rgba32.hpp

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#pragma once
 
// ReSharper disable once CppUnusedIncludeDirective
#include <cstdint>
#include <string>
 
namespace porytiles {
 
class Rgba32 {
    std::uint8_t red_;
    std::uint8_t green_;
    std::uint8_t blue_;
    std::uint8_t alpha_;
 
  public:
    static constexpr std::uint8_t kAlphaTransparent = 0;
    static constexpr std::uint8_t kAlphaOpaque = 255;
 
    constexpr Rgba32() : red_{0}, green_{0}, blue_{0}, alpha_{0} {}
 
    constexpr Rgba32(std::uint8_t red, std::uint8_t green, std::uint8_t blue, std::uint8_t alpha = kAlphaOpaque)
        : red_{red}, green_{green}, blue_{blue}, alpha_{alpha} {}
 
    [[nodiscard]] std::uint8_t red() const {
        return red_;
    }
 
    [[nodiscard]] std::uint8_t green() const {
        return green_;
    }
 
    [[nodiscard]] std::uint8_t blue() const {
        return blue_;
    }
 
    [[nodiscard]] std::uint8_t alpha() const {
        return alpha_;
    }
 
    bool operator==(const Rgba32 &rgba) const = default;
    auto operator<=>(const Rgba32 &rgba) const = default;
 
    [[nodiscard]] std::string ToJascStr() const;
 
    [[nodiscard]] bool EqualsIgnoringAlpha(const Rgba32 &other) const;
 
    // friend std::ostream &operator<<(std::ostream &os, const Rgba32 &rgba);
};
 
inline auto format_as(const Rgba32 &rgba) {
    return rgba.ToJascStr();
}
 
constexpr Rgba32 kRgbaBlack{0, 0, 0, Rgba32::kAlphaOpaque};
constexpr Rgba32 kRgbaWhite{255, 255, 255, Rgba32::kAlphaOpaque};
constexpr Rgba32 kRgbaGrey{128, 128, 128, Rgba32::kAlphaOpaque};
constexpr Rgba32 kRgbaRed{255, 0, 0, Rgba32::kAlphaOpaque};
constexpr Rgba32 kRgbaGreen{0, 255, 0, Rgba32::kAlphaOpaque};
constexpr Rgba32 kRgbaBlue{0, 0, 255, Rgba32::kAlphaOpaque};
constexpr Rgba32 kRgbaYellow{255, 255, 0, Rgba32::kAlphaOpaque};
constexpr Rgba32 kRgbaMagenta{255, 0, 255, Rgba32::kAlphaOpaque};
constexpr Rgba32 kRgbaCyan{0, 255, 255, Rgba32::kAlphaOpaque};
constexpr Rgba32 kRgbaPurple{128, 0, 255, Rgba32::kAlphaOpaque};
constexpr Rgba32 kRgbaLime{128, 255, 128, Rgba32::kAlphaOpaque};
 
// std::size_t hash_value(const Rgba32 &obj) {
//     std::size_t seed = 0x7A22F97A;
//     seed ^= (seed << 6) + (seed >> 2) + 0x7687DDBC + static_cast<std::size_t>(obj.red);
//     seed ^= (seed << 6) + (seed >> 2) + 0x63724761 + static_cast<std::size_t>(obj.green);
//     seed ^= (seed << 6) + (seed >> 2) + 0x3E044131 + static_cast<std::size_t>(obj.blue);
//     seed ^= (seed << 6) + (seed >> 2) + 0x00E64742 + static_cast<std::size_t>(obj.alpha);
//     return seed;
// }
 
} // namespace porytiles
 
template <>
struct std::hash<porytiles::Rgba32> {
    std::size_t operator()(const porytiles::Rgba32 &rgba) const noexcept {
        const std::size_t h1 = std::hash<std::uint8_t>{}(rgba.red());
        const std::size_t h2 = std::hash<std::uint8_t>{}(rgba.green());
        const std::size_t h3 = std::hash<std::uint8_t>{}(rgba.blue());
        const std::size_t h4 = std::hash<std::uint8_t>{}(rgba.alpha());
        return h1 ^ (h2 << 8) ^ (h3 << 16) ^ (h4 << 24);
    }
};