core/modules/Color.cppm

export module Core.Color;

export import Core.Types;

export namespace Core {
    using ColorChannel = u8;

    template<size_t N>
    class Color final {
        static_assert(N >= 1 && N <= 4, "a color has 1 to 4 channels");
        ColorChannel data[N] = {};

    public:
        Color() noexcept = default;

        template<typename OT, typename... Args>
        Color(OT a, Args&&... args) noexcept :
            data(
                static_cast<ColorChannel>(a),
                static_cast<ColorChannel>(args)...) {
            static_assert(
                sizeof...(args) + 1 == N,
                "color channel parameters do not match its size");
        }

        float asFloat(size_t index) const noexcept {
            return data[index] * (1.0f / 255.0f);
        }

        ColorChannel& operator[](size_t index) noexcept {
            return data[index];
        }

        const ColorChannel& operator[](size_t index) const noexcept {
            return data[index];
        }
    };

    using Color4 = Color<4>;
    using Color3 = Color<3>;
    using Color2 = Color<2>;
    using Color1 = Color<1>;
}