TextureImporter.h

#pragma once
 
// Standard.
#include <optional>
#include <filesystem>
 
// Custom.
#include "misc/Error.h"
#include "material/TextureFilteringPreference.h"
 
namespace ne {
    enum class TextureImportFormat {
        R,          //< BC4 compression, only one 8 bit channel, can be used for heightmaps for example.
        RG,         //< BC5 compression, 8 bits for R and 8 bits for G channel, can be used for normal maps.
        RGB,        //< BC1 compression, bits per channel: 5 for R, 6 for G, 5 for B.
        RGB_1BIT_A, //< BC1 compression, bits per channel: 5 for R, 6 for G, 5 for B and 0 or 1 bit for alpha.
        RGB_8BIT_A, //< BC3 compression, bits per channel: 5 for R, 6 for G, 5 for B and 8 bit for alpha.
        HDR,        //< BC6H compression, used for HDR textures.
        RGB_HIGH_QUALITY,  //< BC7 compression, high quality of the compressed image but bigger file size and
                           // longer import.
        RGBA_HIGH_QUALITY, //< BC7 compression, high quality of the compressed image but bigger file size and
                           // longer import.
    };
 
    class TextureImporter {
    public:
        TextureImporter() = delete;
 
        static constexpr std::string_view getImportedFileName() { return sImportedFileName; }
 
        static constexpr std::string_view getImportedTextureSettingsFileName() {
            return sImportedTextureSettingsFileName;
        }
 
        [[nodiscard]] static std::optional<Error> importTexture(
            const std::filesystem::path& pathToTexture,
            TextureImportFormat textureImportFormat,
            const std::string& sPathToOutputDirRelativeRes,
            const std::string& sOutputDirectoryName,
            TextureFilteringPreference filteringPreference =
                TextureFilteringPreference::FROM_RENDER_SETTINGS);
 
    private:
        static constexpr std::string_view sImportedFileName = "t";
 
        static constexpr std::string_view sImportedTextureSettingsFileName = "settings";
    };
}