Refactored SDL mixer manager. Created a SdlMixerManager subclass for Mac OSX.

svn-id: r50198

4 files changed, 238 insertions, 171 deletions

diff --git a/backends/mixer/macosx/macosx-mixer.cpp b/backends/mixer/macosx/macosx-mixer.cpp
new file mode 100644
index 0000000000..d3f960792a
--- /dev/null
+++ b/backends/mixer/macosx/macosx-mixer.cpp
@@ -0,0 +1,130 @@
+/* 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)
+
+#include "backends/mixer/macosx/macosx-mixer.h"
+
+MacOSXMixerManager::MacOSXMixerManager()
+	:
+	_soundMutex(0), _soundCond(0), _soundThread(0),
+	_soundThreadIsRunning(false), _soundThreadShouldQuit(false) {
+	
+}
+
+MacOSXMixerManager::~MacOSXMixerManager() {
+	deinitThreadedMixer();
+}
+
+void MacOSXMixerManager::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 MacOSXMixerManager::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 MacOSXMixerManager::mixerProducerThreadEntry(void *arg) {
+	MacOSXMixerManager *mixer = (MacOSXMixerManager *)arg;
+	assert(mixer);
+	mixer->mixerProducerThread();
+	return 0;
+}
+
+void MacOSXMixerManager::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 MacOSXMixerManager::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
diff --git a/backends/mixer/macosx/macosx-mixer.h b/backends/mixer/macosx/macosx-mixer.h
new file mode 100644
index 0000000000..aa8f800495
--- /dev/null
+++ b/backends/mixer/macosx/macosx-mixer.h
@@ -0,0 +1,55 @@
+/* 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.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+#ifndef BACKENDS_MIXER_MACOSX_H
+#define BACKENDS_MIXER_MACOSX_H
+
+#include "backends/mixer/sdl/sdl-mixer.h"
+
+class MacOSXMixerManager : public SdlMixerManager {
+public:
+	MacOSXMixerManager();
+	~MacOSXMixerManager();
+
+protected:
+	SDL_mutex *_soundMutex;
+	SDL_cond *_soundCond;
+	SDL_Thread *_soundThread;
+	bool _soundThreadIsRunning;
+	bool _soundThreadShouldQuit;
+
+	byte _activeSoundBuf;
+	uint _soundBufSize;
+	byte *_soundBuffers[2];
+
+	void mixerProducerThread();
+	void deinitThreadedMixer();
+	static int SDLCALL mixerProducerThreadEntry(void *arg);
+
+	void startAudio();
+	void callbackHandler(byte *samples, int len);
+};
+
+#endif
diff --git a/backends/mixer/sdl/sdl-mixer.cpp b/backends/mixer/sdl/sdl-mixer.cpp
index 04a97ce5cf..aa87fcb345 100644
--- a/backends/mixer/sdl/sdl-mixer.cpp
+++ b/backends/mixer/sdl/sdl-mixer.cpp
@@ -26,51 +26,55 @@
 #if defined(WIN32) || defined(UNIX) || defined(MACOSX)
 
 #include "backends/mixer/sdl/sdl-mixer.h"
-
+#include "common/system.h"
 #include "common/config-manager.h"
 
 //#define SAMPLES_PER_SEC 11025
 #define SAMPLES_PER_SEC 22050
 //#define SAMPLES_PER_SEC 44100
 
-SdlMixerImpl::SdlMixerImpl(OSystem *system)
+SdlMixerManager::SdlMixerManager()
 	:
-#if MIXER_DOUBLE_BUFFERING
-	_soundMutex(0), _soundCond(0), _soundThread(0),
-	_soundThreadIsRunning(false), _soundThreadShouldQuit(false),
-#endif
-	MixerImpl(system, getSamplesPerSec()) {
-	if (_openAudio) {
-		setReady(true);
-
-#if MIXER_DOUBLE_BUFFERING
-		initThreadedMixer(_obtainedRate.samples * 4);
-#endif
+	_mixer(0) {
 
-		// start the sound system
-		SDL_PauseAudio(0);
-	}
-	else {
-		setReady(false);
-	}
 }
 
-SdlMixerImpl::~SdlMixerImpl() {
-	setReady(false);
+SdlMixerManager::~SdlMixerManager() {
+	_mixer->setReady(false);
 
 	SDL_CloseAudio();
 
-#if MIXER_DOUBLE_BUFFERING
-	deinitThreadedMixer();
-#endif
+	delete _mixer;
 }
 
-uint SdlMixerImpl::getSamplesPerSec() {
-
+void SdlMixerManager::init() {
+	// Start SDL Audio subsystem
 	if (SDL_InitSubSystem(SDL_INIT_AUDIO) == -1) {
 		error("Could not initialize SDL: %s", SDL_GetError());
 	}
 
+	// Get the desired audio specs
+	SDL_AudioSpec desired = getAudioSpec();
+
+	// Start SDL audio with the desired specs
+	if (SDL_OpenAudio(&desired, &_obtainedRate) != 0) {
+		warning("Could not open audio device: %s", SDL_GetError());
+
+		_mixer = new Audio::MixerImpl(g_system, desired.freq);
+		assert(_mixer); 
+		_mixer->setReady(false);
+	} else {
+		debug(1, "Output sample rate: %d Hz", _obtainedRate.freq);
+
+		_mixer = new Audio::MixerImpl(g_system, _obtainedRate.freq);
+		assert(_mixer); 
+		_mixer->setReady(true);
+
+		startAudio();
+	}
+}
+
+SDL_AudioSpec SdlMixerManager::getAudioSpec() {
 	SDL_AudioSpec desired;
 
 	// Determine the desired output sampling frequency.
@@ -93,122 +97,27 @@ uint SdlMixerImpl::getSamplesPerSec() {
 	desired.format = AUDIO_S16SYS;
 	desired.channels = 2;
 	desired.samples = (uint16)samples;
-	desired.callback = mixSdlCallback;
+	desired.callback = sdlCallback;
 	desired.userdata = this;
 
-	if (SDL_OpenAudio(&desired, &_obtainedRate) != 0) {
-		warning("Could not open audio device: %s", SDL_GetError());
-		_openAudio = false;
-	} else {
-		// Note: This should be the obtained output rate, but it seems that at
-		// least on some platforms SDL will lie and claim it did get the rate
-		// even if it didn't. Probably only happens for "weird" rates, though.
-		samplesPerSec = _obtainedRate.freq;
-		debug(1, "Output sample rate: %d Hz", samplesPerSec);
-		_openAudio = true;
-	}
-	return samplesPerSec;
+	return desired;
 }
 
-#if MIXER_DOUBLE_BUFFERING
-
-void SdlMixerImpl::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;
-		mixCallback(_soundBuffers[nextSoundBuffer], _soundBufSize);
-
-		// Swap buffers
-		_activeSoundBuf = nextSoundBuffer;
-	}
-	SDL_UnlockMutex(_soundMutex);
+void SdlMixerManager::startAudio() {
+	// Start the sound system
+	SDL_PauseAudio(0);
 }
 
-int SDLCALL SdlMixerImpl::mixerProducerThreadEntry(void *arg) {
-	SdlMixerImpl *mixer = (SdlMixerImpl *)arg;
-	assert(mixer);
-	mixer->mixerProducerThread();
-	return 0;
+void SdlMixerManager::callbackHandler(byte *samples, int len) {
+	assert(_mixer);
+	_mixer->mixCallback(samples, len);
 }
 
+void SdlMixerManager::sdlCallback(void *this_, byte *samples, int len) {
+	SdlMixerManager *manager = (SdlMixerManager *)this_;
+	assert(manager);
 
-void SdlMixerImpl::initThreadedMixer(uint bufSize) {
-	_soundThreadIsRunning = false;
-	_soundThreadShouldQuit = false;
-
-	// Create mutex and condition variable
-	_soundMutex = SDL_CreateMutex();
-	_soundCond = SDL_CreateCond();
-
-	// Create two sound buffers
-	_activeSoundBuf = 0;
-	_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);
-}
-
-void SdlMixerImpl::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]);
-	}
+	manager->callbackHandler(samples, len);
 }
 
-
-void SdlMixerImpl::mixSdlCallback(void *arg, byte *samples, int len) {
-	SdlMixerImpl *mixer = (SdlMixerImpl *)arg;
-	assert(mixer);
-
-	assert((int)mixer->getSoundBufSize() == len);
-
-	// Lock mutex, to ensure our data is not overwritten by the producer thread
-	g_system->lockMutex((OSystem::MutexRef)mixer->getSoundMutex());
-
-	// Copy data from the current sound buffer
-	memcpy(samples, mixer->getActiveSoundBuf(), len);
-
-	// Unlock mutex and wake up the produced thread
-	g_system->unlockMutex((OSystem::MutexRef)mixer->getSoundMutex());
-	SDL_CondSignal(mixer->getSoundCond());
-}
-
-#else
-
-void SdlMixerImpl::mixSdlCallback(void *sys, byte *samples, int len) {
-	Audio::MixerImpl *mixer = (Audio::MixerImpl *)sys;
-	assert(mixer);
-	mixer->mixCallback(samples, len);
-}
-
-#endif
-
 #endif
diff --git a/backends/mixer/sdl/sdl-mixer.h b/backends/mixer/sdl/sdl-mixer.h
index a21dcfd188..2b1272fa92 100644
--- a/backends/mixer/sdl/sdl-mixer.h
+++ b/backends/mixer/sdl/sdl-mixer.h
@@ -34,51 +34,24 @@
 
 #include "sound/mixer_intern.h"
 
-#if defined(MACOSX)
-// On Mac OS X, we need to double buffer the audio buffer, else anything
-// which produces sampled data with high latency (like the MT-32 emulator)
-// will sound terribly.
-// This could be enabled for more / most ports in the future, but needs some
-// testing.
-#define MIXER_DOUBLE_BUFFERING 1
-#endif
-
-class SdlMixerImpl : public Audio::MixerImpl {
+class SdlMixerManager {
 public:
+	SdlMixerManager();
+	~SdlMixerManager();
+
+	virtual void init();
 
-	SdlMixerImpl(OSystem *system);
-	~SdlMixerImpl();
+	Audio::Mixer *getMixer() { return (Audio::Mixer *)_mixer; }
 
 protected:
+	Audio::MixerImpl *_mixer;
 	SDL_AudioSpec _obtainedRate;
-	bool _openAudio;
-
-	uint getSamplesPerSec();
-
-	static void mixSdlCallback(void *s, byte *samples, int len);
 
-#ifdef MIXER_DOUBLE_BUFFERING
-	SDL_mutex *_soundMutex;
-	SDL_cond *_soundCond;
-	SDL_Thread *_soundThread;
-	bool _soundThreadIsRunning;
-	bool _soundThreadShouldQuit;
+	virtual SDL_AudioSpec getAudioSpec();
+	virtual void startAudio();
 
-	byte _activeSoundBuf;
-	uint _soundBufSize;
-	byte *_soundBuffers[2];
-
-	void mixerProducerThread();
-	static int SDLCALL mixerProducerThreadEntry(void *arg);
-	void initThreadedMixer(uint bufSize);
-	void deinitThreadedMixer();
-
-public:
-	SDL_mutex *getSoundMutex() { return _soundMutex; }
-	SDL_cond *getSoundCond() { return _soundCond; }
-	uint getSoundBufSize() { return _soundBufSize; }
-	byte *getActiveSoundBuf() { return _soundBuffers[_activeSoundBuf]; }
-#endif
+	virtual void callbackHandler(byte *samples, int len);
+	static void sdlCallback(void *this_, byte *samples, int len);
 };
 
 #endif