// ==========================================================

// XYZ to RGB TIFF conversion routines

//

// Design and implementation by

// - Hervé Drolon (drolon@infonie.fr)

//

// This file is part of FreeImage 3

//

// COVERED CODE IS PROVIDED UNDER THIS LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTY

// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES

// THAT THE COVERED CODE IS FREE OF DEFECTS, MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE

// OR NON-INFRINGING. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE COVERED

// CODE IS WITH YOU. SHOULD ANY COVERED CODE PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT

// THE INITIAL DEVELOPER OR ANY OTHER CONTRIBUTOR) ASSUME THE COST OF ANY NECESSARY

// SERVICING, REPAIR OR CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL

// PART OF THIS LICENSE. NO USE OF ANY COVERED CODE IS AUTHORIZED HEREUNDER EXCEPT UNDER

// THIS DISCLAIMER.

//

// Use at your own risk!

// ==========================================================

#include "FreeImage.h"

#include "Utilities.h"

void tiff_ConvertLineXYZToRGB(BYTE *target, BYTE *source, double stonits, int width_in_pixels) {

  FIRGBF *rgbf = (FIRGBF*)target;

  float *xyz = (float*)source;

  for (int cols = 0; cols < width_in_pixels; cols++) {

    // assume CCIR-709 primaries (matrix from tif_luv.c)

    // LOG Luv XYZ (D65) -> sRGB (CIE Illuminant E)

    rgbf->red = (float)( 2.690*xyz[0] + -1.276*xyz[1] + -0.414*xyz[2]);

    rgbf->green = (float)(-1.022*xyz[0] +  1.978*xyz[1] +  0.044*xyz[2]);

    rgbf->blue  = (float)( 0.061*xyz[0] + -0.224*xyz[1] +  1.163*xyz[2]);

    /*

    if (stonits != 0.0) {

      rgbf->red = (float)(rgbf->red   * stonits);

      rgbf->green = (float)(rgbf->green * stonits);

      rgbf->blue  = (float)(rgbf->blue  * stonits);

    } 

    */

    rgbf++;

    xyz += 3;

  }

}

void tiff_ConvertLineRGBToXYZ(BYTE *target, BYTE *source, int width_in_pixels) {

  FIRGBF *rgbf = (FIRGBF*)source;

  float *xyz = (float*)target;

  for (int cols = 0; cols < width_in_pixels; cols++) {

    // assume CCIR-709 primaries, whitepoint x = 1/3 y = 1/3 (D_E)

    // "The LogLuv Encoding for Full Gamut, High Dynamic Range Images" <G.Ward>

    // sRGB ( CIE Illuminant E ) -> LOG Luv XYZ (D65)

    xyz[0] =  (float)(0.497*rgbf->red +  0.339*rgbf->green +  0.164*rgbf->blue);

    xyz[1] =  (float)(0.256*rgbf->red +  0.678*rgbf->green +  0.066*rgbf->blue);

    xyz[2] =  (float)(0.023*rgbf->red +  0.113*rgbf->green +  0.864*rgbf->blue);

    rgbf++;

    xyz += 3;

  }

}