diff options
Diffstat (limited to 'backends/mixer/doublebuffersdl/doublebuffersdl-mixer.cpp')
-rw-r--r-- | backends/mixer/doublebuffersdl/doublebuffersdl-mixer.cpp | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/backends/mixer/doublebuffersdl/doublebuffersdl-mixer.cpp b/backends/mixer/doublebuffersdl/doublebuffersdl-mixer.cpp new file mode 100644 index 0000000000..6b0074862e --- /dev/null +++ b/backends/mixer/doublebuffersdl/doublebuffersdl-mixer.cpp @@ -0,0 +1,129 @@ +/* ScummVM - Graphic Adventure Engine + * + * ScummVM is the legal property of its developers, whose names + * are too numerous to list here. Please refer to the COPYRIGHT + * file distributed with this source distribution. + * + * This program 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; either version 2 + * of the License, or (at your option) any later version. + + * This program 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 this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * $URL$ + * $Id$ + * + */ + +#if defined(MACOSX) || defined(GP2X) + +#include "backends/mixer/doublebuffersdl/doublebuffersdl-mixer.h" + +DoubleBufferSDLMixerManager::DoubleBufferSDLMixerManager() + : + _soundMutex(0), _soundCond(0), _soundThread(0), + _soundThreadIsRunning(false), _soundThreadShouldQuit(false) { + +} + +DoubleBufferSDLMixerManager::~DoubleBufferSDLMixerManager() { + deinitThreadedMixer(); +} + +void DoubleBufferSDLMixerManager::startAudio() { + _soundThreadIsRunning = false; + _soundThreadShouldQuit = false; + + // Create mutex and condition variable + _soundMutex = SDL_CreateMutex(); + _soundCond = SDL_CreateCond(); + + // Create two sound buffers + _activeSoundBuf = 0; + uint bufSize = _obtainedRate.samples * 4; + _soundBufSize = bufSize; + _soundBuffers[0] = (byte *)calloc(1, bufSize); + _soundBuffers[1] = (byte *)calloc(1, bufSize); + + _soundThreadIsRunning = true; + + // Finally start the thread + _soundThread = SDL_CreateThread(mixerProducerThreadEntry, this); + + SdlMixerManager::startAudio(); +} + +void DoubleBufferSDLMixerManager::mixerProducerThread() { + byte nextSoundBuffer; + + SDL_LockMutex(_soundMutex); + while (true) { + // Wait till we are allowed to produce data + SDL_CondWait(_soundCond, _soundMutex); + + if (_soundThreadShouldQuit) + break; + + // Generate samples and put them into the next buffer + nextSoundBuffer = _activeSoundBuf ^ 1; + _mixer->mixCallback(_soundBuffers[nextSoundBuffer], _soundBufSize); + + // Swap buffers + _activeSoundBuf = nextSoundBuffer; + } + SDL_UnlockMutex(_soundMutex); +} + +int SDLCALL DoubleBufferSDLMixerManager::mixerProducerThreadEntry(void *arg) { + DoubleBufferSDLMixerManager *mixer = (DoubleBufferSDLMixerManager *)arg; + assert(mixer); + mixer->mixerProducerThread(); + return 0; +} + +void DoubleBufferSDLMixerManager::deinitThreadedMixer() { + // Kill thread?? _soundThread + + if (_soundThreadIsRunning) { + // Signal the producer thread to end, and wait for it to actually finish. + _soundThreadShouldQuit = true; + SDL_CondBroadcast(_soundCond); + SDL_WaitThread(_soundThread, NULL); + + // Kill the mutex & cond variables. + // Attention: AT this point, the mixer callback must not be running + // anymore, else we will crash! + SDL_DestroyMutex(_soundMutex); + SDL_DestroyCond(_soundCond); + + _soundThreadIsRunning = false; + + free(_soundBuffers[0]); + free(_soundBuffers[1]); + } +} + +void DoubleBufferSDLMixerManager::callbackHandler(byte *samples, int len) { + assert(_mixer); + assert((int)_soundBufSize == len); + + // Lock mutex, to ensure our data is not overwritten by the producer thread + SDL_LockMutex(_soundMutex); + + // Copy data from the current sound buffer + memcpy(samples, _soundBuffers[_activeSoundBuf], len); + + // Unlock mutex and wake up the produced thread + SDL_UnlockMutex(_soundMutex); + SDL_CondSignal(_soundCond); +} + +#endif |