Rec2100.hpp

// Copyright 2020 Pokitec
// All rights reserved.
 
#pragma once
 
#include "TTauri/Foundation/Rec2020.hpp"
#include "TTauri/Foundation/float16.hpp"
#include "TTauri/Foundation/mat.hpp"
#include <cmath>
#include <array>
 
namespace tt {
 
inline mat Rec2100_to_XYZ = Rec2020_to_XYZ;
 
inline mat XYZ_to_Rec2100 = XYZ_to_Rec2020;
 
[[nodiscard]] inline float Rec2100_linear_to_gamma(float L) noexcept
{
    constexpr float c1 =  0.8359375f;
    constexpr float c2 = 18.8515625f;
    constexpr float c3 = 18.6875f;
    constexpr float m1 =  0.1593017578125f;
    constexpr float m2 = 78.84375;
 
    auto Lm1 = std::pow(L, m1);
 
    return std::pow((c1 + c2 * Lm1) / (1.0f + c3 * Lm1), m2);
}
 
[[nodiscard]] inline float Rec2100_gamma_to_linear(float N) noexcept
{
    constexpr float c1 =  0.8359375f;
    constexpr float c2 = 18.8515625f;
    constexpr float c3 = 18.6875f;
    constexpr float m1 =  0.1593017578125f;
    constexpr float m2 = 78.84375;
 
    auto Nm2 = std::pow(N, 1.0f / m2);
 
    return std::pow((Nm2 - c1) / ( c2 - c3 * Nm2), 1.0f / m1);
}
 
}