Beispiel #1
0
/**
 * @brief Initializes the sound subsystem.
 *
 *    @return 0 on success.
 */
int sound_al_init (void)
{
   int ret;
   const ALchar* dev;
   ALuint s;
   ALint freq;
   ALint attribs[4] = { 0, 0, 0, 0 };

   /* Default values. */
   ret = 0;

   /* we'll need a mutex */
   sound_lock = SDL_CreateMutex();
   soundLock();

   /* Get the sound device. */
   dev = alcGetString( NULL, ALC_DEFAULT_DEVICE_SPECIFIER );

   /* opening the default device */
   al_device = alcOpenDevice(NULL);
   if (al_device == NULL) {
      WARN("Unable to open default sound device");
      ret = -1;
      goto snderr_dev;
   }

   /* Query EFX extension. */
   if (conf.al_efx) {
      al_info.efx = alcIsExtensionPresent( al_device, "ALC_EXT_EFX" );
      if (al_info.efx == AL_TRUE) {
         attribs[0] = ALC_MAX_AUXILIARY_SENDS;
         attribs[1] = 4;
      }
   }
   else
      al_info.efx = AL_FALSE;

   /* Create the OpenAL context */
   al_context = alcCreateContext( al_device, attribs );
   if (sound_lock == NULL) {
      WARN("Unable to create OpenAL context");
      ret = -2;
      goto snderr_ctx;
   }

   /* Clear the errors */
   alGetError();

   /* Set active context */
   if (alcMakeContextCurrent( al_context )==AL_FALSE) {
      WARN("Failure to set default context");
      ret = -4;
      goto snderr_act;
   }

   /* Get context information. */
   alcGetIntegerv( al_device, ALC_FREQUENCY, sizeof(freq), &freq );

   /* Try to enable EFX. */
   if (al_info.efx == AL_TRUE)
      al_enableEFX();
   else {
      al_info.efx_reverb = AL_FALSE;
      al_info.efx_echo   = AL_FALSE;
   }

   /* Allocate source for music. */
   alGenSources( 1, &music_source );

   /* Check for errors. */
   al_checkErr();

   /* Start allocating the sources - music has already taken his */
   source_nstack  = 0;
   source_mstack  = 0;
   while (source_nstack < SOUND_MAX_SOURCES) {
      if (source_mstack < source_nstack+1) { /* allocate more memory */
         source_mstack += 32;
         source_stack = realloc( source_stack, sizeof(ALuint) * source_mstack );
      }
      alGenSources( 1, &s );
      source_stack[source_nstack] = s;

      /* Distance model defaults. */
      alSourcef( s, AL_MAX_DISTANCE,       5000. );
      alSourcef( s, AL_ROLLOFF_FACTOR,     1. );
      alSourcef( s, AL_REFERENCE_DISTANCE, 500. );

      /* Set the filter. */
      if (al_info.efx == AL_TRUE)
         alSource3i( s, AL_AUXILIARY_SEND_FILTER, efx_directSlot, 0, AL_FILTER_NULL );

      /* Check for error. */
      if (alGetError() == AL_NO_ERROR)
         source_nstack++;
      else
         break;
   }
   /* Reduce ram usage. */
   source_mstack = source_nstack;
   source_stack  = realloc( source_stack, sizeof(ALuint) * source_mstack );
   /* Copy allocated sources to total stack. */
   source_ntotal = source_mstack;
   source_total  = malloc( sizeof(ALuint) * source_mstack );
   memcpy( source_total, source_stack, sizeof(ALuint) * source_mstack );
   /* Copy allocated sources to all stack. */
   source_nall   = source_mstack;
   source_all    = malloc( sizeof(ALuint) * source_mstack );
   memcpy( source_all, source_stack, sizeof(ALuint) * source_mstack );

   /* Set up how sound works. */
   alDistanceModel( AL_INVERSE_DISTANCE_CLAMPED );
   alDopplerFactor( 1. );
   sound_al_env( SOUND_ENV_NORMAL, 0. );

   /* Check for errors. */
   al_checkErr();

   /* we can unlock now */
   soundUnlock();

   /* debug magic */
   DEBUG("OpenAL started: %d Hz", freq);
   DEBUG("Renderer: %s", alGetString(AL_RENDERER));
   if (al_info.efx == AL_FALSE)
      DEBUG("Version: %s without EFX", alGetString(AL_VERSION));
   else
      DEBUG("Version: %s with EFX %d.%d", alGetString(AL_VERSION),
            al_info.efx_major, al_info.efx_minor);
   DEBUG();

   return 0;

   /*
    * error handling
    */
snderr_act:
   alcDestroyContext( al_context );
snderr_ctx:
   al_context = NULL;
   alcCloseDevice( al_device );
snderr_dev:
   al_device = NULL;
   soundUnlock();
   SDL_DestroyMutex( sound_lock );
   sound_lock = NULL;
   return ret;
}
Beispiel #2
0
/**
 * @brief Initializes the sound subsystem.
 *
 *    @return 0 on success.
 */
int sound_al_init (void)
{
   int ret;
   ALuint s;
   ALint freq;
   ALint attribs[4] = { 0, 0, 0, 0 };

   /* Default values. */
   ret = 0;

   /* we'll need a mutex */
   sound_lock = SDL_CreateMutex();
   soundLock();

   /* opening the default device */
   al_device = alcOpenDevice(NULL);
   if (al_device == NULL) {
      WARN(_("Unable to open default sound device"));
      ret = -1;
      goto snderr_dev;
   }

   /* Query EFX extension. */
   if (conf.al_efx) {
      al_info.efx = alcIsExtensionPresent( al_device, "ALC_EXT_EFX" );
      if (al_info.efx == AL_TRUE) {
         attribs[0] = ALC_MAX_AUXILIARY_SENDS;
         attribs[1] = 4;
      }
   }
   else
      al_info.efx = AL_FALSE;

   /* Create the OpenAL context */
   al_context = alcCreateContext( al_device, attribs );
   if (al_context == NULL) {
      WARN(_("Unable to create OpenAL context"));
      ret = -2;
      goto snderr_ctx;
   }

   /* Clear the errors */
   alGetError();

   /* Set active context */
   if (alcMakeContextCurrent( al_context )==AL_FALSE) {
      WARN(_("Failure to set default context"));
      ret = -4;
      goto snderr_act;
   }

   /* Get context information. */
   alcGetIntegerv( al_device, ALC_FREQUENCY, sizeof(freq), &freq );

   /* Try to enable EFX. */
   if (al_info.efx == AL_TRUE)
      al_enableEFX();
   else {
      al_info.efx_reverb = AL_FALSE;
      al_info.efx_echo   = AL_FALSE;
   }

   /* Allocate source for music. */
   alGenSources( 1, &music_source );

   /* Check for errors. */
   al_checkErr();

   /* Start allocating the sources - music has already taken his */
   source_nstack  = 0;
   source_mstack  = 0;
   while (source_nstack < conf.snd_voices) {
      if (source_mstack < source_nstack+1) { /* allocate more memory */
         if (source_mstack == 0)
            source_mstack = conf.snd_voices;
         else
            source_mstack *= 2;
         source_stack = realloc( source_stack, sizeof(ALuint) * source_mstack );
      }
      alGenSources( 1, &s );
      source_stack[source_nstack] = s;

      /* How OpenAL distance model works:
       *
       * Clamped:
       *  gain = distance_function( CLAMP( AL_REFERENCE_DISTANCE, AL_MAX_DISTANCE, distance ) );
       *
       * Distance functions:
       *                                       AL_REFERENCE_DISTANCE
       *  * Inverse = ------------------------------------------------------------------------------
       *              AL_REFERENCE_DISTANCE + AL_ROLLOFF_FACTOR ( distance - AL_REFERENCE_DISTANCE )
       *
       *             1 - AL_ROLLOFF_FACTOR ( distance - AL_REFERENCE_DISTANCE )
       *  * Linear = ----------------------------------------------------------
       *                      AL_MAX_DISTANCE - AL_REFERENCE_DISTANCE
       *
       *                  /       distance        \ -AL_ROLLOFF_FACTOR
       *  * Exponential = | --------------------- |
       *                  \ AL_REFERENCE_DISTANCE /
       *
       *
       * Some values:
       *
       *  model    falloff  reference   100     1000    5000   10000
       *  linear     1        500      1.000   0.947   0.526   0.000
       *  inverse    1        500      1.000   0.500   0.100   0.050
       *  exponent   1        500      1.000   0.500   0.100   0.050
       *  inverse   0.5       500      1.000   0.667   0.182   0.095
       *  exponent  0.5       500      1.000   0.707   0.316   0.223
       *  inverse    2        500      1.000   0.333   0.052   0.026
       *  exponent   2        500      1.000   0.250   0.010   0.003
       */
      alSourcef( s, AL_REFERENCE_DISTANCE, 500. ); /* Close distance to clamp at (doesn't get louder). */
      alSourcef( s, AL_MAX_DISTANCE,       25000. ); /* Max distance to clamp at (doesn't get quieter). */
      alSourcef( s, AL_ROLLOFF_FACTOR,     1. ); /* Determines how it drops off. */

      /* Set the filter. */
      if (al_info.efx == AL_TRUE)
         alSource3i( s, AL_AUXILIARY_SEND_FILTER, efx_directSlot, 0, AL_FILTER_NULL );

      /* Check for error. */
      if (alGetError() == AL_NO_ERROR)
         source_nstack++;
      else
         break;
   }
   /* Reduce ram usage. */
   source_mstack = source_nstack;
   source_stack  = realloc( source_stack, sizeof(ALuint) * source_mstack );
   /* Copy allocated sources to total stack. */
   source_ntotal = source_mstack;
   source_total  = malloc( sizeof(ALuint) * source_mstack );
   memcpy( source_total, source_stack, sizeof(ALuint) * source_mstack );
   /* Copy allocated sources to all stack. */
   source_nall   = source_mstack;
   source_all    = malloc( sizeof(ALuint) * source_mstack );
   memcpy( source_all, source_stack, sizeof(ALuint) * source_mstack );

   /* Set up how sound works. */
   alDistanceModel( AL_INVERSE_DISTANCE_CLAMPED ); /* Clamping is fundamental so it doesn't sound like crap. */
   alDopplerFactor( 1. );
   sound_al_env( SOUND_ENV_NORMAL, 0. );

   /* Check for errors. */
   al_checkErr();

   /* we can unlock now */
   soundUnlock();

   /* debug magic */
   DEBUG(_("OpenAL started: %d Hz"), freq);
   DEBUG(_("Renderer: %s"), alGetString(AL_RENDERER));
   if (al_info.efx == AL_FALSE)
      DEBUG(_("Version: %s without EFX"), alGetString(AL_VERSION));
   else
      DEBUG(_("Version: %s with EFX %d.%d"), alGetString(AL_VERSION),
            al_info.efx_major, al_info.efx_minor);
   DEBUG("");

   return ret;

   /*
    * error handling
    */
snderr_act:
   alcDestroyContext( al_context );
snderr_ctx:
   al_context = NULL;
   alcCloseDevice( al_device );
snderr_dev:
   al_device = NULL;
   soundUnlock();
   SDL_DestroyMutex( sound_lock );
   sound_lock = NULL;
   return ret;
}