Exemplo n.º 1
0
/**
 * @brief Creates a sound environment.
 */
int sound_al_env( SoundEnv_t env, double param )
{
   int i;
   ALuint s;
   ALfloat f;

   soundLock();
   switch (env) {
      case SOUND_ENV_NORMAL:
         /* Set global parameters. */
         alSpeedOfSound( 3433. );

         if (al_info.efx == AL_TRUE) {
            /* Disconnect the effect. */
            nalAuxiliaryEffectSloti( efx_directSlot,
                  AL_EFFECTSLOT_EFFECT, AL_EFFECT_NULL );

            /* Set per-source parameters. */
            for (i=0; i<source_ntotal; i++) {
               s = source_total[i];
               alSourcef( s, AL_AIR_ABSORPTION_FACTOR, 0. );
            }
         }
         break;

      case SOUND_ENV_NEBULA:
         f = param / 1000.;

         /* Set global parameters. */
         alSpeedOfSound( 3433./(1. + f*2.) );

         if (al_info.efx == AL_TRUE) {

            if (al_info.efx_reverb == AL_TRUE) {
               /* Tweak the reverb. */
               nalEffectf( efx_reverb, AL_REVERB_DECAY_TIME, 10. );
               nalEffectf( efx_reverb, AL_REVERB_DECAY_HFRATIO, 0.5 );

               /* Connect the effect. */
               nalAuxiliaryEffectSloti( efx_directSlot,
                     AL_EFFECTSLOT_EFFECT, efx_reverb );
            }

            /* Set per-source parameters. */
            for (i=0; i<source_ntotal; i++) {
               s = source_total[i];
               alSourcef( s, AL_AIR_ABSORPTION_FACTOR, 3.*f );
            }
         }
         break;
   }

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

   soundUnlock();

   return 0;
}
Exemplo n.º 2
0
/**
 * @brief Creates a sound environment.
 */
int sound_al_env( SoundEnv_t env, double param )
{
   int i;
   ALuint s;
   ALfloat f;

   soundLock();
   switch (env) {
      case SOUND_ENV_NORMAL:
         /* Set global parameters. */
         alSpeedOfSound( 3433. );

         if (al_info.efx == AL_TRUE) {
            /* Disconnect the effect. */
            nalAuxiliaryEffectSloti( efx_directSlot,
                  AL_EFFECTSLOT_EFFECT, AL_EFFECT_NULL );

            /* Set per-source parameters. */
            for (i=0; i<source_ntotal; i++) {
               s = source_total[i];
               alSourcef( s, AL_AIR_ABSORPTION_FACTOR, 0. );
            }
         }
         break;

      case SOUND_ENV_NEBULA:
         f = param / 1000.;

         /* Set global parameters. */
         alSpeedOfSound( 3433./(1. + f*2.) );

         if (al_info.efx == AL_TRUE) {

            if (al_info.efx_reverb == AL_TRUE) {
               /* Tweak the reverb. */
               nalEffectf( efx_reverb, AL_REVERB_DECAY_TIME,    10. );
               nalEffectf( efx_reverb, AL_REVERB_DECAY_HFRATIO, 0.5 );

               /* Connect the effect. */
               nalAuxiliaryEffectSloti( efx_directSlot,
                     AL_EFFECTSLOT_EFFECT, efx_reverb );
            }

            /* Set per-source parameters. */
            for (i=0; i<source_ntotal; i++) {
               s = source_total[i];
               /* Value is from 0. (normal) to 10..
                * It represents the attenuation per meter. In this case it decreases by
                * 0.05*AB_FACTOR dB/meter where AB_FACTOR is the air absoprtion factor.
                * In our case each pixel represents 5 meters.
                */
               alSourcef( s, AL_AIR_ABSORPTION_FACTOR, 3.*f );
            }
         }
         break;
   }

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

   soundUnlock();

   return 0;
}