OpenSpace/modules/globebrowsing/tile/asynctiledataprovider.h

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 * OpenSpace                                                                             *
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 * Copyright (c) 2014-2017                                                               *
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#ifndef __OPENSPACE_MODULE_GLOBEBROWSING___ASYNC_TILE_DATAPROVIDER___H__
#define __OPENSPACE_MODULE_GLOBEBROWSING___ASYNC_TILE_DATAPROVIDER___H__

#include <modules/globebrowsing/globebrowsingmodule.h>

#include <modules/globebrowsing/other/prioritizingconcurrentjobmanager.h>
#include <modules/globebrowsing/other/pixelbuffercontainer.h>
#include <modules/globebrowsing/tile/tileindex.h>

#include <ghoul/misc/boolean.h>
#include <ghoul/opengl/ghoul_gl.h>

#include <map>
#include <set>
#include <unordered_map>

namespace openspace::globebrowsing {
    
//class GlobeBrowsingModule;
struct RawTile;
class RawTileDataReader;

/**
 * The responsibility of this class is to enqueue tile requests and fetching finished
 * <code>RawTile</code>s that has been asynchronously loaded.
 */
class AsyncTileDataProvider {
public:
    /**
     * \param textureDataProvider is the reader that will be used for the asynchronos
     * tile loading.
     */
    AsyncTileDataProvider(const std::string& name,
                          std::shared_ptr<RawTileDataReader> textureDataProvider);

    /**
     * Creates a job which asynchronously loads a raw tile. This job is enqueued.
     */
    bool enqueueTileIO(const TileIndex& tileIndex);

    /**
     * Get all finished jobs.
     */
    std::vector<std::shared_ptr<RawTile>> getRawTiles();

    /**
     * Get one finished job.
     */
    std::shared_ptr<RawTile> popFinishedRawTile();

    void update();
    void reset();
    void prepairToBeDeleted();

    bool shouldBeDeleted();

    std::shared_ptr<RawTileDataReader> getRawTileDataReader() const;
    float noDataValueAsFloat() const;

protected:
    using ResetRawTileDataReader = ghoul::Boolean;

    enum class ResetMode {
        ShouldResetAll,
        ShouldResetAllButRawTileDataReader,
        ShouldBeDeleted,
        ShouldNotReset
    };

    /**
     * \returns true if tile of index <code>tileIndex</code> is not already enqueued.
     */
    bool satisfiesEnqueueCriteria(const TileIndex& tileIndex);

    /**
     * An unfinished job is a load tile job that has been popped from the thread pool due
     * to its low priority. Once it has been popped, it is marked as unfinished and needs
     * to be explicitly ended.
     */
    void endUnfinishedJobs();

    void endEnqueuedJobs();

    void updatePboUsage();

    void performReset(ResetRawTileDataReader resetRawTileDataReader);

private:
    const std::string _name;
    GlobeBrowsingModule* _globeBrowsingModule;
    /// The reader used for asynchronous reading
    std::shared_ptr<RawTileDataReader> _rawTileDataReader;
    
    PrioritizingConcurrentJobManager<RawTile, TileIndex::TileHashKey>
        _concurrentJobManager;

    /// nullptr if pbo is not used for texture uploading. Otherwise initialized.
    std::unique_ptr<PixelBufferContainer<TileIndex::TileHashKey>> _pboContainer;
    std::set<TileIndex::TileHashKey> _enqueuedTileRequests;

    ResetMode _resetMode;
    bool _shouldBeDeleted;
};

} // namespace openspace::globebrowsing

#endif // __OPENSPACE_MODULE_GLOBEBROWSING___ASYNC_TILE_DATAPROVIDER___H__