color.hpp

// Copyright Take Vos 2021.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt)
 
#pragma once
 
#include "../rapid/numeric_array.hpp"
 
namespace tt {
 
class color {
public:
    constexpr color(color const &) noexcept = default;
    constexpr color(color &&) noexcept = default;
    constexpr color &operator=(color const &) noexcept = default;
    constexpr color &operator=(color &&) noexcept = default;
 
    [[nodiscard]] constexpr explicit color(f32x4 other) noexcept : _v(std::move(other))
    {
        tt_axiom(is_valid());
    }
    [[nodiscard]] constexpr explicit operator f32x4() const noexcept
    {
        return _v;
    }
 
    [[nodiscard]] constexpr color() noexcept : _v(0.0, 0.0, 0.0, 1.0) {}
    [[nodiscard]] constexpr color(float r, float g, float b, float a = 1.0) noexcept : _v(r, g, b, a) {}
    [[nodiscard]] constexpr color(double r, double g, double b, double a = 1.0) noexcept :
        _v(static_cast<float>(r), static_cast<float>(g), static_cast<float>(b), static_cast<float>(a))
    {
    }
 
    [[nodiscard]] static constexpr color transparent() noexcept
    {
        return {0.0f, 0.0f, 0.0f, 0.0f};
    }
 
    [[nodiscard]] static constexpr color white() noexcept
    {
        return {1.0f, 1.0f, 1.0f, 1.0f};
    }
 
    [[nodiscard]] static constexpr color black() noexcept
    {
        return {0.0f, 0.0f, 0.0f, 1.0f};
    }
 
    [[nodiscard]] constexpr float &r() noexcept
    {
        return _v.x();
    }
 
    [[nodiscard]] constexpr float &g() noexcept
    {
        return _v.y();
    }
 
    [[nodiscard]] constexpr float &b() noexcept
    {
        return _v.z();
    }
 
    [[nodiscard]] constexpr float &a() noexcept
    {
        return _v.w();
    }
 
    [[nodiscard]] constexpr float const &r() const noexcept
    {
        return _v.x();
    }
 
    [[nodiscard]] constexpr float const &g() const noexcept
    {
        return _v.y();
    }
 
    [[nodiscard]] constexpr float const &b() const noexcept
    {
        return _v.z();
    }
 
    [[nodiscard]] constexpr float const &a() const noexcept
    {
        return _v.w();
    }
 
    [[nodiscard]] constexpr bool is_valid() const noexcept
    {
        return _v.w() >= 0.0 && _v.w() <= 1.0;
    }
 
    [[nodiscard]] constexpr friend bool operator==(color const &lhs, color const &rhs) noexcept
    {
        return lhs._v == rhs._v;
    }
 
    [[nodiscard]] constexpr friend color operator*(color const &lhs, color const &rhs) noexcept
    {
        return color{lhs._v * rhs._v};
    }
 
    [[nodiscard]] constexpr friend color composit(color const &lhs, color const &rhs) noexcept
    {
        return color{composit(lhs._v, rhs._v)};
    }
 
    [[nodiscard]] constexpr friend color pre_multiply_alpha(color const &rhs) noexcept
    {
        auto r = rhs._v * rhs.a();
        r.a() = rhs.a();
        return color{r};
    }
 
private:
    f32x4 _v;
};
 
} // namespace tt