///////////////////////////////////////////////////////////////////////////

//

// Copyright (c) 2004, Industrial Light & Magic, a division of Lucas

// Digital Ltd. LLC

// 

// All rights reserved.

// 

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are

// met:

// *       Redistributions of source code must retain the above copyright

// notice, this list of conditions and the following disclaimer.

// *       Redistributions in binary form must reproduce the above

// copyright notice, this list of conditions and the following disclaimer

// in the documentation and/or other materials provided with the

// distribution.

// *       Neither the name of Industrial Light & Magic nor the names of

// its contributors may be used to endorse or promote products derived

// from this software without specific prior written permission. 

// 

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

//

///////////////////////////////////////////////////////////////////////////

#include "ImfZip.h"

#include "ImfCheckedArithmetic.h"

#include "ImfNamespace.h"

#include "Iex.h"

#include <math.h>

#include <zlib.h>

OPENEXR_IMF_INTERNAL_NAMESPACE_SOURCE_ENTER

Imf::Zip::Zip(size_t maxRawSize):

    _maxRawSize(maxRawSize),

    _tmpBuffer(0)

{

    _tmpBuffer = new char[_maxRawSize];

}

Imf::Zip::Zip(size_t maxScanLineSize, size_t numScanLines):

    _maxRawSize(0),

    _tmpBuffer(0)

{

    _maxRawSize = uiMult (maxScanLineSize, numScanLines);

    _tmpBuffer  = new char[_maxRawSize];

}

Imf::Zip::~Zip()

{

    if (_tmpBuffer) delete[] _tmpBuffer;

}

size_t

Imf::Zip::maxRawSize()

{

    return _maxRawSize;

}

size_t

Imf::Zip::maxCompressedSize()

{

    return uiAdd (uiAdd (_maxRawSize,

               size_t (ceil (_maxRawSize * 0.01))),

                  size_t (100));

}

int

Imf::Zip::compress(const char *raw, int rawSize, char *compressed)

{

    //

    // Reorder the pixel data.

    //

    {

        char *t1 = _tmpBuffer;

        char *t2 = _tmpBuffer + (rawSize + 1) / 2;

        const char *stop = raw + rawSize;

        while (true)

        {

            if (raw < stop)

            *(t1++) = *(raw++);

            else

            break;

            if (raw < stop)

            *(t2++) = *(raw++);

            else

            break;

        }

    }

    //

    // Predictor.

    //

    {

        unsigned char *t    = (unsigned char *) _tmpBuffer + 1;

        unsigned char *stop = (unsigned char *) _tmpBuffer + rawSize;

        int p = t[-1];

        while (t < stop)

        {

            int d = int (t[0]) - p + (128 + 256);

            p = t[0];

            t[0] = d;

            ++t;

        }

    }

    //

    // Compress the data using zlib

    //

    uLongf outSize = int(ceil(rawSize * 1.01)) + 100;

    if (Z_OK != ::compress ((Bytef *)compressed, &outSize,

                (const Bytef *) _tmpBuffer, rawSize))

    {

        throw Iex::BaseExc ("Data compression (zlib) failed.");

    }

    return outSize;

}

int

Imf::Zip::uncompress(const char *compressed, int compressedSize,

                                            char *raw)

{

    //

    // Decompress the data using zlib

    //

    uLongf outSize = _maxRawSize;

    if (Z_OK != ::uncompress ((Bytef *)_tmpBuffer, &outSize,

                     (const Bytef *) compressed, compressedSize))

    {

        throw Iex::InputExc ("Data decompression (zlib) failed.");

    }

    //

    // Predictor.

    //

    {

        unsigned char *t    = (unsigned char *) _tmpBuffer + 1;

        unsigned char *stop = (unsigned char *) _tmpBuffer + outSize;

        while (t < stop)

        {

            int d = int (t[-1]) + int (t[0]) - 128;

            t[0] = d;

            ++t;

        }

    }

    //

    // Reorder the pixel data.

    //

    {

        const char *t1 = _tmpBuffer;

        const char *t2 = _tmpBuffer + (outSize + 1) / 2;

        char *s = raw;

        char *stop = s + outSize;

        while (true)

        {

            if (s < stop)

            *(s++) = *(t1++);

            else

            break;

            if (s < stop)

            *(s++) = *(t2++);

            else

            break;

        }

    }

    return outSize;

}

OPENEXR_IMF_INTERNAL_NAMESPACE_SOURCE_EXIT