Add an int to I_PlaySound to tell an interface which channel number SRB2 is using.

I've voided this out on other sound interfaces than SDL Mixer ones because I'm both not sure whether they need it, and not sure how to make them work with it if they do.

src/djgppdos/i_sound.c

@@ -165,9 +165,11 @@ INT32 I_StartSound ( sfxenum_t     id,
                    INT32         vol,
                    INT32         sep,
                    INT32         pitch,
-                   INT32         priority )
+                   INT32         priority
+				   INT32         channel)
 {
 	int voice;
+	(void)channel;
 
 	if (nosound)
 	return 0;

src/dummy/i_sound.c

@@ -23,13 +23,14 @@ void I_UpdateSound(void){};
 //  SFX I/O
 //
 
-INT32 I_StartSound(sfxenum_t id, UINT8 vol, UINT8 sep, UINT8 pitch, UINT8 priority)
+INT32 I_StartSound(sfxenum_t id, UINT8 vol, UINT8 sep, UINT8 pitch, UINT8 priority, INT32 channel)
 {
 	(void)id;
 	(void)vol;
 	(void)sep;
 	(void)pitch;
 	(void)priority;
+	(void)channel;
 	return -1;
 }
 

src/i_sound.h

@@ -64,7 +64,7 @@ void I_ShutdownSound(void);
 
 	\return	sfx handle
 */
-INT32 I_StartSound(sfxenum_t id, UINT8 vol, UINT8 sep, UINT8 pitch, UINT8 priority);
+INT32 I_StartSound(sfxenum_t id, UINT8 vol, UINT8 sep, UINT8 pitch, UINT8 priority, INT32 channel);
 
 /**	\brief	Stops a sound channel.
 

src/nds/i_sound.c

@@ -21,13 +21,14 @@ void I_ShutdownSound(void){}
 //  SFX I/O
 //
 
-INT32 I_StartSound(sfxenum_t id, INT32 vol, INT32 sep, INT32 pitch, INT32 priority)
+INT32 I_StartSound(sfxenum_t id, INT32 vol, INT32 sep, INT32 pitch, INT32 priority, INT32 channel)
 {
 	(void)id;
 	(void)vol;
 	(void)sep;
 	(void)pitch;
 	(void)priority;
+	(void)channel;
 	return -1;
 }
 

src/s_sound.c

@@ -529,7 +529,7 @@ void S_StartSoundAtVolume(const void *origin_p, sfxenum_t sfx_id, INT32 volume)
 
 		// Assigns the handle to one of the channels in the
 		// mix/output buffer.
-		channels[cnum].handle = I_StartSound(sfx_id, volume, sep, pitch, priority);
+		channels[cnum].handle = I_StartSound(sfx_id, volume, sep, pitch, priority, cnum);
 	}
 
 dontplay:
@@ -579,7 +579,7 @@ dontplay:
 
 	// Assigns the handle to one of the channels in the
 	// mix/output buffer.
-	channels[cnum].handle = I_StartSound(sfx_id, volume, sep, pitch, priority);
+	channels[cnum].handle = I_StartSound(sfx_id, volume, sep, pitch, priority, cnum);
 }
 
 void S_StartSound(const void *origin, sfxenum_t sfx_id)

src/sdl/mixer_sound.c

@@ -419,10 +419,10 @@ void I_FreeSfx(sfxinfo_t *sfx)
 	sfx->lumpnum = LUMPERROR;
 }
 
-INT32 I_StartSound(sfxenum_t id, UINT8 vol, UINT8 sep, UINT8 pitch, UINT8 priority)
+INT32 I_StartSound(sfxenum_t id, UINT8 vol, UINT8 sep, UINT8 pitch, UINT8 priority, INT32 channel)
 {
 	UINT8 volume = (((UINT16)vol + 1) * (UINT16)sfx_volume) / 62; // (256 * 31) / 62 == 127
-	INT32 handle = Mix_PlayChannel(-1, S_sfx[id].data, 0);
+	INT32 handle = Mix_PlayChannel(channel, S_sfx[id].data, 0);
 	Mix_Volume(handle, volume);
 	Mix_SetPanning(handle, min((UINT16)(0xff-sep)<<1, 0xff), min((UINT16)(sep)<<1, 0xff));
 	(void)pitch; // Mixer can't handle pitch

src/sdl/sdl_sound.c

@@ -604,10 +604,11 @@ void I_FreeSfx(sfxinfo_t * sfx)
 // Pitching (that is, increased speed of playback)
 //  is set, but currently not used by mixing.
 //
-INT32 I_StartSound(sfxenum_t id, UINT8 vol, UINT8 sep, UINT8 pitch, UINT8 priority)
+INT32 I_StartSound(sfxenum_t id, UINT8 vol, UINT8 sep, UINT8 pitch, UINT8 priority, INT32 channel)
 {
 	(void)priority;
 	(void)pitch;
+	(void)channel;
 
 	if (nosound)
 		return 0;

src/sdl12/mixer_sound.c

@@ -376,10 +376,10 @@ void I_FreeSfx(sfxinfo_t *sfx)
 	sfx->data = NULL;
 }
 
-INT32 I_StartSound(sfxenum_t id, UINT8 vol, UINT8 sep, UINT8 pitch, UINT8 priority)
+INT32 I_StartSound(sfxenum_t id, UINT8 vol, UINT8 sep, UINT8 pitch, UINT8 priority, INT32 channel)
 {
 	UINT8 volume = (((UINT16)vol + 1) * (UINT16)sfx_volume) / 62; // (256 * 31) / 62 == 127
-	INT32 handle = Mix_PlayChannel(-1, S_sfx[id].data, 0);
+	INT32 handle = Mix_PlayChannel(channel, S_sfx[id].data, 0);
 	Mix_Volume(handle, volume);
 	Mix_SetPanning(handle, min((UINT16)(0xff-sep)<<1, 0xff), min((UINT16)(sep)<<1, 0xff));
 	(void)pitch; // Mixer can't handle pitch

src/sdl12/sdl_sound.c

@@ -621,10 +621,11 @@ void I_FreeSfx(sfxinfo_t * sfx)
 // Pitching (that is, increased speed of playback)
 //  is set, but currently not used by mixing.
 //
-INT32 I_StartSound(sfxenum_t id, UINT8 vol, UINT8 sep, UINT8 pitch, UINT8 priority)
+INT32 I_StartSound(sfxenum_t id, UINT8 vol, UINT8 sep, UINT8 pitch, UINT8 priority, INT32 channel)
 {
 	(void)priority;
 	(void)pitch;
+	(void)channel;
 
 	if (nosound)
 		return 0;

src/win32/win_snd.c

@@ -353,12 +353,13 @@ void I_FreeSfx(sfxinfo_t *sfx)
 	sfx->data = NULL;
 }
 
-INT32 I_StartSound(sfxenum_t id, UINT8 vol, UINT8 sep, UINT8 pitch, UINT8 priority)
+INT32 I_StartSound(sfxenum_t id, UINT8 vol, UINT8 sep, UINT8 pitch, UINT8 priority, INT32 channel)
 {
 	FMOD_SOUND *sound;
 	FMOD_CHANNEL *chan;
 	INT32 i;
 	float frequency;
+	(void)channel;
 
 	sound = (FMOD_SOUND *)S_sfx[id].data;
 	I_Assert(sound != NULL);

src/win32ce/win_snd.c

@@ -538,7 +538,8 @@ INT32 I_StartSound (sfxenum_t      id,
                   INT32          vol,
                   INT32          sep,
                   INT32          pitch,
-                  INT32          priority)
+                  INT32          priority
+				  INT32          channel)
 {
 	HRESULT     hr;
 	LPDIRECTSOUNDBUFFER     dsbuffer;
@@ -549,6 +550,7 @@ INT32 I_StartSound (sfxenum_t      id,
 #ifdef SURROUND
 	LPDIRECTSOUNDBUFFER     dssurround;
 #endif
+	(void)channel;
 
 	if (nosound)
 		return -1;