💿🐜 Antkeeper source code
https://antkeeper.com
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88 lines
2.6 KiB
88 lines
2.6 KiB
/*
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* Copyright (C) 2021 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_CCT_HPP
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#define ANTKEEPER_COLOR_CCT_HPP
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#include "math/math.hpp"
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#include "ucs.hpp"
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#include "xyy.hpp"
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namespace color {
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/// Functions which operate on correlated color temperature (CCT).
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namespace cct {
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/**
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* Calculates CIE 1960 UCS colorspace chromaticity coordinates given a correlated color temperature using Krystek's algorithm.
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*
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* @param t Correlated color temperature, in Kelvin.
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* @return CIE 1960 UCS colorspace chromaticity coordinates.
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*
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* @see Krystek, M. (1985), An algorithm to calculate correlated colour temperature. Color Res. Appl., 10: 38-40.
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*/
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template <class T>
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math::vector2<T> to_ucs(T t);
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/**
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* Calculates CIE xyY colorspace chromaticity coordinates given a correlated color temperature using Krystek's algorithm.
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*
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* @param t Correlated color temperature, in Kelvin.
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* @return CIE xyY color with `Y = 1`.
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*/
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template <class T>
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math::vector3<T> to_xyy(T t);
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/**
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* Calculates CIE XYZ colorspace chromaticity coordinates given a correlated color temperature using Krystek's algorithm.
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*
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* @param t Correlated color temperature, in Kelvin.
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* @return CIE XYZ color with `Y = 1`.
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*/
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template <class T>
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math::vector3<T> to_xyz(T t);
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template <class T>
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math::vector2<T> to_ucs(T t)
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{
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// Approximate the Planckian locus in CIE 1960 UCS colorspace (Krystek's algorithm)
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const T tt = t * t;
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return math::vector2<T>
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{
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(T(0.860117757) + T(1.54118254e-4) * t + T(1.28641212e-7) * tt) / (T(1.0) + T(8.42420235e-4) * t + T(7.08145163e-7) * tt),
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(T(0.317398726) + T(4.22806245e-5) * t + T(4.20481691e-8) * tt) / (T(1.0) - T(2.89741816e-5) * t + T(1.61456053e-7) * tt)
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};
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}
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template <class T>
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math::vector3<T> to_xyy(T t)
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{
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return ucs::to_xyy(to_ucs(t), T(1.0));
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}
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template <class T>
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math::vector3<T> to_xyz(T t)
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{
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return xyy::to_xyz(to_xyy(t));
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}
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} // namespace cct
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} // namespace color
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#endif // ANTKEEPER_COLOR_CCT_HPP
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