/*

File: SoundEngine.cpp
Abstract: These functions play background music tracks, multiple sound effects,
and support stereo panning with a low-latency response.

Version: 1.7

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Copyright (C) 2008 Apple Inc. All Rights Reserved.

*/

// Local Includes
#include "SoundEngine.h"

#ifndef WIN32
/*==================================================================================================
	SoundEngine.cpp
==================================================================================================*/

//==================================================================================================
//	Includes
//==================================================================================================

//	System Includes
#include <AudioToolbox/AudioToolbox.h>
#include <CoreFoundation/CFURL.h>
#include <OpenAL/al.h>
#include <OpenAL/alc.h>
#include <map>
#include <vector>
#include <pthread.h>
#include <mach/mach.h>
#include <string>


#define	AssertNoError(inMessage, inHandler)						\
			if(result != noErr)									\
			{													\
				printf("%s: %d\n", inMessage, (int)result);		\
				goto inHandler;									\
			}
			
#define AssertNoOALError(inMessage, inHandler)					\
			if((result = alGetError()) != AL_NO_ERROR)			\
			{													\
				printf("%s: %x\n", inMessage, (int)result);		\
				goto inHandler;									\
			}

#define kNumberBuffers 3

class OpenALObject;
class BackgroundTrackMgr;

static OpenALObject			*sOpenALObject = NULL;
static BackgroundTrackMgr	*sBackgroundTrackMgr = NULL;
static Float32				gMasterVolumeGain = 1.0f;
static bool					isInitialized = false;
static bool                 gInterrupted = false;


// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
typedef ALvoid	AL_APIENTRY	(*alBufferDataStaticProcPtr) (const ALint bid, ALenum format, ALvoid* data, ALsizei size, ALsizei freq);
ALvoid  alBufferDataStaticProc(const ALint bid, ALenum format, ALvoid* data, ALsizei size, ALsizei freq)
{
	static	alBufferDataStaticProcPtr	proc = NULL;
    
    if (proc == NULL) {
        proc = (alBufferDataStaticProcPtr) alcGetProcAddress(NULL, (const ALCchar*) "alBufferDataStatic");
    }
    
    if (proc)
        proc(bid, format, data, size, freq);

    return;
}

// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
typedef ALvoid	AL_APIENTRY	(*alcMacOSXMixerOutputRateProcPtr) (const ALdouble value);
ALvoid  alcMacOSXMixerOutputRateProc(const ALdouble value)
{
	static	alcMacOSXMixerOutputRateProcPtr	proc = NULL;
    
    if (proc == NULL) {
        proc = (alcMacOSXMixerOutputRateProcPtr) alcGetProcAddress(NULL, (const ALCchar*) "alcMacOSXMixerOutputRate");
    }
    
    if (proc)
        proc(value);

    return;
}

#pragma mark ***** OpenALThread *****
//==================================================================================================
//	Threading functions
//==================================================================================================
class	OpenALThread
{
// returns the thread's priority as it was last set by the API
#define OpenALThread_SET_PRIORITY				0
// returns the thread's priority as it was last scheduled by the Kernel
#define OpenALThread_SCHEDULED_PRIORITY		1

//	Types
public:
	typedef void*			(*ThreadRoutine)(void* inParameter);

//	Constants
public:
	enum
	{
							kMinThreadPriority = 1,
							kMaxThreadPriority = 63,
							kDefaultThreadPriority = 31
	};

//	Construction/Destruction
public:
	OpenALThread(ThreadRoutine inThreadRoutine, void* inParameter)
		:	mPThread(0),
			mSpawningThreadPriority(getScheduledPriority(pthread_self(), OpenALThread_SET_PRIORITY)),
			mThreadRoutine(inThreadRoutine),
			mThreadParameter(inParameter),
			mPriority(kDefaultThreadPriority),
			mFixedPriority(false),
			mAutoDelete(true) { }

	~OpenALThread() { }

//	Properties
	bool IsRunning() const { return 0 != mPThread; }
	void SetAutoDelete(bool b) { mAutoDelete = b; }

	void SetPriority(UInt32 inPriority, bool inFixedPriority)
	{
		OSStatus result = noErr;
		mPriority = inPriority;
		mFixedPriority = inFixedPriority;
		if(mPThread != 0)
		{
			if (mFixedPriority)
			{
				thread_extended_policy_data_t		theFixedPolicy;
				theFixedPolicy.timeshare = false;	// set to true for a non-fixed thread
				result  = thread_policy_set(pthread_mach_thread_np(mPThread), THREAD_EXTENDED_POLICY, (thread_policy_t)&theFixedPolicy, THREAD_EXTENDED_POLICY_COUNT);
				if (result) {
					printf("OpenALThread::SetPriority: failed to set the fixed-priority policy");
					return;
				}
			}
			// We keep a reference to the spawning thread's priority around (initialized in the constructor), 
			// and set the importance of the child thread relative to the spawning thread's priority.
			thread_precedence_policy_data_t		thePrecedencePolicy;
			
			thePrecedencePolicy.importance = mPriority - mSpawningThreadPriority;
			result =thread_policy_set(pthread_mach_thread_np(mPThread), THREAD_PRECEDENCE_POLICY, (thread_policy_t)&thePrecedencePolicy, THREAD_PRECEDENCE_POLICY_COUNT);
			if (result) {
				printf("OpenALThread::SetPriority: failed to set the precedence policy");
				return;
			}
		} 
	}
//	Actions
	void Start()
	{
		if(mPThread != 0)
		{
			printf("OpenALThread::Start: can't start because the thread is already running\n");
			return;
		}

		OSStatus			result;
		pthread_attr_t		theThreadAttributes;
		
		result = pthread_attr_init(&theThreadAttributes);
			AssertNoError("Error initializing thread", end);
		
		result = pthread_attr_setdetachstate(&theThreadAttributes, PTHREAD_CREATE_DETACHED);
			AssertNoError("Error setting thread detach state", end);
				
		result = pthread_create(&mPThread, &theThreadAttributes, (ThreadRoutine)OpenALThread::Entry, this);
			AssertNoError("Error creating thread", end);
		
		pthread_attr_destroy(&theThreadAttributes);
			AssertNoError("Error destroying thread attributes", end);
end:
		return;
	}

//	Implementation
protected:
	static void* Entry(OpenALThread* inOpenALThread)
	{
		void* theAnswer = NULL;

		inOpenALThread->SetPriority(inOpenALThread->mPriority, inOpenALThread->mFixedPriority);

		if(inOpenALThread->mThreadRoutine != NULL)
		{
			theAnswer = inOpenALThread->mThreadRoutine(inOpenALThread->mThreadParameter);
		}

		inOpenALThread->mPThread = 0;
		if (inOpenALThread->mAutoDelete)
			delete inOpenALThread;
		return theAnswer;
	}

	static UInt32 getScheduledPriority(pthread_t inThread, int inPriorityKind)
	{
		thread_basic_info_data_t			threadInfo;
		policy_info_data_t					thePolicyInfo;
		unsigned int						count;

		if (inThread == NULL)
			return 0;
		
		// get basic info
		count = THREAD_BASIC_INFO_COUNT;
		thread_info (pthread_mach_thread_np (inThread), THREAD_BASIC_INFO, (thread_info_t)&threadInfo, &count);
		
		switch (threadInfo.policy) {
			case POLICY_TIMESHARE:
				count = POLICY_TIMESHARE_INFO_COUNT;
				thread_info(pthread_mach_thread_np (inThread), THREAD_SCHED_TIMESHARE_INFO, (thread_info_t)&(thePolicyInfo.ts), &count);
				if (inPriorityKind == OpenALThread_SCHEDULED_PRIORITY) {
					return thePolicyInfo.ts.cur_priority;
				}
				return thePolicyInfo.ts.base_priority;
				break;
				
			case POLICY_FIFO:
				count = POLICY_FIFO_INFO_COUNT;
				thread_info(pthread_mach_thread_np (inThread), THREAD_SCHED_FIFO_INFO, (thread_info_t)&(thePolicyInfo.fifo), &count);
				if ( (thePolicyInfo.fifo.depressed) && (inPriorityKind == OpenALThread_SCHEDULED_PRIORITY) ) {
					return thePolicyInfo.fifo.depress_priority;
				}
				return thePolicyInfo.fifo.base_priority;
				break;
				
			case POLICY_RR:
				count = POLICY_RR_INFO_COUNT;
				thread_info(pthread_mach_thread_np (inThread), THREAD_SCHED_RR_INFO, (thread_info_t)&(thePolicyInfo.rr), &count);
				if ( (thePolicyInfo.rr.depressed) && (inPriorityKind == OpenALThread_SCHEDULED_PRIORITY) ) {
					return thePolicyInfo.rr.depress_priority;
				}
				return thePolicyInfo.rr.base_priority;
				break;
		}
		
		return 0;
	}

	pthread_t				mPThread;
    UInt32					mSpawningThreadPriority;
	ThreadRoutine			mThreadRoutine;
	void*					mThreadParameter;
	SInt32					mPriority;
    bool					mFixedPriority;
	bool					mAutoDelete;		// delete self when thread terminates
};

//==================================================================================================
//	Helper functions
//==================================================================================================
OSStatus OpenFile(const char *inFilePath, AudioFileID &outAFID)
{
	
	CFURLRef theURL = CFURLCreateFromFileSystemRepresentation(kCFAllocatorDefault, (UInt8*)inFilePath, strlen(inFilePath), false);
	if (theURL == NULL)
		return kSoundEngineErrFileNotFound;

#if TARGET_OS_IPHONE
	OSStatus result = AudioFileOpenURL(theURL, kAudioFileReadPermission, 0, &outAFID);
#else
	OSStatus result = AudioFileOpenURL(theURL, fsRdPerm, 0, &outAFID);
#endif
	CFRelease(theURL);
		AssertNoError("Error opening file", end);
	end:
		return result;
}

OSStatus LoadFileDataInfo(const char *inFilePath, AudioFileID &outAFID, AudioStreamBasicDescription &outFormat, UInt64 &outDataSize)
{
	UInt32 thePropSize = sizeof(outFormat);				
	OSStatus result = OpenFile(inFilePath, outAFID);
		AssertNoError("Error opening file", end);

	result = AudioFileGetProperty(outAFID, kAudioFilePropertyDataFormat, &thePropSize, &outFormat);
		AssertNoError("Error getting file format", end);
	
	thePropSize = sizeof(UInt64);
	result = AudioFileGetProperty(outAFID, kAudioFilePropertyAudioDataByteCount, &thePropSize, &outDataSize);
		AssertNoError("Error getting file data size", end);

end:
	return result;
}

void CalculateBytesForTime (AudioStreamBasicDescription & inDesc, UInt32 inMaxPacketSize, Float64 inSeconds, UInt32 *outBufferSize, UInt32 *outNumPackets)
{
	static const UInt32 maxBufferSize = 0x10000; // limit size to 64K
	static const UInt32 minBufferSize = 0x4000; // limit size to 16K

	if (inDesc.mFramesPerPacket) {
		Float64 numPacketsForTime = inDesc.mSampleRate / inDesc.mFramesPerPacket * inSeconds;
		*outBufferSize = (long unsigned int)numPacketsForTime * inMaxPacketSize;
	} else {
		// if frames per packet is zero, then the codec has no predictable packet == time
		// so we can't tailor this (we don't know how many Packets represent a time period
		// we'll just return a default buffer size
		*outBufferSize = maxBufferSize > inMaxPacketSize ? maxBufferSize : inMaxPacketSize;
	}
	
		// we're going to limit our size to our default
	if (*outBufferSize > maxBufferSize && *outBufferSize > inMaxPacketSize)
		*outBufferSize = maxBufferSize;
	else {
		// also make sure we're not too small - we don't want to go the disk for too small chunks
		if (*outBufferSize < minBufferSize)
			*outBufferSize = minBufferSize;
	}
	*outNumPackets = *outBufferSize / inMaxPacketSize;
}

static Boolean MatchFormatFlags(const AudioStreamBasicDescription& x, const AudioStreamBasicDescription& y)
{
	UInt32 xFlags = x.mFormatFlags;
	UInt32 yFlags = y.mFormatFlags;
	
	// match wildcards
	if (x.mFormatID == 0 || y.mFormatID == 0 || xFlags == 0 || yFlags == 0) 
		return true;
	
	if (x.mFormatID == kAudioFormatLinearPCM)
	{		 		
		// knock off the all clear flag
		xFlags = xFlags & ~kAudioFormatFlagsAreAllClear;
		yFlags = yFlags & ~kAudioFormatFlagsAreAllClear;
	
		// if both kAudioFormatFlagIsPacked bits are set, then we don't care about the kAudioFormatFlagIsAlignedHigh bit.
		if (xFlags & yFlags & kAudioFormatFlagIsPacked) {
			xFlags = xFlags & ~kAudioFormatFlagIsAlignedHigh;
			yFlags = yFlags & ~kAudioFormatFlagIsAlignedHigh;
		}
		
		// if both kAudioFormatFlagIsFloat bits are set, then we don't care about the kAudioFormatFlagIsSignedInteger bit.
		if (xFlags & yFlags & kAudioFormatFlagIsFloat) {
			xFlags = xFlags & ~kAudioFormatFlagIsSignedInteger;
			yFlags = yFlags & ~kAudioFormatFlagIsSignedInteger;
		}
		
		//	if the bit depth is 8 bits or less and the format is packed, we don't care about endianness
		if((x.mBitsPerChannel <= 8) && ((xFlags & kAudioFormatFlagIsPacked) == kAudioFormatFlagIsPacked))
		{
			xFlags = xFlags & ~kAudioFormatFlagIsBigEndian;
		}
		if((y.mBitsPerChannel <= 8) && ((yFlags & kAudioFormatFlagIsPacked) == kAudioFormatFlagIsPacked))
		{
			yFlags = yFlags & ~kAudioFormatFlagIsBigEndian;
		}
		
		//	if the number of channels is 0 or 1, we don't care about non-interleavedness
		if (x.mChannelsPerFrame <= 1 && y.mChannelsPerFrame <= 1) {
			xFlags &= ~kLinearPCMFormatFlagIsNonInterleaved;
			yFlags &= ~kLinearPCMFormatFlagIsNonInterleaved;
		}
	}
	return xFlags == yFlags;
}

Boolean FormatIsEqual(AudioStreamBasicDescription x, AudioStreamBasicDescription y)
{
	//	the semantics for equality are:
	//		1) Values must match exactly
	//		2) wildcard's are ignored in the comparison
	
#define MATCH(name) ((x.name) == 0 || (y.name) == 0 || (x.name) == (y.name))
	
	return 
		((x.mSampleRate==0.) || (y.mSampleRate==0.) || (x.mSampleRate==y.mSampleRate)) 
		&& MATCH(mFormatID)
		&& MatchFormatFlags(x, y)  
		&& MATCH(mBytesPerPacket) 
		&& MATCH(mFramesPerPacket) 
		&& MATCH(mBytesPerFrame) 
		&& MATCH(mChannelsPerFrame) 		
		&& MATCH(mBitsPerChannel) ;
}

#pragma mark ***** BackgroundTrackMgr *****
//==================================================================================================
//	BackgroundTrackMgr class
//==================================================================================================
class BackgroundTrackMgr
	{	
#define CurFileInfo THIS->mBGFileInfo[THIS->mCurrentFileIndex]
	public:
		typedef struct BG_FileInfo {
			std::string						mFilePath;
			AudioFileID						mAFID;
			AudioStreamBasicDescription		mFileFormat;
			UInt64							mFileDataSize;
			//UInt64							mFileNumPackets; // this is only used if loading file to memory
			Boolean							mLoadAtOnce;
			Boolean							mFileDataInQueue;
		} BackgroundMusicFileInfo;
		
		BackgroundTrackMgr();
		~BackgroundTrackMgr();
		
		void Teardown();
		void ClearFileInfo();
		
		AudioStreamPacketDescription *GetPacketDescsPtr();
		
		UInt32 GetNumPacketsToRead(BackgroundTrackMgr::BG_FileInfo *inFileInfo);
		
		static OSStatus AttachNewCookie(AudioQueueRef inQueue, BackgroundTrackMgr::BG_FileInfo *inFileInfo);
		static void QueueStoppedProc( void * inUserData, AudioQueueRef inAQ, AudioQueuePropertyID inID );
		static Boolean DisposeBuffer(AudioQueueRef inAQ, std::vector<AudioQueueBufferRef> inDisposeBufferList, AudioQueueBufferRef inBufferToDispose);
		
		enum {
			kQueueState_DoNothing		= 0,
			kQueueState_ResizeBuffer	= 1,
			kQueueState_NeedNewCookie	= 2,
			kQueueState_NeedNewBuffers	= 3,
			kQueueState_NeedNewQueue	= 4,
		};
		
		static SInt8 GetQueueStateForNextBuffer(BackgroundTrackMgr::BG_FileInfo *inFileInfo, BackgroundTrackMgr::BG_FileInfo *inNextFileInfo);
		static void QueueCallback( void * inUserData, AudioQueueRef inAQ, AudioQueueBufferRef inCompleteAQBuffer);
		
		OSStatus SetupQueue(BG_FileInfo *inFileInfo);
		OSStatus SetupBuffers(BG_FileInfo *inFileInfo);
		OSStatus LoadTrack(const char* inFilePath, Boolean inAddToQueue, Boolean inLoadAtOnce);
		
		OSStatus UpdateGain();
		OSStatus SetVolume(Float32 inVolume);
		Float32 GetVolume() const;
		
		OSStatus Start();
		OSStatus Stop(Boolean inStopAtEnd);
		
	private:
		AudioQueueRef						mQueue;
		AudioQueueBufferRef					mBuffers[kNumberBuffers];
		UInt32								mBufferByteSize;
		SInt64								mCurrentPacket;
		UInt32								mNumPacketsToRead;
		Float32								mVolume;
		AudioStreamPacketDescription *		mPacketDescs;
		std::vector<BG_FileInfo*>			mBGFileInfo;
		UInt32								mCurrentFileIndex;
		Boolean								mMakeNewQueueWhenStopped;
		Boolean								mStopAtEnd;
		std::vector<AudioQueueBufferRef>	mBuffersToDispose;
	};

BackgroundTrackMgr::BackgroundTrackMgr() 
		:	mQueue(0),
		mBufferByteSize(0),
		mCurrentPacket(0),
		mNumPacketsToRead(0),
		mVolume(1.0f),
		mPacketDescs(NULL),
		mCurrentFileIndex(0),
		mMakeNewQueueWhenStopped(false),
		mStopAtEnd(false)
{ }
		
BackgroundTrackMgr::~BackgroundTrackMgr() {
	Teardown();
}
		
void BackgroundTrackMgr::Teardown() {
	if (mQueue) {
		AudioQueueDispose(mQueue, true);
	}
	for (UInt32 i=0; i < mBGFileInfo.size(); i++) {
		if (mBGFileInfo[i]->mAFID) {
			AudioFileClose(mBGFileInfo[i]->mAFID);
		}
	}
	
	if (mPacketDescs) {
		delete mPacketDescs;
	}
	
	ClearFileInfo();
}
		
void BackgroundTrackMgr::ClearFileInfo() {
	std::vector< BG_FileInfo* >::iterator itr = mBGFileInfo.begin();
	std::vector< BG_FileInfo* >::iterator endItr = mBGFileInfo.end();
	for( ; itr != endItr; ++itr ) {
		delete *itr;
		*itr = NULL;
	}
	mBGFileInfo.clear();
}
		
AudioStreamPacketDescription *BackgroundTrackMgr::GetPacketDescsPtr() {
	return mPacketDescs;
}
		
UInt32 BackgroundTrackMgr::GetNumPacketsToRead(BackgroundTrackMgr::BG_FileInfo *inFileInfo) { 
	(void)inFileInfo;
	return mNumPacketsToRead; 
}
		
OSStatus BackgroundTrackMgr::AttachNewCookie(AudioQueueRef inQueue, BackgroundTrackMgr::BG_FileInfo *inFileInfo)	{
	OSStatus result = noErr;
	UInt32 size = sizeof(UInt32);
	result = AudioFileGetPropertyInfo (inFileInfo->mAFID, kAudioFilePropertyMagicCookieData, &size, NULL);
	if (!result && size) {
		char* cookie = new char [size];		
		result = AudioFileGetProperty (inFileInfo->mAFID, kAudioFilePropertyMagicCookieData, &size, cookie);
		AssertNoError("Error getting cookie data", end);
		result = AudioQueueSetProperty(inQueue, kAudioQueueProperty_MagicCookie, cookie, size);
		delete [] cookie;
		AssertNoError("Error setting cookie data for queue", end);
	}
	return noErr;
			
	end:
	return noErr;
}
		
void BackgroundTrackMgr::QueueStoppedProc( void * inUserData, AudioQueueRef inAQ, AudioQueuePropertyID inID ) {
	(void)inID;
	UInt32 isRunning;
	UInt32 propSize = sizeof(isRunning);
			
	BackgroundTrackMgr *THIS = (BackgroundTrackMgr*)inUserData;
	OSStatus result = AudioQueueGetProperty(inAQ, kAudioQueueProperty_IsRunning, &isRunning, &propSize);
			
	if ((!isRunning) && (THIS->mMakeNewQueueWhenStopped)) {
		result = AudioQueueDispose(inAQ, true);
		AssertNoError("Error disposing queue", end);
		result = THIS->SetupQueue(CurFileInfo);
		AssertNoError("Error setting up new queue", end);
		result = THIS->SetupBuffers(CurFileInfo);
		AssertNoError("Error setting up new queue buffers", end);
		result = THIS->Start();
		AssertNoError("Error starting queue", end);
	}
	end:
	return;
}
		
Boolean BackgroundTrackMgr::DisposeBuffer(AudioQueueRef inAQ, std::vector<AudioQueueBufferRef> inDisposeBufferList, AudioQueueBufferRef inBufferToDispose) {
	for (unsigned int i=0; i < inDisposeBufferList.size(); i++)	{
		if (inBufferToDispose == inDisposeBufferList[i]) {
			OSStatus result = AudioQueueFreeBuffer(inAQ, inBufferToDispose);
			if (result == noErr) {
				inDisposeBufferList.pop_back();
			}
			return true;
		}
	}
	return false;
}
		
SInt8 BackgroundTrackMgr::GetQueueStateForNextBuffer(BackgroundTrackMgr::BG_FileInfo *inFileInfo, BackgroundTrackMgr::BG_FileInfo *inNextFileInfo) {
	inFileInfo->mFileDataInQueue = false;
			
	// unless the data formats are the same, we need a new queue
	if (!FormatIsEqual(inFileInfo->mFileFormat, inNextFileInfo->mFileFormat)) {
		return kQueueState_NeedNewQueue;
	}
			
	// if going from a load-at-once file to streaming or vice versa, we need new buffers
	if (inFileInfo->mLoadAtOnce != inNextFileInfo->mLoadAtOnce) {
		return kQueueState_NeedNewBuffers;
	}
			
	// if the next file is smaller than the current, we just need to resize
	if (inNextFileInfo->mLoadAtOnce) {
		return (inFileInfo->mFileDataSize >= inNextFileInfo->mFileDataSize) ? kQueueState_ResizeBuffer : kQueueState_NeedNewBuffers;
	}
			
	return kQueueState_NeedNewCookie;
}
		
void BackgroundTrackMgr::QueueCallback( void * inUserData, AudioQueueRef inAQ, AudioQueueBufferRef inCompleteAQBuffer ) {
	// dispose of the buffer if no longer in use
	OSStatus result = noErr;
	BackgroundTrackMgr *THIS = (BackgroundTrackMgr*)inUserData;
	if (DisposeBuffer(inAQ, THIS->mBuffersToDispose, inCompleteAQBuffer)) {
		return;
	}	

	UInt32 nPackets = 0;
	// loop the current buffer if the following:
	// 1. file was loaded into the buffer previously
	// 2. only one file in the queue
	// 3. we have not been told to stop at playlist completion
	if ((CurFileInfo->mFileDataInQueue) && (THIS->mBGFileInfo.size() == 1) && (!THIS->mStopAtEnd)) {
		nPackets = THIS->GetNumPacketsToRead(CurFileInfo);
	} else {
		UInt32 numBytes;
		while (nPackets == 0) {
			// if loadAtOnce, get all packets in the file, otherwise ~.5 seconds of data
			nPackets = THIS->GetNumPacketsToRead(CurFileInfo);					
			result = AudioFileReadPackets(CurFileInfo->mAFID, false, &numBytes, THIS->mPacketDescs, THIS->mCurrentPacket, &nPackets, 
										  inCompleteAQBuffer->mAudioData);
			AssertNoError("Error reading file data", end);
			
			inCompleteAQBuffer->mAudioDataByteSize = numBytes;	
			
			if (nPackets == 0) { // no packets were read, this file has ended.
				if (CurFileInfo->mLoadAtOnce) {
					CurFileInfo->mFileDataInQueue = true;
				}
						
				THIS->mCurrentPacket = 0;
				UInt32 theNextFileIndex = (THIS->mCurrentFileIndex < THIS->mBGFileInfo.size()-1) ? THIS->mCurrentFileIndex+1 : 0;
						
				// we have gone through the playlist. if mStopAtEnd, stop the queue here
				if (theNextFileIndex == 0 && THIS->mStopAtEnd) {
					result = AudioQueueStop(inAQ, false);
					AssertNoError("Error stopping queue", end);
					return;
				}
						
				SInt8 theQueueState = GetQueueStateForNextBuffer(CurFileInfo, THIS->mBGFileInfo[theNextFileIndex]);
				if (theNextFileIndex != THIS->mCurrentFileIndex) {
					// if were are not looping the same file. Close the old one and open the new
					result = AudioFileClose(CurFileInfo->mAFID);
					AssertNoError("Error closing file", end);
					THIS->mCurrentFileIndex = theNextFileIndex;
							
					result = LoadFileDataInfo(CurFileInfo->mFilePath.c_str(), CurFileInfo->mAFID, CurFileInfo->mFileFormat, CurFileInfo->mFileDataSize);
					AssertNoError("Error opening file", end);
				}
						
				switch (theQueueState) {							
						// if we need to resize the buffer, set the buffer's audio data size to the new file's size
						// we will also need to get the new file cookie
					case kQueueState_ResizeBuffer:
						inCompleteAQBuffer->mAudioDataByteSize = (UInt32)CurFileInfo->mFileDataSize;							
						// if the data format is the same but we just need a new cookie, attach a new cookie
					case kQueueState_NeedNewCookie:
						result = AttachNewCookie(inAQ, CurFileInfo);
						AssertNoError("Error attaching new file cookie data to queue", end);
						break;
						
						// we can keep the same queue, but not the same buffer(s)
					case kQueueState_NeedNewBuffers:
						THIS->mBuffersToDispose.push_back(inCompleteAQBuffer);
						THIS->SetupBuffers(CurFileInfo);
						break;
								
						// if the data formats are not the same, we need to dispose the current queue and create a new one
					case kQueueState_NeedNewQueue:
						THIS->mMakeNewQueueWhenStopped = true;
						result = AudioQueueStop(inAQ, false);
						AssertNoError("Error stopping queue", end);
						return;
								
					default:
						break;
				}
			}
		}
	}
			
	result = AudioQueueEnqueueBuffer(inAQ, inCompleteAQBuffer, (THIS->mPacketDescs ? nPackets : 0), THIS->mPacketDescs);
    if(result != noErr) {
        result = AudioQueueFreeBuffer(inAQ, inCompleteAQBuffer);
		AssertNoError("Error freeing buffers that didn't enqueue", end);
    }
	AssertNoError("Error enqueuing new buffer", end);
	if (CurFileInfo->mLoadAtOnce) {
		CurFileInfo->mFileDataInQueue = true;
	}
	
	THIS->mCurrentPacket += nPackets;
			
	end:
	return;
}
		
OSStatus BackgroundTrackMgr::SetupQueue(BG_FileInfo *inFileInfo) {
	UInt32 size = 0;
	OSStatus result = AudioQueueNewOutput(&inFileInfo->mFileFormat, QueueCallback, this, CFRunLoopGetCurrent(), kCFRunLoopCommonModes, 0, &mQueue);
	OSStatus err = noErr;
	
	AssertNoError("Error creating queue", end);
			
	// (2) If the file has a cookie, we should get it and set it on the AQ
	size = sizeof(UInt32);
	result = AudioFileGetPropertyInfo (inFileInfo->mAFID, kAudioFilePropertyMagicCookieData, &size, NULL);
			
	if (!result && size) {
		char* cookie = new char [size];		
		result = AudioFileGetProperty (inFileInfo->mAFID, kAudioFilePropertyMagicCookieData, &size, cookie);
		AssertNoError("Error getting magic cookie", end);
		result = AudioQueueSetProperty(mQueue, kAudioQueueProperty_MagicCookie, cookie, size);
		delete [] cookie;
		AssertNoError("Error setting magic cookie", end);
	}
			
	// channel layout
	err = AudioFileGetPropertyInfo(inFileInfo->mAFID, kAudioFilePropertyChannelLayout, &size, NULL);
	if (err == noErr && size > 0) {
		AudioChannelLayout *acl = (AudioChannelLayout *)malloc(size);
		result = AudioFileGetProperty(inFileInfo->mAFID, kAudioFilePropertyChannelLayout, &size, acl);
		AssertNoError("Error getting channel layout from file", end);
		result = AudioQueueSetProperty(mQueue, kAudioQueueProperty_ChannelLayout, acl, size);
		free(acl);
		AssertNoError("Error setting channel layout on queue", end);
	}
			
	// add a notification proc for when the queue stops
	result = AudioQueueAddPropertyListener(mQueue, kAudioQueueProperty_IsRunning, QueueStoppedProc, this);
	AssertNoError("Error adding isRunning property listener to queue", end);
			
	// we need to reset this variable so that if the queue is stopped mid buffer we don't dispose it 
	mMakeNewQueueWhenStopped = false;
		
	// volume
	result = SetVolume(mVolume);
			
	end:
	return result;
}
		
OSStatus BackgroundTrackMgr::SetupBuffers(BG_FileInfo *inFileInfo) {
	int numBuffersToQueue = kNumberBuffers;
	UInt32 maxPacketSize;
	UInt32 size = sizeof(maxPacketSize);
	bool isFormatVBR = false;
	
	// we need to calculate how many packets we read at a time, and how big a buffer we need
	// we base this on the size of the packets in the file and an approximate duration for each buffer
			
	// first check to see what the max size of a packet is - if it is bigger
	// than our allocation default size, that needs to become larger
	OSStatus result = AudioFileGetProperty(inFileInfo->mAFID, kAudioFilePropertyPacketSizeUpperBound, &size, &maxPacketSize);
	AssertNoError("Error getting packet upper bound size", end);
	isFormatVBR = (inFileInfo->mFileFormat.mBytesPerPacket == 0 || inFileInfo->mFileFormat.mFramesPerPacket == 0);
			
	CalculateBytesForTime(inFileInfo->mFileFormat, maxPacketSize, 0.5/*seconds*/, &mBufferByteSize, &mNumPacketsToRead);
		
	// if the file is smaller than the capacity of all the buffer queues, always load it at once
	if ((mBufferByteSize * numBuffersToQueue) > inFileInfo->mFileDataSize) {
		inFileInfo->mLoadAtOnce = true;
	}
			
	if (inFileInfo->mLoadAtOnce) {
		UInt64 theFileNumPackets;
		size = sizeof(UInt64);
		result = AudioFileGetProperty(inFileInfo->mAFID, kAudioFilePropertyAudioDataPacketCount, &size, &theFileNumPackets);
		AssertNoError("Error getting packet count for file", end);
				
		mNumPacketsToRead = (UInt32)theFileNumPackets;
		mBufferByteSize = (UInt32)inFileInfo->mFileDataSize;
		numBuffersToQueue = 1;
	} else {
		mNumPacketsToRead = mBufferByteSize / maxPacketSize;
	}
			
	if (isFormatVBR) {
		mPacketDescs = new AudioStreamPacketDescription [mNumPacketsToRead];
	} else {
		mPacketDescs = NULL; // we don't provide packet descriptions for constant bit rate formats (like linear PCM)	
	}
			
	// allocate the queue's buffers
	for (int i = 0; i < numBuffersToQueue; ++i) {
		result = AudioQueueAllocateBuffer(mQueue, mBufferByteSize, &mBuffers[i]);
		AssertNoError("Error allocating buffer for queue", end);
		QueueCallback (this, mQueue, mBuffers[i]);
		if (inFileInfo->mLoadAtOnce) {
			inFileInfo->mFileDataInQueue = true;
		}
	}
			
	end:
	return result;
}
		
OSStatus BackgroundTrackMgr::LoadTrack(const char* inFilePath, Boolean inAddToQueue, Boolean inLoadAtOnce) {
	BG_FileInfo *fileInfo = new BG_FileInfo;
	fileInfo->mFilePath = inFilePath;
	OSStatus result = LoadFileDataInfo(fileInfo->mFilePath.c_str(), fileInfo->mAFID, fileInfo->mFileFormat, fileInfo->mFileDataSize);
	AssertNoError("Error getting file data info", fail);
	fileInfo->mLoadAtOnce = inLoadAtOnce;
	fileInfo->mFileDataInQueue = false;
	// if not adding to the queue, clear the current file vector
	if (!inAddToQueue) {
		ClearFileInfo();
	}
			
	mBGFileInfo.push_back(fileInfo);
			
	// setup the queue if this is the first (or only) file
	if (mBGFileInfo.size() == 1) {
		result = SetupQueue(fileInfo);
		AssertNoError("Error setting up queue", fail);
		result = SetupBuffers(fileInfo);
		AssertNoError("Error setting up queue buffers", fail);					
	} else { // if this is just part of the playlist, close the file for now
		result = AudioFileClose(fileInfo->mAFID);
		AssertNoError("Error closing file", fail);
	}	
	return result;
			
	fail:
	if (fileInfo) {
		delete fileInfo;
	}
	return result;
}
		
OSStatus BackgroundTrackMgr::UpdateGain() {
	return SetVolume(mVolume);
}
		
OSStatus BackgroundTrackMgr::SetVolume(Float32 inVolume) {
	mVolume = inVolume;
	return AudioQueueSetParameter(mQueue, kAudioQueueParam_Volume, mVolume * gMasterVolumeGain);
}
		
Float32 BackgroundTrackMgr::GetVolume() const {
	return mVolume;
}
		
OSStatus BackgroundTrackMgr::Start() {
    if(gInterrupted) {
		printf("Start called, but interrupted so ignoring.\n");
        return noErr;
    }
			
	OSStatus result = AudioQueuePrime(mQueue, 1, NULL);	
	if (result)	{
		printf("Error priming queue: %d\n", (int)result);
		return result;
	}
	return AudioQueueStart(mQueue, NULL);
}
		
OSStatus BackgroundTrackMgr::Stop(Boolean inStopAtEnd) {
	if (inStopAtEnd) {
		mStopAtEnd = true;
		return noErr;
	} else {
		return AudioQueueStop(mQueue, true);
	}
}
		

#pragma mark ***** SoundEngineEffect *****
//==================================================================================================
//	SoundEngineEffect class
//==================================================================================================
class SoundEngineEffect
{
	public:	
		// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		SoundEngineEffect(const char* inLoopPath, const char* inAttackPath, const char* inDecayPath, Boolean inDoLoop) 
			:	mSourceID(0),
				mAttackBufferID(0),
				mLoopBufferID(0),
				mDecayBufferID(0),
				mLoopPath(inLoopPath),
				mAttackPath(inAttackPath),
				mDecayPath(inDecayPath),
				mLoopData(NULL),
				mAttackData(NULL),
				mDecayData(NULL),
				mLoopDataSize(0),
				mAttackDataSize(0),
				mDecayDataSize(0),
				mIsLoopingEffect(inDoLoop),
				mPlayThread(NULL),
				mPlayThreadState(kPlayThreadState_Loop) { alGenSources(1, &mSourceID); }
		
		~SoundEngineEffect()
		{
			alDeleteSources(1, &mSourceID);
			
			if (mLoopData)
				free(mLoopData);
			if (mAttackData)
				free(mAttackData);
			if (mDecayData)
				free(mDecayData);
		}
		
		// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		// Accessors
		// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		UInt32	GetEffectID() { return mSourceID; }
		UInt32	GetPlayThreadState() { return mPlayThreadState; }
		Boolean	HasAttackBuffer() { return mAttackBufferID != 0; }

		// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		// Helper Functions
		// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		ALenum GetALFormat(AudioStreamBasicDescription inFileFormat)
		{
			if (inFileFormat.mFormatID != kAudioFormatLinearPCM)
				return kSoundEngineErrInvalidFileFormat;
				
			if ((inFileFormat.mChannelsPerFrame > 2) || (inFileFormat.mChannelsPerFrame < 1))
				return kSoundEngineErrInvalidFileFormat;
			
			if(inFileFormat.mBitsPerChannel == 8)
				return (inFileFormat.mChannelsPerFrame == 1) ? AL_FORMAT_MONO8 : AL_FORMAT_STEREO8;
			else if(inFileFormat.mBitsPerChannel == 16)
				return (inFileFormat.mChannelsPerFrame == 1) ? AL_FORMAT_MONO16 : AL_FORMAT_STEREO16;

			return kSoundEngineErrInvalidFileFormat;
		}

		OSStatus LoadFileData(const char *inFilePath, void* &outData, UInt32 &outDataSize, ALuint &outBufferID)
		{
			AudioFileID theAFID = 0;
			OSStatus result = noErr;
			UInt64 theFileSize = 0;
			AudioStreamBasicDescription theFileFormat;
			
			result = LoadFileDataInfo(inFilePath, theAFID, theFileFormat, theFileSize);
			outDataSize = (UInt32)theFileSize;
				AssertNoError("Error loading file info", fail)

			outData = malloc(outDataSize);

			result = AudioFileReadBytes(theAFID, false, 0, &outDataSize, outData);
				AssertNoError("Error reading file data", fail)
				
			if (!TestAudioFormatNativeEndian(theFileFormat) && (theFileFormat.mBitsPerChannel > 8)) 
				return kSoundEngineErrInvalidFileFormat;
		
			alGenBuffers(1, &outBufferID);
				AssertNoOALError("Error generating buffer\n", fail);
			
			alBufferDataStaticProc(outBufferID, GetALFormat(theFileFormat), outData, outDataSize, (ALsizei)theFileFormat.mSampleRate);
				AssertNoOALError("Error attaching data to buffer\n", fail);

			AudioFileClose(theAFID);
			return result;
			
		fail:			
			if (theAFID)
				AudioFileClose(theAFID);
			if (outData)
			{
				free(outData);
				outData = NULL;
			}
			return result;
		}
		
		OSStatus AttachFilesToSource()
		{
			OSStatus result = AL_NO_ERROR;			
			// first check for the attack file. That will be first in the queue if present
			if (mAttackPath)
			{
				result = LoadFileData(mAttackPath, mAttackData, mAttackDataSize, mAttackBufferID);
					AssertNoError("Error loading attack file info", end)
			}
			
			result = LoadFileData(mLoopPath, mLoopData, mLoopDataSize, mLoopBufferID);
				AssertNoError("Error loading looping file info", end)
			
			// if one-shot effect, attach the buffer to the source now
			if (!mIsLoopingEffect)
			{
				alSourcei(mSourceID, AL_BUFFER, mLoopBufferID);
					AssertNoOALError("Error attaching file data to effect", end)
			}

			if (mDecayPath)
			{
				result = LoadFileData(mDecayPath, mDecayData, mDecayDataSize, mDecayBufferID);
					AssertNoError("Error loading decay file info", end)
			}
		end:
			return result;
		}
		
		OSStatus ClearSourceBuffers()
		{
			OSStatus result = AL_NO_ERROR;
			ALint numQueuedBuffers = 0;
			ALuint *bufferIDs = (ALuint*)malloc(numQueuedBuffers * sizeof(ALint));
			alGetSourcei(mSourceID, AL_BUFFERS_QUEUED, &numQueuedBuffers);
				AssertNoOALError("Error getting OpenAL queued buffer size", end)
				
			alSourceUnqueueBuffers(mSourceID, numQueuedBuffers, bufferIDs);
				AssertNoOALError("Error unqueueing buffers from source", end)
				
		end:
			free(bufferIDs);
			return result;
		}

		static void* PlaybackProc(void *args)
		{
			OSStatus result = AL_NO_ERROR;
			SoundEngineEffect *THIS = (SoundEngineEffect*)args;
												
			alSourcePlay(THIS->GetEffectID());
				AssertNoOALError("Error starting effect playback", end)
			
			// if attack buffer is present, wait until it has completed, then turn looping on
			if (THIS->HasAttackBuffer())
			{
				ALint numBuffersProcessed = 0;						
				while (numBuffersProcessed < 1)
				{
					alGetSourcei(THIS->GetEffectID(), AL_BUFFERS_PROCESSED, &numBuffersProcessed);
						AssertNoOALError("Error getting processed buffer number", end)
				}
				
				ALuint tmpBuffer = 0;
				alSourceUnqueueBuffers(THIS->GetEffectID(), 1, &tmpBuffer);
					AssertNoOALError("Error unqueueing buffers from source", end)
			}
				// now that we have processed the attack buffer, loop the main one
			THIS->SetLooping(true);

		end:	
			return NULL;
		}
				
		// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		// Effect management
		// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		OSStatus Start()
		{
			OSStatus result = AL_NO_ERROR;				
			alSourceStop(mSourceID);
				AssertNoOALError("Error stopping source", end)

			if (!mIsLoopingEffect)
			{
				// if we are just playing one-short effects, start playback here
				alSourcePlay(mSourceID);
				return alGetError();
			}
			// for loops we need to spawn a new thread					
			mPlayThread = new OpenALThread(PlaybackProc, (void*)this);
			// we want this to delete upon thread completion
			mPlayThreadState = kPlayThreadState_Loop;
			// clean up remnants from any previous playback of the source
			result = ClearSourceBuffers();
				AssertNoError("Error clearing buffers", end)
			
			// if the effect has an attack sample, queue this first
			if (HasAttackBuffer())
			{
				alSourceQueueBuffers(mSourceID, 1, &mAttackBufferID);
					AssertNoOALError("Error queueing buffers for attack", end)
				// turn on looping after the attack buffer has been processed
				SetLooping(false);
			}

			alSourceQueueBuffers(mSourceID, 1, &mLoopBufferID);
				AssertNoOALError("Error queueing looping buffer", end)
			mPlayThread->Start();
		end:			
			return result;
		}
		
		OSStatus StartDecay()
		{
			// turn off looping, and queue the decay buffer
			OSStatus result = AL_NO_ERROR;
			alSourcei(mSourceID, AL_LOOPING, 0);
				AssertNoOALError("Error turning off looping", end)
			alSourceQueueBuffers(mSourceID, 1, &mDecayBufferID);
				AssertNoOALError("Error queueing decay file", end)
		end:
			return result;
		}
		
		OSStatus Stop(Boolean inDoDecay)
		{
			OSStatus result = AL_NO_ERROR;
			// for non looped effects and loops with no decay sample
			if ((mDecayBufferID == 0) || !inDoDecay)
			{
				// if no decay to play, just stop the source
				alSourceStop(mSourceID);
					AssertNoOALError("Error stopping source", end)
			}
			else
				return StartDecay();
		end:
			return result;
		}

		OSStatus SetPitch(Float32 inValue)
		{
			alSourcef(mSourceID, AL_PITCH, inValue);
			return alGetError();
		}
				
		OSStatus SetLooping(Boolean inDoLoop)
		{
			ALint doLoop = inDoLoop ? 1 : 0;
			alSourcei(mSourceID, AL_LOOPING, doLoop);
			return alGetError();
		}
		
		OSStatus SetPosition(Float32 inX, Float32 inY, Float32 inZ)
		{
			alSource3f(mSourceID, AL_POSITION, inX, inY, inZ);
			return alGetError();
		}

		OSStatus SetMaxDistance(Float32 inValue)
		{
			alSourcef(mSourceID, AL_MAX_DISTANCE, inValue);
			return alGetError();
		}

		OSStatus SetReferenceDistance(Float32 inValue)
		{
			alSourcef(mSourceID, AL_REFERENCE_DISTANCE, inValue);
			return alGetError();
		}
		
		OSStatus SetLevel(Float32 inValue)
		{
			alSourcef(mSourceID, AL_GAIN, inValue * gMasterVolumeGain);
			return alGetError();
		}
		
		enum {
			kPlayThreadState_Loop	= 0,
			kPlayThreadState_Decay	= 1,
			kPlayThreadState_End	= 2
		};
		
	private:
		ALuint					mSourceID;
		ALuint					mAttackBufferID;
		ALuint					mLoopBufferID;
		ALuint					mDecayBufferID;		
		UInt32					mNumberBuffers;
		const char*				mLoopPath;
		const char*				mAttackPath;
		const char*				mDecayPath;
		void*					mLoopData;
		void*					mAttackData;
		void*					mDecayData;
		UInt32					mLoopDataSize;
		UInt32					mAttackDataSize;
		UInt32					mDecayDataSize;
		Boolean					mIsLoopingEffect;
		OpenALThread*			mPlayThread;
		UInt32					mPlayThreadState;
};

#pragma mark ***** SoundEngineEffectMap *****
//==================================================================================================
//	SoundEngineEffectMap class
//==================================================================================================
class SoundEngineEffectMap 
	: std::multimap<UInt32, SoundEngineEffect*, std::less<ALuint> > 
{
	public:
    // add a new context to the map
    void Add (const	ALuint	inEffectToken, SoundEngineEffect **inEffect)
	{
		iterator	it = upper_bound(inEffectToken);
		insert(it, value_type (inEffectToken, *inEffect));
	}

    SoundEngineEffect* Get(ALuint	inEffectToken) 
	{
        iterator	it = find(inEffectToken);
        if (it != end())
            return ((*it).second);
		return (NULL);
    }

    void Remove (const	ALuint	inSourceToken) {
        iterator 	it = find(inSourceToken);
        if (it != end())
            erase(it);
    }
	
    SoundEngineEffect* GetEffectByIndex(UInt32	inIndex) {
        iterator	it = begin();

		for (UInt32 i = 0; i < inIndex; i++) {
            if (it != end())
                ++it;
            else
                i = inIndex;
        }
        
        if (it != end())
            return ((*it).second);		
		return (NULL);
    }

	iterator GetIterator() { return begin(); }
	
    UInt32 Size () const { return size(); }
    bool Empty () const { return empty(); }
};

#pragma mark ***** OpenALObject *****
//==================================================================================================
//	OpenALObject class
//==================================================================================================
class OpenALObject
{	
	public:	
		OpenALObject(Float32 inMixerOutputRate)
			:	mOutputRate(inMixerOutputRate),
				mGain(1.0f),
				mContext(NULL),
				mDevice(NULL),
				mEffectsMap(NULL) 
		{
			mEffectsMap = new SoundEngineEffectMap();
		}
		
		~OpenALObject() { Teardown(); }

		OSStatus Initialize()
		{
			OSStatus result = noErr;
			mDevice = alcOpenDevice(NULL);
				AssertNoOALError("Error opening output device", end)
			if(mDevice == NULL) { return kSoundEngineErrDeviceNotFound; }
			
			// if a mixer output rate was specified, set it here
			// must be done before the alcCreateContext() call
			if (mOutputRate)
				alcMacOSXMixerOutputRateProc(mOutputRate);
			
			// Create an OpenAL Context
			mContext = alcCreateContext(mDevice, NULL);
				AssertNoOALError("Error creating OpenAL context", end)
			
			alcMakeContextCurrent(mContext);
				AssertNoOALError("Error setting current OpenAL context", end)
			 
		end:
			return result;
		}
		
		void Teardown()
		{
			if (mEffectsMap) 
			{
				for (UInt32  i = 0; i < mEffectsMap->Size(); i++)
				{
					SoundEngineEffect	*theEffect = mEffectsMap->GetEffectByIndex(0);
					if (theEffect)
					{
						mEffectsMap->Remove(theEffect->GetEffectID());
						delete theEffect;
					}
				}
				delete mEffectsMap;
			}
			
			if (mContext) alcDestroyContext(mContext);
			
			if (mDevice) alcCloseDevice(mDevice);
		}

		OSStatus SetListenerPosition(Float32 inX, Float32 inY, Float32 inZ)
		{
			alListener3f(AL_POSITION, inX, inY, inZ);
			return alGetError();
		}
	
		OSStatus SetListenerDirection(Float32 inX, Float32 inY, Float32 inZ)
		{
			alListener3f(AL_DIRECTION, inX, inY, inZ);
			return alGetError();
		}

		OSStatus SetListenerGain(Float32 inValue)
		{
			alListenerf(AL_GAIN, inValue);
			return alGetError();
		}
		
		OSStatus SetMaxDistance(Float32 inValue)
		{
			OSStatus result = 0;
			for (UInt32 i=0; i < mEffectsMap->Size(); i++)
			{
				SoundEngineEffect *theEffect = mEffectsMap->GetEffectByIndex(i);
				if ((result = theEffect->SetMaxDistance(inValue)) != AL_NO_ERROR)
					return result;
			}
			return result;			
		}

		OSStatus SetReferenceDistance(Float32 inValue)
		{
			OSStatus result = 0;
			for (UInt32 i=0; i < mEffectsMap->Size(); i++)
			{
				SoundEngineEffect *theEffect = mEffectsMap->GetEffectByIndex(i);
				if ((result = theEffect->SetReferenceDistance(inValue)) != AL_NO_ERROR)
					return result;
			}
			return result;	
		}
	
		OSStatus SetEffectReferenceDistance(UInt32 inEffectID, Float32 inValue)
		{
			SoundEngineEffect *theEffect = mEffectsMap->Get(inEffectID);
			return (theEffect) ?  theEffect->SetReferenceDistance(inValue) : kSoundEngineErrInvalidID;
		}

		OSStatus SetEffectsVolume(Float32 inValue)
		{
			OSStatus result = 0;
			for (UInt32 i=0; i < mEffectsMap->Size(); i++)
			{
				SoundEngineEffect *theEffect = mEffectsMap->GetEffectByIndex(i);
				if ((result = theEffect->SetLevel(inValue)) != AL_NO_ERROR)
					return result;
			}
			mGain = inValue;
			return result;	
		}
	
		Float32 GetEffectsVolume() const
		{
			return mGain;
		}

		OSStatus UpdateGain()
		{
			return SetEffectsVolume(mGain);
		}
						
		OSStatus LoadEffect(const char *inFilePath, UInt32 *outEffectID)
		{
			SoundEngineEffect *theEffect = new SoundEngineEffect(inFilePath, NULL, NULL, false);
			OSStatus result = theEffect->AttachFilesToSource();
			if (result == noErr)
			{
				*outEffectID = theEffect->GetEffectID();
				mEffectsMap->Add(*outEffectID, &theEffect);
			}
			return result;
		}

		OSStatus LoadLoopingEffect(const char *inLoopFilePath, const char *inAttackFilePath, const char *inDecayFilePath, UInt32 *outEffectID)
		{
			SoundEngineEffect *theEffect = new SoundEngineEffect(inLoopFilePath, inAttackFilePath, inDecayFilePath, true);
			OSStatus result = theEffect->AttachFilesToSource();
			if (result == noErr)
			{
				*outEffectID = theEffect->GetEffectID();
				mEffectsMap->Add(*outEffectID, &theEffect);
			}
			return result;
		}
				
		OSStatus UnloadEffect(UInt32 inEffectID)
		{
			SoundEngineEffect *theEffect = mEffectsMap->Get(inEffectID);
			if (theEffect)
			{
				mEffectsMap->Remove(inEffectID);
				delete theEffect;
			}
			return 0;
		}

		OSStatus StartEffect(UInt32 inEffectID)
		{
			SoundEngineEffect *theEffect = mEffectsMap->Get(inEffectID);
			return (theEffect) ? theEffect->Start() : kSoundEngineErrInvalidID;
		}
		
		OSStatus StopEffect(UInt32 inEffectID, Boolean inDoDecay)
		{
			SoundEngineEffect *theEffect = mEffectsMap->Get(inEffectID);
			return (theEffect) ? theEffect->Stop(inDoDecay) : kSoundEngineErrInvalidID;
		}
		
		OSStatus SetEffectPitch(UInt32 inEffectID, Float32 inValue)
		{
			SoundEngineEffect *theEffect = mEffectsMap->Get(inEffectID);
			return (theEffect) ? theEffect->SetPitch(inValue) : kSoundEngineErrInvalidID;			
		}

		OSStatus SetEffectVolume(UInt32 inEffectID, Float32 inValue)
		{
			SoundEngineEffect *theEffect = mEffectsMap->Get(inEffectID);
			return (theEffect) ?  theEffect->SetLevel(inValue * mGain) : kSoundEngineErrInvalidID;
		}
				
		OSStatus SetEffectPosition(UInt32 inEffectID, Float32 inX, Float32 inY, Float32 inZ)	
		{
			SoundEngineEffect *theEffect = mEffectsMap->Get(inEffectID);
			return (theEffect) ? theEffect->SetPosition(inX, inY, inZ) : kSoundEngineErrInvalidID;
		}
				
	private:
		Float32									mOutputRate;
		Float32									mGain;
		ALCcontext*								mContext;
		ALCdevice*								mDevice;
		SoundEngineEffectMap*					mEffectsMap;
};


#pragma mark ***** API *****
//==================================================================================================
//	Sound Engine
//==================================================================================================


extern "C"
void interruptionCallback(void* arg, UInt32 interruptionState)
{
	(void)arg;
	
    printf("Excuse this interruption...\n");
    switch(interruptionState)
    {
    case kAudioSessionBeginInterruption:
            printf("begin interruption\n");
            SoundEngine_Teardown();
        gInterrupted = true;
        break;
        
// SCD: TODO Revisit when building with 2.2 where this callback is actually supposed to be made...
//    case kAudioSessionEndInterruption:
//            printf("end interruption.\n");
//        gInterrupted = false;
//        break;
    }
}


#endif // WIN32

extern "C"
OSStatus SoundEngine_Reactivate()
{
#ifndef WIN32
    gInterrupted = false;
    return noErr;
#else
	return 0;
#endif
}


extern "C"
OSStatus  SoundEngine_Initialize(Float32 inMixerOutputRate)
{
#ifndef WIN32
    if(gInterrupted)
        return noErr;

	if( !isInitialized ) 
	{
 		AudioSessionInitialize( NULL, NULL, interruptionCallback, NULL );
//		UInt32 sessionCategory = kAudioSessionCategory_AmbientSound;
//		AudioSessionSetProperty( kAudioSessionProperty_AudioCategory, sizeof( sessionCategory ), &sessionCategory );
 		isInitialized = true;
 	}
	
	if (sOpenALObject)
		delete sOpenALObject;

	if (sBackgroundTrackMgr)
		delete sBackgroundTrackMgr;

	sOpenALObject = new OpenALObject(inMixerOutputRate);	
	sBackgroundTrackMgr = new BackgroundTrackMgr();
	
	return sOpenALObject->Initialize();
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_Teardown()
{
#ifndef WIN32
	if (sOpenALObject)
	{
		delete sOpenALObject;
		sOpenALObject = NULL;
	}
	
	if (sBackgroundTrackMgr)
	{
		delete sBackgroundTrackMgr;
		sBackgroundTrackMgr = NULL;	
	}
	
	return 0; 
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_SetMasterVolume(Float32 inValue)
{
#ifndef WIN32
	OSStatus result = noErr;
	gMasterVolumeGain = inValue;
	if (sBackgroundTrackMgr)
		result = sBackgroundTrackMgr->UpdateGain();
	
	if (result) return result;
		
	if (sOpenALObject) 
		return sOpenALObject->UpdateGain();
	
	return result;
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_SetListenerPosition(Float32 inX, Float32 inY, Float32 inZ)
{	
#ifndef WIN32
	return (sOpenALObject) ? sOpenALObject->SetListenerPosition(inX, inY, inZ) : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_SetListenerDirection(Float32 inX, Float32 inY, Float32 inZ)
{	
#ifndef WIN32
	return (sOpenALObject) ? sOpenALObject->SetListenerDirection(inX, inY, inZ) : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}


extern "C"
OSStatus  SoundEngine_SetListenerGain(Float32 inValue)
{
#ifndef WIN32
	return (sOpenALObject) ? sOpenALObject->SetListenerGain(inValue) : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_LoadBackgroundMusicTrack(const char* inPath, Boolean inAddToQueue, Boolean inLoadAtOnce)
{
#ifndef WIN32
    if(gInterrupted)
        return noErr;

	if (sBackgroundTrackMgr == NULL)
		sBackgroundTrackMgr = new BackgroundTrackMgr();
	return sBackgroundTrackMgr->LoadTrack(inPath, inAddToQueue, inLoadAtOnce);
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_UnloadBackgroundMusicTrack()
{
#ifndef WIN32
	if (sBackgroundTrackMgr)
	{
		delete sBackgroundTrackMgr;
		sBackgroundTrackMgr = NULL;
	}
		
	return 0;
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_StartBackgroundMusic()
{
#ifndef WIN32
	return (sBackgroundTrackMgr) ? sBackgroundTrackMgr->Start() : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_StopBackgroundMusic(Boolean stopAtEnd)
{
#ifndef WIN32
	return (sBackgroundTrackMgr) ?  sBackgroundTrackMgr->Stop(stopAtEnd) : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_SetBackgroundMusicVolume(Float32 inValue)
{
#ifndef WIN32
	return (sBackgroundTrackMgr) ? sBackgroundTrackMgr->SetVolume(inValue) : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}

extern "C"
Float32  SoundEngine_GetBackgroundMusicVolume()
{
#ifndef WIN32
	return (sBackgroundTrackMgr) ? sBackgroundTrackMgr->GetVolume() : 0.0f;
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_LoadEffect(const char* inPath, UInt32* outEffectID)
{
#ifndef WIN32
	OSStatus result = noErr;
	if (sOpenALObject == NULL)
	{
		sOpenALObject = new OpenALObject(0.0f);
		result = sOpenALObject->Initialize();
	}	
	return (result) ? result : sOpenALObject->LoadEffect(inPath, outEffectID);
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_LoadLoopingEffect(const char* inLoopFilePath, const char* inAttackFilePath, const char* inDecayFilePath, UInt32* outEffectID)
{
#ifndef WIN32
	OSStatus result = noErr;
	if (sOpenALObject == NULL)
	{
		sOpenALObject = new OpenALObject(0.0f);
		result = sOpenALObject->Initialize();
	}	
	return (result) ? result : sOpenALObject->LoadLoopingEffect(inLoopFilePath, inAttackFilePath, inDecayFilePath, outEffectID);
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_UnloadEffect(UInt32 inEffectID)
{
#ifndef WIN32
	return (sOpenALObject) ? sOpenALObject->UnloadEffect(inEffectID) : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}


extern "C"
OSStatus  SoundEngine_StartEffect(UInt32 inEffectID)
{
#ifndef WIN32
	return (sOpenALObject) ? sOpenALObject->StartEffect(inEffectID) : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_StopEffect(UInt32 inEffectID, Boolean inDoDecay)
{	
#ifndef WIN32
	return (sOpenALObject) ?  sOpenALObject->StopEffect(inEffectID, inDoDecay) : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}
		
extern "C"
OSStatus  SoundEngine_SetEffectPitch(UInt32 inEffectID, Float32 inValue)
{
#ifndef WIN32
	return (sOpenALObject) ? sOpenALObject->SetEffectPitch(inEffectID, inValue) : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_SetEffectLevel(UInt32 inEffectID, Float32 inValue)
{
#ifndef WIN32
	return (sOpenALObject) ? sOpenALObject->SetEffectVolume(inEffectID, inValue) : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_SetEffectPosition(UInt32 inEffectID, Float32 inX, Float32 inY, Float32 inZ)
{
#ifndef WIN32
	return (sOpenALObject) ? sOpenALObject->SetEffectPosition(inEffectID, inX, inY, inZ) : kSoundEngineErrUnitialized;	
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_SetEffectsVolume(Float32 inValue)
{
#ifndef WIN32
	return (sOpenALObject) ? sOpenALObject->SetEffectsVolume(inValue) : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}

extern "C" 
Float32  SoundEngine_GetEffectsVolume()
{
#ifndef WIN32
	return (sOpenALObject) ? sOpenALObject->GetEffectsVolume() : 0.0f;
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_SetMaxDistance(Float32 inValue)
{
#ifndef WIN32
	return (sOpenALObject) ? sOpenALObject->SetMaxDistance(inValue) : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}

extern "C"
OSStatus  SoundEngine_SetReferenceDistance(Float32 inValue)
{
#ifndef WIN32
	return (sOpenALObject) ? sOpenALObject->SetReferenceDistance(inValue) : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}

extern "C" 
OSStatus SoundEngine_SetEffectReferenceDistance(UInt32 inEffectID, Float32 inValue)
{
#ifndef WIN32
	return (sOpenALObject) ? sOpenALObject->SetEffectReferenceDistance(inEffectID, inValue) : kSoundEngineErrUnitialized;
#else
	return 0;
#endif
}

