Changeset 6417 for code/trunk/src/orxonox/sound/SoundManager.cc

Timestamp:

Dec 25, 2009, 10:23:58 PM (14 years ago)

Author:

rgrieder

Message:

Merged presentation2 branch back to trunk.
Major new features:

• Actual GUI with settings, etc.
• Improved space ship steering (human interaction)
• Rocket fire and more particle effects
• Advanced sound framework

Location:

code/trunk

Files:

• . (modified) (1 prop)
• src/orxonox/sound/SoundManager.cc (modified) (3 diffs)

code/trunk/src/orxonox/sound/SoundManager.cc

@@ -22 +22 @@
  *   Author:
  *       Erwin 'vaiursch' Herrsche
+ *       Kevin Young
+ *       Reto Grieder
  *   Co-authors:
  *      ...
@@ -30 +32 @@
 
 #include <AL/alut.h>
+#include <utility>
 
 #include "util/Exception.h"
 #include "util/Math.h"
 #include "util/ScopeGuard.h"
+#include "util/Clock.h"
+#include "core/ConfigValueIncludes.h"
+#include "core/CoreIncludes.h"
 #include "core/GameMode.h"
 #include "core/ScopedSingletonManager.h"
+#include "core/Resource.h"
+#include "SoundBuffer.h"
+#include "BaseSound.h"
+#include "AmbientSound.h"
+#include "WorldSound.h"
 
 namespace orxonox
 {
-    SoundManager* SoundManager::singletonPtr_s = NULL;
     ManageScopedSingleton(SoundManager, ScopeID::Graphics, true);
 
+    std::string SoundManager::getALErrorString(ALenum code)
+    {
+        switch (code)
+        {
+        case AL_NO_ERROR:          return "No error";
+        case AL_INVALID_NAME:      return "Invalid AL parameter name";
+        case AL_INVALID_ENUM:      return "Invalid AL enum";
+        case AL_INVALID_VALUE:     return "Invalid AL value";
+        case AL_INVALID_OPERATION: return "Invalid AL operation";
+        case AL_OUT_OF_MEMORY:     return "AL reports out of memory";
+        default:                   return "Unknown AL error";
+        }
+    }
+
     SoundManager::SoundManager()
-    {
-        if (!alutInitWithoutContext(NULL,NULL))
-            ThrowException(InitialisationFailed, "OpenAL ALUT error: " << alutGetErrorString(alutGetError()));
+        : effectsPoolSize_(0)
+    {
+        RegisterRootObject(SoundManager);
+
+        // See whether we even want to load
+        bool bDisableSound_ = false;
+        SetConfigValue(bDisableSound_, false);
+        if (bDisableSound_)
+            ThrowException(InitialisationAborted, "Sound: Not loading at all");
+
+        if (!alutInitWithoutContext(NULL, NULL))
+            ThrowException(InitialisationFailed, "Sound Error: ALUT initialisation failed: " << alutGetErrorString(alutGetError()));
         Loki::ScopeGuard alutExitGuard = Loki::MakeGuard(&alutExit);
 
-        COUT(3) << "OpenAL: Opening sound device..." << std::endl;
+/*
+        // Get list of available sound devices and display them
+        const char* devices = alcGetString(NULL, ALC_DEVICE_SPECIFIER);
+        char* device = new char[strlen(devices)+1];
+        strcpy(device, devices);
+        std::string renderDevice;
+        SetConfigValue(renderDevice, std::string(device)).description("Sound device used for rendering");
+        COUT(4) << "Sound: Available devices: ";
+        while (true)
+        {
+            this->deviceNames_.push_back(devices);
+            COUT(4) << '"' << devices << "\", ";
+            devices += strlen(devices) + 1;
+            if (*devices == '\0')
+                break;
+        }
+        COUT(4) << std::endl;
+
+        // Open the selected device
+        COUT(3) << "Sound: Opening device \"" << renderDevice << '\' << std::endl;
+        this->device_ = alcOpenDevice(renderDevice.c_str());
+*/
         this->device_ = alcOpenDevice(NULL);
         if (this->device_ == NULL)
         {
-            COUT(0) << "OpenaAL: Could not open sound device. Have you installed OpenAL?" << std::endl;
+            COUT(1) << "Sound: Could not open sound device. Have you installed OpenAL?" << std::endl;
 #ifdef ORXONOX_PLATFORM_WINDOWS
-            COUT(0) << "Just getting the DLL with the dependencies is not enough for Windows (esp. Windows 7)!" << std::endl;
+            COUT(1) << "Sound: Just getting the DLL with the dependencies is not enough for Windows (esp. Windows 7)!" << std::endl;
 #endif
-            ThrowException(InitialisationFailed, "OpenAL error: Could not open sound device.");
+            ThrowException(InitialisationFailed, "Sound Error: Could not open sound device.");
         }
         Loki::ScopeGuard closeDeviceGuard = Loki::MakeGuard(&alcCloseDevice, this->device_);
 
-        COUT(3) << "OpenAL: Sound device opened" << std::endl;
+        // Create sound context and make it the currently used one
         this->context_ = alcCreateContext(this->device_, NULL);
         if (this->context_ == NULL)
-            ThrowException(InitialisationFailed, "OpenAL error: Could not create sound context");
+            ThrowException(InitialisationFailed, "Sound Error: Could not create ALC context");
         Loki::ScopeGuard desroyContextGuard = Loki::MakeGuard(&alcDestroyContext, this->context_);
-
-        if (alcMakeContextCurrent(this->context_) == AL_TRUE)
-            COUT(3) << "OpenAL: Context " << this->context_ << " loaded" << std::endl;
-
-        COUT(4) << "Sound: OpenAL ALUT version: " << alutGetMajorVersion() << "." << alutGetMinorVersion() << std::endl;
-
-        const char* str = alutGetMIMETypes(ALUT_LOADER_BUFFER);
-        if (str == NULL)
-            COUT(2) << "OpenAL ALUT error: " << alutGetErrorString(alutGetError()) << std::endl;
+        if (!alcMakeContextCurrent(this->context_))
+            ThrowException(InitialisationFailed, "Sound Error: Could not use ALC context");
+
+        GameMode::setPlaysSound(true);
+        Loki::ScopeGuard resetPlaysSoundGuard = Loki::MakeGuard(&GameMode::setPlaysSound, false);
+
+        // Get some information about the sound
+        if (const char* version = alGetString(AL_VERSION))
+            COUT(4) << "Sound: --- OpenAL Version: " << version << std::endl;
+        if (const char* vendor = alGetString(AL_VENDOR))
+            COUT(4) << "Sound: --- OpenAL Vendor : " << vendor << std::endl;
+        if (const char* types = alutGetMIMETypes(ALUT_LOADER_BUFFER))
+            COUT(4) << "Sound: --- Supported MIME Types: " << types << std::endl;
         else
-            COUT(4) << "OpenAL ALUT supported MIME types: " << str << std::endl;
-
-        GameMode::setPlaysSound(true);
+            COUT(2) << "Sound Warning: MIME Type retrieval failed: " << alutGetErrorString(alutGetError()) << std::endl;
+
+        this->mute_[SoundType::All]     = 1.0f;
+        this->mute_[SoundType::Music]   = 1.0f;
+        this->mute_[SoundType::Effects] = 1.0f;
+
+        this->setConfigValues();
+
+        // Try to get at least one source
+        ALuint source;
+        alGenSources(1, &source);
+        if (!alGetError() && alIsSource(source))
+            this->availableSoundSources_.push_back(source);
+        else
+            ThrowException(InitialisationFailed, "Sound Error: Could not create even a single source");
+        // Create a few initial sources
+        this->createSoundSources(this->minSources_ - 1);
+
         // Disarm guards
         alutExitGuard.Dismiss();
         closeDeviceGuard.Dismiss();
         desroyContextGuard.Dismiss();
+        resetPlaysSoundGuard.Dismiss();
+
+        COUT(4) << "Sound: Initialisation complete" << std::endl;
     }
 
     SoundManager::~SoundManager()
     {
+        // Erase fade lists because of the smart pointers
+        this->fadeInList_.clear();
+        this->fadeOutList_.clear();
+
+        // If there are still used buffers around, well, that's just very bad...
+        if (this->soundBuffers_.size() != this->effectsPool_.size())
+            COUT(1) << "Sound Error: Some sound buffers are still in use but OpenAL is about to shut down. Fix this!" << std::endl;
+        // Empty buffer pool and buffer list
+        this->effectsPool_.clear();
+        this->soundBuffers_.clear();
+
+        // There should not be any sources in use anymore
+        if (!this->usedSoundSources_.empty())
+            COUT(1) << "Sound Error: Some sound sources are still in use but OpenAL is about to shut down. Fix this!" << std::endl;
+        while (!this->availableSoundSources_.empty())
+        {
+            alDeleteSources(1, &this->availableSoundSources_.back());
+            this->availableSoundSources_.pop_back();
+        }
+
         GameMode::setPlaysSound(false);
+
+        // Relieve context to destroy it
+        if (!alcMakeContextCurrent(NULL))
+            COUT(1) << "Sound Error: Could not unset ALC context" << std::endl;
         alcDestroyContext(this->context_);
+        if (ALCenum error = alcGetError(this->device_))
+        {
+            if (error == AL_INVALID_OPERATION)
+                COUT(1) << "Sound Error: Could not destroy ALC context because it is the current one" << std::endl;
+            else
+                COUT(1) << "Sound Error: Could not destroy ALC context because it is invalid" << std::endl;
+        }
+#ifdef AL_VERSION_1_1
+        if (!alcCloseDevice(this->device_))
+            COUT(1) << "Sound Error: Could not destroy ALC device. This might be because there are still buffers in use!" << std::endl;
+#else
         alcCloseDevice(this->device_);
-        alutExit();
+#endif
+        if (!alutExit())
+            COUT(1) << "Sound Error: Closing ALUT failed: " << alutGetErrorString(alutGetError()) << std::endl;
+    }
+
+    void SoundManager::setConfigValues()
+    {
+        SetConfigValue(crossFadeStep_, 0.2f)
+            .description("Determines how fast sounds should fade, per second.")
+            .callback(this, &SoundManager::checkFadeStepValidity);
+
+        SetConfigValueAlias(volume_[SoundType::All], "soundVolume_", 1.0f)
+            .description("Defines the overall volume.")
+            .callback(this, &SoundManager::checkSoundVolumeValidity);
+        SetConfigValueAlias(volume_[SoundType::Music], "ambientVolume_", 1.0f)
+            .description("Defines the ambient volume.")
+            .callback(this, &SoundManager::checkAmbientVolumeValidity);
+        SetConfigValueAlias(volume_[SoundType::Effects], "effectsVolume_", 1.0f)
+            .description("Defines the effects volume.")
+            .callback(this, &SoundManager::checkEffectsVolumeValidity);
+
+        SetConfigValue(minSources_, 16)
+            .description("Minimum number of sources being generated (if possible)");
+        SetConfigValue(maxSources_, 1024)
+            .description("Maximum number of sources to be made available");
+    }
+
+    void SoundManager::preUpdate(const Clock& time)
+    {
+        this->processCrossFading(time.getDeltaTime());
+
+        // Check whether a sound object has stopped playing
+        for (unsigned int i = 0; i < this->usedSoundSources_.size(); ++i)
+        {
+            ALint state;
+            alGetSourcei(this->usedSoundSources_[i].first, AL_SOURCE_STATE, &state);
+            if (state == AL_STOPPED)
+            {
+                this->usedSoundSources_[i].second->stop();
+                --i;
+            }
+        }
+    }
+
+    void SoundManager::checkFadeStepValidity()
+    {
+        if (crossFadeStep_ <= 0.0 || crossFadeStep_ >= 1.0 )
+        {
+            COUT(2) << "Sound warning: fade step out of range, ignoring change." << std::endl;
+            ResetConfigValue(crossFadeStep_);
+        }
+    }
+
+    void SoundManager::checkVolumeValidity(SoundType::Value type)
+    {
+        float clampedVolume = clamp(this->volume_[type], 0.0f, 1.0f);
+        if (clampedVolume != this->volume_[type])
+            COUT(2) << "Sound warning: Volume setting (" << type << ") out of range, clamping." << std::endl;
+        this->updateVolume(type);
+    }
+
+    void SoundManager::setVolume(float vol, SoundType::Value type)
+    {
+        if (type < 0 || type > SoundType::Effects)
+            return;
+        this->volume_[type] = vol;
+        this->checkVolumeValidity(type);
+    }
+
+    float SoundManager::getVolume(SoundType::Value type)
+    {
+        if (type < 0 || type > SoundType::Effects)
+            return 0.0f;
+        return this->volume_[type];
+    }
+
+    float SoundManager::getRealVolume(SoundType::Value type)
+    {
+        if (type != SoundType::Music && type != SoundType::Effects)
+            return 0.0f;
+        return this->volume_[SoundType::All] * this->mute_[SoundType::All] * this->volume_[type] * this->mute_[type];
+    }
+
+    void SoundManager::updateVolume(SoundType::Value type)
+    {
+        switch(type)
+        {
+        case SoundType::All:
+            for (ObjectList<BaseSound>::iterator it = ObjectList<BaseSound>::begin(); it != ObjectList<BaseSound>::end(); ++it)
+                (*it)->updateVolume();
+            break;
+        case SoundType::Music:
+            for (ObjectList<AmbientSound>::iterator it = ObjectList<AmbientSound>::begin(); it != ObjectList<AmbientSound>::end(); ++it)
+                (*it)->updateVolume();
+            break;
+        case SoundType::Effects:
+            for (ObjectList<WorldSound>::iterator it = ObjectList<WorldSound>::begin(); it != ObjectList<WorldSound>::end(); ++it)
+                (*it)->updateVolume();
+            break;
+        default:
+            assert(false);
+        }
+    }
+
+    void SoundManager::toggleMute(SoundType::Value type)
+    {
+        if (type < 0 || type > SoundType::Effects)
+            return;
+        this->mute_[type] = (this->mute_[type] == 0) ? 1.0f : 0.0f;
+        this->updateVolume(type);
+    }
+
+    bool SoundManager::getMute(SoundType::Value type)
+    {
+        if (type < 0 || type > SoundType::Effects)
+            return true;
+        return (this->mute_[type] == 0);
     }
 
@@ -103 +330 @@
     {
         // update listener orientation
-        Vector3 up = orientation.xAxis(); // just a wild guess
-        Vector3 at = orientation.zAxis();
-
-        ALfloat orient[6] = { at.x, at.y, at.z,
-                              up.x, up.y, up.z };
-
-        alListenerfv(AL_POSITION, orient);
+        const Vector3& direction = -orientation.zAxis();
+        const Vector3& up = orientation.yAxis();
+
+        ALfloat orient[6] = { direction.x, direction.y, direction.z, up.x, up.y, up.z };
+
+        alListenerfv(AL_ORIENTATION, orient);
         ALenum error = alGetError();
         if (error == AL_INVALID_VALUE)
             COUT(2) << "Sound: OpenAL: Invalid listener orientation" << std::endl;
     }
+
+    void SoundManager::registerAmbientSound(AmbientSound* newAmbient)
+    {
+        if (newAmbient != NULL)
+        {
+            for (AmbientList::const_iterator it = this->ambientSounds_.begin(); it != this->ambientSounds_.end(); ++it)
+            {
+                if (it->first == newAmbient)
+                {
+                    COUT(2) << "Sound warning: Will not play an AmbientSound twice." << std::endl;
+                    return;
+                }
+            }
+
+            if (!this->ambientSounds_.empty())
+            {
+                this->fadeOut(ambientSounds_.front().first);
+            }
+            this->ambientSounds_.push_front(std::make_pair(newAmbient, false));
+            newAmbient->doPlay();
+            this->fadeIn(newAmbient);
+        }
+    }
+
+    void SoundManager::unregisterAmbientSound(AmbientSound* oldAmbient)
+    {
+        if (oldAmbient == NULL || ambientSounds_.empty())
+            return;
+
+        if (this->ambientSounds_.front().first == oldAmbient)
+        {
+            this->fadeOut(oldAmbient);
+            this->ambientSounds_.pop_front();
+            if (!this->ambientSounds_.empty())
+            {
+                if (!this->ambientSounds_.front().second) // Not paused before
+                {
+                    this->ambientSounds_.front().first->doPlay();
+                }
+                this->fadeIn(this->ambientSounds_.front().first);
+            }
+        }
+        else
+        {
+            for (AmbientList::iterator it = this->ambientSounds_.begin(); it != this->ambientSounds_.end(); ++it)
+            {
+                if (it->first == oldAmbient)
+                {
+                    this->fadeOut(oldAmbient);
+                    this->ambientSounds_.erase(it);
+                    break;
+                }
+            }
+        }
+    }
+
+    void SoundManager::pauseAmbientSound(AmbientSound* ambient)
+    {
+        if (ambient != NULL)
+        {
+            for (AmbientList::iterator it = this->ambientSounds_.begin(); it != this->ambientSounds_.end(); ++it)
+            {
+                if (it->first == ambient)
+                {
+                    it->second = true;
+                    this->fadeOut(it->first);
+                    return;
+                }
+            }
+        }
+    }
+
+    void SoundManager::fadeIn(const SmartPtr<AmbientSound>& sound)
+    {
+        // If we're already fading out --> remove that
+        for (std::list<SmartPtr<AmbientSound> >::iterator it = this->fadeOutList_.begin(); it != this->fadeOutList_.end(); it++)
+        {
+            if (*it == sound)
+            {
+                this->fadeOutList_.erase(it);
+                break;
+            }
+        }
+        // No duplicate entries
+        if (std::find(this->fadeInList_.begin(), this->fadeInList_.end(), sound) == this->fadeInList_.end())
+            this->fadeInList_.push_back(sound);
+    }
+
+    void SoundManager::fadeOut(const SmartPtr<AmbientSound>& sound)
+    {
+        // If we're already fading in --> remove that
+        for (std::list<SmartPtr<AmbientSound> >::iterator it = this->fadeInList_.begin(); it != this->fadeInList_.end(); it++)
+        {
+            if (*it == sound)
+            {
+                this->fadeInList_.erase(it);
+                break;
+            }
+        }
+        // No duplicate entries
+        if (std::find(this->fadeOutList_.begin(), this->fadeOutList_.end(), sound) == this->fadeOutList_.end())
+            this->fadeOutList_.push_back(sound);
+    }
+
+    void SoundManager::processCrossFading(float dt)
+    {
+
+        // Hacky solution to the fade delay while loading a level.
+        if(dt > 0.2)
+        {
+            return;
+        }
+
+        // FADE IN
+        for (std::list<SmartPtr<AmbientSound> >::iterator it= this->fadeInList_.begin(); it != this->fadeInList_.end(); )
+        {
+            if ((*it)->getVolume() + this->crossFadeStep_*dt > 1.0f)
+            {
+                (*it)->setVolume(1.0f);
+                this->fadeInList_.erase(it++);
+            }
+            else
+            {
+                (*it)->setVolume((*it)->getVolume() + this->crossFadeStep_*dt);
+                ++it;
+            }
+        }
+
+        // FADE OUT
+        for (std::list<SmartPtr<AmbientSound> >::iterator it = this->fadeOutList_.begin(); it != this->fadeOutList_.end(); )
+        {
+            if ((*it)->getVolume() - this->crossFadeStep_*dt < 0.0f)
+            {
+                (*it)->setVolume(0.0f);
+
+                // If sound is in the ambient list --> pause
+                for (AmbientList::const_iterator it2 = this->ambientSounds_.begin(); it2 != this->ambientSounds_.end(); ++it2)
+                {
+                    if (it2->first == *it)
+                    {
+                        (*it)->doPause();
+                        break;
+                    }
+                }
+                // If not pause (by loop above for instance) --> stop
+                if (!(*it)->isPaused())
+                    (*it)->doStop();
+
+                this->fadeOutList_.erase(it++);
+            }
+            else
+            {
+                (*it)->setVolume((*it)->getVolume() - this->crossFadeStep_*dt);
+                ++it;
+            }
+        }
+    }
+
+    shared_ptr<SoundBuffer> SoundManager::getSoundBuffer(const std::string& filename)
+    {
+        shared_ptr<SoundBuffer> buffer;
+        // Check active or pooled buffers
+        SoundBufferMap::const_iterator it = this->soundBuffers_.find(filename);
+        if (it != this->soundBuffers_.end())
+        {
+            buffer = it->second;
+
+            // Remove from effects pool if not active used before
+            if (buffer->poolIterator_ != this->effectsPool_.end())
+            {
+                this->effectsPoolSize_ -= buffer->getSize();
+                this->effectsPool_.erase(buffer->poolIterator_);
+                buffer->poolIterator_ = this->effectsPool_.end();
+            }
+        }
+        else
+        {
+            try
+            {
+                buffer.reset(new SoundBuffer(filename, this->effectsPool_.end()));
+            }
+            catch (...)
+            {
+                COUT(1) << Exception::handleMessage() << std::endl;
+                return buffer;
+            }
+            this->soundBuffers_[filename] = buffer;
+        }
+        return buffer;
+    }
+
+    void SoundManager::releaseSoundBuffer(const shared_ptr<SoundBuffer>& buffer, bool bPoolBuffer)
+    {
+        // Check if others are still using the buffer
+        if (buffer.use_count() != 2)
+            return;
+        SoundBufferMap::iterator it = this->soundBuffers_.find(buffer->getFilename());
+        if (it != this->soundBuffers_.end())
+        {
+            if (bPoolBuffer)
+            {
+                // Pool already too large?
+                while (this->effectsPoolSize_ + it->second->getSize() > this->maxEffectsPoolSize_s && !this->effectsPool_.empty())
+                {
+                    shared_ptr<SoundBuffer> bufferDel = this->effectsPool_.back();
+                    this->effectsPoolSize_ -= bufferDel->getSize();
+                    bufferDel->poolIterator_ = this->effectsPool_.end();
+                    this->effectsPool_.pop_back();
+                    // Remove from buffer map too
+                    SoundBufferMap::iterator itDel = this->soundBuffers_.find(bufferDel->getFilename());
+                    if (itDel != this->soundBuffers_.end())
+                        this->soundBuffers_.erase(itDel);
+                }
+                // Put buffer into the pool
+                this->effectsPoolSize_ += it->second->getSize();
+                this->effectsPool_.push_front(it->second);
+                it->second->poolIterator_ = this->effectsPool_.begin();
+            }
+            else
+                this->soundBuffers_.erase(it);
+        }
+    }
+
+    ALuint SoundManager::getSoundSource(BaseSound* object)
+    {
+        if (!this->availableSoundSources_.empty())
+        {
+            ALuint source = this->availableSoundSources_.back();
+            this->availableSoundSources_.pop_back();
+            this->usedSoundSources_.push_back(std::make_pair(source, object));
+            return source;
+        }
+        else
+        {
+            if (this->usedSoundSources_.size() < this->maxSources_)
+            {
+                ALuint source;
+                alGenSources(1, &source);
+                // Try to create new sources (50% more, but at least one)
+                if (alIsSource(source) && !alGetError())
+                {
+                    this->usedSoundSources_.push_back(std::make_pair(source, object));
+                    return source;
+                }
+            }
+            // Return no source ID
+            ALuint source = 123456789;
+            while (alIsSource(++source));
+            return source;
+        }
+    }
+
+    void SoundManager::releaseSoundSource(ALuint source)
+    {
+#ifndef NDEBUG
+        for (std::vector<ALuint>::const_iterator it = this->availableSoundSources_.begin(); it != this->availableSoundSources_.end(); ++it)
+            assert((*it) != source);
+#endif
+        this->availableSoundSources_.push_back(source);
+        for (std::vector<std::pair<ALuint, BaseSound*> >::iterator it = this->usedSoundSources_.begin();
+            it != this->usedSoundSources_.end(); ++it)
+        {
+            if (it->first == source)
+            {
+                this->usedSoundSources_.erase(it);
+                break;
+            }
+        }
+        int used = std::max((unsigned int)(this->usedSoundSources_.size()), this->minSources_);
+        // Subtract those we added in the statement above trough std::max
+        int available = (int)this->availableSoundSources_.size() - (used - (int)this->usedSoundSources_.size());
+        // Delete sources again to free resources if appropriate (more than 50% more available than used)
+        int toDelete = available - used / 2;
+        while (toDelete-- > 0)
+        {
+            alDeleteSources(1, &this->availableSoundSources_.back());
+            if (alGetError())
+                COUT(1) << "Sound Error: Failed to delete a source --> lost forever" << std::endl;
+            this->availableSoundSources_.pop_back();
+        }
+    }
+
+    unsigned int SoundManager::createSoundSources(unsigned int n)
+    {
+        unsigned int count = this->availableSoundSources_.size() + this->usedSoundSources_.size();
+        while (count < this->maxSources_ && count <= n)
+        {
+            ALuint source;
+            alGenSources(1, &source);
+            if (alIsSource(source) && !alGetError())
+                this->availableSoundSources_.push_back(source);
+            else
+                break;
+            ++count;
+        }
+        return count - this->availableSoundSources_.size() - this->usedSoundSources_.size();
+    }
 }