# T8aD +0x04 bit 0x02 vs the blend the GAME uses -- 35 elements, 3 screens.
# 2026-08-31. cargo run -p sylpheed-formats --example blend_vs_t8ad_bit
#
# ⚠️ REFUTED.md kills this claim: "T8aD +0x04 bit 0x02 selects an additive blend
# -> mine, and refuted. Blending those sprites additively worsens every measure
# against the capture." That refutation is a claim about OUR RENDERER, which the
# corpus's own rule says is a hypothesis under test. The blend has since been
# measured off the GPU, so the claim can be tested against the oracle instead.
#
# Every label below is an RB_BLENDCONTROL0 value read out of the guest command
# stream and attributed to an element by quad size -- see
# data/ui-blend-mode-measured.txt, data/ui-blend-title-and-replication.txt and
# data/ui-blend-extras-complete.txt.
#
# The pair that no confound survives: ptbtn00 = 0x0110 and ptbtn00f = 0x0112, the
# PRESS (A) plate and its own highlight, same screen, same draw order, differing
# in exactly this bit -- and the game draws one alpha-over and the other additive.

entry      sprite                 +0x04        bit 0x02  measured blend
4          ptbase2.t32            00008830        false  alpha-over
4          ptlogo1.t32            00008830        false  alpha-over
4          ptlogo2.t32            00008830        false  alpha-over
4          ptlogo_tm.t32          00008830        false  alpha-over
4          ptcopyright.t32        00008830        false  alpha-over
4          ptlogo_back2.t32       00008830        false  alpha-over
4          ptlogo_back2eff.t32    00008830        false  alpha-over
2          ptbtn00.t32            00000110        false  alpha-over
2          ptbtn00f.t32           00000112         true  ADDITIVE
5          ptbase.t32             00008830        false  alpha-over
5          ptmsg.t32              00008830        false  alpha-over
5          ptbtn01f.t32           00008130        false  alpha-over
5          ptbtneff01.t32         00008130        false  alpha-over
5          pteff10.t32            00008832         true  ADDITIVE
5          pteff12.t32            00008832         true  ADDITIVE
5          ptframe1.t32           00008832         true  ADDITIVE
5          ptframe2.t32           00008832         true  ADDITIVE
5          pteff03.t32            00008832         true  ADDITIVE
5          pteff03a.t32           00008832         true  ADDITIVE
6          ptbase.t32             00008830        false  alpha-over
6          ptmsg2.t32             00008830        false  alpha-over
6          pttitle.t32            00008830        false  alpha-over
6          ptbtn11f.t32           00008130        false  alpha-over
6          ptbtn12.t32            00008130        false  alpha-over
6          ptbtn13.t32            00008130        false  alpha-over
6          ptbtneff02.t32         00008130        false  alpha-over
6          pteff10.t32            00008832         true  ADDITIVE
6          pteff20.t32            00008832         true  ADDITIVE
6          pteff21.t32            00008832         true  ADDITIVE
6          pteff22.t32            00008832         true  ADDITIVE
6          pteff23.t32            00008832         true  ADDITIVE
6          ptframe3.t32           00008832         true  ADDITIVE
6          ptframe4.t32           00008832         true  ADDITIVE
6          pteff03.t32            00008832         true  ADDITIVE
6          pteff03a.t32           00008832         true  ADDITIVE

bit set & additive      16
bit clear & alpha-over  19
bit set & alpha-over    0   <- false positives
bit clear & additive    0   <- false negatives
sprite not found        0

PERFECT PARTITION on every element whose blend was measured.

RIVAL FIELDS — other bits of the first 12 header words that separate
the same 35 elements with zero errors: 1
   +0x04 bit 1 (0x2)
   -> the sample singles out ONE field. Nothing else in the header does it.