From a72e7c614eb6b08d55a128ce0624378875723932 Mon Sep 17 00:00:00 2001 From: Sylpheed RE agent Date: Fri, 28 Aug 2026 21:02:14 +0000 Subject: [PATCH] re: the last keyframe time is the chunk terminator -- observed, not assumed Continuing the pulse's cycle length, which I had called a structural limit of the format. It is, and now I can show it rather than assert it. Dumping past what I thought was the final keyframe found an EIGHTH block: fade 0x00ffffff at the same position, so the glow returns to fully transparent and the pulse is a closed cycle rather than a one-shot ramp. That is worth having on its own -- the port knows the animation ends where it starts. And the eighth block's time slot contains the four bytes "end ", the record's ASCII terminator. So the corpus's rule that a group's last block has no time of its own holds here in a second form: not the next group's element index, but the chunk terminator. The value does not exist. That goes into ui-rat-layout.md, because it generalises beyond this record. The measured 2.3 s would need a final step of about 33 units. I have written that number down explicitly labelled as fitted to the measurement rather than read from the file, so nobody later re-derives it as a decode. One thing I had half-assumed and can now rule out: the word at +0x004 is not a keyframe count. It reads 60 here with 8 keyframes and 30 in the loop records with 3. Unknown, and marked so. --- docs/port/HANDOFF.md | 15 ++++++++++----- docs/re/structures/ui-rat-layout.md | 17 ++++++++++++++++- docs/re/ui-title-build-map.md | 21 +++++++++++++++++---- 3 files changed, 43 insertions(+), 10 deletions(-) diff --git a/docs/port/HANDOFF.md b/docs/port/HANDOFF.md index 0553af83..fe1ee447 100644 --- a/docs/port/HANDOFF.md +++ b/docs/port/HANDOFF.md @@ -72,11 +72,16 @@ authored version can be deleted. screen — a capture's per-tile amplitude map puts **sd 7.65** in the band x ≈ 318–954, y ≈ 560–672 against **0.06** on the wordmark. It is `ptbtn00f.rat`, the plate's highlight variant (build **2**, not build 4), - whose alpha ramps **`0x00 → 0x06 → 0x4a → 0x50` (hold) `→ 0x4a → 0x06`** - across `t = 6 … 105` — a glow that fades in and back out. - 🟡 Its full cycle is **not** readable: the keyframe group's last block carries no - time (that slot belongs to the next group), so the declared span is **≥ 105 - units = 1.75 s** against a measured **≈ 2.3 s**. Consistent, not confirmed. + whose alpha ramps **`0x00 → 0x06 → 0x4a → 0x50` (hold) `→ 0x4a → 0x06 → 0x00`** + over **eight** keyframes at `t = 6, 29, 35, 50, 58, 97, 105, ?` — a glow that + fades in and back out, **closing on fully transparent**, so it is a complete + cycle rather than a one-shot ramp. + 🟡 Its cycle **length** is not readable, and this is now observed rather than + assumed: the eighth block's time slot literally contains the ASCII terminator + `end `, so the record ends there and the value does not exist. Declared span is + therefore **≥ 105 units = 1.75 s** against a measured **≈ 2.3 s** — which would + need a final step of ≈ 33 units. That number is **fitted to the measurement, not + read**; the port should take ≈ 2.3 s as measured. ⚠️ An earlier version of this bullet said "the title screen loops at ≈ 2.2 s" and attributed it to `ptloop01/02`. Both halves were wrong: it is the **plate**, and it is a different build. diff --git a/docs/re/structures/ui-rat-layout.md b/docs/re/structures/ui-rat-layout.md index 05d77aef..24b69e45 100644 --- a/docs/re/structures/ui-rat-layout.md +++ b/docs/re/structures/ui-rat-layout.md @@ -695,4 +695,19 @@ rule, and the kind of moderate split that would be easy to over-read. rather than untried, and the field is at least correctly *sized*. Assigning meanings almost certainly needs the game observed with individual bundles loaded, not more static correlation — every property visible in the file has now -been tried. \ No newline at end of file +been tried. + +## A leaf record's last keyframe time is the chunk terminator (2026-08-28) + +The build placement region's "a group's data stops 4 bytes short of its final +block's time slot — that word is already the next group's element index" has a +second form in **leaf `.rat` records**, where there is no next group. + +`ptbtn00f.rat` (`GP_TITLE` build 2, `RATC` at `0x04115e`) holds 8 keyframe blocks +of the ordinary 40-byte layout starting at `+0x68`. The eighth block's time slot +at `+0x1a4` contains **`end `** — the record's ASCII terminator. So the last +keyframe's time is not merely unread, it is **not present**, and any animation's +full cycle length has to come from measurement. + +❔ The word at `+0x004` is **not** the keyframe count: `0x003c0000` (60) with 8 +keyframes here, `0x001e0000` (30) with 3 in `ptloop01.rat`/`ptloop02.rat`. diff --git a/docs/re/ui-title-build-map.md b/docs/re/ui-title-build-map.md index 8bc60a2c..70798096 100644 --- a/docs/re/ui-title-build-map.md +++ b/docs/re/ui-title-build-map.md @@ -284,10 +284,23 @@ Decoding `ptbtn00f.rat`, the plate's highlight variant, gives the pulse directly A glow that fades in to `0x50` and back out — exactly a "press start" pulse. -🟡 **The cycle length is still not readable.** The group's last block has no time -(that slot belongs to the next group), so the declared span is **≥ 105 units = -1.75 s** against the measured **≈ 2.3 s** (138 units). Consistent with a final -block extending the tail; not confirmed. +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