Alt+Tab Keep Sound Playing (Windows)

Added s_alttabmute CVAR with default value 1. Setting this CVAR to 0
will keep sound playing when game is minimized or out of focus. (Windows
only)

code/client/snd_dma.c

@@ -88,6 +88,7 @@ cvar_t		*s_dev;
 cvar_t		*s_show;
 cvar_t		*s_mixahead;
 cvar_t		*s_mixPreStep;
+cvar_t      *s_alttabmute;
 
 loopSound_t		loopSounds[MAX_GENTITIES];
 static	channel_t		*freelist = NULL;
@@ -1484,6 +1485,7 @@ qboolean S_Base_Init( soundInterface_t *si ) {
 	s_show = Cvar_Get ("s_show", "0", CVAR_CHEAT);
 	s_testsound = Cvar_Get ("s_testsound", "0", CVAR_CHEAT);
 	s_dev = Cvar_Get ("s_dev", "", CVAR_ARCHIVE);
+    s_alttabmute = Cvar_Get ("s_alttabmute", "1", CVAR_ARCHIVE);
 
 	Cmd_AddCommand( "s_devlist", S_dmaHD_devlist );
 

code/win32/win_snd.c

@@ -44,6 +44,7 @@ static LPGUID g_dsguid = NULL;
 
 extern cvar_t		*s_khz;
 extern cvar_t		*s_dev;
+extern cvar_t       *s_alttabmute;
 
 static const char *DSoundError( int error ) {
 	switch ( error ) {
@@ -293,6 +294,7 @@ int SNDDMA_InitDS ()
 
 	// Micah: take advantage of 2D hardware.if available.
 	dsbuf.dwFlags = DSBCAPS_LOCHARDWARE;
+    if (s_alttabmute->integer == 0) dsbuf.dwFlags |= DSBCAPS_STICKYFOCUS; // Keep playing when out of focus.
 	if (use8) {
 		dsbuf.dwFlags |= DSBCAPS_GETCURRENTPOSITION2;
 	}
@@ -312,6 +314,7 @@ int SNDDMA_InitDS ()
 		if (use8) {
 			dsbuf.dwFlags |= DSBCAPS_GETCURRENTPOSITION2;
 		}
+        if (s_alttabmute->integer == 0) dsbuf.dwFlags |= DSBCAPS_STICKYFOCUS; // Keep playing when out of focus.
 		if (DS_OK != pDS->lpVtbl->CreateSoundBuffer(pDS, &dsbuf, &pDSBuf, NULL)) {
 			Com_Printf( "failed\n" );
 			SNDDMA_Shutdown ();