2 Commits

Author SHA1 Message Date
sylph-decoder
9ea6ee7555 re: the blend bit was challenged on pteff10 and SURVIVES; finding 3 loses its second candidate
The port isolated main_menu's 10.88 -> 13.02 regression to pteff10 and
asked whether the per-draw log shows it alpha-over, which would be a
counter-example to ui-blend-mode-decoded.md.

It does not. blend-bit-vs-oracle.txt has pteff10 ADDITIVE on entry 5 (main
menu) AND entry 6 (extras), both labels read out of the guest command
stream, and HANDOFF states it from three independent menu sessions, every
frame.

The premise came from a stale coverage table of mine that the same HANDOFF
entry had already corrected in place. Recording that: a correction which
leaves the wrong table visible upstream of it has not landed.

And the regression was predicted on this exact element before adoption --
HANDOFF flagged pteff10 as the one row the port's renderer would not
corroborate, because for a dim wholly-semi-transparent glow (max alpha 130)
over a dark background additive and alpha-over nearly coincide. A renderer
metric getting worse while the render gets more correct is the standing
rule with a number on it.

Separately, the port answered my finding-3 candidate: a frozen sweep of the
plate region rises monotonically across the declared 214->236, so the port
fades rather than pops and its t=236 is a completion. That kills the onset
branch.

Two of the play-test's four named candidates for finding 3 are now dead --
units/s (measured at 60) and the ramp. Finding 3 has no surviving named
cause. The clock origin is the one to take next, because every measurement
so far is a DIFFERENCE between two events and a difference cannot detect a
common offset.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Jc4pciRArGHfxGGhEbwp5t
2026-09-01 18:55:50 +00:00
sylph-decoder
bac8e17a7f re: the blend mode IS on the disc -- T8aD +0x04 bit 0x02, DECODED
Reverses two of my own pages. t32-blend-mode-not-on-disc.md said the mode is not
on the disc; ui-blend-mode-measured.md classified it measured and told the port
that which field selects it was unknown. Both were honest and neither is current.

Bit 0x02 of +0x04 set means the game draws that sprite ADDITIVE
(RB_BLENDCONTROL0 = 0x01010101); clear means premultiplied alpha-over.

Fit: 35 elements over three screens, 16 set/additive and 19 clear/alpha-over,
zero errors, every label read out of the guest command stream rather than off a
render.

Control: of every bit of the first twelve header words, exactly one separates
those 35 without error. Nothing ties with it -- which is precisely what the
+0x08 = 0x8050 candidate failed.

Within-pair: ptbtn00 0x0110 alpha-over against ptbtn00f 0x0112 additive, same
screen, same bundle, adjacent draws, one bit apart. And other f variants are
bit-clear and alpha-over, so it is not 'focused variants are additive'.

Out of sample: a prediction committed at 088df91, before its capture, on a
different archive -- GP_OPTIONS entry 19, 3 additive of 16, falsified if any
other element drew additive. The game drew exactly po_menu_eff01/02/03 additive
and nothing else.

This revives a claim REFUTED.md killed. The refutation said blending those
sprites additively worsens every measure against the capture -- a claim about
our renderer, made while that renderer had a stale keyframe association, no leaf
geometry and no rotation. Recorded as a revival with its evidence;
check_refuted.py passes with 0 unmarked assertions.

Two other readings of the same bit stay refuted and are explicitly not revived:
'the name contains eff' and 'premultiplied storage'. Those were the bit's
meaning; this is its effect.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Wuu56cE8vJGTBtn1ppsk8v
2026-08-31 07:20:12 +00:00