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Glass cockpit lamps: sweep every frame so lit buttons track the sim under load

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Playtesters (all on the glass surround) reported the cockpit lighting
sometimes going slow or nonexistent while the 3D view stayed perfectly
smooth.  The RIO serial/lamp stack is byte-identical to pod-proven Red
Planet (diffed L4LAMP/L4RIO/L4SERIAL), so the wiring was fine -- the defect
is the glass UPDATE CADENCE:

The lit buttons draw every frame (BTDrawCockpitPanels, reading
PadRIO::GetLampState), but the lamp STATE sweep that fills that store
(LampManager::Update -> AssertNewLampValue -> SetLamp) rides the gauge
renderer's FOREGROUND turn, which fires only once per full gauge cycle
(foreground->background->copy).  The cycle can't reach the next foreground
turn until the throttled background gauge sweep drains the ~140-instrument
active list -- and that background task starves under MP load (issue #45,
"instruments freeze while fps stays healthy").  So the lamp sweep ran
~1x/second: buttons froze / flashes stalled while the view (a separate
per-frame foreground render) stayed smooth.

Fix: BTGlassSweepLamps() runs the lamp sweep EVERY frame on the dev/glass
composite path (L4VB16.cpp, in BTDrawGaugeInset), decoupled from the gauge
cycle.  It is cheap -- deduped state pushes over ~72 lamps, no raster.  The
pod never enters BTDrawGaugeInset (real gauge hardware), so its authentic
bandwidth-paced serial lamp cadence is untouched.  BT_GLASS_LAMP_SWEEP=0
restores the authentic once-per-cycle behaviour.

Verified: Release links clean (only the 40 tolerated /FORCE externals);
glass surround boots and runs, lamp sweep pushes state (43 [lamp] pushes,
buttons lit), ~60 fps, no crash.  The under-load win is structural (the
sweep is now an unconditional per-frame call); true MP-starvation repro
needs multiple nodes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
Cyd
2026-08-04 09:41:04 -05:00
co-authored by Claude Opus 4.8
parent 08ca66e5b5
commit f99003cf50
3 changed files with 60 additions and 1 deletions
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@@ -427,6 +427,7 @@ default-ON (`'0'` disables).
| `BT_SECTOR_LOG` | SectorDisplay Make/Execute |
| `BT_NET_TRACE` | `[net-tx]/[net-rx]/[net-upd]` MP tracing |
| `BT_DEV_GAUGES` | render the 6 pod MFD surfaces in a separate dev window |
| `BT_GLASS_LAMP_SWEEP` | `0` = restore authentic once-per-gauge-cycle cockpit-lamp updates; default (on) sweeps the lamps EVERY frame in the dev/glass composite path so the lit buttons track the sim even when the throttled background gauge sweep starves under MP load (`L4VB16.cpp` `BTGlassSweepLamps`; the "lighting slow/nonexistent" fix — glass-only, pod serial cadence untouched) |
| `BT_AIM="x y"` | pin the reticle crosshair (reticle coords) — headless aim harness |
| `BT_AIM_LOG` | `[pick]` ray/box/hit diagnostics (Mech::PickRayHit) |
| `BT_FIRE_ARC=<deg>` | OPT-IN external-camera fire-arc clamp (unset = authentic no-arc) |