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