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/*
* This file is part of OpenTTD.
* OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
* OpenTTD 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 General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file allegro_s.cpp Playing sound via Allegro. */
#ifdef WITH_ALLEGRO
#include "../stdafx.h"
#include "../mixer.h"
#include "../debug.h"
#include "allegro_s.h"
#include <allegro.h>
#include "../safeguards.h"
static FSoundDriver_Allegro iFSoundDriver_Allegro;
/** The stream we are writing too */
static AUDIOSTREAM *_stream = nullptr;
/** The number of samples in the buffer */
static int _buffer_size;
void SoundDriver_Allegro::MainLoop()
{
/* We haven't opened a stream yet */
if (_stream == nullptr) return;
void *data = get_audio_stream_buffer(_stream);
/* We don't have to fill the stream yet */
if (data == nullptr) return;
/* Mix the samples */
MxMixSamples(data, _buffer_size);
/* Allegro sound is always unsigned, so we need to correct that */
uint16 *snd = (uint16*)data;
for (int i = 0; i < _buffer_size * 2; i++) snd[i] ^= 0x8000;
/* Tell we've filled the stream */
free_audio_stream_buffer(_stream);
}
/**
* There are multiple modules that might be using Allegro and
* Allegro can only be initiated once.
*/
extern int _allegro_instance_count;
const char *SoundDriver_Allegro::Start(const StringList &parm)
{
if (_allegro_instance_count == 0 && install_allegro(SYSTEM_AUTODETECT, &errno, nullptr)) {
Debug(driver, 0, "allegro: install_allegro failed '{}'", allegro_error);
return "Failed to set up Allegro";
}
_allegro_instance_count++;
/* Initialise the sound */
if (install_sound(DIGI_AUTODETECT, MIDI_AUTODETECT, nullptr) != 0) {
Debug(driver, 0, "allegro: install_sound failed '{}'", allegro_error);
return "Failed to set up Allegro sound";
}
/* Okay, there's no soundcard */
if (digi_card == DIGI_NONE) {
Debug(driver, 0, "allegro: no sound card found");
return "No sound card found";
}
int hz = GetDriverParamInt(parm, "hz", 44100);
_buffer_size = GetDriverParamInt(parm, "samples", 1024) * hz / 11025;
_stream = play_audio_stream(_buffer_size, 16, true, hz, 255, 128);
MxInitialize(hz);
return nullptr;
}
void SoundDriver_Allegro::Stop()
{
if (_stream != nullptr) {
stop_audio_stream(_stream);
_stream = nullptr;
}
remove_sound();
if (--_allegro_instance_count == 0) allegro_exit();
}
#endif /* WITH_ALLEGRO */
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