/*

 Copyright (C) 2016 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 TPart of CoreAudio Utility Classes.

*/

#include "AUOutputBL.h"

#if !defined(__COREAUDIO_USE_FLAT_INCLUDES__)

    #include <AudioUnit/AUComponent.h>

#else

    #include <AUComponent.h>

#endif

/*

struct AudioBufferList

{

    UInt32      mNumberBuffers;

    AudioBuffer mBuffers[1];

};

struct AudioBuffer

{

    UInt32  mNumberChannels;    //  number of interleaved channels in the buffer

    UInt32  mDataByteSize;      //  the size of the buffer pointed to by mData

    void*   mData;              //  the pointer to the buffer

};

*/

AUOutputBL::AUOutputBL (const CAStreamBasicDescription &inDesc, UInt32 inDefaultNumFrames) 

        : mFormat (inDesc),

          mBufferMemory(NULL),

          mBufferList (NULL),

          mNumberBuffers (0), // keep this here, so can ensure integrity of ABL

          mBufferSize (0),

          mFrames(inDefaultNumFrames)

{

    mNumberBuffers = mFormat.IsInterleaved() ? 1 : mFormat.NumberChannels();

    mBufferList = reinterpret_cast<AudioBufferList*>(new Byte[offsetof(AudioBufferList, mBuffers) + (mNumberBuffers * sizeof(AudioBuffer))]);

}

AUOutputBL::~AUOutputBL()

{

    if (mBufferMemory)

        delete[] mBufferMemory;

    if (mBufferList)

        delete [] (Byte *)mBufferList;

}

void    AUOutputBL::Prepare (UInt32 inNumFrames, bool inWantNullBufferIfAllocated) 

{

    UInt32 channelsPerBuffer = mFormat.IsInterleaved() ? mFormat.NumberChannels() : 1;

    if (mBufferMemory == NULL || inWantNullBufferIfAllocated)

    {

        mBufferList->mNumberBuffers = mNumberBuffers;

        AudioBuffer *buf = &mBufferList->mBuffers[0];

        for (UInt32 i = 0; i < mNumberBuffers; ++i, ++buf) {

            buf->mNumberChannels = channelsPerBuffer;

            buf->mDataByteSize = mFormat.FramesToBytes (inNumFrames);

            buf->mData = NULL;

        }

    }

    else

    {

        UInt32 nBytes = mFormat.FramesToBytes (inNumFrames);

        if ((nBytes * mNumberBuffers) > AllocatedBytes())

            throw OSStatus(kAudioUnitErr_TooManyFramesToProcess);

        mBufferList->mNumberBuffers = mNumberBuffers;

        AudioBuffer *buf = &mBufferList->mBuffers[0];

        Byte* p = mBufferMemory;

        for (UInt32 i = 0; i < mNumberBuffers; ++i, ++buf) {

            buf->mNumberChannels = channelsPerBuffer;

            buf->mDataByteSize = nBytes;

            buf->mData = p;

            p += mBufferSize;

        }

    }

}

void    AUOutputBL::Allocate (UInt32 inNumFrames)

{

    if (inNumFrames) 

    {

        UInt32 nBytes = mFormat.FramesToBytes (inNumFrames);

        if (nBytes <= AllocatedBytes()) 

            return;

            // align successive buffers for Altivec and to take alternating

            // cache line hits by spacing them by odd multiples of 16

        if (mNumberBuffers > 1)

            nBytes = (nBytes + (0x10 - (nBytes & 0xF))) | 0x10;

        mBufferSize = nBytes;

        UInt32 memorySize = mBufferSize * mNumberBuffers;

        Byte *newMemory = new Byte[memorySize];

        memset(newMemory, 0, memorySize);   // make buffer "hot"

        Byte *oldMemory = mBufferMemory;

        mBufferMemory = newMemory;

        delete[] oldMemory;

        mFrames = inNumFrames;

    } 

    else 

    {

        if (mBufferMemory) {

            delete [] mBufferMemory;

            mBufferMemory = NULL;

        }

        mBufferSize = 0;

        mFrames = 0;

    }

}

//#if DEBUG

void            AUOutputBL::Print()

{

    printf ("AUOutputBL::Print\n");

    mFormat.Print();

    printf ("Num Buffers:%d, mFrames:%d, allocatedMemory:%c\n", (int)mBufferList->mNumberBuffers, (int)mFrames, (mBufferMemory != NULL ? 'T' : 'F'));

    AudioBuffer *buf = &mBufferList->mBuffers[0];

    for (UInt32 i = 0; i < mBufferList->mNumberBuffers; ++i, ++buf)

        printf ("\tBuffer:%d, Size:%d, Chans:%d, Buffer:%p\n", (int)i, (int)buf->mDataByteSize, (int)buf->mNumberChannels, buf->mData);

}

//#endif