ThumbnailManager.hpp

#pragma once
 
#include <unordered_map>
#include <filesystem>
#include <vector>
 
#include <Common/ResourcePipeline/Uuid.hpp>
#include <EngineCore/Assets/Asset.hpp>
#include <Common/Graphics/Image.hpp>
 
namespace Grindstone::GraphicsAPI {
    class Image;
    class DescriptorSet;
}
 
namespace Grindstone::Editor {
    using ThumbnailGenerateFn = bool(*)(Grindstone::Uuid uuid);
    class ThumbnailManager {
    public:
        struct AtlasCoords {
            float uv0x;
            float uv0y;
            float uv1x;
            float uv1y;
        };
 
        void RegisterGenerator(AssetType type, ThumbnailGenerateFn generator);
        void DeregisterGenerator(AssetType type, ThumbnailGenerateFn generator);
 
        bool Initialize();
 
        Grindstone::GraphicsAPI::DescriptorSet* GetAtlasTextureDescriptorSet();
 
        AtlasCoords GetCoordsByIndex(uint32_t index) const;
 
        AtlasCoords GetFolderIconCoords() const;
        AtlasCoords GetGenericBinaryIconCoords() const;
        AtlasCoords GetPluginIconCoords() const;
        AtlasCoords GetDotnetIconCoords() const;
        AtlasCoords GetCmakeIconCoords() const;
 
        // This function will get existing icons but will not request new icons to be generated.
        AtlasCoords GetThumbnailCoordsFromCache(AssetType type, Grindstone::Uuid uuid);
 
        // Frees existing thumbnails from memory.
        bool FreeThumbnailFromMemory(Grindstone::Uuid uuid);
 
        // This function will get existing icons and will request new icons to be generated if none exist.
        ThumbnailManager::AtlasCoords RequestThumbnail(AssetType type, Grindstone::Uuid uuid);
 
        // Frees existing thumbnails from storage if it exists.
        bool DeleteThumbnailFromStorage(Grindstone::Uuid uuid);
 
        // Creates all thumbnails dispatched via RequestThumbnail.
        void CreateRequestedThumbnails();
 
    protected:
        uint16_t LoadDdsBufferToAtlas(std::string_view name, Grindstone::Containers::BufferSpan inputBuffer);
        uint16_t LoadNamedAssetToAtlas(std::string_view name);
        uint16_t LoadThumbnailByPathToAtlas(const std::filesystem::path& path);
 
    protected:
        enum class IconStatus {
            Pending,
            Failed,
            Loading,
            Generating,
            Resolved
        };
        struct IconData {
            IconStatus status = IconStatus::Pending;
            AtlasCoords coords;
        };
        std::unordered_map<AssetType, ThumbnailGenerateFn> generators;
        std::unordered_map<Grindstone::Uuid, IconData> iconsByUuid;
        std::vector<std::pair<Grindstone::AssetType, Grindstone::Uuid>> requestedThumbnails;
 
        Grindstone::GraphicsAPI::Image* thumbnailAtlasImage = nullptr;
        Grindstone::GraphicsAPI::DescriptorSet* thumbnailAtlasDescriptorSet = nullptr;
 
        std::vector<uint16_t> freeIndices;
 
        struct {
            uint16_t folder;
            uint16_t plugin;
            uint16_t generic;
            uint16_t dotnet;
            uint16_t cmake;
            uint16_t asset[static_cast<size_t>(AssetType::Count)];
        } defaultIcons;
 
        uint32_t thumbnailFreeCount = 0;
        uint32_t thumbnailCapacity = 0;
        uint32_t thumbnailPixelSize = 0; // Width or height, as thumbnails are square.
        uint32_t atlasPixelWidth = 0;
        uint32_t atlasPixelHeight = 0;
        uint32_t thumbnailsPerAtlasRow = 0;
    };
}