From f9d70530ed5b11abf6444df0109c92ad22faefa9 Mon Sep 17 00:00:00 2001
From: Eidolon <furyhunter600@gmail.com>
Date: Tue, 30 Apr 2024 23:31:18 -0500
Subject: [PATCH] Add snd_mixingbuffersize cvar

Allows the user to configure the mixing buffer size to reduce
latency at the cost of higher CPU usage, or vice versa.

This also raises the default buffer size from 1024 to 2048, to
address some underrun problems people have with the current buffer
size.
---
 src/cvars.cpp               |  5 +++++
 src/menus/options-sound.cpp |  3 +++
 src/s_sound.c               | 11 +++++++++--
 src/s_sound.h               |  2 ++
 src/sdl/new_sound.cpp       | 12 +++++-------
 5 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/cvars.cpp b/src/cvars.cpp
index bc247a3d4..447fa8911 100644
--- a/src/cvars.cpp
+++ b/src/cvars.cpp
@@ -409,6 +409,11 @@ consvar_t cv_netticbuffer = Player("netticbuffer", "1").min_max(0, 3);
 void SetChannelsNum(void);
 consvar_t cv_numChannels = Player("snd_channels", "64").values(CV_Unsigned).onchange(SetChannelsNum);
 
+extern CV_PossibleValue_t soundmixingbuffersize_cons_t[];
+consvar_t cv_soundmixingbuffersize = Player("snd_mixingbuffersize", "2048")
+	.values(soundmixingbuffersize_cons_t)
+	.onchange_noinit([]() { COM_ImmedExecute("restartaudio"); });
+
 extern CV_PossibleValue_t perfstats_cons_t[];
 consvar_t cv_perfstats = Player("perfstats", "Off").dont_save().values(perfstats_cons_t);
 
diff --git a/src/menus/options-sound.cpp b/src/menus/options-sound.cpp
index 370dab611..fd7b1b701 100644
--- a/src/menus/options-sound.cpp
+++ b/src/menus/options-sound.cpp
@@ -304,6 +304,9 @@ menuitem_t OPTIONS_Sound[] =
 	{IT_STRING | IT_CVAR, "Hear Tabbed-out", "Keep playing game audio when the window is out of focus (FOCUS LOST).",
 		NULL, {.cvar = &cv_bgaudio}, 0, 0},
 
+	{IT_STRING | IT_CVAR, "Mixing Buffer Size", "Audio buffer size. Higher is faster but more delay.",
+		NULL, {.cvar = &cv_soundmixingbuffersize}, 0, 0},
+
 	{IT_SPACE | IT_NOTHING, NULL,  NULL,
 		NULL, {NULL}, 0, 0},
 
diff --git a/src/s_sound.c b/src/s_sound.c
index c4d1993bf..c1d9a4df2 100644
--- a/src/s_sound.c
+++ b/src/s_sound.c
@@ -43,6 +43,15 @@
 
 extern consvar_t cv_mastervolume;
 
+CV_PossibleValue_t soundmixingbuffersize_cons_t[] = {
+	{256, "256"},
+	{512, "512"},
+	{1024, "1024"},
+	{2048, "2048"},
+	{4096, "4096"},
+	{0, NULL}
+};
+
 static boolean S_AdjustSoundParams(const mobj_t *listener, const mobj_t *source, INT32 *vol, INT32 *sep, INT32 *pitch, sfxinfo_t *sfxinfo);
 
 static void Command_Tunes_f(void);
@@ -2424,8 +2433,6 @@ static void Command_RestartAudio_f(void)
 	S_SetMusicVolume();
 	S_SetMasterVolume();
 
-	S_StartSound(NULL, sfx_strpst);
-
 	S_AttemptToRestoreMusic();
 }
 
diff --git a/src/s_sound.h b/src/s_sound.h
index 981d1bd5c..1a7b6a8c9 100644
--- a/src/s_sound.h
+++ b/src/s_sound.h
@@ -38,6 +38,8 @@ extern consvar_t cv_soundvolume, cv_closedcaptioning, cv_digmusicvolume;
 
 extern consvar_t surround;
 extern consvar_t cv_numChannels;
+extern CV_PossibleValue_t soundmixingbuffersize_cons_t[];
+extern consvar_t cv_soundmixingbuffersize;
 
 extern consvar_t cv_gamedigimusic;
 
diff --git a/src/sdl/new_sound.cpp b/src/sdl/new_sound.cpp
index a55fafd1c..5330b8aff 100644
--- a/src/sdl/new_sound.cpp
+++ b/src/sdl/new_sound.cpp
@@ -183,7 +183,7 @@ void initialize_sound()
 	SDL_AudioSpec desired;
 	desired.format = AUDIO_F32SYS;
 	desired.channels = 2;
-	desired.samples = 1024;
+	desired.samples = cv_soundmixingbuffersize.value;
 	desired.freq = 44100;
 	desired.callback = audio_callback;
 
@@ -215,6 +215,7 @@ void initialize_sound()
 		master->add_source(gain_sound_effects);
 		master->add_source(gain_music_channel);
 		mixer_music->add_source(gain_music_player);
+		sound_effect_channels.clear();
 		for (size_t i = 0; i < static_cast<size_t>(cv_numChannels.value); i++)
 		{
 			shared_ptr<SoundEffectPlayer> player = make_shared<SoundEffectPlayer>();
@@ -236,13 +237,10 @@ void I_StartupSound(void)
 
 void I_ShutdownSound(void)
 {
-	SdlAudioLockHandle _;
+	SDL_CloseAudio();
+	SDL_QuitSubSystem(SDL_INIT_AUDIO);
 
-	for (auto& channel : sound_effect_channels)
-	{
-		if (channel)
-			*channel = audio::SoundEffectPlayer();
-	}
+	sound_started = false;
 }
 
 void I_UpdateSound(void)