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2 Commits
Author SHA1 Message Date
CydandClaude Fable 5 943219345a BT410 5.3.84: the yellow bar and the MFD bleed are ONE bug -- BTSEC1.PCX index 254, and the offender is named
Second operator report, same day: "what is that yellow orange artifact on the
display, it too shows up here and in bt411 but not in the original" -- a
solid vertical bar beside the RANGE readout on the colour head.

It is the same defect as 5.3.83's MFD bleed.  Not a similar one: the same
676 pixels.

HOW IT WAS CAUGHT.  5.3.83 shipped a fix that could not be verified, because
the fix makes something INVISIBLE and the A/B rig's boot cockpit already
showed zero MFD extras -- the unfixed build looked perfectly clean.  So this
commit adds a POSITIVE CONTROL instead of another argument:

  BT_TRANS_PROVOKE fills the colour head's uninitialised
  translationTable[64..255] with 0xFF00 -- every high-byte head bit --
  rather than the zero the fix installs.  Any draw that indexes the tail
  then lights ALL the mono heads at once.

On the boot cockpit that lights exactly 1030 pixels: Eng1/Eng2/Eng3 +1030
each, Mfd1 +684, Mfd2 +704, Mfd3 +1074, Comm +676, against 0 extras with the
fix.  The bug was firing the whole time.  Our heap simply happened to hold
zeros in that tail -- the same luck the shipped binary has been having, which
is exactly why the operator sees the artifact and the A/B rig does not.

THE OFFENDER, NAMED.  oormask.py renders which pixels those are and prints
their horizontal run lengths.  The mask is a glyph cluster plus 52 runs of
13px -- a SOLID 13x52 BAR at screen (526,228)-(538,279).  Solid means a
rectangle in the source art, so decode the art:

  BTSEC1.PCX, the colour head's own 480x640 background, contains exactly
  ONE out-of-range value in the entire image: index 254, exactly 676
  pixels, a solid 52x13 rectangle at (199,526)-(250,538).

  The sec port is configured at ROTATION 270, mapping source (x,y) ->
  screen (y, 479-x).  That puts the rectangle at screen x 526..538,
  y 229..280.  Measured mask: x 526..538, y 228..279.  Same rectangle, to
  the pixel.

ONE READ, TWO SYMPTOMS.  translationTable[254] is never written (
BuildSecondaryTranslation fills only 1<<numberOfBits = 64 entries), and
DrawPoint ORs the result in unmasked.  Whatever the heap left there decides
which symptom the operator sees:

  low 6 bits set  -> a coloured block on the COLOUR head, beside the RANGE
                     readout.  The yellow-orange bar.
  high 8 bits set -> garbage in the MFD / ENG / COMM planes.  The bleed.

Both reports, one uninitialised int.  It also explains the "not in the
original" asymmetry without needing the original to differ in code: it does
not differ, it is just getting zeros there.  And it explains BT411 showing it
too -- both reconstructions inherit the read from the archive.

5.3.83's zero-fill therefore cures both, and turns a heap-lottery into a
guarantee.  Still not DIRECTLY observed cured, because no rig we have was
showing the artifact to begin with; that honesty is recorded in the file
header rather than smoothed over.

ALSO IN: oormask.py, barbox.py, vis_provoke.conf, and a README section on
positive controls -- when a fix replaces garbage with a benign value, build
the variant that replaces it with a maximally LOUD value, because that turns
"I see no difference" into a number and separates "the fix works" from "this
screen never exercised the path".

METHOD NOTE, recorded in the README because it nearly cost the fix: three
grabs of one running instance score IDENTICALLY, so the within-boot noise
floor is zero -- and that is the wrong floor.  Judging a rebuild needs the
ACROSS-boot floor (~6px on the MFD heads).  A single bad grab, caught
mid-draw, read as a 2700px regression and nearly got a correct change
reverted.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-29 22:36:59 -05:00
CydandClaude Fable 5 740ef2b0a7 BT410 Phase 5.3.32: the per-head A/B -- three engineering heads now exact
The gauge framebuffer is PLANE-PACKED: L4GAUGE.CFG gives each port a bit
mask, not a rectangle, so all six heads share the same x/y and are separated
only by bit -- the packing the VDB splits into the pod's physical screens.
Comparing RGB was therefore measuring nothing useful; the "magenta artifact"
just meant the wrong heads were lit at that pixel.

New instruments (emulator/render-bridge/gauge-ab/, with a README):
  planes.py  per-head scoreboard -- shipped vs ours, missing vs extra, per
             port mask, recovering the 16-bit word from DOSBox's RGB565
  BT_VIS_LOG a complete cockpit widget map from the single dispatch every
             gauge widget is built through (MethodDescription::Execute),
             printing name + port + authored position
  ab.sh      stages the fresh build over BTL4REC.EXE and kills any running
             DOSBox before launching -- see below

The fix: the Comm page's pilot roster is the POD roster (the viewpoint mech's
ControlsMapper pilot array, mapper attributes 15/16), not the mission's
player list.  It is zero in a solo mission, so the shipped page draws empty;
ours resolved the local player and painted its icon in colour 0xff.  The gate
belongs in the row source, not PilotList::Execute -- Execute's empty branch
still has to run, because erasing is what the shipped page draws.

  head    shipped    ours   missing   extra          (was)
  Eng1      17981   17981         0       0     (0 / 1030)
  Eng2      17981   17981         0       0
  Eng3      17981   17981         0       0
  Comm      15656   13557      2099       0     (2099 / 1253)
  Heat      21374   20913       566     105     (566 / 990)

Title-band magenta 404 -> 0.  The 2099 Comm pixels we are missing were
missing before the gate, so it is a strict improvement.

Method note, which cost more than the bug: the rig's confs run BTL4REC.EXE
out of the mount while the build writes build410/btl4opt.exe, and nothing
connected the two.  Three measurements ran an hour-old binary, so a change
that "did nothing" three times had never been tested -- and the correct first
hypothesis was discarded on that evidence.  ab.sh now re-stages every launch.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-27 12:04:43 -05:00