xyz.cpp

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// SPDX-License-Identifier: GPL-2.0-or-later
 * Authors:
 *   2015 Alexei Boronine (original idea, JavaScript implementation)
 *   2015 Roger Tallada (Obj-C implementation)
 *   2017 Martin Mitas (C implementation, based on Obj-C implementation)
 *   2021 Massinissa Derriche (C++ implementation for Inkscape, based on C implementation)
 *   2023 Martin Owens (New Color classes)
 *
 * Copyright (C) 2023 Authors
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */
 
#include "xyz.h"
 
#include <cmath>
 
#include "colors/printer.h"
 
namespace Inkscape::Colors::Space {
 
static double dot_product(std::vector<double> const &t1, std::vector<double> const &t2)
{
    return (t1[0] * t2[0] + t1[1] * t2[1] + t1[2] * t2[2]);
}
 
void XYZ::toLinearRGB(std::vector<double> &in_out)
{
    std::vector<double> result = in_out; // copy
    for (size_t i : {0, 1, 2}) {
        result[i] = dot_product(d65[i], in_out);
    }
    in_out = result;
}
 
void XYZ::fromLinearRGB(std::vector<double> &in_out)
{
    std::vector<double> result = in_out; // copy
    for (size_t i : {0, 1, 2}) {
        result[i] = dot_product(in_out, d65_inv[i]);
    }
    in_out = result;
}
 
std::string XYZ::toString(std::vector<double> const &values, bool opacity) const
{
    auto os = CssColorPrinter(3, "xyz");
    os << values;
    if (opacity && values.size() == 4)
        os << values[3];
    return os;
}
 
}; // namespace Inkscape::Colors::Space