DOOM-iOS/code/iphone/SoundEngine.cpp

/*

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

Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple Inc.
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use, installation, modification or redistribution of this Apple software
constitutes acceptance of these terms.  If you do not agree with these terms,
please do not use, install, modify or redistribute this Apple software.

In consideration of your agreement to abide by the following terms, and subject
to these terms, Apple grants you a personal, non-exclusive license, under
Apple's copyrights in this original Apple software (the "Apple Software"), to
use, reproduce, modify and redistribute the Apple Software, with or without
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the Apple Software in its entirety and without modifications, you must retain
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of the Apple Software.
Neither the name, trademarks, service marks or logos of Apple Inc. may be used
to endorse or promote products derived from the Apple Software without specific
prior written permission from Apple.  Except as expressly stated in this notice,
no other rights or licenses, express or implied, are granted by Apple herein,
including but not limited to any patent rights that may be infringed by your
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incorporated.

The Apple Software is provided by Apple on an "AS IS" basis.  APPLE MAKES NO
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN
COMBINATION WITH YOUR PRODUCTS.

IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR
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APPLE HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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);
	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
	OSStatus 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);
	// 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);
	bool 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"
static void interruptionCallback(void* arg, UInt32 interruptionState)
{
    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
}