From e0560b41a1796a02b15937b0ae5453bca745e5ff Mon Sep 17 00:00:00 2001
From: Holger Schemel <info@artsoft.org>
Date: Sun, 10 Dec 2000 01:21:29 +0100
Subject: [PATCH] rnd-20001210-1-src

---
 src/files.c          |  24 ++++----
 src/game.c           |   6 +-
 src/init.c           |   2 +-
 src/libgame/misc.c   |   4 +-
 src/libgame/msdos.c  |  10 +++-
 src/libgame/msdos.h  |   2 +-
 src/libgame/pcx.c    |   2 +-
 src/libgame/sdl.c    |  31 +++++++---
 src/libgame/sdl.h    |   2 +-
 src/libgame/sound.c  | 132 +++++++++++++++++++++++++++++++------------
 src/libgame/sound.h  |  38 +++++++++++--
 src/libgame/system.c |  51 ++++++++---------
 src/libgame/system.h |  22 ++++++--
 13 files changed, 224 insertions(+), 102 deletions(-)

diff --git a/src/files.c b/src/files.c
index 884571eb..0fa192c3 100644
--- a/src/files.c
+++ b/src/files.c
@@ -456,7 +456,7 @@ void LoadLevel(int level_nr)
   /* always start with reliable default values */
   setLevelInfoToDefaults();
 
-  if (!(file = fopen(filename, "r")))
+  if (!(file = fopen(filename, MODE_READ)))
   {
     Error(ERR_WARN, "cannot read level '%s' - creating new level", filename);
     return;
@@ -620,7 +620,7 @@ void SaveLevel(int level_nr)
   char *oldest_possible_cookie;
   FILE *file;
 
-  if (!(file = fopen(filename, "w")))
+  if (!(file = fopen(filename, MODE_WRITE)))
   {
     Error(ERR_WARN, "cannot save level file '%s'", filename);
     return;
@@ -730,7 +730,7 @@ void LoadTape(int level_nr)
   /* at least one (default: the first) player participates in every tape */
   num_participating_players = 1;
 
-  if (!(file = fopen(filename, "r")))
+  if (!(file = fopen(filename, MODE_READ)))
     return;
 
   /* check file identifier */
@@ -892,7 +892,7 @@ void SaveTape(int level_nr)
     }
   }
 
-  if (!(file = fopen(filename, "w")))
+  if (!(file = fopen(filename, MODE_WRITE)))
   {
     Error(ERR_WARN, "cannot save level recording file '%s'", filename);
     return;
@@ -952,7 +952,7 @@ void LoadScore(int level_nr)
     highscore[i].Score = 0;
   }
 
-  if (!(file = fopen(filename, "r")))
+  if (!(file = fopen(filename, MODE_READ)))
     return;
 
   /* check file identifier */
@@ -997,7 +997,7 @@ void SaveScore(int level_nr)
 
   InitScoreDirectory(leveldir_current->filename);
 
-  if (!(file = fopen(filename, "w")))
+  if (!(file = fopen(filename, MODE_WRITE)))
   {
     Error(ERR_WARN, "cannot save score for level %d", level_nr);
     return;
@@ -1304,7 +1304,7 @@ static struct SetupFileList *loadSetupFileList(char *filename)
 
   FILE *file;
 
-  if (!(file = fopen(filename, "r")))
+  if (!(file = fopen(filename, MODE_READ)))
   {
     Error(ERR_WARN, "cannot open configuration file '%s'", filename);
     return NULL;
@@ -1782,7 +1782,7 @@ static void SaveUserLevelInfo()
 
   filename = getPath2(getUserLevelDir(getLoginName()), LEVELINFO_FILENAME);
 
-  if (!(file = fopen(filename, "w")))
+  if (!(file = fopen(filename, MODE_WRITE)))
   {
     Error(ERR_WARN, "cannot write level info file '%s'", filename);
     free(filename);
@@ -1926,7 +1926,7 @@ void SaveSetup()
 
   filename = getPath2(getSetupDir(), SETUP_FILENAME);
 
-  if (!(file = fopen(filename, "w")))
+  if (!(file = fopen(filename, MODE_WRITE)))
   {
     Error(ERR_WARN, "cannot write setup file '%s'", filename);
     free(filename);
@@ -2014,7 +2014,7 @@ void SaveLevelSetup_LastSeries()
 
   filename = getPath2(getSetupDir(), LEVELSETUP_FILENAME);
 
-  if (!(file = fopen(filename, "w")))
+  if (!(file = fopen(filename, MODE_WRITE)))
   {
     Error(ERR_WARN, "cannot write setup file '%s'", filename);
     free(filename);
@@ -2159,7 +2159,7 @@ void SaveLevelSetup_SeriesInfo()
 
   filename = getPath2(getLevelSetupDir(level_subdir), LEVELSETUP_FILENAME);
 
-  if (!(file = fopen(filename, "w")))
+  if (!(file = fopen(filename, MODE_WRITE)))
   {
     Error(ERR_WARN, "cannot write setup file '%s'", filename);
     free(filename);
@@ -2178,3 +2178,5 @@ void SaveLevelSetup_SeriesInfo()
 
   chmod(filename, SETUP_PERMS);
 }
+/*  LocalWords:  Rocks'n
+ */
diff --git a/src/game.c b/src/game.c
index ab7dbb55..031fd785 100644
--- a/src/game.c
+++ b/src/game.c
@@ -762,7 +762,7 @@ void InitGame()
   OpenDoor(DOOR_OPEN_ALL);
 
   if (setup.sound_music)
-    PlaySoundLoop(background_loop[level_nr % num_bg_loops]);
+    PlayMusic(background_loop[level_nr % num_bg_loops]);
 
   KeyboardAutoRepeatOff();
 
@@ -6227,12 +6227,12 @@ static void HandleGameButtons(struct GadgetInfo *gi)
       if (setup.sound_music)
       { 
 	setup.sound_music = FALSE;
-	FadeSound(background_loop[level_nr % num_bg_loops]);
+	FadeMusic();
       }
       else if (audio.loops_available)
       { 
 	setup.sound = setup.sound_music = TRUE;
-	PlaySoundLoop(background_loop[level_nr % num_bg_loops]);
+	PlayMusic(background_loop[level_nr % num_bg_loops]);
       }
       break;
 
diff --git a/src/init.c b/src/init.c
index 304b1037..b4efdc4e 100644
--- a/src/init.c
+++ b/src/init.c
@@ -132,7 +132,7 @@ void InitSound()
 {
   int i;
 
-  OpenAudio(&audio);
+  OpenAudio();
 
   AllocSoundArray(NUM_SOUNDS);
 
diff --git a/src/libgame/misc.c b/src/libgame/misc.c
index 5814e8d1..e62229a4 100644
--- a/src/libgame/misc.c
+++ b/src/libgame/misc.c
@@ -1314,7 +1314,7 @@ FILE *openErrorFile()
   FILE *error_file;
 
   filename = getPath2(getUserDataDir(), ERROR_FILENAME);
-  error_file = fopen(filename, "a");
+  error_file = fopen(filename, MODE_APPEND);
   free(filename);
 
   return error_file;
@@ -1326,7 +1326,7 @@ void dumpErrorFile()
   FILE *error_file;
 
   filename = getPath2(getUserDataDir(), ERROR_FILENAME);
-  error_file = fopen(filename, "r");
+  error_file = fopen(filename, MODE_READ);
   free(filename);
 
   if (error_file != NULL)
diff --git a/src/libgame/msdos.c b/src/libgame/msdos.c
index 5b037e02..75f92a05 100644
--- a/src/libgame/msdos.c
+++ b/src/libgame/msdos.c
@@ -952,9 +952,15 @@ void AllegroDrawLine(Drawable d, int from_x, int from_y, int to_x, int to_y,
   freeze_mouse_flag = FALSE;
 }
 
-Bool MSDOSOpenAudio(void)
+void MSDOSOpenAudio(void)
 {
-  return allegro_init_audio();
+  if (allegro_init_audio())
+  {
+    audio.sound_available = TRUE;
+    audio.music_available = TRUE;
+    audio.loops_available = TRUE;
+    audio.sound_enabled = TRUE;
+  }
 }
 
 void MSDOSCloseAudio(void)
diff --git a/src/libgame/msdos.h b/src/libgame/msdos.h
index d071cf03..af865235 100644
--- a/src/libgame/msdos.h
+++ b/src/libgame/msdos.h
@@ -733,7 +733,7 @@ void XAutoRepeatOff(Display *);
 
 void AllegroDrawLine(Drawable, int, int, int, int, Pixel);
 
-Bool MSDOSOpenAudio(void);
+void MSDOSOpenAudio(void);
 void MSDOSCloseAudio(void);
 
 void NetworkServer(int, int);
diff --git a/src/libgame/pcx.c b/src/libgame/pcx.c
index 069adf7d..f50e2c9a 100644
--- a/src/libgame/pcx.c
+++ b/src/libgame/pcx.c
@@ -138,7 +138,7 @@ Image *Read_PCX_to_Image(char *filename)
 
   errno_pcx = PCX_Success;
 
-  if (!(file = fopen(filename, "r")))
+  if (!(file = fopen(filename, MODE_READ)))
   {
     errno_pcx = PCX_OpenFailed;
     return NULL;
diff --git a/src/libgame/sdl.c b/src/libgame/sdl.c
index a4fbf7de..18de01b3 100644
--- a/src/libgame/sdl.c
+++ b/src/libgame/sdl.c
@@ -12,6 +12,7 @@
 ***********************************************************/
 
 #include "system.h"
+#include "sound.h"
 #include "misc.h"
 
 
@@ -705,24 +706,40 @@ Bitmap *SDLLoadImage(char *filename)
 /* audio functions                                                           */
 /* ========================================================================= */
 
-inline boolean SDLOpenAudio(void)
+inline void SDLOpenAudio(void)
 {
   if (SDL_InitSubSystem(SDL_INIT_AUDIO) < 0)
   {
     Error(ERR_WARN, "SDL_InitSubSystem() failed: %s", SDL_GetError());
-    return FALSE;
+    return;
   }
 
-  if (Mix_OpenAudio(22050, AUDIO_S16, 2, 512) < 0)
+  if (Mix_OpenAudio(DEFAULT_AUDIO_SAMPLE_RATE, AUDIO_S16,
+		    AUDIO_STEREO_CHANNELS,
+		    DEFAULT_AUDIO_FRAGMENT_SIZE) < 0)
   {
     Error(ERR_WARN, "Mix_OpenAudio() failed: %s", SDL_GetError());
-    return FALSE;
+    return;
   }
 
-  Mix_Volume(-1, SDL_MIX_MAXVOLUME / 4);
-  Mix_VolumeMusic(SDL_MIX_MAXVOLUME / 4);
+  audio.sound_available = TRUE;
+  audio.music_available = TRUE;
+  audio.loops_available = TRUE;
+  audio.sound_enabled = TRUE;
+
+  /* determine number of available channels */
+  audio.channels = Mix_AllocateChannels(MIX_CHANNELS);
+
+  if (!audio.mods_available)	/* reserve first channel for music loops */
+  {
+    if (Mix_ReserveChannels(1) == 1)
+      audio.music_channel = 0;
+    else
+      audio.music_available = FALSE;
+  }
 
-  return TRUE;
+  Mix_Volume(-1, SOUND_MAX_VOLUME);
+  Mix_VolumeMusic(SOUND_MAX_VOLUME);
 }
 
 inline void SDLCloseAudio(void)
diff --git a/src/libgame/sdl.h b/src/libgame/sdl.h
index e6543a9e..e6508859 100644
--- a/src/libgame/sdl.h
+++ b/src/libgame/sdl.h
@@ -326,7 +326,7 @@ void sge_Line(SDL_Surface *, Sint16, Sint16, Sint16, Sint16, Uint32);
 
 Bitmap *SDLLoadImage(char *);
 
-inline boolean SDLOpenAudio(void);
+inline void SDLOpenAudio(void);
 inline void SDLCloseAudio(void);
 
 #endif /* SDL_H */
diff --git a/src/libgame/sound.c b/src/libgame/sound.c
index a7298a84..c690993c 100644
--- a/src/libgame/sound.c
+++ b/src/libgame/sound.c
@@ -15,6 +15,7 @@
 #include <unistd.h>
 #include <fcntl.h>
 
+#include "system.h"
 #include "sound.h"
 #include "misc.h"
 
@@ -81,7 +82,7 @@ int OpenAudioDevice(char *audio_device_name)
   return audio_fd;
 }
 
-void UnixOpenAudio(struct AudioSystemInfo *audio)
+void UnixOpenAudio(void)
 {
   static char *audio_device_name[] =
   {
@@ -104,19 +105,20 @@ void UnixOpenAudio(struct AudioSystemInfo *audio)
 
   close(audio_fd);
 
-  audio->device_name = audio_device_name[i];
-  audio->sound_available = TRUE;
-  audio->sound_enabled = TRUE;
+  audio.device_name = audio_device_name[i];
+  audio.sound_available = TRUE;
+  audio.sound_enabled = TRUE;
 
 #if defined(AUDIO_STREAMING_DSP)
-  audio->loops_available = TRUE;
+  audio.music_available = TRUE;
+  audio.loops_available = TRUE;
 #endif
 }
 
-void UnixCloseAudio(struct AudioSystemInfo *audio)
+void UnixCloseAudio(void)
 {
-  if (audio->device_fd)
-    close(audio->device_fd);
+  if (audio.device_fd)
+    close(audio.device_fd);
 }
 
 #endif	/* PLATFORM_UNIX */
@@ -202,26 +204,34 @@ void SoundServer()
       byte *sample_ptr;
       long sample_size;
       static long max_sample_size = 0;
-      static long fragment_size = 0;
-      /* Even if the stereo flag is used as being boolean, it must be
-	 defined as an integer, else 'ioctl()' will fail! */
+      static long fragment_size = DEFAULT_AUDIO_FRAGMENT_SIZE;
+      int sample_rate = DEFAULT_AUDIO_SAMPLE_RATE;
       int stereo = TRUE;
-#if 0
-      int sample_rate = 8000;
-#else
-      int sample_rate = 22050;
-#endif
+      /* 'ioctl()' expects pointer to integer value for stereo flag
+	 (boolean is defined as 'char', which will not work here) */
 
       if (playing_sounds ||
 	  (audio.device_fd = OpenAudioDevice(audio.device_name)) >= 0)
       {
 	if (!playing_sounds)	/* we just opened the audio device */
 	{
-	  /* 2 buffers / 512 bytes, giving 1/16 second resolution */
-	  /* (with stereo the effective buffer size will shrink to 256) */
-	  fragment_size = 0x00020009;
+	  unsigned long fragment_spec = 0;
+
+	  /* determine logarithm (log2) of the fragment size */
+	  for (fragment_spec=0; (1 << fragment_spec) < fragment_size;
+	       fragment_spec++);
+
+	  /* use two fragments (play one fragment, prepare the other);
+	     one fragment would result in interrupted audio output, more
+	     than two fragments would raise audio output latency to much */
+	  fragment_spec |= 0x00020000;
+
+	  /* Example for fragment specification:
+	     - 2 buffers / 512 bytes (giving 1/16 second resolution for 8 kHz)
+	     - (with stereo the effective buffer size will shrink to 256)
+	     => fragment_size = 0x00020009 */
 
-	  if (ioctl(audio.device_fd,SNDCTL_DSP_SETFRAGMENT,&fragment_size) < 0)
+	  if (ioctl(audio.device_fd,SNDCTL_DSP_SETFRAGMENT,&fragment_spec) < 0)
 	    Error(ERR_EXIT_SOUND_SERVER,
 		  "cannot set fragment size of /dev/dsp - no sounds");
 
@@ -262,7 +272,7 @@ void SoundServer()
 	  FD_SET(audio.soundserver_pipe[0], &sound_fdset);
 
 	  /* first clear the last premixing buffer */
-	  memset(premix_last_buffer,0,fragment_size*sizeof(int));
+	  memset(premix_last_buffer, 0, fragment_size * sizeof(int));
 
 	  for(i=0;i<MAX_SOUNDS_PLAYING;i++)
 	  {
@@ -345,7 +355,7 @@ void SoundServer()
 	  }
 
 	  /* put last mixing buffer to final playing buffer */
-	  for(i=0;i<fragment_size;i++)
+	  for(i=0; i<fragment_size; i++)
 	  {
 	    if (premix_last_buffer[i]<-255)
 	      playing_buffer[i] = 0;
@@ -356,7 +366,7 @@ void SoundServer()
 	  }
 
 	  /* finally play the sound fragment */
-	  write(audio.device_fd, playing_buffer,fragment_size);
+	  write(audio.device_fd, playing_buffer, fragment_size);
 	}
 
 	/* if no sounds playing, free device for other sound programs */
@@ -834,7 +844,7 @@ boolean LoadSound(int sound_nr, char *sound_name)
 
 #if !defined(PLATFORM_MSDOS)
 
-  if ((file = fopen(filename, "r")) == NULL)
+  if ((file = fopen(filename, MODE_READ)) == NULL)
   {
     Error(ERR_WARN, "cannot open sound file '%s' - no sounds", filename);
     return FALSE;
@@ -903,6 +913,28 @@ boolean LoadSound(int sound_nr, char *sound_name)
   return TRUE;
 }
 
+void PlayMusic(int nr)
+{
+  if (!audio.music_available)
+    return;
+
+#if defined(TARGET_SDL)
+  if (audio.mods_available)
+  {
+    Mix_VolumeMusic(SOUND_MAX_VOLUME);
+    /* start playing module */
+  }
+  else	/* play music loop */
+  {
+    Mix_Volume(audio.music_channel, SOUND_MAX_VOLUME);
+    Mix_PlayChannel(audio.music_channel, Sound[nr].mix_chunk, -1);
+  }
+#else
+  audio.music_nr = nr;
+  PlaySoundLoop(nr);
+#endif
+}
+
 void PlaySound(int nr)
 {
   PlaySoundExt(nr, PSND_MAX_VOLUME, PSND_MIDDLE, PSND_NO_LOOP);
@@ -944,23 +976,29 @@ void PlaySoundExt(int nr, int volume, int stereo, boolean loop)
   snd_ctrl.data_len	= Sound[nr].data_len;
 
 #if defined(TARGET_SDL)
-
-  Mix_Volume(-1, SDL_MIX_MAXVOLUME / 4);
-  Mix_VolumeMusic(SDL_MIX_MAXVOLUME / 4);
-
+  Mix_Volume(-1, SOUND_MAX_VOLUME);
   Mix_PlayChannel(-1, Sound[nr].mix_chunk, (loop ? -1 : 0));
-
-#else
-#if !defined(PLATFORM_MSDOS)
+#elif defined(PLATFORM_UNIX)
   if (write(audio.soundserver_pipe[1], &snd_ctrl, sizeof(snd_ctrl)) < 0)
   {
     Error(ERR_WARN, "cannot pipe to child process - no sounds");
     audio.sound_available = audio.sound_enabled = FALSE;
     return;
   }
-#else
+#elif defined(PLATFORM_MSDOS)
   sound_handler(snd_ctrl);
 #endif
+}
+
+void FadeMusic(void)
+{
+#if defined(TARGET_SDL)
+  if (audio.mods_available)
+    Mix_FadeOutMusic(SOUND_FADING_INTERVAL);
+  else
+    Mix_FadeOutChannel(audio.music_channel, SOUND_FADING_INTERVAL);
+#else
+  FadeSound(audio.music_nr);
 #endif
 }
 
@@ -974,6 +1012,18 @@ void FadeSounds()
   StopSoundExt(-1, SSND_FADE_ALL_SOUNDS);
 }
 
+void StopMusic(void)
+{
+#if defined(TARGET_SDL)
+  if (audio.mods_available)
+    Mix_HaltMusic();
+  else
+    Mix_HaltChannel(audio.music_channel);
+#else
+  StopSound(audio.music_nr);
+#endif
+}
+
 void StopSound(int nr)
 {
   StopSoundExt(nr, SSND_STOP_SOUND);
@@ -1006,13 +1056,23 @@ void StopSoundExt(int nr, int method)
 
   if (SSND_FADING(method))
   {
-    Mix_FadeOutChannel(-1, 1000);
-    Mix_FadeOutMusic(1000);
+    int i;
+
+    for (i=0; i<audio.channels; i++)
+      if (i != audio.music_channel || snd_ctrl.stop_all_sounds)
+	Mix_FadeOutChannel(i, SOUND_FADING_INTERVAL);
+    if (snd_ctrl.stop_all_sounds)
+      Mix_FadeOutMusic(SOUND_FADING_INTERVAL);
   }
   else
   {
-    Mix_HaltChannel(-1);
-    Mix_HaltMusic();
+    int i;
+
+    for (i=0; i<audio.channels; i++)
+      if (i != audio.music_channel || snd_ctrl.stop_all_sounds)
+	Mix_HaltChannel(i);
+    if (snd_ctrl.stop_all_sounds)
+      Mix_HaltMusic();
   }
 
 #else
diff --git a/src/libgame/sound.h b/src/libgame/sound.h
index d50b4a22..d2c94f23 100644
--- a/src/libgame/sound.h
+++ b/src/libgame/sound.h
@@ -37,10 +37,37 @@
 #define AUDIO_STREAMING_DSP
 #endif
 
+#define AUDIO_SAMPLE_RATE_8000			8000
+#define AUDIO_SAMPLE_RATE_22050			22050
+
+#define AUDIO_FRAGMENT_SIZE_512			512
+#define AUDIO_FRAGMENT_SIZE_1024		1024
+#define AUDIO_FRAGMENT_SIZE_2048		2048
+#define AUDIO_FRAGMENT_SIZE_4096		4096
+
+#define AUDIO_MONO_CHANNEL			1
+#define AUDIO_STEREO_CHANNELS			2
+
+#if defined(TARGET_SDL)
+/* one second fading interval == 1000 ticks (milliseconds) */
+#define SOUND_FADING_INTERVAL			1000
+#define SOUND_MAX_VOLUME			(SDL_MIX_MAXVOLUME / 4)
+#endif
+
+#define DEFAULT_AUDIO_SAMPLE_RATE		AUDIO_SAMPLE_RATE_22050
+#define DEFAULT_AUDIO_FRAGMENT_SIZE_UNIX	AUDIO_FRAGMENT_SIZE_512
+#define DEFAULT_AUDIO_FRAGMENT_SIZE_WIN32	AUDIO_FRAGMENT_SIZE_2048
+
+#if defined(PLATFORM_UNIX)
+#define DEFAULT_AUDIO_FRAGMENT_SIZE	DEFAULT_AUDIO_FRAGMENT_SIZE_UNIX
+#else
+#define DEFAULT_AUDIO_FRAGMENT_SIZE	DEFAULT_AUDIO_FRAGMENT_SIZE_WIN32
+#endif
+
 #if !defined(PLATFORM_MSDOS)
-#define MAX_SOUNDS_PLAYING	16
+#define MAX_SOUNDS_PLAYING			16
 #else
-#define MAX_SOUNDS_PLAYING	8
+#define MAX_SOUNDS_PLAYING			8
 #endif
 
 #if !defined(PLATFORM_HPUX)
@@ -153,8 +180,8 @@ struct SoundControl
 };
 
 /* general sound functions */
-void UnixOpenAudio(struct AudioSystemInfo *);
-void UnixCloseAudio(struct AudioSystemInfo *);
+void UnixOpenAudio(void);
+void UnixCloseAudio(void);
 
 /* sound server functions */ 
 void SoundServer(void);
@@ -162,12 +189,15 @@ void SoundServer(void);
 /* sound client functions */
 void AllocSoundArray(int);
 boolean LoadSound(int, char *);
+void PlayMusic(int);
 void PlaySound(int);
 void PlaySoundStereo(int, int);
 void PlaySoundLoop(int);
 void PlaySoundExt(int, int, int, boolean);
+void FadeMusic(void);
 void FadeSound(int);
 void FadeSounds(void);
+void StopMusic(void);
 void StopSound(int);
 void StopSounds(void);
 void StopSoundExt(int, int);
diff --git a/src/libgame/system.c b/src/libgame/system.c
index 341da455..8a5feabe 100644
--- a/src/libgame/system.c
+++ b/src/libgame/system.c
@@ -87,6 +87,7 @@ void InitPlatformDependantStuff(void)
 #endif
 
 #if !defined(PLATFORM_UNIX)
+  program.userdata_directory = "userdata";
   initErrorFile();
 #endif
 
@@ -573,50 +574,44 @@ Bitmap *LoadImage(char *basename)
 /* audio functions                                                           */
 /* ========================================================================= */
 
-inline boolean OpenAudio(struct AudioSystemInfo *audio)
+inline void OpenAudio(void)
 {
-  audio->sound_available = FALSE;
-  audio->loops_available = FALSE;
-  audio->sound_enabled = FALSE;
-  audio->soundserver_pipe[0] = audio->soundserver_pipe[1] = 0;
-  audio->soundserver_pid = 0;
-  audio->device_name = NULL;
-  audio->device_fd = 0;
+  /* always start with reliable default values */
+  audio.sound_available = FALSE;
+  audio.music_available = FALSE;
+  audio.loops_available = FALSE;
+  audio.mods_available = FALSE;
+  audio.sound_enabled = FALSE;
+
+  audio.soundserver_pipe[0] = audio.soundserver_pipe[1] = 0;
+  audio.soundserver_pid = 0;
+  audio.device_name = NULL;
+  audio.device_fd = 0;
+
+  audio.channels = 0;
+  audio.music_channel = 0;
+  audio.music_nr = 0;
 
 #if defined(TARGET_SDL)
-  if (SDLOpenAudio())
-  {
-    audio->sound_available = TRUE;
-    audio->loops_available = TRUE;
-    audio->sound_enabled = TRUE;
-  }
+  SDLOpenAudio();
 #elif defined(PLATFORM_MSDOS)
-  if (MSDOSOpenAudio())
-  {
-    audio->sound_available = TRUE;
-    audio->loops_available = TRUE;
-    audio->sound_enabled = TRUE;
-  }
+  MSDOSOpenAudio();
 #elif defined(PLATFORM_UNIX)
-  UnixOpenAudio(audio);
+  UnixOpenAudio();
 #endif
-
-  return audio->sound_available;
 }
 
-inline void CloseAudio(struct AudioSystemInfo *audio)
+inline void CloseAudio(void)
 {
 #if defined(TARGET_SDL)
   SDLCloseAudio();
 #elif defined(PLATFORM_MSDOS)
   MSDOSCloseAudio();
 #elif defined(PLATFORM_UNIX)
-  UnixCloseAudio(audio);
+  UnixCloseAudio();
 #endif
 
-  audio->sound_available = FALSE;
-  audio->loops_available = FALSE;
-  audio->sound_enabled = FALSE;
+  audio.sound_enabled = FALSE;
 }
 
 inline void SetAudioMode(boolean enabled)
diff --git a/src/libgame/system.h b/src/libgame/system.h
index 3ff406f0..e9a6d190 100644
--- a/src/libgame/system.h
+++ b/src/libgame/system.h
@@ -30,10 +30,15 @@
 
 /* contant definitions */
 
-#define DEFAULT_DEPTH			0
+/* the additional 'b' is needed for Win32 to open files in binary mode */
+#define MODE_READ		"rb"
+#define MODE_WRITE		"wb"
+#define MODE_APPEND		"ab"
 
-#define FULLSCREEN_NOT_AVAILABLE	FALSE
-#define FULLSCREEN_AVAILABLE		TRUE
+#define DEFAULT_DEPTH		0
+
+#define FULLSCREEN_NOT_AVAILABLE FALSE
+#define FULLSCREEN_AVAILABLE	 TRUE
 
 /* values for button_status */
 #define MB_NOT_PRESSED		FALSE
@@ -166,12 +171,19 @@ struct VideoSystemInfo
 struct AudioSystemInfo
 {
   boolean sound_available;
+  boolean music_available;
   boolean loops_available;
+  boolean mods_available;
   boolean sound_enabled;
+
   int soundserver_pipe[2];
   int soundserver_pid;
   char *device_name;
   int device_fd;
+
+  int channels;
+  int music_channel;
+  int music_nr;
 };
 
 struct GfxInfo
@@ -290,8 +302,8 @@ inline boolean ChangeVideoModeIfNeeded(boolean);
 
 Bitmap *LoadImage(char *);
 
-inline boolean OpenAudio(struct AudioSystemInfo *);
-inline void CloseAudio(struct AudioSystemInfo *);
+inline void OpenAudio(void);
+inline void CloseAudio(void);
 inline void SetAudioMode(boolean);
 
 inline void InitEventFilter(EventFilter);
-- 
2.34.1