User report: footfalls silent for the first 10-20 s of every mission (all
mechs), then solid. Root cause was three interlocking layers, each measured
with timestamped traces:
1. The authored footstep volume chain (LocalAcceleration [0,10]->ctl100 +
LocalVelocity [0,0.6]->ctl101 through authored N=30/N=15
AudioControlSmoothers, fill 0) hangs off the SOURCE's watcher chain
(scale watches smoother watches mixer watches source), and an idle
source's chain executes only at Start attempts -- one smoother sample
per stride.
2. Each hop is frame-gated (AudioComponent::ExecuteWatchers,
DefaultAudioFrameDelay), so any burst collapses to one execution.
3. The transient drop gate (vol < 0.3, AUDREND) rejected every Start while
the smoother average crawled up 1/30th per attempt -> ~25 dropped strides
before the first audible step, then per-frame execution while playing
kept it warm forever ("solid after that").
Fixes (engine-level, each documented in place):
- AudioScaleOf<T>::Execute now sends EVERY poll (scales are continuous
value-feeders; the base bitwise change-gate -- Motion::operator== is
memcmp -- froze on our deterministic gait math, where the original's
noisy physics floats never bit-repeated. Triggers/matchers keep the
change gate: their semantics are edge-based).
- Component/AudioComponent::PrimeWatchers(passes): recursive, GATE-FREE
watcher pump; AUDREND runs 30 passes on every transient Start request so
the authored smoothers evaluate at their true steady state before the
drop gate reads the volume.
- localAcceleration derives via the binary's exact structure: 15-sample
ring buffers of the raw position derivative + dt (ctor part_012.c:9836,
derive :15169-15195), in the PerformAndWatch tail so it runs every frame.
- AttributeWatcherOf::GrabCurrentValue private -> protected (the scale
override calls it).
Verified (30 s walk from cold start): drops 25 -> 3 (the survivors are
authentic quiet-stride gating: first gentle strides at vol ~0.28 vs the 0.3
gate), footfalls deliver from the first stride, 43 delivered with live
per-stride gain variation. Diag traces added: [accwatch]/[fsscale]/
[smooth]/[smoothcfg]/[motionscalecfg] + timestamps on DROP/volset.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The previous 'chirp killed' verification was WRONG: it checked the 1/s playing
snapshot (which misses 0.12s pulses) instead of delivery counts -- the run had
186 ProgramButton deliveries. Corrected metric + trigcfg now prints its target
component, revealing NINE thresh=-1 Start triggers on the configure-ticker
sequence: ConfigureActivePress on Avionics + Myomers (backed real, -1) AND
SEVEN more subsystems still on the inert pad (0 = "button 0 held" -> ticker on).
Fix: a TYPED pad in the missing-attribute redirect -- ConfigureActivePress
resolves to a shared static int = -1 (the authored none-held idle) instead of
the zero pad; every other missing attr keeps the zero pad. Covers all
configurable subsystems at once with no layout changes; self-clears per
subsystem as each gets a real driven member.
VERIFIED BY DELIVERY COUNT: ProgramButton01 deliveries = 0 (was 31-186/run);
7 attrs took the -1 pad; the rest of the soundscape intact (weapon cycles,
loops, translocate).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Chain (every hop verified live): FootStep pulse (SetBodyAnimation, decay in
PerformAndWatch) -> AudioMatchOf match=1 -> Start(2.0) on the FootFall
DirectPatchSource... which the renderer DROPS because its volume is 0:
an AudioControlMixer (outCtl=3/Volume + a second outCtl=5 mixer) feeds the
source, and BOTH mixer inputs are 0 -- nothing ever sends them.
Eliminated as senders (all traced): AudioScaleOf scales (29 total, none target
the mixer), AudioControlMultiplier (one instance, other target), Random/
AudioSampleAndHold (RNG verified WORKING -- varied samples; RANDOM.cpp is in
the build, the self-init ctor runs).
HYPOTHESIS [T4, next session]: the mixer inputs are fed by AudioStateTriggers
on AnimationState keyed to the AUTHORED gait-clip ids (walk 2/3, run 8/9 =
per-gait footstep volume). Our runtime body SM walks in states 12<->13 --
which the recovered MechAnimationState enum names RightStandToReverse/
LeftStandToReverse. If the authored audio expects 2/3 for forward walk, the
runtime clip NUMBERING in the reconstructed gait SM is offset from the
authentic ids -- a locomotion-layer mismatch with implications beyond audio
(the audio config is an independent witness to the true clip numbering).
Verify via the AudioStateTrigger configs on the AnimationState watcher
(trigcfg dump exists) and cross-check the SetBodyAnimation clip table.
New diagnostics: [snh] SampleAndHold sends, [mix] mixer forwards with input
index + sum, [scalecfg] authored scale bindings/boundaries, [volset].
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Footstep chain progress (each step empirically verified):
- The FootStep watcher is an AudioMatchOf<Logical> (AudioLogicalTrigger extends
AudioMatchOf, NOT AudioTriggerOf): authored config match=1 -> Start(2.0) on a
DirectPatchSource. [trigcfg]/[matchcfg] ctor dumps added.
- The pulse was pinned at 1: the decay lived in IntegrateMotion, which the
current gait path NEVER CALLS. Moved to Mech::PerformAndWatch (provably
per-frame) with a time-based 150ms window sized to the ~10Hz watcher poll.
The matcher now fires per stride (14/run, was 1).
- Every footstep Start is DROPPED at the renderer: the source's volumeScale is
0 (five VolumeAudioHandler sends of exactly 0 = inert/one-shot primes). The
volume arrives through the authored control chain (AudioControlMultiplier
inputs ctl 100+; one 0 input pins the product). Chain scales identified on
this entity: LocalVelocity (live), LocalAcceleration (live), Myomers.
SpeedEffect (=1.0 healthy; one authored scale maps [0,1]->[1,0] INVERTED),
UnstablePercentage (INERT PAD -- always 0!), HeatSink.CurrentTemperature.
PRIME SUSPECT: an UnstablePercentage-fed multiplier input primes 0 once and
never updates (the pad never changes), pinning footstep volume at 0.
- SF2 numbering fact recorded: 38 presets in AUDIO1 / 5 in AUDIO2 have
wPreset != file index (gap at preset 77); my table keys by wPreset. The
184x ProgramButton01 (bank1 patch83) storm at ~7/s needs an identity check
against index-numbering (it may be the wrong sample for that patch id).
Diagnostics added (BT_AUDIO_SPATIAL/BT_ATTRBIND_LOG): [trigcfg]/[matchcfg]
ctor dumps, [matchfire] with component ptr+class, [volset] VolumeAudioHandler,
[mult0] multiplier zero-products, scale sends with authored boundaries,
[fswatch] dedicated footstep watcher tracer (g_btFootStepAddr), SetupPatch
ENTRY with bank/patch/state, Simulation::DebugAudioWatcherCount.
NEXT: back UnstablePercentage with a real (live) member -- it is the mech's
stability 0..1 (the stabilityAlarm/gyro family) -- or confirm via a one-run
chain dump which multiplier input pins the FS source; then the footstep
transient should clear the 0.3 drop gate at walking speed.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Instrumentation (all BT_AUDIO_LOG/BT_AUDIO_SPATIAL-gated): mech watcher-poll
probe (delayed flag + socket count via new Simulation::DebugAudioWatcherCount),
per-sim audio-socket size in ExecuteWatchers, trigger notifications (val>0),
watcher poll-rate/change probes, footstep pulse address trace.
VERIFIED working: FootStep binds to the real member (pulse addr == bound ptr,
same run); pulses fire per stride (40/run); the watcher registers on the mech
(audioWatchers=20 after audio-object creation); the mech's poll runs
(delayed=0, simFlags=0x1110); Logical == int (STYLE.H:132) matches the member
type. The idle<->moving engine crossfade (AudioMotionScale on LocalVelocity
through the restored watcher poll) is CONFIRMED audible in play.
REMAINING: the FootFall transient still doesn't reach SetupPatch -- next probe
is the trigger's streamed threshold/inverse config and the speed-scaled
transient volume at the renderer drop gate (LowAudioVolumeThreshold=0.3).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
User: "when I start moving all the sounds fade away, no footsteps." Diagnosis
chain (all empirical, BT_AUDIO_SPATIAL/BT_ATTRBIND_LOG traces):
- The audio head DOES track the mech (listener-relative positioning verified
while driving) -- not a spatial bug.
- The idle sounds correctly STOP on leaving the standing state; the MOVING
sounds never started because every POLLED audio watcher was dead:
the reconstructed Mech::PerformAndWatch replaced the engine performance but
dropped the ExecuteWatchers() step from the engine tail (Simulation::
PerformAndWatch = Perform -> ExecuteWatchers -> WriteSimulationUpdate).
Only PUSHED StateIndicator watchers (SetState->Execute) ever fired -- which
is exactly why state sounds worked but footsteps/motion-scaled audio didn't.
FIX: poll ExecuteWatchers() (AreWatchersDelayed-gated) before the update
write. Immediately unlocks the polled family: MissileLoaded01/LaserLoaded01
ready dings, ProgramButton01, motion scales (PlayNote 15 -> 30 per run).
- FootStep (0x1e) backed REAL: was the inert attrPad (an AudioLogicalTrigger
polls it -- threshold-crossing pulse per foot plant). New footStep member,
pulsed by SetBodyAnimation on entering any locomotion clip 1..0x17 (runtime
stride alternation MEASURED as body states 12<->13 -- the enum-name numbering
does not match runtime clip ids), decayed by IntegrateMotion (~1/3 s).
- Footstep volume is speed-scaled (AudioMotionScale on LocalVelocity): at
standstill the transient start computes volume 0 and the renderer drops it
(LowAudioVolumeThreshold) -- so footfalls are audible at real walking speed.
Diagnostics kept (BT_AUDIO_SPATIAL): spatial dist/vol per source, CLIPPED/DROP/
START at the request gate, vol=0 factor breakdown, scale->0 sends, trigger
notifications, watcher poll-rate probe.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Clean, self-contained extraction of the BattleTech-specific work from the
reverse-engineering workspace -- engine + game + content + build, with nothing
from Red Planet or the raw archive dumps. Builds green (Win32) and runs the
single-player drive->animate->target->fire->damage->destroy loop out of the box.
Layout:
engine/ MUNGA + MUNGA_L4 shared 2007 engine, carrying our BT render/loader
work (bgfload/L4D3D/L4VIDEO: BSL bit-slice decode, LOD/ground/shadow
models) + image codec; the minimal rp/ headers the audio HAL needs
game/ reconstructed BT logic + surviving-original BT source + fwd shims
+ WinMain launcher
content/ full runtime tree (BTL4.RES, VIDEO/, GAUGE/, AUDIO/, eggs, BTDPL.INI)
docs/ format specs + reconstruction ledgers
reference/ raw Ghidra pseudocode (recon source-of-truth) + decomp exporter
tools/ MP console emulator + map/resource scanners
One top-level CMake builds munga_engine lib + bt410_l4 game lib + btl4.exe.
All paths relativized (186 fwd shims + ~437 CMake abs paths -> repo-relative);
DXSDK is the one external, overridable via -DDXSDK. Verified: builds to a
byte-identical 2.27MB exe and runs combat (TARGET DESTROYED, 0 crashes) against
the bundled content.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
