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

//

// Copyright (c) 2002, 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.

//

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

//-----------------------------------------------------------------------------

//

//	class RleCompressor

//

//-----------------------------------------------------------------------------

#include "ImfRleCompressor.h"

#include "ImfCheckedArithmetic.h"

#include "ImfRle.h"

#include "Iex.h"

#include "ImfNamespace.h"

OPENEXR_IMF_INTERNAL_NAMESPACE_SOURCE_ENTER

RleCompressor::RleCompressor (const Header &hdr, size_t maxScanLineSize):

    Compressor (hdr),

    _maxScanLineSize (maxScanLineSize),

    _tmpBuffer (0),

    _outBuffer (0)

{

    _tmpBuffer = new char [maxScanLineSize];

    _outBuffer = new char [uiMult (maxScanLineSize, size_t (3)) / 2];

}

RleCompressor::~RleCompressor ()

{

    delete [] _tmpBuffer;

    delete [] _outBuffer;

}

int

RleCompressor::numScanLines () const

{

    //

    // This compressor compresses individual scan lines.

    //

    return 1;

}

int

RleCompressor::compress (const char *inPtr,

			 int inSize,

			 int minY,

			 const char *&outPtr)

{

    //

    // Special case �- empty input buffer

    //

    if (inSize == 0)

    {

	outPtr = _outBuffer;

	return 0;

    }

    //

    // Reorder the pixel data.

    //

    {

	char *t1 = _tmpBuffer;

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

	const char *stop = inPtr + inSize;

	while (true)

	{

	    if (inPtr < stop)

		*(t1++) = *(inPtr++);

	    else

		break;

	    if (inPtr < stop)

		*(t2++) = *(inPtr++);

	    else

		break;

	}

    }

    //

    // Predictor.

    //

    {

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

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

	int p = t[-1];

	while (t < stop)

	{

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

	    p = t[0];

	    t[0] = d;

	    ++t;

	}

    }

    //

    // Run-length encode the data.

    //

    outPtr = _outBuffer;

    return rleCompress (inSize, _tmpBuffer, (signed char *) _outBuffer);

}

int

RleCompressor::uncompress (const char *inPtr,

			   int inSize,

			   int minY,

			   const char *&outPtr)

{

    //

    // Special case �- empty input buffer

    //

    if (inSize == 0)

    {

	outPtr = _outBuffer;

	return 0;

    }

    //

    // Decode the run-length encoded data

    //

    int outSize;

    if (0 == (outSize = rleUncompress (inSize, _maxScanLineSize,

				       (const signed char *) inPtr,

				       _tmpBuffer)))

    {

	throw IEX_NAMESPACE::InputExc ("Data decoding (rle) 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 = _outBuffer;

	char *stop = s + outSize;

	while (true)

	{

	    if (s < stop)

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

	    else

		break;

	    if (s < stop)

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

	    else

		break;

	}

    }

    outPtr = _outBuffer;

    return outSize;

}

OPENEXR_IMF_INTERNAL_NAMESPACE_SOURCE_EXIT