/*
     File: AUBuffer.h
 Abstract: Part of CoreAudio Utility Classes
  Version: 1.1

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*/
#ifndef __AUBuffer_h__
#define __AUBuffer_h__

#include <TargetConditionals.h>
#if !defined(__COREAUDIO_USE_FLAT_INCLUDES__)
	#include <AudioUnit/AudioUnit.h>
#else
	#include <AudioUnit.h>
#endif

#include <string.h>
#include "CAStreamBasicDescription.h"
#include "CAAutoDisposer.h"
#include "CADebugMacros.h"

// make this usable outside the stricter context of AudiUnits
#ifndef COMPONENT_THROW
	#define COMPONENT_THROW(err) \
		do { DebugMessage(#err); throw static_cast<OSStatus>(err); } while (0)
#endif


	/*! @class AUBufferList */
class AUBufferList {
	enum EPtrState {
		kPtrsInvalid,
		kPtrsToMyMemory,
		kPtrsToExternalMemory
	};
public:
	/*! @ctor AUBufferList */
	AUBufferList() : mPtrState(kPtrsInvalid), mExternalMemory(false), mPtrs(NULL), mMemory(NULL),
		mAllocatedStreams(0), mAllocatedFrames(0), mAllocatedBytes(0) { }
	/*! @dtor ~AUBufferList */
	~AUBufferList();

	/*! @method PrepareBuffer */
	AudioBufferList &	PrepareBuffer(const CAStreamBasicDescription &format, UInt32 nFrames);
	/*! @method PrepareNullBuffer */
	AudioBufferList &	PrepareNullBuffer(const CAStreamBasicDescription &format, UInt32 nFrames);

	/*! @method SetBufferList */
	AudioBufferList &	SetBufferList(const AudioBufferList &abl) {
							if (mAllocatedStreams < abl.mNumberBuffers)
								COMPONENT_THROW(-1);
							mPtrState = kPtrsToExternalMemory;
							memcpy(mPtrs, &abl, (char *)&abl.mBuffers[abl.mNumberBuffers] - (char *)&abl);
							return *mPtrs;
						}

	/*! @method SetBuffer */
	void				SetBuffer(UInt32 index, const AudioBuffer &ab) {
							if (mPtrState == kPtrsInvalid || index >= mPtrs->mNumberBuffers)
								COMPONENT_THROW(-1);
							mPtrState = kPtrsToExternalMemory;
							mPtrs->mBuffers[index] = ab;
						}

	/*! @method InvalidateBufferList */
	void				InvalidateBufferList() { mPtrState = kPtrsInvalid; }

	/*! @method GetBufferList */
	AudioBufferList &	GetBufferList() const {
							if (mPtrState == kPtrsInvalid)
								COMPONENT_THROW(-1);
							return *mPtrs;
						}

	/*! @method CopyBufferListTo */
	void				CopyBufferListTo(AudioBufferList &abl) const {
							if (mPtrState == kPtrsInvalid)
								COMPONENT_THROW(-1);
							memcpy(&abl, mPtrs, (char *)&abl.mBuffers[abl.mNumberBuffers] - (char *)&abl);
						}

	/*! @method CopyBufferContentsTo */
	void				CopyBufferContentsTo(AudioBufferList &abl) const {
							if (mPtrState == kPtrsInvalid)
								COMPONENT_THROW(-1);
							const AudioBuffer *srcbuf = mPtrs->mBuffers;
							AudioBuffer *destbuf = abl.mBuffers;

							for (UInt32 i = 0; i < abl.mNumberBuffers; ++i, ++srcbuf, ++destbuf) {
								if (i >= mPtrs->mNumberBuffers) // duplicate last source to additional outputs [4341137]
									--srcbuf;
								if (destbuf->mData != srcbuf->mData)
									memmove(destbuf->mData, srcbuf->mData, srcbuf->mDataByteSize);
								destbuf->mDataByteSize = srcbuf->mDataByteSize;
							}
						}

	/*! @method Allocate */
	void				Allocate(const CAStreamBasicDescription &format, UInt32 nFrames);
	/*! @method Deallocate */
	void				Deallocate();

	/*! @method UseExternalBuffer */
	void				UseExternalBuffer(const CAStreamBasicDescription &format, const AudioUnitExternalBuffer &buf);

	// AudioBufferList utilities
	/*! @method ZeroBuffer */
	static void			ZeroBuffer(AudioBufferList &abl) {
							AudioBuffer *buf = abl.mBuffers;
							for (UInt32 i = abl.mNumberBuffers ; i--; ++buf)
								memset(buf->mData, 0, buf->mDataByteSize);
						}
#if DEBUG
	/*! @method PrintBuffer */
	static void			PrintBuffer(const char *label, int subscript, const AudioBufferList &abl, UInt32 nFrames = 8, bool asFloats = true);
#endif

	/*! @method GetAllocatedFrames */
	UInt32				GetAllocatedFrames() const { return mAllocatedFrames; }

private:
	/*! @ctor AUBufferList */
	AUBufferList(AUBufferList &) { }	// prohibit copy constructor

	/*! @var mPtrState */
	EPtrState					mPtrState;
	/*! @var mExternalMemory */
	bool						mExternalMemory;
	/*! @var mPtrs */
	AudioBufferList *			mPtrs;
	/*! @var mMemory */
	Byte *						mMemory;
	/*! @var mAllocatedStreams */
	UInt32						mAllocatedStreams;
	/*! @var mAllocatedFrames */
	UInt32						mAllocatedFrames;
	/*! @var mAllocatedBytes */
	UInt32						mAllocatedBytes;
};


// Allocates an array of samples (type T), to be optimally aligned for the processor
	/*! @class TAUBuffer */
template <class T>
class TAUBuffer {
public:
	enum {
		kAlignInterval = 0x10,
		kAlignMask = kAlignInterval - 1
	};

	/*! @ctor TAUBuffer.0 */
	TAUBuffer() :	mMemObject(NULL), mAlignedBuffer(NULL), mBufferSizeBytes(0)
	{
	}

	/*! @ctor TAUBuffer.1 */
	TAUBuffer(UInt32 numElems, UInt32 numChannels) :	mMemObject(NULL), mAlignedBuffer(NULL),
														mBufferSizeBytes(0)
	{
		Allocate(numElems, numChannels);
	}

	/*! @dtor ~TAUBuffer */
	~TAUBuffer()
	{
		Deallocate();
	}

	/*! @method Allocate */
	void	Allocate(UInt32 numElems)			// can also re-allocate
	{
		UInt32 reqSize = numElems * sizeof(T);

		if (mMemObject != NULL && reqSize == mBufferSizeBytes)
			return;	// already allocated

		mBufferSizeBytes = reqSize;
		mMemObject = CA_realloc(mMemObject, reqSize);
		UInt32 misalign = (uintptr_t)mMemObject & kAlignMask;
		if (misalign) {
			mMemObject = CA_realloc(mMemObject, reqSize + kAlignMask);
			mAlignedBuffer = (T *)((char *)mMemObject + kAlignInterval - misalign);
		} else
			mAlignedBuffer = (T *)mMemObject;
	}

	/*! @method Deallocate */
	void	Deallocate()
	{
		if (mMemObject == NULL) return;			// so this method has no effect if we're using
												// an external buffer

		free(mMemObject);
		mMemObject = NULL;
		mAlignedBuffer = NULL;
		mBufferSizeBytes = 0;
	}

	/*! @method AllocateClear */
	void	AllocateClear(UInt32 numElems)		// can also re-allocate
	{
		Allocate(numElems);
		Clear();
	}

	/*! @method Clear */
	void	Clear()
	{
		memset(mAlignedBuffer, 0, mBufferSizeBytes);
	}

	// accessors

	/*! @method operator T *()@ */
	operator T *()				{ return mAlignedBuffer; }

private:
	/*! @var mMemObject */
	void *		mMemObject;			// null when using an external buffer
	/*! @var mAlignedBuffer */
	T *			mAlignedBuffer;		// always valid once allocated
	/*! @var mBufferSizeBytes */
	UInt32		mBufferSizeBytes;
};

#endif // __AUBuffer_h__
