photometry.hpp

Go to the documentation of this file.

/*
 * 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_PHYSICS_LIGHT_PHOTOMETRY_HPP
#define ANTKEEPER_PHYSICS_LIGHT_PHOTOMETRY_HPP
 
#include <engine/math/numbers.hpp>
#include <engine/math/quadrature.hpp>
 
namespace physics {
namespace light {
 
template <class T>
constexpr T max_luminous_efficacy = T(683.002);
 
template <class T, class UnaryOp1, class UnaryOp2, class InputIt>
T luminous_efficiency(UnaryOp1 spd, UnaryOp2 lef, InputIt first, InputIt last)
{
    auto spd_lef = [spd, lef](T x) -> T
    {
        return spd(x) * lef(x);
    };
    
    const T num = math::quadrature::simpson(spd_lef, first, last);
    const T den = math::quadrature::simpson(spd, first, last);
    
    return num / den;
}
 
template <class T>
T luminous_efficacy(T efficiency)
{
    return max_luminous_efficacy<T> * efficiency;
}
 
template <class T>
T watts_to_lumens(T radiant_flux, T efficiency)
{
    return radiant_flux * luminous_efficacy(efficiency);
}
 
} // namespace light
} // namespace physics
 
#endif // ANTKEEPER_PHYSICS_LIGHT_PHOTOMETRY_HPP