text: /*
      SDL - Simple DirectMedia Layer
      Copyright (C) 1997-2009 Sam Lantinga
  
      This library is free software; you can redistribute it and/or
      modify it under the terms of the GNU Lesser General Public
      License as published by the Free Software Foundation; either
      version 2.1 of the License, or (at your option) any later version.
  
      This library is distributed in the hope that it will be useful,
      but WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      Lesser General Public License for more details.
  
      You should have received a copy of the GNU Lesser General Public
      License along with this library; if not, write to the Free Software
      Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  
      Sam Lantinga
      slouken@libsdl.org
  */
  #include "SDL_config.h"
  
  /* Allow access to a raw mixing buffer (For IRIX 6.5 and higher) */
  /* patch for IRIX 5 by Georg Schwarz 18/07/2004 */
  
  #include "SDL_timer.h"
  #include "SDL_audio.h"
  #include "../SDL_audiomem.h"
  #include "../SDL_audio_c.h"
  #include "SDL_irixaudio.h"
  
  
  #ifndef AL_RESOURCE /* as a test whether we use the old IRIX audio libraries */
  #define OLD_IRIX_AUDIO
  #define alClosePort(x) ALcloseport(x)
  #define alFreeConfig(x) ALfreeconfig(x)
  #define alGetFillable(x) ALgetfillable(x)
  #define alNewConfig() ALnewconfig()
  #define alOpenPort(x,y,z) ALopenport(x,y,z)
  #define alSetChannels(x,y) ALsetchannels(x,y)
  #define alSetQueueSize(x,y) ALsetqueuesize(x,y)
  #define alSetSampFmt(x,y) ALsetsampfmt(x,y)
  #define alSetWidth(x,y) ALsetwidth(x,y)
  #endif
  
  /* Audio driver functions */
  static int AL_OpenAudio(_THIS, SDL_AudioSpec *spec);
  static void AL_WaitAudio(_THIS);
  static void AL_PlayAudio(_THIS);
  static Uint8 *AL_GetAudioBuf(_THIS);
  static void AL_CloseAudio(_THIS);
  
  /* Audio driver bootstrap functions */
  
  static int Audio_Available(void)
  {
  	return 1;
  }
  
  static void Audio_DeleteDevice(SDL_AudioDevice *device)
  {
  	SDL_free(device->hidden);
  	SDL_free(device);
  }
  
  static SDL_AudioDevice *Audio_CreateDevice(int devindex)
  {
  	SDL_AudioDevice *this;
  
  	/* Initialize all variables that we clean on shutdown */
  	this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice));
  	if ( this ) {
  		SDL_memset(this, 0, (sizeof *this));
  		this->hidden = (struct SDL_PrivateAudioData *)
  				SDL_malloc((sizeof *this->hidden));
  	}
  	if ( (this == NULL) || (this->hidden == NULL) ) {
  		SDL_OutOfMemory();
  		if ( this ) {
  			SDL_free(this);
  		}
  		return(0);
  	}
  	SDL_memset(this->hidden, 0, (sizeof *this->hidden));
  
  	/* Set the function pointers */
  	this->OpenAudio = AL_OpenAudio;
  	this->WaitAudio = AL_WaitAudio;
  	this->PlayAudio = AL_PlayAudio;
  	this->GetAudioBuf = AL_GetAudioBuf;
  	this->CloseAudio = AL_CloseAudio;
  
  	this->free = Audio_DeleteDevice;
  
  	return this;
  }
  
  AudioBootStrap DMEDIA_bootstrap = {
  	"AL", "IRIX DMedia audio",
  	Audio_Available, Audio_CreateDevice
  };
  
  
  void static AL_WaitAudio(_THIS)
  {
  	Sint32 timeleft;
  
  	timeleft = this->spec.samples - alGetFillable(audio_port);
  	if ( timeleft > 0 ) {
  		timeleft /= (this->spec.freq/1000);
  		SDL_Delay((Uint32)timeleft);
  	}
  }
  
  static void AL_PlayAudio(_THIS)
  {
  	/* Write the audio data out */
  	if ( alWriteFrames(audio_port, mixbuf, this->spec.samples) < 0 ) {
  		/* Assume fatal error, for now */
  		this->enabled = 0;
  	}
  }
  
  static Uint8 *AL_GetAudioBuf(_THIS)
  {
  	return(mixbuf);
  }
  
  static void AL_CloseAudio(_THIS)
  {
  	if ( mixbuf != NULL ) {
  		SDL_FreeAudioMem(mixbuf);
  		mixbuf = NULL;
  	}
  	if ( audio_port != NULL ) {
  		alClosePort(audio_port);
  		audio_port = NULL;
  	}
  }
  
  static int AL_OpenAudio(_THIS, SDL_AudioSpec * spec)
  {
  	Uint16 test_format = SDL_FirstAudioFormat(spec->format);
  	long width = 0;
  	long fmt = 0;
  	int valid = 0;
  
  #ifdef OLD_IRIX_AUDIO
  	{
  		long audio_param[2];
  		audio_param[0] = AL_OUTPUT_RATE;
  		audio_param[1] = spec->freq;
  		valid = (ALsetparams(AL_DEFAULT_DEVICE, audio_param, 2) < 0);
  	}
  #else
  	{
  		ALpv audio_param;
  		audio_param.param = AL_RATE;
  		audio_param.value.i = spec->freq;
  		valid = (alSetParams(AL_DEFAULT_OUTPUT, &audio_param, 1) < 0);
  	}
  #endif
  
  	while ((!valid) && (test_format)) {
  		valid = 1;
  		spec->format = test_format;
  
  		switch (test_format) {
  			case AUDIO_S8:
  				width = AL_SAMPLE_8;
  				fmt = AL_SAMPFMT_TWOSCOMP;
  				break;
  
  			case AUDIO_S16SYS:
  				width = AL_SAMPLE_16;
  				fmt = AL_SAMPFMT_TWOSCOMP;
  				break;
  
  			default:
  				valid = 0;
  				test_format = SDL_NextAudioFormat();
  				break;
  		}
  
  		if (valid) {
  			ALconfig audio_config = alNewConfig();
  			valid = 0;
  			if (audio_config) {
  				if (alSetChannels(audio_config, spec->channels) < 0) {
  					if (spec->channels > 2) {  /* can't handle > stereo? */
  						spec->channels = 2;  /* try again below. */
  					}
  				}
  
  				if ((alSetSampFmt(audio_config, fmt) >= 0) &&
  				    ((!width) || (alSetWidth(audio_config, width) >= 0)) &&
  				    (alSetQueueSize(audio_config, spec->samples * 2) >= 0) &&
  				    (alSetChannels(audio_config, spec->channels) >= 0)) {
  
  					audio_port = alOpenPort("SDL audio", "w", audio_config);
  					if (audio_port == NULL) {
  						/* docs say AL_BAD_CHANNELS happens here, too. */
  						int err = oserror();
  						if (err == AL_BAD_CHANNELS) {
  							spec->channels = 2;
  							alSetChannels(audio_config, spec->channels);
  							audio_port = alOpenPort("SDL audio", "w",
  							                        audio_config);
  						}
  					}
  
  					if (audio_port != NULL) {
  						valid = 1;
  					}
  				}
  
  				alFreeConfig(audio_config);
  			}
  		}
  	}
  
  	if (!valid) {
  		SDL_SetError("Unsupported audio format");
  		return (-1);
  	}
  
  	/* Update the fragment size as size in bytes */
  	SDL_CalculateAudioSpec(spec);
  
  	/* Allocate mixing buffer */
  	mixbuf = (Uint8 *) SDL_AllocAudioMem(spec->size);
  	if (mixbuf == NULL) {
  		SDL_OutOfMemory();
  		return (-1);
  	}
  	SDL_memset(mixbuf, spec->silence, spec->size);
  
  	/* We're ready to rock and roll. :-) */
  	return (0);
  }
  
  