Implements what the pod actually does (pod-hardware.md THE RGB SPLIT): a VGA
port's R/G/B lines each drive a separate mono MFD monitor, so a window is not
one MFD -- it is one PORT carrying up to three. BT_POD_RGB=1 collapses the
five MFD windows into the two ports the cab drives (Port A: Comm=red,
Mfd2=green, Heat=blue; Port B: Mfd1=red, Mfd3=green) and composites each
group's planes into the colour channels, leaving the radar on its own
full-colour port. Channel comes from the live port (GetEnableID), never a
hardcoded table, so an Eng-page swap follows automatically; BlankColor planes
contribute nothing, exactly as on the pod. Implies BT_POD_SURFACES (bare
640x480 pictures -- the cab's buttons are physical).
Verified locally (bare windows, "RGB COMPOSITE of 2 plane(s): Comm Mfd2") and
LIVE ON NICK'S CRASH CART over the tailnet: Port A -> DISPLAY4, Port B ->
DISPLAY2, radar -> DISPLAY1, all exact-fit. Pod scratch kit included (ssh
helper, layout cfgs for both modes, launcher; the mission-egg launcher fix --
a bare MP.EGG exits the mission loop with no relay, and BT_FE_SOLO parks at
the menu, so neither lights the panels).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Answering 'how do the panels split RGB into 3 monitors' from primary sources
rather than inference:
- content/GAUGE/L4GAUGE.CFG (the authentic 1996 pod config) configures each
gauge port with a bit-plane mask AND A COLOUR CHANNEL: Comm=red,
Mfd2=green, Heat=blue on clut2 (the upper row); Mfd1=red, Mfd3=green on
clut1 (the lower row, blue spare); sec/radar = full rgb, rotation 270 (the
portrait CRT). Eng1/2/3 are the engineering-page twins on the same
monitors, swapped in/out via reconfigure() with 'blank'.
- L4GraphicsPort::BuildSecondaryColor (L4VB16.cpp) proves the mechanism at
T0: it walks the palette entries owned by the port's bit group and writes
exactly ONE component (RedChannel->Red, GreenChannel->Green,
BlueChannel->Blue, AllChannels->whole triplet); BlankColor blanks the
group. So one palettized framebuffer emits three independent pictures on
the R/G/B analog lines, and the splitter feeds each line to its own mono
monitor -- which is also what the '1280x480 horizontally spanned' MFD
surface actually is: two VGA outputs x three channels.
Port consequence recorded: the per-panel window path (BT_POD_SURFACES) is
right for per-panel outputs but WRONG for splitter-wired glass, which needs a
channel-composite mode (three planes -> one RGB image, pure primary tints).
ExpandPlaneToBGRA already does the per-plane half. Open: how Nick's cart is
actually wired. Also lands the pod bring-up scratch (ssh helper, layout cfg,
launcher, firestorm repo browser).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
