test_color.cpp

// Description: Testing for Color
// DocumentationOf: color.h

#include "test/test_init.h"

#include "pastel/gfx/image_file/pcx.h"
#include "pastel/gfx/color/color_space.h"
#include "pastel/gfx/color/color_tools.h"
#include "pastel/gfx/color/color_illuminant.h"
#include "pastel/gfx/drawing.h"

#include "pastel/sys/string.h"
#include "pastel/sys/view.h"

#include <iostream>

namespace
{

    TEST_CASE("Chromaticity (Chromaticity)")
    {
        real Width = 500;
        real Height = 500;
        Array<Color, 2> image(Vector2i(Width, Height));

        for (integer i = 0;i < 20;++i)
        {
            real Y = (real)(i + 1) / 20;
            for (integer y = 0;y < Height;++y)
            {
                for (integer x = 0;x < Width;++x)
                {
                    real u = (real)x / (Width - 1);
                    real v = (real)y / (Height - 1);

                    Color xyzColor =
                        xyyToXyz(
                        Color(u, v, Y));

                    image(x, y) = fitColor(xyzToSrgb(xyzColor));
                }
            }

            savePcx(image, "chromaticity_" + integerToString(i, 2) + ".pcx");
        }
    }

    TEST_CASE("ChromaticAdaptation (ChromaticAdaptation)")
    {
        Color lmsObserved(
            xyzToLms(srgbToXyz(Color(142, 98, 29) / 255)));

        Color lmsDesired(
            xyzToLms(srgbToXyz(Color(1, 1, 1))));

        Matrix<real32> observedToDesired = 
            xyzToLinearSrgbTransform() * 
            lmsToXyzTransform();

        for (integer j = 0;j < 3;++j)
        {
            for (integer i = 0;i < 3;++i)
            {
                observedToDesired(i, j) *= 0.1 * lmsDesired[i] / lmsObserved[i];
            }
        }

        observedToDesired *=
            xyzToLmsTransform() * linearSrgbToXyzTransform();

        Array<Color> image;
        loadPcx("lena.pcx", image);

        transform(arrayView(image), [&](const Color& observed)
        {
            return 
                linearSrgbToSrgb(
                    fitColor(
                        observedToDesired * srgbToLinearSrgb(observed)
                    )
                );
        });

        savePcx(image, "chromatic_adaptation.pcx");
    }

}