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/* $Id$ */

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/** @file allegro_s.cpp Playing sound via Allegro. */

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#ifdef WITH_ALLEGRO

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#include "../stdafx.h"

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#include "../driver.h"

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#include "../mixer.h"

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#include "../sdl.h"

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#include "allegro_s.h"

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#include <allegro.h>

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static FSoundDriver_Allegro iFSoundDriver_Allegro;

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/** The stream we are writing too */

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static AUDIOSTREAM *_stream = NULL;

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/** The number of samples in the buffer */

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static const int BUFFER_SIZE = 512;

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void SoundDriver_Allegro::MainLoop()

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{

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	/* We haven't opened a stream yet */

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	if (_stream == NULL) return;

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	void *data = get_audio_stream_buffer(_stream);

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	/* We don't have to fill the stream yet */

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	if (data == NULL) return;

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	/* Mix the samples */

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	MxMixSamples(data, BUFFER_SIZE);

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	/* Allegro sound is always unsigned, so we need to correct that */

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	uint16 *snd = (uint16*)data;

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	for (int i = 0; i < BUFFER_SIZE * 2; i++) snd[i] ^= 0x8000;

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	/* Tell we've filled the stream */

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	free_audio_stream_buffer(_stream);

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}

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/** There are multiple modules that might be using Allegro and

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 * Allegro can only be initiated once. */

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const char *SoundDriver_Allegro::Start(const char * const *parm)

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{

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	/* Initialise the sound */

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	if (install_sound(DIGI_AUTODETECT, MIDI_AUTODETECT, NULL) != 0) return NULL;

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	/* Okay, there's no soundcard */

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	if (digi_card == DIGI_NONE) {

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		DEBUG(driver, 0, "allegro: no sound card found");

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		return NULL;

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	}

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	_stream = play_audio_stream(BUFFER_SIZE, 16, true, 11025, 255, 128);

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	return NULL;

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}

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void SoundDriver_Allegro::Stop()

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{

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	if (_stream != NULL) {

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		stop_audio_stream(_stream);

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		_stream = NULL;

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	}

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	remove_sound();

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}

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#endif /* WITH_ALLEGRO */