run scales
`100 → 101 → 103 → 112 → 150` during the build-in, so there the wrong pivot *does*
displace them — during the animation, not at rest.

### 🟡 So the swoosh defect is a BLEND problem, by elimination

Position and size are the texture's own and are right; fade is white-with-alpha;
tint is white; the texture is blue-leaning, not pink. What remains is how the
seven overlapping sprites are combined — `ptlogo_back2` is only **5.4 % opaque**,
its glow 10.3 %, the five `eff` segments 10–23 %, all white or warm. Stacked with
plain alpha-over they saturate toward opaque white, which is what we draw and
would read as "thicker" beside the game's thin coloured stroke. ❔ Not diagnosed —
no blend mode has been identified in the data.

### 🔴 Refuted on the way

The obvious guess — *our dim is applied over the whole frame instead of beneath
the UI, where its layer key puts it* — is **wrong**. If it were, the logo would
render too dark; it reads **+2.36** against a background of **−0.74**. The
compositor honours the paint order here.


## 🔴 The swoosh is not displaced either — and the residual is restated

Two more candidates eliminated, and the residual is smaller than earlier sections
implied.

**Not a displacement.** Shifting the render's swoosh band over ±80 px × ±8 px and
re-correlating peaks **sharply at (0, 0)** — 0.7342, falling to 0.22 at ±24 px and
0.10 at ±48. The swoosh is where it should be.

**Not additive blending.** See
[`structures/ui-paint-order-key.md`](structures/ui-paint-order-key.md): every
measure worsens.

**And the residual, restated with the current best render** (`--black
--primitives`, `rest()` fixed):

| | |
|---|---|
| whole-frame mean diff | **+0.55** |
| swoosh-band mean diff | **+1.83** |
| swoosh-band edge-correlation | **0.6971** (vs ≈ 0.92 frame-wide) |

⚠️ Earlier sections quoted band tiles at **+16 … +34**. Those were measured on a
render **without** `--primitives`. With the dim drawn the band's *average* is
nearly right; what is wrong is its **structure** — the tiles run −38.6 then +33.8
across the band and cancel. So the defect is neither brightness, nor position, nor
additive blending: it is a shape difference in one band, and it is **not
diagnosed**. Six candidates eliminated: pivot (twice — inert at scale 100, and no
measured displacement), `fade`, `tint`, texture colour, additive blend.

### 🔴 The capture IS settled — my own caveat, tested and withdrawn

The previous version of this section worried that the plate-free capture, at
t ≈ 4.0 s, might be too early: elements have keyframes to t = 600 (10 s), and
"settled" had been judged from mean luminance, which cannot see a thin sprite
still moving.

The plate sits at y ≈ 550–600, **disjoint** from the swoosh band at y 112–225, so
a *late* capture works even with the plate present. Correlating the render's band
against the same band at several ages of the screen:

| capture | band edge-corr | band mean |
|---|---|---|
| t = 4.0 s (plate-free) | **0.7342** | 126.63 |
| t = 6.0 s | 0.7351 | 126.97 |
| t = 12.0 s | 0.7352 | 126.98 |
| t = 18.0 s | 0.7353 | 126.98 |
| t = 21.5 s | 0.7353 | 126.98 |

Identical to within 0.001 over 17.5 s. **The band is settled by t = 4.0 s**, the
capture handed to the port agent is sound, and the caveat is withdrawn. It also
corroborates that the groups **hold**: nothing crosses that band in 22 s.

## The swoosh — SOLVED by draw capture (see below); the elimination trail kept

Seven candidates eliminated, none confirmed:

| candidate | verdict |
|---|---|
| element **pivot** (off by 59 px, authored for the other language) | inert — `blit` sizes from the texture and applies the pivot only when scale ≠ 100; all seven elements are scale `(100,100)` |
| **displacement** | none — shifting ±80 × ±8 px peaks sharply at (0,0), 0.734 → 0.22 at ±24 px |
| **`fade`** | `0x??ffffff` on every keyframe: white RGB, alpha only |
| **`tint`** | `0xffffffff` throughout |
| **texture colour** | blue-leaning (175,174,198); the glow warm — neither pink |
| **additive blend** via `T8aD +0x04` bit `0x02` | refuted: every measure worsens |
| **capture not settled** | refuted above |

The residual is stable and modest: band mean **+1.83**, band edge-correlation
**0.6971–0.735** against ≈ 0.92 frame-wide. Real, persistent, and **not located in
any field this project can read from the disc**.

**Where a next attempt should start, and it is not another field** — but check
what the tool actually records first, because the obvious phrasing of this is
wrong.

⚠️ **The per-draw capture does NOT record blend state.** Reading
`command_processor.cc`, each captured draw carries: primitive type, index count,
index-buffer address, vertex- and pixel-shader `ucode_data_hash`, the pixel
shader's **texture bindings** (base, dimensions, format), and **vertex attribute
0 of binding 0**. There is no `RB_BLENDCONTROL` / `RB_COLORCONTROL` dump. An
earlier version of this section claimed the capture "reads the actual blend
state"; it does not.

So the route splits:

* ✅ **Testable today, no code change** — whether the game passes a **vertex
  colour** for those draws. The capture dumps vertex attributes, and a pink vertex
  colour would explain white-versus-pink directly.
* ❔ **Needs a Canary change** — the blend mode itself, which means adding an
  `RB_BLENDCONTROL` dump to the same capture path.

Either way it is instrumentation of the running guest, not another field in the
file.


## ✅ SOLVED — the game draws the swoosh as ROTATED QUADS, which our blit cannot

The route named in the previous section was run: `--ui_draw_capture_frames=3`,
armed with F10 on the settled title.
[`title-draw-capture-vertex-colours.log`](captures/title-builds/title-draw-capture-vertex-colours.log)
is the capture, 22 draws over 3 frames.

### 🔴 First, the vertex-colour hypothesis dies

Every vertex colour in the entire capture is `<alpha>FFFFFF` — **white RGB**, only
the alpha varying: `FFFFFFFF`, `C5FFFFFF`, `C3FFFFFF`, `B8FFFFFF`, `B6FFFFFF`,
`31FFFFFF`, `1EFFFFFF`. The game passes no colour. That was the eighth candidate.

### ✅ And the ninth is the answer — it is the GEOMETRY

Draw 2 submits **two parallelograms, neither axis-aligned**:

| quad | corners (NDC) | edge `v0→v1` | axis-aligned? |
|---|---|---|---|
| A | `(0.70,1.58) (1.24,1.02) (0.40,−1.57) (−0.14,−1.02)` | `(0.54, −0.56)` | **no** |
| B | `(−1.29,1.02) (−0.85,1.81) (0.75,−1.02) (0.31,−1.81)` | `(0.44, 0.79)` | **no** |

Both verified parallelograms (opposite edges equal to 0.01), both **rotated** —
roughly 45° and 61° — and both extending to `y = ±1.81`, well beyond the screen.
That is the diagonal `Z` stroke.

**Our compositor cannot draw that.** `ui_layout::blit` walks destination rows and
columns of an **axis-aligned rectangle** (`for row in 0..dh { for col in 0..dw`),
sampling the source by a straight ratio. It has no rotation. So the swoosh is
blitted upright where the game draws it skewed — which is exactly the observed
signature: **right on average (+1.83), right in position (peak at (0,0)), wrong in
structure (edge-corr 0.70)**, dark on one side of the true stroke and bright on
the other.

### ❔ And a real gap in the decoded format

The keyframe carries `fade`, `scale_x`, `scale_y`, `tint`, `x`, `y`, `time`
([`ui_layout.rs`](../../crates/sylpheed-formats/src/ui_layout.rs)) — **no
rotation**. So where the game's rotation comes from is **not decoded**: either a
field not yet identified, or the element is positioned by code rather than by its
keyframes. That is the open question this leaves.

⚠️ **The "pink versus white" reading is now suspect.** It was a visual comparison
of two differently-*shaped* renderings. Whether any colour difference survives
correct geometry is **untested**, and should be re-checked rather than carried
forward as a separate defect.

## 🟡 Three angle fields found — and they are NOT the title's rotation

The obvious place to look for the rotation was the keyframe block's three words
at `+4`, `+8`, `+12`, which `ui_layout.rs` documented as `0`.

**They are not zero.** Over **72 287** keyframe blocks disc-wide:

| word | non-zero | commonest values (signed) |
|---|---|---|
| `+4` | **4.81 %** | `180`, `−180`, `22`, `90` |
| `+8` | **4.56 %** | `180`, `90`, `−180`, `178` |
| `+12` | **15.82 %** | `90`, `−90`, `120`, `−58` |

Values clustering on ±180, ±90, 120 read as **degrees**, and three of them suggests
rotation about three axes. 🟡 That reading is **not tied to an observed rotation** —
it is the shape of the numbers, nothing more. The doc comment is corrected either
way: "0 on every frame seen" was a sample artefact.

### ✅ They *do* explain this screen — the earlier negative was wrong about reach

~~**Every element of `GP_TITLE` build 4 has all three at zero** — checked element
by element. So the title's rotation comes from outside the keyframe data.~~
**Withdrawn (2026-08-28).** That check walked build 4's **top-level declaration
table**. The rotated quads belong to its two **nested leaf records**, and there
`+12` reads **30** and **−45** — against a measured **+30.26°** and **−45.28°**.
The bytes were read correctly; the *region* was too small. See
[`structures/ui-keyframe-rotation.md`](structures/ui-keyframe-rotation.md).

⚠️ **One thing I should not have stated flatly:** that the skewed draw *is* the
swoosh. It is the only skewed geometry in the capture and the swoosh is the only
diagonal element on the screen, so the inference is reasonable — but it was not
confirmed by matching the draw's texture or screen position to that element, and
should be.

## 🔴 The skewed draw is NOT the swoosh — my identification was wrong

Converting draw 2's quads from NDC to screen space settles it:

| quad | screen corners | bbox |
|---|---|---|
| A | (1088,−209) (1434,−7) (896,925) (550,727) | x 550…1434, **y −209…925** |
| B | (−186,−7) (96,−292) (1120,727) (838,1012) | x −186…1120, **y −292…1012** |

These span the **full screen height and well beyond it**. The swoosh
(`ptlogo_back2`, rest `(71,126)`, 1118 × 262) is a **band** at y 126…360. Draw 2
is not it.

## ✅ It is the two `ptloop` sweeps — confirmed

The bounding box was the wrong measurement; the quads are rotated, so what
identifies them is their **edge lengths**:

| quad | size | rotation | centre |
|---|---|---|---|
| A | 400.1 × 1076.3 | **+30.26°** | (992.0, 359.1) |
| B | 400.2 × 1444.5 | **−45.28°** | (467.2, 360.0) |

| quad | element | sprite × declared scale |
|---|---|---|
| A | `ptloop01.rat` | `pteff03.t32` 399×180 @ 100 %,**600 %** = 399 × **1080** |
| B | `ptloop02.rat` | `pteff03a.t32` 399×180 @ 100 %,**800 %** = 399 × **1440** |

Five independent agreements, listed in
[`structures/ui-keyframe-rotation.md`](structures/ui-keyframe-rotation.md): the
count (two quads, two `ptloop` elements), both widths (400 vs 399), **both
heights, which are different numbers that both land**, the direction each quad
moves between the capture's two frames (matching each record's own sweep
direction), and the vertex alphas falling inside the declared ramps.

The known-positives in the same capture pass the same test: draw 5 measures
915 × 115 (`ptlogo1.t32` 919×113), draw 7 measures 691 × 18 (`ptcopyright.t32`
694×20) and 512 × 50 (`ptbtn00.t32` 513×50).

### ✅ And "a keyframe group holds" survives

The consequence I flagged conditionally last iteration resolves the *other* way.
Our renderer parks these two sweeps at their final keyframe (`x = 1521` and
`−839`, both off-screen); the game draws them across the screen. That is not a
contradiction — the capture caught them **mid-sweep**: the quad centres, x = 992
and x = 467, both fall inside the decoded `t = 150…600` / `150…720` travel, the
alphas are mid-ramp, and the sprites move in the decoded direction between
frames. The capture is of the **build-in**, not of the settled screen, and the
18 s stillness measurement (sd ≤ 0.01) still says the groups stop. No change to
[the holds-not-loops finding](#-a-keyframe-group-holds-at-its-last-keyframe--it-does-not-loop).

### What this costs

Five iterations of swoosh work — the additive-blend test, the pivot analysis, the
vertex-colour capture — were built on "the skewed draw is the swoosh", an
identification made by *elimination on one screen* and never checked against the
draw's own coordinates. The eliminations themselves stand (they were measured
against the capture, not against the identification), but the chain of reasoning
that pointed at `ptlogo_back2*` did not.