rlm@1: // VisualBoyAdvance - Nintendo Gameboy/GameboyAdvance (TM) emulator.
rlm@1: // Copyright (C) 2008 VBA-M development team
rlm@1: 
rlm@1: // This program is free software; you can redistribute it and/or modify
rlm@1: // it under the terms of the GNU General Public License as published by
rlm@1: // the Free Software Foundation; either version 2, or(at your option)
rlm@1: // any later version.
rlm@1: //
rlm@1: // This program is distributed in the hope that it will be useful,
rlm@1: // but WITHOUT ANY WARRANTY; without even the implied warranty of
rlm@1: // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
rlm@1: // GNU General Public License for more details.
rlm@1: //
rlm@1: // You should have received a copy of the GNU General Public License
rlm@1: // along with this program; if not, write to the Free Software Foundation,
rlm@1: // Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
rlm@1: 
rlm@1: #include "SoundSDL.h"
rlm@1: 
rlm@1: extern int emulating;
rlm@1: extern bool speedup;
rlm@1: 
rlm@1: // Hold up to 100 ms of data in the ring buffer
rlm@1: const float SoundSDL::_delay = 0.1f;
rlm@1: 
rlm@1: SoundSDL::SoundSDL():
rlm@1: 	_rbuf(0),
rlm@1: 	_initialized(false)
rlm@1: {
rlm@1: 
rlm@1: }
rlm@1: 
rlm@1: void SoundSDL::soundCallback(void *data, u8 *stream, int len)
rlm@1: {
rlm@1: 	reinterpret_cast<SoundSDL*>(data)->read(reinterpret_cast<u16 *>(stream), len);
rlm@1: }
rlm@1: 
rlm@1: void SoundSDL::read(u16 * stream, int length)
rlm@1: {
rlm@1: 	if (!_initialized || length <= 0 || !emulating)
rlm@1: 		return;
rlm@1: 
rlm@1: 	SDL_mutexP(_mutex);
rlm@1: 	_rbuf.read(stream, std::min(static_cast<std::size_t>(length) / 2, _rbuf.used()));
rlm@1: 
rlm@1: 	SDL_CondSignal(_cond);
rlm@1: 	SDL_mutexV(_mutex);
rlm@1: }
rlm@1: 
rlm@1: void SoundSDL::write(u16 * finalWave, int length)
rlm@1: {
rlm@1: 	if (!_initialized)
rlm@1: 		return;
rlm@1: 
rlm@1: 	if (SDL_GetAudioStatus() != SDL_AUDIO_PLAYING)
rlm@1: 		SDL_PauseAudio(0);
rlm@1: 
rlm@1: 	SDL_mutexP(_mutex);
rlm@1: 
rlm@1: 	unsigned int samples = length / 4;
rlm@1: 
rlm@1: 	std::size_t avail;
rlm@1: 	while ((avail = _rbuf.avail() / 2) < samples)
rlm@1: 	{
rlm@1: 		_rbuf.write(finalWave, avail * 2);
rlm@1: 
rlm@1: 		finalWave += avail * 2;
rlm@1: 		samples -= avail;
rlm@1: 
rlm@1: 		// If emulating and not in speed up mode, synchronize to audio
rlm@1: 		// by waiting till there is enough room in the buffer
rlm@1: 		if (emulating && !speedup)
rlm@1: 		{
rlm@1: 			SDL_CondWait(_cond,_mutex);
rlm@1: 		}
rlm@1: 		else
rlm@1: 		{
rlm@1: 			// Drop the remaining of the audio data
rlm@1: 			SDL_mutexV(_mutex);
rlm@1: 			return;
rlm@1: 		}
rlm@1: 	}
rlm@1: 
rlm@1: 	_rbuf.write(finalWave, samples * 2);
rlm@1: 
rlm@1: 	SDL_mutexV(_mutex);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: bool SoundSDL::init()
rlm@1: {
rlm@1: 	SDL_AudioSpec audio;
rlm@1: 	audio.freq = SDL_SAMPLE_RATE;
rlm@1: 	audio.format = AUDIO_S16SYS;
rlm@1: 	audio.channels = 2;
rlm@1: 	audio.samples = 1024;
rlm@1: 	audio.callback = soundCallback;
rlm@1: 	audio.userdata = this;
rlm@1: 
rlm@1: 	if(SDL_OpenAudio(&audio, NULL))
rlm@1: 	{
rlm@1: 		fprintf(stderr,"Failed to open audio: %s\n", SDL_GetError());
rlm@1: 		return false;
rlm@1: 	}
rlm@1: 
rlm@1: 	_rbuf.reset(_delay * SDL_SAMPLE_RATE * 2);
rlm@1: 
rlm@1: 	_cond  = SDL_CreateCond();
rlm@1: 	_mutex = SDL_CreateMutex();
rlm@1: 	_initialized = true;
rlm@1: 
rlm@1: 	return true;
rlm@1: }
rlm@1: 
rlm@1: SoundSDL::~SoundSDL()
rlm@1: {
rlm@1: 	if (!_initialized)
rlm@1: 		return;
rlm@1: 
rlm@1: 	SDL_mutexP(_mutex);
rlm@1: 	int iSave = emulating;
rlm@1: 	emulating = 0;
rlm@1: 	SDL_CondSignal(_cond);
rlm@1: 	SDL_mutexV(_mutex);
rlm@1: 
rlm@1: 	SDL_DestroyCond(_cond);
rlm@1: 	_cond = NULL;
rlm@1: 
rlm@1: 	SDL_DestroyMutex(_mutex);
rlm@1: 	_mutex = NULL;
rlm@1: 
rlm@1: 	SDL_CloseAudio();
rlm@1: 
rlm@1: 	emulating = iSave;
rlm@1: }
rlm@1: 
rlm@1: void SoundSDL::pause()
rlm@1: {
rlm@1: 	if (!_initialized)
rlm@1: 		return;
rlm@1: 
rlm@1: 	SDL_PauseAudio(1);
rlm@1: }
rlm@1: 
rlm@1: void SoundSDL::resume()
rlm@1: {
rlm@1: 	if (!_initialized)
rlm@1: 		return;
rlm@1: 
rlm@1: 	SDL_PauseAudio(0);
rlm@1: }
rlm@1: 
rlm@1: void SoundSDL::reset()
rlm@1: {
rlm@1: }
rlm@1: 
rlm@1: bool SoundSDL::setThrottle(unsigned short throttle){
rlm@1: 	switch(throttle){
rlm@1: 		case 25:
rlm@1: 		case 50:
rlm@1: 		case 100:
rlm@1: 		case 200:
rlm@1: 		case 400:
rlm@1: 			break;
rlm@1: 		default:
rlm@1: 			return false;
rlm@1: 	}
rlm@1: 	SDL_CloseAudio();
rlm@1: 	SDL_AudioSpec audio;
rlm@1: 	audio.freq = SDL_SAMPLE_RATE*throttle/100;
rlm@1: 	audio.format = AUDIO_S16SYS;
rlm@1: 	audio.channels = 2;
rlm@1: 	audio.samples = 1024;
rlm@1: 	audio.callback = soundCallback;
rlm@1: 	audio.userdata = this;
rlm@1: 	_rbuf.reset((_delay * SDL_SAMPLE_RATE * throttle * 2)/100);
rlm@1: 	return !SDL_OpenAudio(&audio,NULL);
rlm@1: }