set_sound with channel, undocumented feature ;)

src/sdl-instead/game.c

@@ -1104,14 +1104,26 @@ void game_sound_player(void)
 {
 	wav_t		w;
 	char		*snd;
+	int		chan = -1;
+	
 	if (!snd_volume_mus(-1))
 		return;	
+	snd = instead_eval("return get_sound_chan()");
+	if (snd) {
+		chan = atoi(snd);
+		free(snd);
+	}
+	
 	snd = instead_eval("return get_sound()");
-	if (!snd)
+	if (!snd) {
+		if (chan != -1) {
+			/* halt channel */
+			snd_halt_chan(chan);
+		}
 		return;
-		
+	}	
 	do { /* reset sound */
-		char *p = instead_eval("set_sound(nil)");
+		char *p = instead_eval("set_sound(nil, -1)");
 		if (p)
 			free(p);
 	} while(0);
@@ -1123,7 +1135,7 @@ void game_sound_player(void)
 	free(snd);
 	if (!w)
 		return;
-	snd_play(w);
+	snd_play(w, chan);
 }
 
 char *horiz_inv(char *invstr)
@@ -1646,7 +1658,7 @@ int game_click(int x, int y, int action, int filter)
 		if (mouse_filter(filter))
 			return 0;
 		if (opt_click)
-			snd_play(game_theme.click);
+			snd_play(game_theme.click, -1);
 		game_cmd(buf);
 		return 1;
 
@@ -1669,7 +1681,7 @@ int game_click(int x, int y, int action, int filter)
 	disable_use();
 
 	if (opt_click)
-		snd_play(game_theme.click);
+		snd_play(game_theme.click, -1);
 		
 	game_cmd(buf);
 	return 1;

src/sdl-instead/sound.c

@@ -109,6 +109,11 @@ void	snd_free_wav(wav_t w)
 	Mix_FreeChunk((Mix_Chunk*)w);
 }
 
+void snd_halt_chan(int han)
+{
+	Mix_HaltChannel(han);
+}
+
 Mix_Music *snd_load_mus(const char *fname)
 {
 	Mix_Music *mus;
@@ -183,13 +188,13 @@ void snd_free_mus(mus_t mus)
 	Mix_FreeMusic((Mix_Music*) mus);
 }
 
-void snd_play(void *chunk)
+void snd_play(void *chunk, int channel)
 {
 	if (!sound_on)
 		return;
 	if (!chunk)
 		return;	
-	Mix_PlayChannel(-1, (Mix_Chunk*)chunk, 0);
+	Mix_PlayChannel(channel, (Mix_Chunk*)chunk, 0);
 }
 
 void snd_done(void)

src/sdl-instead/sound.h

@@ -16,7 +16,9 @@ typedef void*  mus_t;
 extern void	snd_free_mus(mus_t mus);
 extern int	snd_init(int hz);
 extern int	snd_hz(void);
-extern void	snd_play(wav_t chunk);
+extern void	snd_play(wav_t chunk, int channel);
+extern void 	snd_halt_chan(int han);
+
 extern void	snd_free_wav(wav_t chunk);
 extern wav_t	snd_load_wav(const char *fname);
 extern int      snd_play_mus(char *music, int ms, int loop);

stead/stead.lua

@@ -2063,8 +2063,17 @@ function get_sound()
 	return game._sound;
 end
 
-function set_sound(s)
+function get_sound_chan()
+	return game._sound_channel
+end
+
+function set_sound(s, chan)
 	game._sound = s;
+	if not tonumber(chan) then
+		game._sound_channel = -1;
+	else
+		game._sound_channel = tonumber(chan);
+	end
 end
 
 function change_pl(p)