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

//

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

// Entertainment Company Ltd.  Portions contributed and copyright held by

// others as indicated.  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.

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

//       any other contributors to this software may be used to endorse or

//       promote products derived from this software without specific prior

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

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

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

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

//

//	Conversion between RGBA and YCA data.

//

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

#include <ImfRgbaYca.h>

#include <assert.h>

#include <algorithm>

using namespace IMATH_NAMESPACE;

using namespace std;

#include "ImfNamespace.h"

OPENEXR_IMF_INTERNAL_NAMESPACE_SOURCE_ENTER

namespace RgbaYca {

V3f

computeYw (const Chromaticities &cr)

{

    M44f m = RGBtoXYZ (cr, 1);

    return V3f (m[0][1], m[1][1], m[2][1]) / (m[0][1] + m[1][1] + m[2][1]);

}

void

RGBAtoYCA (const V3f &yw,

	   int n,

	   bool aIsValid,

	   const Rgba rgbaIn[/*n*/],

	   Rgba ycaOut[/*n*/])

{

    for (int i = 0; i < n; ++i)

    {

	Rgba in = rgbaIn[i];

	Rgba &out = ycaOut[i];

	//

	// Conversion to YCA and subsequent chroma subsampling

	// work only if R, G and B are finite and non-negative.

	//

	if (!in.r.isFinite() || in.r < 0)

	    in.r = 0;

	if (!in.g.isFinite() || in.g < 0)

	    in.g = 0;

	if (!in.b.isFinite() || in.b < 0)

	    in.b = 0;

	if (in.r == in.g && in.g == in.b)

	{

	    //

	    // Special case -- R, G and B are equal. To avoid rounding

	    // errors, we explicitly set the output luminance channel

	    // to G, and the chroma channels to 0.

	    //

	    // The special cases here and in YCAtoRGBA() ensure that

	    // converting black-and white images from RGBA to YCA and

	    // back is lossless.

	    //

	    out.r = 0;

	    out.g = in.g;

	    out.b = 0;

	}

	else

	{

	    out.g = in.r * yw.x + in.g * yw.y + in.b * yw.z;

	    float Y = out.g;

	    if (abs (in.r - Y) < HALF_MAX * Y)

		out.r = (in.r - Y) / Y;

	    else

		out.r = 0;

	    if (abs (in.b - Y) < HALF_MAX * Y)

		out.b = (in.b - Y) / Y;

	    else

		out.b = 0;

	}

	if (aIsValid)

	    out.a = in.a;

	else

	    out.a = 1;

    }

}

void

decimateChromaHoriz (int n,

		     const Rgba ycaIn[/*n+N-1*/],

		     Rgba ycaOut[/*n*/])

{

    #ifdef DEBUG

	assert (ycaIn != ycaOut);

    #endif

    int begin = N2;

    int end = begin + n;

    for (int i = begin, j = 0; i < end; ++i, ++j)

    {

	if ((j & 1) == 0)

	{

	    ycaOut[j].r = ycaIn[i - 13].r *  0.001064f +

			  ycaIn[i - 11].r * -0.003771f +

			  ycaIn[i -  9].r *  0.009801f +

			  ycaIn[i -  7].r * -0.021586f +

			  ycaIn[i -  5].r *  0.043978f +

			  ycaIn[i -  3].r * -0.093067f +

			  ycaIn[i -  1].r *  0.313659f +

			  ycaIn[i     ].r *  0.499846f +

			  ycaIn[i +  1].r *  0.313659f +

			  ycaIn[i +  3].r * -0.093067f +

			  ycaIn[i +  5].r *  0.043978f +

			  ycaIn[i +  7].r * -0.021586f +

			  ycaIn[i +  9].r *  0.009801f +

			  ycaIn[i + 11].r * -0.003771f +

			  ycaIn[i + 13].r *  0.001064f;

	    ycaOut[j].b = ycaIn[i - 13].b *  0.001064f +

			  ycaIn[i - 11].b * -0.003771f +

			  ycaIn[i -  9].b *  0.009801f +

			  ycaIn[i -  7].b * -0.021586f +

			  ycaIn[i -  5].b *  0.043978f +

			  ycaIn[i -  3].b * -0.093067f +

			  ycaIn[i -  1].b *  0.313659f +

			  ycaIn[i     ].b *  0.499846f +

			  ycaIn[i +  1].b *  0.313659f +

			  ycaIn[i +  3].b * -0.093067f +

			  ycaIn[i +  5].b *  0.043978f +

			  ycaIn[i +  7].b * -0.021586f +

			  ycaIn[i +  9].b *  0.009801f +

			  ycaIn[i + 11].b * -0.003771f +

			  ycaIn[i + 13].b *  0.001064f;

	}

	ycaOut[j].g = ycaIn[i].g;

	ycaOut[j].a = ycaIn[i].a;

    }

}

void

decimateChromaVert (int n,

		    const Rgba * const ycaIn[N],

		    Rgba ycaOut[/*n*/])

{

    for (int i = 0; i < n; ++i)

    {

	if ((i & 1) == 0)

	{

	    ycaOut[i].r = ycaIn[ 0][i].r *  0.001064f +

			  ycaIn[ 2][i].r * -0.003771f +

			  ycaIn[ 4][i].r *  0.009801f +

			  ycaIn[ 6][i].r * -0.021586f +

			  ycaIn[ 8][i].r *  0.043978f +

			  ycaIn[10][i].r * -0.093067f +

			  ycaIn[12][i].r *  0.313659f +

			  ycaIn[13][i].r *  0.499846f +

			  ycaIn[14][i].r *  0.313659f +

			  ycaIn[16][i].r * -0.093067f +

			  ycaIn[18][i].r *  0.043978f +

			  ycaIn[20][i].r * -0.021586f +

			  ycaIn[22][i].r *  0.009801f +

			  ycaIn[24][i].r * -0.003771f +

			  ycaIn[26][i].r *  0.001064f;

	    ycaOut[i].b = ycaIn[ 0][i].b *  0.001064f +

			  ycaIn[ 2][i].b * -0.003771f +

			  ycaIn[ 4][i].b *  0.009801f +

			  ycaIn[ 6][i].b * -0.021586f +

			  ycaIn[ 8][i].b *  0.043978f +

			  ycaIn[10][i].b * -0.093067f +

			  ycaIn[12][i].b *  0.313659f +

			  ycaIn[13][i].b *  0.499846f +

			  ycaIn[14][i].b *  0.313659f +

			  ycaIn[16][i].b * -0.093067f +

			  ycaIn[18][i].b *  0.043978f +

			  ycaIn[20][i].b * -0.021586f +

			  ycaIn[22][i].b *  0.009801f +

			  ycaIn[24][i].b * -0.003771f +

			  ycaIn[26][i].b *  0.001064f;

	}

	ycaOut[i].g = ycaIn[13][i].g;

	ycaOut[i].a = ycaIn[13][i].a;

    }

}

void

roundYCA (int n,

	  unsigned int roundY,

	  unsigned int roundC,

	  const Rgba ycaIn[/*n*/],

	  Rgba ycaOut[/*n*/])

{

    for (int i = 0; i < n; ++i)

    {

	ycaOut[i].g = ycaIn[i].g.round (roundY);

	ycaOut[i].a = ycaIn[i].a;

	if ((i & 1) == 0)

	{

	    ycaOut[i].r = ycaIn[i].r.round (roundC);

	    ycaOut[i].b = ycaIn[i].b.round (roundC);

	}

    }

}

void

reconstructChromaHoriz (int n,

			const Rgba ycaIn[/*n+N-1*/],

			Rgba ycaOut[/*n*/])

{

    #ifdef DEBUG

	assert (ycaIn != ycaOut);

    #endif

    int begin = N2;

    int end = begin + n;

    for (int i = begin, j = 0; i < end; ++i, ++j)

    {

	if (j & 1)

	{

	    ycaOut[j].r = ycaIn[i - 13].r *  0.002128f +

			  ycaIn[i - 11].r * -0.007540f +

			  ycaIn[i -  9].r *  0.019597f +

			  ycaIn[i -  7].r * -0.043159f +

			  ycaIn[i -  5].r *  0.087929f +

			  ycaIn[i -  3].r * -0.186077f +

			  ycaIn[i -  1].r *  0.627123f +

			  ycaIn[i +  1].r *  0.627123f +

			  ycaIn[i +  3].r * -0.186077f +

			  ycaIn[i +  5].r *  0.087929f +

			  ycaIn[i +  7].r * -0.043159f +

			  ycaIn[i +  9].r *  0.019597f +

			  ycaIn[i + 11].r * -0.007540f +

			  ycaIn[i + 13].r *  0.002128f;

	    ycaOut[j].b = ycaIn[i - 13].b *  0.002128f +

			  ycaIn[i - 11].b * -0.007540f +

			  ycaIn[i -  9].b *  0.019597f +

			  ycaIn[i -  7].b * -0.043159f +

			  ycaIn[i -  5].b *  0.087929f +

			  ycaIn[i -  3].b * -0.186077f +

			  ycaIn[i -  1].b *  0.627123f +

			  ycaIn[i +  1].b *  0.627123f +

			  ycaIn[i +  3].b * -0.186077f +

			  ycaIn[i +  5].b *  0.087929f +

			  ycaIn[i +  7].b * -0.043159f +

			  ycaIn[i +  9].b *  0.019597f +

			  ycaIn[i + 11].b * -0.007540f +

			  ycaIn[i + 13].b *  0.002128f;

	}

	else

	{

	    ycaOut[j].r = ycaIn[i].r;

	    ycaOut[j].b = ycaIn[i].b;

	}

	ycaOut[j].g = ycaIn[i].g;

	ycaOut[j].a = ycaIn[i].a;

    }

}

void

reconstructChromaVert (int n,

		       const Rgba * const ycaIn[N],

		       Rgba ycaOut[/*n*/])

{

    for (int i = 0; i < n; ++i)

    {

	ycaOut[i].r = ycaIn[ 0][i].r *  0.002128f +

		      ycaIn[ 2][i].r * -0.007540f +

		      ycaIn[ 4][i].r *  0.019597f +

		      ycaIn[ 6][i].r * -0.043159f +

		      ycaIn[ 8][i].r *  0.087929f +

		      ycaIn[10][i].r * -0.186077f +

		      ycaIn[12][i].r *  0.627123f +

		      ycaIn[14][i].r *  0.627123f +

		      ycaIn[16][i].r * -0.186077f +

		      ycaIn[18][i].r *  0.087929f +

		      ycaIn[20][i].r * -0.043159f +

		      ycaIn[22][i].r *  0.019597f +

		      ycaIn[24][i].r * -0.007540f +

		      ycaIn[26][i].r *  0.002128f;

	ycaOut[i].b = ycaIn[ 0][i].b *  0.002128f +

		      ycaIn[ 2][i].b * -0.007540f +

		      ycaIn[ 4][i].b *  0.019597f +

		      ycaIn[ 6][i].b * -0.043159f +

		      ycaIn[ 8][i].b *  0.087929f +

		      ycaIn[10][i].b * -0.186077f +

		      ycaIn[12][i].b *  0.627123f +

		      ycaIn[14][i].b *  0.627123f +

		      ycaIn[16][i].b * -0.186077f +

		      ycaIn[18][i].b *  0.087929f +

		      ycaIn[20][i].b * -0.043159f +

		      ycaIn[22][i].b *  0.019597f +

		      ycaIn[24][i].b * -0.007540f +

		      ycaIn[26][i].b *  0.002128f;

	ycaOut[i].g = ycaIn[13][i].g;

	ycaOut[i].a = ycaIn[13][i].a;

    }

}

void

YCAtoRGBA (const IMATH_NAMESPACE::V3f &yw,

	   int n,

	   const Rgba ycaIn[/*n*/],

	   Rgba rgbaOut[/*n*/])

{

    for (int i = 0; i < n; ++i)

    {

	const Rgba &in = ycaIn[i];

	Rgba &out = rgbaOut[i];

	if (in.r == 0 && in.b == 0)

	{

	    //

	    // Special case -- both chroma channels are 0.  To avoid

	    // rounding errors, we explicitly set the output R, G and B

	    // channels equal to the input luminance.

	    //

	    // The special cases here and in RGBAtoYCA() ensure that

	    // converting black-and white images from RGBA to YCA and

	    // back is lossless.

	    //

	    out.r = in.g;

	    out.g = in.g;

	    out.b = in.g;

	    out.a = in.a;

	}

	else

	{

	    float Y =  in.g;

	    float r = (in.r + 1) * Y;

	    float b = (in.b + 1) * Y;

	    float g = (Y - r * yw.x - b * yw.z) / yw.y;

	    out.r = r;

	    out.g = g;

	    out.b = b;

	    out.a = in.a;

	}

    }

}

namespace {

inline float

saturation (const Rgba &in)

{

    float rgbMax = max (in.r, max (in.g, in.b));

    float rgbMin = min (in.r, min (in.g, in.b));

    if (rgbMax > 0)

	return 1 - rgbMin / rgbMax;

    else

	return 0;

}

void

desaturate (const Rgba &in, float f, const V3f &yw, Rgba &out)

{

    float rgbMax = max (in.r, max (in.g, in.b));

    out.r = max (float (rgbMax - (rgbMax - in.r) * f), 0.0f);

    out.g = max (float (rgbMax - (rgbMax - in.g) * f), 0.0f);

    out.b = max (float (rgbMax - (rgbMax - in.b) * f), 0.0f);

    out.a = in.a;

    float Yin  = in.r  * yw.x + in.g  * yw.y + in.b  * yw.z;

    float Yout = out.r * yw.x + out.g * yw.y + out.b * yw.z;

    if (Yout > 0)

    {

	out.r *= Yin / Yout;

	out.g *= Yin / Yout;

	out.b *= Yin / Yout;

    }

}

} // namespace

void

fixSaturation (const IMATH_NAMESPACE::V3f &yw,

	       int n,

	       const Rgba * const rgbaIn[3],

	       Rgba rgbaOut[/*n*/])

{

    float neighborA2 = saturation (rgbaIn[0][0]);

    float neighborA1 = neighborA2;

    float neighborB2 = saturation (rgbaIn[2][0]);

    float neighborB1 = neighborB2;

    for (int i = 0; i < n; ++i)

    {

	float neighborA0 = neighborA1;

	neighborA1 = neighborA2;

	float neighborB0 = neighborB1;

	neighborB1 = neighborB2;

	if (i < n - 1)

	{

	    neighborA2 = saturation (rgbaIn[0][i + 1]);

	    neighborB2 = saturation (rgbaIn[2][i + 1]);

	}

	//

	// A0       A1       A2

	//      rgbaOut[i]

	// B0       B1       B2

	//

	float sMean = min (1.0f, 0.25f * (neighborA0 + neighborA2 +

					  neighborB0 + neighborB2));

	const Rgba &in  = rgbaIn[1][i];

	Rgba &out = rgbaOut[i];

	float s = saturation (in);

	if (s > sMean)

	{

	    float sMax = min (1.0f, 1 - (1 - sMean) * 0.25f);

	    if (s > sMax)

	    {

		desaturate (in, sMax / s, yw, out);

		continue;

	    }

	}

	out = in;

    }

}

} // namespace RgbaYca

OPENEXR_IMF_INTERNAL_NAMESPACE_SOURCE_EXIT