/*
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* Copyright (C) 2023 Christopher J. Howard
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*
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* This file is part of Antkeeper source code.
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*
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* Antkeeper source code is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Antkeeper source code is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Antkeeper source code. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef ANTKEEPER_COLOR_XYY_HPP
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#define ANTKEEPER_COLOR_XYY_HPP
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#include "math/vector.hpp"
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namespace color {
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/// CIE xyY color space.
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namespace xyy {
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/**
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* Returns the luminance of a CIE xyY color.
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*
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* @param x CIE xyY color.
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* @return return Luminance of @p x.
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*/
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template <class T>
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inline constexpr T luminance(const math::vector3<T>& x)
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{
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return x[2];
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}
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/**
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* Transforms a CIE xyY color into the CIE 1960 UCS colorspace.
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*
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* @param x CIE xyY color.
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* @return CIE 1960 UCS color.
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*/
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template <class T>
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constexpr math::vector2<T> to_ucs(const math::vector3<T>& x)
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{
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const T d = (T{1} / (T{-2} * x[0] + T{12} * x[1] + T{3}));
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return math::vector2<T>{(T{4} * x[0]) * d, (T{6} * x[1]) * d};
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}
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/**
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* Transforms a CIE xyY color into the CIE XYZ colorspace.
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*
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* @param x CIE xyY color.
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* @return CIE XYZ color.
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*/
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template <class T>
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constexpr math::vector3<T> to_xyz(const math::vector3<T>& x)
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{
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return math::vector3<T>{(x[0] * x[2]) / x[1], x[2], ((T{1} - x[0] - x[1]) * x[2]) / x[1]};
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}
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} // namespace xyy
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} // namespace color
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#endif // ANTKEEPER_COLOR_XYY_HPP
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