dng_1d_table.cpp

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/*****************************************************************************/
// Copyright 2006-2008 Adobe Systems Incorporated
// All Rights Reserved.
//
// NOTICE:  Adobe permits you to use, modify, and distribute this file in
// accordance with the terms of the Adobe license agreement accompanying it.
/*****************************************************************************/

/* $Id: //mondo/dng_sdk_1_3/dng_sdk/source/dng_1d_table.cpp#1 $ */
/* $DateTime: 2009/06/22 05:04:49 $ */
/* $Change: 578634 $ */
/* $Author: tknoll $ */

/*****************************************************************************/

#include "dng_1d_table.h"

#include "dng_1d_function.h"
#include "dng_memory.h"
#include "dng_utils.h"

/*****************************************************************************/

dng_1d_table::dng_1d_table ()

    :   fBuffer ()
    ,   fTable  (NULL)

    {

    }

/*****************************************************************************/

dng_1d_table::~dng_1d_table ()
    {

    }

/*****************************************************************************/

void dng_1d_table::SubDivide (const dng_1d_function &function,
                              uint32 lower,
                              uint32 upper,
                              real32 maxDelta)
    {

    uint32 range = upper - lower;

    bool subDivide = (range > (kTableSize >> 8));

    if (!subDivide)
        {

        real32 delta = Abs_real32 (fTable [upper] -
                                   fTable [lower]);

        if (delta > maxDelta)
            {

            subDivide = true;

            }

        }

    if (subDivide)
        {

        uint32 middle = (lower + upper) >> 1;

        fTable [middle] = (real32) function.Evaluate (middle * (1.0 / (real64) kTableSize));

        if (range > 2)
            {

            SubDivide (function, lower, middle, maxDelta);

            SubDivide (function, middle, upper, maxDelta);

            }

        }

    else
        {

        real64 y0 = fTable [lower];
        real64 y1 = fTable [upper];

        real64 delta = (y1 - y0) / (real64) range;

        for (uint32 j = lower + 1; j < upper; j++)
            {

            y0 += delta;

            fTable [j] = (real32) y0;

            }

        }

    }

/*****************************************************************************/

void dng_1d_table::Initialize (dng_memory_allocator &allocator,
                               const dng_1d_function &function,
                               bool subSample)
    {

    fBuffer.Reset (allocator.Allocate ((kTableSize + 2) * sizeof (real32)));

    fTable = fBuffer->Buffer_real32 ();

    if (subSample)
        {

        fTable [0         ] = (real32) function.Evaluate (0.0);
        fTable [kTableSize] = (real32) function.Evaluate (1.0);

        real32 maxDelta = Max_real32 (Abs_real32 (fTable [kTableSize] -
                                                  fTable [0         ]), 1.0f) *
                          (1.0f / 256.0f);

        SubDivide (function,
                   0,
                   kTableSize,
                   maxDelta);

        }

    else
        {

        for (uint32 j = 0; j <= kTableSize; j++)
            {

            real64 x = j * (1.0 / (real64) kTableSize);

            real64 y = function.Evaluate (x);

            fTable [j] = (real32) y;

            }

        }

    fTable [kTableSize + 1] = fTable [kTableSize];

    }

/*****************************************************************************/

void dng_1d_table::Expand16 (uint16 *table16) const
    {

    real64 step = (real64) kTableSize / 65535.0;

    real64 y0 = fTable [0];
    real64 y1 = fTable [1];

    real64 base  = y0 * 65535.0 + 0.5;
    real64 slope = (y1 - y0) * 65535.0;

    uint32 index = 1;
    real64 fract = 0.0;

    for (uint32 j = 0; j < 0x10000; j++)
        {

        table16 [j] = (uint16) (base + slope * fract);

        fract += step;

        if (fract > 1.0)
            {

            index += 1;
            fract -= 1.0;

            y0 = y1;
            y1 = fTable [index];

            base  = y0 * 65535.0 + 0.5;
            slope = (y1 - y0) * 65535.0;

            }

        }

    }

/*****************************************************************************/