PixelPalette.h

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// SPDX-FileCopyrightText: 2026 Valentin Eloy
// SPDX-License-Identifier: GPL-3.0-or-later
 
#pragma once
 
#include <cstdint>
#include <filesystem>
#include <string>
#include <string_view>
#include <vector>
 
#include "HMI/Graphics/TextureLoader.h"

 
namespace hmi {

struct PixelPaletteEntry {
    std::string name;
    std::uint32_t color = 0xFF000000u;  
 
    [[nodiscard]] friend bool operator==(const PixelPaletteEntry&,
                                         const PixelPaletteEntry&) noexcept = default;
};

class PixelPalette {
public:
    static constexpr int FORMAT_VERSION = 1;

    [[nodiscard]] static PixelPalette loadFromString(std::string_view json);

    [[nodiscard]] static PixelPalette loadFromFile(const std::filesystem::path& path);

    [[nodiscard]] std::string toJsonString() const;

    [[nodiscard]] bool saveToFile(const std::filesystem::path& path) const;

    [[nodiscard]] const std::vector<PixelPaletteEntry>& entries() const noexcept {
        return _entries;
    }

    void add(std::string name, std::uint32_t color);
    bool removeAt(std::size_t index);
    bool renameAt(std::size_t index, std::string newName);
    bool moveEntry(std::size_t from, std::size_t to);
 
private:
    std::vector<PixelPaletteEntry> _entries;
};

struct PixelPaletteExtractionEntry {
    std::uint32_t color = 0;
    int count = 0;
};

[[nodiscard]] std::vector<PixelPaletteExtractionEntry> extractPalette(const DecodedImage& image);

[[nodiscard]] std::uint32_t nearestPaletteColor(std::uint32_t color,
                                                const std::vector<std::uint32_t>& palette) noexcept;
 
}  // namespace hmi