Audio: ENABLE the engine (relax dead AWE-card gate) + diagnose the real silence (task #50)

User reported never hearing any audio. Root-caused: the KB "Audio: DONE" was wrong.
The OpenAL playback chain IS fully implemented (device/buffers/sources; PlayNote
really calls alSourcePlay), but three gaps kept it silent:

1. GATED OFF (the "no sound" root cause): BTL4Application::MakeAudioRenderer returned
   NULL unless the pod's AWE_FRONT/AWE_REAR AWE32-card env vars were set -- authentic
   1995 pod behavior, dead on modern hardware, so the renderer was NEVER created.
   FIXED: default audio ON (BT_NO_AUDIO=1 restores silence; AWE vars still force-on).
   Verified: the OpenAL device now opens with no env vars ([audio] device OPENED).
2. Soundbank STUB: allPresets[2][100] (btstubs.cpp) is zero-init -> PRESET_isImplemented
   false -> 0 buffers load. Sample data exists (AUDIO1/2.RES: EnginePower/LaserAFire/...)
   but the event->sample map is gone (not in the decomp). STILL OPEN.
3. No triggering: the reconstructed game never creates AudioEntities on events. STILL OPEN.

So the device opens but nothing loads/plays yet -- enabling real sound needs the
soundbank reconstructed + the game triggers wired (a proper audio wave). Added a
BT_AUDIO_LOG trace harness across L4AUDRND/L4AUDRES/L4AUDLVL. KB corrected.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

context/project-overview.md

@@ -42,7 +42,9 @@ fire → damage → destroy → respawn** single-player loop (task #52). **2-nod
 end-to-end** — replication, cross-pod targeting/damage/kill, beam visuals, replicant gait (tasks
 #46-#51, [[multiplayer]]). All 8 cockpit canopies are authentic + the horizontal-FOV fix (task #55,
 [[cockpit-view]]); the Gyroscope is live byte-exact with hit-bounce (task #56); the **gauge system
-is complete** ([[gauges-hud]]). The engine/renderer/HAL/audio are done (WinTesla); the active work
+is complete** ([[gauges-hud]]). The engine/renderer/HAL are done (WinTesla); AUDIO is the exception —
+the OpenAL engine is ported + now on by default (2026-07-15) but the soundbank + game triggering are
+unbuilt, so it's still SILENT (see [[wintesla-port]] Audio). The active work
 is reconstructing each BT subsystem's authentic behavior from the binary. Remaining: pod-LAN
 config, Mech-level update records, per-subsystem waves. [T2]
 

context/wintesla-port.md

@@ -16,7 +16,19 @@ on top of it. Full detail: `docs/PROGRESS_LOG.md §5b, §8`.
 ## What WinTesla already did (do NOT rebuild)
 - **Renderer bypass: DONE** — `MUNGA_L4/L4D3D.cpp` + `DXUtils` replace libDPL / the IG board with
   Direct3D9. No `libdpl.lib` in the tree. (The early from-scratch D3D9 viewer was retired and removed.) [T1]
-- **Audio: DONE** — OpenAL + libsndfile replacing the HMI "SOS" engine. [T1]
+- **Audio: ENGINE ported but NOT wired end-to-end** [T2, corrected 2026-07-15 — the old "DONE"
+  was wrong]. OpenAL + libsndfile replace the HMI "SOS" engine, and the renderer→device→buffer→
+  source→play chain IS all implemented (`L4AUDRND`/`L4AUDRES`/`L4AUDLVL`; `PatchLevelOfDetail::PlayNote`
+  really calls `alSourcePlay`). But there were THREE gaps, so the game is SILENT: (1) it was gated
+  OFF — `BTL4Application::MakeAudioRenderer` returned NULL unless the pod's `AWE_FRONT`/`AWE_REAR`
+  sound-card env vars were set (dead on modern HW; the real "no sound" root cause). **RELAXED
+  2026-07-15 to default-on** (`BT_NO_AUDIO=1` disables); the OpenAL device now opens. (2) The
+  soundbank preset table `allPresets[2][100]` (btstubs.cpp) is a zero-init **STUB** — no
+  sound-event→sample mapping, so 0 buffers load. The sample DATA exists in `AUDIO1/2.RES`
+  (`EnginePower01`, `LaserAFire01-03`, `LaserASustain`, …) but the map is gone (not in the decomp).
+  (3) The reconstructed game **never creates AudioEntities** — no triggering on weapon fire / steps /
+  engine. So enabling real audio = reconstruct the soundbank + wire the game triggers (a proper audio
+  wave). Diagnostic harness: `BT_AUDIO_LOG` traces the chain (Initialize → device → buffers → play).
 - **L4 HAL on Windows + the VS build system: DONE.** [T1]
 - **Red Planet game logic: COMPLETE & buildable** — `VTV/VTVMPPR/WEAPSYS/...`. RP is at/near playable. [T1]
 - **Multiplayer: the DOS `NETNUB` driver is already replaced by a ~3.5k-line WinSock2 TCP

engine/MUNGA_L4/L4AUDLVL.cpp

@@ -1,3 +1,4 @@
+#include <cstdlib>
 #include "mungal4.h"
 #pragma hdrstop
 
@@ -140,6 +141,7 @@ void
 			if (sourceState == AL_INITIAL)
 			{
 				alSourcei(sourceSet.sources[i],AL_BUFFER,AL_getBuffer(info.bufferIndex));
+				{ static int s_a=0; if (getenv("BT_AUDIO_LOG") && s_a++<8) DEBUG_STREAM << "[audio] SetupPatch attach bank=" << (int)bankID << " patch=" << (int)patchID << " buf=" << info.bufferIndex << "\n" << std::flush; }
 				alSourcei(sourceSet.sources[i],AL_SOURCE_RELATIVE,AL_TRUE);
 
 				AudioRenderer *render = application->GetAudioRenderer();
@@ -188,6 +190,7 @@ void PatchLevelOfDetail::PlayNote(SourceSet sourceSet)
 			if (state != AL_PLAYING)
 			{
 				alSourcePlay(sourceSet.sources[i]);
+				{ static int s_p=0; if (getenv("BT_AUDIO_LOG") && s_p++<8) DEBUG_STREAM << "[audio] PlayNote alSourcePlay src=" << sourceSet.sources[i] << "\n" << std::flush; }
 			}
 
 			ALenum error = alGetError();

engine/MUNGA_L4/L4AUDRES.cpp

@@ -1,3 +1,4 @@
+#include <cstdlib>
 #include "mungal4.h"
 #pragma hdrstop
 
@@ -558,6 +559,7 @@ void
 		alGetError();
 		g_buffers = new ALuint[g_numBuffers];
 		alGenBuffers(g_numBuffers,g_buffers);
+		if (getenv("BT_AUDIO_LOG")) DEBUG_STREAM << "[audio] alGenBuffers count=" << g_numBuffers << "\n" << std::flush;
 		ALenum error;
 		if ((error = alGetError()) != AL_NO_ERROR)
 		{

engine/MUNGA_L4/L4AUDRND.cpp

@@ -1,3 +1,4 @@
+#include <cstdlib>
 #include "mungal4.h"
 #pragma hdrstop
 
@@ -98,6 +99,7 @@ void
 	L4AudioRenderer::Initialize()
 {
 	Check(this);
+	if (getenv("BT_AUDIO_LOG")) DEBUG_STREAM << "[audio] L4AudioRenderer::Initialize ENTERED\n" << std::flush;
 
 	//
 	//----------------------------------------------------------------------
@@ -133,6 +135,7 @@ void
 
 	NotationFile notation_file(audio_file_name);
 	Check(&notation_file);
+	if (getenv("BT_AUDIO_LOG")) DEBUG_STREAM << "[audio] notation file opened; about to read scalars\n" << std::flush;
 
 	//
 	//----------------------------------------------------------------------
@@ -379,6 +382,11 @@ void
 	{
 		ALCcontext *context = alcCreateContext(device,NULL);
 		alcMakeContextCurrent(context);
+		if (getenv("BT_AUDIO_LOG")) DEBUG_STREAM << "[audio] OpenAL device OPENED + context current\n" << std::flush;
+	}
+	else
+	{
+		if (getenv("BT_AUDIO_LOG")) DEBUG_STREAM << "[audio] OpenAL device FAILED to open (alcOpenDevice NULL)\n" << std::flush;
 	}
 
 	//

game/reconstructed/btl4app.cpp

@@ -266,7 +266,15 @@ BTL4Application::SharedData
 		char *front_card = getenv(AWE_FRONT_ENV_VAR);	// FUN_004dee74
 		char *rear_card  = getenv(AWE_REAR_ENV_VAR);
 
-		if (front_card == NULL || rear_card == NULL)
+		// AUTHENTIC 1995 gate: the pod carried TWO AWE32 cards (front/rear) and
+		// audio was OFF unless both AWE_FRONT/AWE_REAR were set.  Those cards don't
+		// exist on modern hardware, so this check silenced audio on every machine
+		// (root cause of "no sound" -- the renderer was never created).
+		// MODERNIZED (task #50, 2026-07-15): default audio ON through the WinTesla
+		// OpenAL renderer (the OS default output device).  BT_NO_AUDIO=1 restores
+		// the silent/no-renderer behavior; the AWE vars still force it on too.
+		(void)front_card; (void)rear_card;
+		if (getenv("BT_NO_AUDIO"))
 		{
 			return NULL;
 		}