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

//

// 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

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

#ifndef INCLUDED_IMF_LUT_H

#define INCLUDED_IMF_LUT_H

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

//

//	Lookup tables for efficient application

//	of half --> half functions to pixel data,

//	and some commonly applied functions.

//

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

#include "ImfRgbaFile.h"

#include "ImfFrameBuffer.h"

#include "ImathBox.h"

#include "halfFunction.h"

#include "ImfNamespace.h"

#include "ImfExport.h"

OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_ENTER

//

// Lookup table for individual half channels.

//

class IMF_EXPORT HalfLut

{

  public:

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

    // Constructor

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

    template <class Function>

    HalfLut (Function f);

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

    // Apply the table to data[0], data[stride] ... data[(nData-1) * stride]

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

    void apply (half *data,

		int nData,

		int stride = 1) const;

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

    // Apply the table to a frame buffer slice (see ImfFrameBuffer.h)

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

    void apply (const Slice &data,

		const IMATH_NAMESPACE::Box2i &dataWindow) const;

  private:

    halfFunction <half>	_lut;

};

//

// Lookup table for combined RGBA data.

//

class IMF_EXPORT RgbaLut

{

  public:

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

    // Constructor

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

    template <class Function>

    RgbaLut (Function f, RgbaChannels chn = WRITE_RGB);

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

    // Apply the table to data[0], data[stride] ... data[(nData-1) * stride]

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

    void apply (Rgba *data,

		int nData,

		int stride = 1) const;

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

    // Apply the table to a frame buffer (see RgbaOutpuFile.setFrameBuffer())

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

    void apply (Rgba *base,

		int xStride,

		int yStride,

		const IMATH_NAMESPACE::Box2i &dataWindow) const;

  private:

    halfFunction <half>	_lut;

    RgbaChannels	_chn;

};

//

// 12bit log rounding reduces data to 20 stops with 200 steps per stop.

// That makes 4000 numbers.  An extra 96 just come along for the ride.

// Zero explicitly remains zero.  The first non-zero half will map to 1

// in the 0-4095 12log space.  A nice power of two number is placed at

// the center [2000] and that number is near 0.18.

//

IMF_EXPORT 

half round12log (half x);

//

// Round to n-bit precision (n should be between 0 and 10).

// After rounding, the significand's 10-n least significant

// bits will be zero.

//

struct roundNBit

{

    roundNBit (int n): n(n) {}

    half operator () (half x) {return x.round(n);}

    int n;

};

//

// Template definitions

//

template <class Function>

HalfLut::HalfLut (Function f):

    _lut(f, -HALF_MAX, HALF_MAX, half (0),

	 half::posInf(), half::negInf(), half::qNan())

{

    // empty

}

template <class Function>

RgbaLut::RgbaLut (Function f, RgbaChannels chn):

    _lut(f, -HALF_MAX, HALF_MAX, half (0),

	 half::posInf(), half::negInf(), half::qNan()),

    _chn(chn)

{

    // empty

}

OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_EXIT

#endif