92 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			92 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
/*
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 * This file is part of OpenTTD.
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 * 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.
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 * 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.
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 * 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/>.
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 */
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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 "../mixer.h"
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#include "../debug.h"
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#include "allegro_s.h"
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#include <allegro.h>
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#include "../safeguards.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 = nullptr;
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/** The number of samples in the buffer */
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static int _buffer_size;
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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 == nullptr) 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 == nullptr) 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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/**
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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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 */
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extern int _allegro_instance_count;
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const char *SoundDriver_Allegro::Start(const StringList &parm)
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{
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	if (_allegro_instance_count == 0 && install_allegro(SYSTEM_AUTODETECT, &errno, nullptr)) {
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		DEBUG(driver, 0, "allegro: install_allegro failed '%s'", allegro_error);
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		return "Failed to set up Allegro";
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	}
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	_allegro_instance_count++;
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	/* Initialise the sound */
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	if (install_sound(DIGI_AUTODETECT, MIDI_AUTODETECT, nullptr) != 0) {
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		DEBUG(driver, 0, "allegro: install_sound failed '%s'", allegro_error);
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		return "Failed to set up Allegro sound";
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	}
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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 "No sound card found";
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	}
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	int hz = GetDriverParamInt(parm, "hz", 44100);
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	_buffer_size = GetDriverParamInt(parm, "samples", 1024) * hz / 11025;
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	_stream = play_audio_stream(_buffer_size, 16, true, hz, 255, 128);
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	MxInitialize(hz);
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	return nullptr;
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}
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void SoundDriver_Allegro::Stop()
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{
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	if (_stream != nullptr) {
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		stop_audio_stream(_stream);
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		_stream = nullptr;
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	}
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	remove_sound();
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	if (--_allegro_instance_count == 0) allegro_exit();
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}
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#endif /* WITH_ALLEGRO */
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