re: the splashes have NO post-process -- one pass, source-over, alpha in the vertex stream

Play-test finding 4 asked, in order: is there a pass, what is it, where do
its parameters come from, only then what curve. All four, from GPU state.

1. NO post-process pass. Over all 1 048 draws of frames 4..226 (both boot
   splashes): rt0=[tile=0 fmt=0 exp=0] on 1048/1048, pitch=1280 msaa=0 on
   1048/1048, edram_mode only ever kColorDepth or kCopy, resolve dests only
   the two alternating front buffers, and NO texture base anywhere in the
   capture equals a resolve destination. The only texture bound in the whole
   splash region is the sprite page 0x11A50000. No blur, no bloom, no fade
   quad over a resolved image, no tone curve, no resolve-and-resample.

2. What it is: per frame, a full-screen replace triangle (the clear), a
   full-screen black quad through the ordinary blend, ONE batched sprite
   draw carrying every visible element (indices 4/8/12/24), and the two
   presentation resolves.

3. Where the parameters come from: NOT the constant banks -- the splash
   pixel shaders read zero float constants, ps_c[n=0] on 1048/1048, taken
   off each shader's own float_bitmap. NOT immediates. The fade is the
   per-vertex k_8_8_8_8 colour in a vertex buffer the guest rewrites every
   frame.

4. The curve falls out of 3 and is the corpus's existing 34/frame law,
   reproduced on an independent capture. Not claimed as new.

And the composite is ORDINARY SOURCE-OVER, confirmed from the shader ucode
rather than inferred from the blend register: the register reads
ONE/ONE_MINUS_SRC_ALPHA, which looks premultiplied, and is -- because the
shader premultiplies. The two together are src*A + dst*(1-A). So the 'more
pronounced' fade is neither a blend difference nor a pass.

The likely mechanism instead: the developer splash submits SIX quads, three
logos plus three slightly-larger companions that lead them by 8 frames and
are gone 79 frames early. Two over-blended copies of the same art at
different scale is a halo, on screen only during the entry.

Refutation attempt, recorded: REFUTED.md's re-opened rest() pair states its
settling condition as 'a draw capture of the developer splash naming which
of the three glows is submitted at rest'. This is that capture. All three
companions ARE submitted in all 21 frames -- so no rule that hides one
describes this stream -- but they are NOT interchangeable: Q6 leaves the
plateau on its own -5.6/frame decay while Q4 and Q5 hold 255. The one-byte
sibling difference is drawn.

Trap recorded with the evidence: censusing the whole 600-frame log finds six
640x360 textures sampled ~330 times each, which reads exactly like a
half-resolution blur chain. They are the attract movie's chroma planes and
first appear at frame 234, after both splashes. Restricting the window is
what separates them.

Evidence: docs/re/data/splash-draw-pass-census.txt,
docs/re/data/splash-quad-timeline.txt, docs/re/data/shaders/*.ucode.frag.
Logger: canary sylpheed-re d90d14e02.

docs/re/INDEX.md

@@ -137,6 +137,7 @@ files, which is how the same ground got covered twice.
 | [`structures/stage-mission-tables.md`](structures/stage-mission-tables.md) | The stage table set — phases, routes, sub-objectives and AI parameters | ✅ the table set and how the stage record reaches it, validated across; **`AIParams` disc-wide: 23 objects, one shared 34-profile roster (782 records), loader `sub_8233C368`; `Type`→field-count holds except the two `_Test` templates** |
 | [`structures/texture-color-k8888.md`](structures/texture-color-k8888.md) | Texture colour interpretation — `k_8_8_8_8` (32bpp UI/HUD textures) | — |
 | [`ui-keyframe-time-unit.md`](ui-keyframe-time-unit.md) | What a keyframe time is worth, and what shape the ramp has |  ✅ CONFIRMED from the running game's own draw stream — the ramp is **linear** (a declared 15-unit fade lands on `round(255·k/15)` for all seven samples) and the animation clock advances **2 time units per submitted frame**. 🟡 the seconds conversion (`1 unit = 1/60 s`) rests on a measured 27.6 present-frames/second |
+| [`ui-splash-draw-pass.md`](ui-splash-draw-pass.md) | The splash draw pass — is there a post-process, and where does the fade come from | ✅ **decoded from GPU state, 2026-09-01.** **No post-process pass exists**: over all 1 048 draws of both splashes, one render target (`rt0=[tile=0…]` 1 048/1 048), one pitch, no MSAA, only kColorDepth/kCopy modes, resolve destinations only the two front buffers, and **no texture base anywhere equals a resolve destination**. The only texture bound is the sprite page. Three trivial pixel shaders; the sprite shader **premultiplies**, so `ONE/ONE_MINUS_SRC_ALPHA` is algebraically **source-over**. Parameters come from **per-vertex `k_8_8_8_8` colour** in a per-frame vertex buffer — the shaders read **zero** float constants (`ps_c[n=0]` 1 048/1 048). Ramp reproduces the ✅ 34/frame law. ⚠️ Censusing the whole 600-frame log instead finds the attract movie's 640×360 chroma planes and reads as a half-res blur chain — the frame window is what avoids that. |
 | [`ui-keyframe-record-layout.md`](ui-keyframe-record-layout.md) | A keyframe's time word comes **before** its pose — the placement record, decoded | ✅ CONFIRMED, **decoded**. A group is an 8-byte header then `frames` records of `{u32 time; 36-byte pose}`, so the time precedes the pose; the group's lead-in word at `header+8` is pose 0's time and **every** pose is timed. Disc-wide over 13 991 groups in 33 archives, each test with a control: lead-in prepended is non-decreasing **13 991/13 991**; a non-zero lead-in is strictly below the next time **5 058/5 058** (control 70.9 %); a multi-segment alpha ramp runs at a constant `dα/dt` **857/1 540** against **0/1 042** under the old reading. 🔴 Retires two long-standing corpus claims — *"a group's data stops 4 bytes short of its final block's time slot"* and *"the last keyframe carries no time"* — both of which were this off-by-one. Adoption is free: all 12 `GP_TITLE` builds render byte-identically, and over 217 builds only two elements pick a different `rest()` pose, both between equally invisible ones. ❔ the executable's own parser was **not** found (the 40/60 stride query is weak, not negative) |
 | [`structures/ui-composable-bundles.md`](structures/ui-composable-bundles.md) | A screen build is not the only thing `compose` can draw |  ✅ CONFIRMED by measurement over the disc, with the artifact to |
 | [`structures/ui-focus-and-effect-elements.md`](structures/ui-focus-and-effect-elements.md) | `_eff` glow layers are not focused-state records |  ✅ CONFIRMED by measurement over all 965 screen builds on the disc, |