From 317710e9c45e8c948a0876617449496702b390b7 Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Fri, 23 May 2008 01:45:47 +0000
Subject: [PATCH] - Added volume reduction for stereo sounds played in 3D to
 obtain levels   closer to FMOD 3, which downmixed all stereo sounds to mono
 before   playing them in 3D. Also added experimental 3D spread for stereo
 sounds   so that you can actually hear them in stereo.

SVN r989 (trunk)
---
 docs/rh-log.txt         |  6 ++++++
 src/sound/fmodsound.cpp | 15 +++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/docs/rh-log.txt b/docs/rh-log.txt
index ccccd9e1d..e07623a85 100644
--- a/docs/rh-log.txt
+++ b/docs/rh-log.txt
@@ -1,3 +1,9 @@
+May 22, 2008
+- Added volume reduction for stereo sounds played in 3D to obtain levels
+  closer to FMOD 3, which downmixed all stereo sounds to mono before
+  playing them in 3D. Also added experimental 3D spread for stereo sounds
+  so that you can actually hear them in stereo.
+
 May 22, 2008 (Changes by Graf Zahl)
 - Reworked a few options that previously depended on LEVEL_HEXENFORMAT
   (actors being forced to the ground by instantly moving sectors, strife
diff --git a/src/sound/fmodsound.cpp b/src/sound/fmodsound.cpp
index e43990a6c..1af5aa2cc 100644
--- a/src/sound/fmodsound.cpp
+++ b/src/sound/fmodsound.cpp
@@ -1364,6 +1364,8 @@ FSoundChan *FMODSoundRenderer::StartSound(sfxinfo_t *sfx, float vol, int pitch,
 //
 //==========================================================================
 
+CVAR(Float, snd_3dspread, 180, 0)
+
 FSoundChan *FMODSoundRenderer::StartSound3D(sfxinfo_t *sfx, float vol, float distscale,
 	int pitch, int priority, float pos[3], float vel[3], int chanflags)
 {
@@ -1373,6 +1375,7 @@ FSoundChan *FMODSoundRenderer::StartSound3D(sfxinfo_t *sfx, float vol, float dis
 	FMOD::Channel *chan;
 	float freq;
 	float def_freq, def_vol, def_pan;
+	int numchans;
 	int def_priority;
 
 	if (FMOD_OK == ((FMOD::Sound *)sfx->data)->getDefaults(&def_freq, &def_vol, &def_pan, &def_priority))
@@ -1398,6 +1401,17 @@ FSoundChan *FMODSoundRenderer::StartSound3D(sfxinfo_t *sfx, float vol, float dis
 		((FMOD::Sound *)sfx->data)->setDefaults(def_freq, def_vol, def_pan, def_priority);
 	}
 
+	// Reduce volume of stereo sounds, because each channel will be summed together
+	// and is likely to be very similar, resulting in an amplitude twice what it
+	// would have been had it been mixed to mono.
+	if (FMOD_OK == ((FMOD::Sound *)sfx->data)->getFormat(NULL, NULL, &numchans, NULL))
+	{
+		if (numchans > 1)
+		{
+			vol *= 0.5f;
+		}
+	}
+
 	if (FMOD_OK == result)
 	{
 		result = chan->getMode(&mode);
@@ -1418,6 +1432,7 @@ FSoundChan *FMODSoundRenderer::StartSound3D(sfxinfo_t *sfx, float vol, float dis
 		}
 		chan->setVolume(vol);
 		chan->set3DAttributes((FMOD_VECTOR *)pos, (FMOD_VECTOR *)vel);
+		chan->set3DSpread(snd_3dspread);
 		chan->setDelay(FMOD_DELAYTYPE_DSPCLOCK_START, DSPClockHi, DSPClockLo);
 		chan->setPaused(false);
 		FSoundChan *schan = CommonChannelSetup(chan);