color.hpp

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#pragma once
 
#include <cstdint>
 
namespace epaper {
 
struct RGB {
  std::uint8_t b; 
  std::uint8_t g; 
  std::uint8_t r; 
 
  constexpr RGB() : b(0), g(0), r(0) {}
 
  constexpr RGB(std::uint8_t red, std::uint8_t green, std::uint8_t blue) : b(blue), g(green), r(red) {}
 
  constexpr auto operator==(const RGB &other) const noexcept -> bool = default;
 
  [[nodiscard]] constexpr auto to_grayscale() const noexcept -> std::uint8_t {
    return static_cast<std::uint8_t>((0.299 * static_cast<double>(r)) + (0.587 * static_cast<double>(g)) +
                                     (0.114 * static_cast<double>(b)));
  }
};
 
struct RGBA {
  std::uint8_t a; 
  std::uint8_t b; 
  std::uint8_t g; 
  std::uint8_t r; 
 
  constexpr RGBA() : a(255), b(0), g(0), r(0) {}
 
  constexpr RGBA(std::uint8_t red, std::uint8_t green, std::uint8_t blue, std::uint8_t alpha = 255)
      : a(alpha), b(blue), g(green), r(red) {}
 
  constexpr explicit RGBA(const RGB &rgb) : a(255), b(rgb.b), g(rgb.g), r(rgb.r) {}
 
  constexpr auto operator==(const RGBA &other) const noexcept -> bool = default;
 
  [[nodiscard]] constexpr auto to_rgb() const noexcept -> RGB { return RGB{r, g, b}; }
 
  [[nodiscard]] constexpr auto to_grayscale() const noexcept -> std::uint8_t {
    return static_cast<std::uint8_t>((0.299 * static_cast<double>(r)) + (0.587 * static_cast<double>(g)) +
                                     (0.114 * static_cast<double>(b)));
  }
};
 
// Predefined colors
namespace colors {
constexpr RGB Black{0, 0, 0};
constexpr RGB White{255, 255, 255};
constexpr RGB Red{255, 0, 0};
constexpr RGB Green{0, 255, 0};
constexpr RGB Blue{0, 0, 255};
constexpr RGB Yellow{255, 255, 0};
constexpr RGB Cyan{0, 255, 255};
constexpr RGB Magenta{255, 0, 255};
constexpr RGB Gray{128, 128, 128};
constexpr RGB DarkGray{64, 64, 64};
constexpr RGB LightGray{192, 192, 192};
} // namespace colors
 
} // namespace epaper