OpenSpace/modules/globebrowsing/tile/tileprovider/texttileprovider.h

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* OpenSpace                                                                             *
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* Copyright (c) 2014-2016                                                               *
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#ifndef __TEXT_TILE_PROVIDER_H__
#define __TEXT_TILE_PROVIDER_H__

#include <memory>

#include <ghoul/logging/logmanager.h>
#include <ghoul/filesystem/filesystem.h> // absPath
#include <ghoul/opengl/texture.h>

#include <ghoul/io/texture/texturereader.h>

#include <ghoul/font/fontrenderer.h>
#include <ghoul/font/fontmanager.h>

#include <modules/globebrowsing/tile/asynctilereader.h>
#include <modules/globebrowsing/tile/tileprovider/tileprovider.h>
#include <modules/globebrowsing/other/lrucache.h>
#include <modules/globebrowsing/geometry/ellipsoid.h>


//////////////////////////////////////////////////////////////////////////////////////////
//                                    TILE PROVIDER                                        //
//////////////////////////////////////////////////////////////////////////////////////////


namespace openspace {
    using namespace ghoul::fontrendering;

    /**
     * This abstract class implements the TilProvider interface and enables a simple way 
     * of providing tiles with any type of rendered text. 
     * Internally it handles setting up a FBO for rendering the text, and defines a new 
     * interface, consisting of only a single method for subclasses to implement: 
     * \code  renderText(const FontRenderer&, const ChunkIndex&) const \endcode 
     */
    class TextTileProvider : public TileProvider {
    public:

        TextTileProvider(const glm::uvec2& textureSize = {512, 512}, size_t fontSize = 48);
        virtual ~TextTileProvider();

        // The TileProvider interface below is implemented in this class

        virtual Tile getTile(const ChunkIndex& chunkIndex);
        virtual Tile getDefaultTile();
        virtual Tile::Status getTileStatus(const ChunkIndex& index);
        virtual TileDepthTransform depthTransform();
        virtual void update();
        virtual void reset();
        virtual int maxLevel();

        // Returns the tile which will be used to draw text onto.
        // Default implementation returns a tile with a plain transparent texture.
        virtual Tile backgroundTile(const ChunkIndex& chunkIndex) const;

        // Default implementation uses ChunkIndex::hashKey()
        virtual ChunkHashKey toHash(const ChunkIndex& chunkIndex) const;
        
        // This method is pure and should be implemented by subclasses
        virtual void renderText(const FontRenderer& fontRenderer, const ChunkIndex& chunkIndex) const = 0;

    protected:
        std::shared_ptr<ghoul::fontrendering::Font> _font;
        glm::uvec2 _textureSize;
        size_t _fontSize;

    private:
        Tile createChunkIndexTile(const ChunkIndex& chunkIndex);
        std::unique_ptr<ghoul::fontrendering::FontRenderer> _fontRenderer;

        TileCache _tileCache;
        GLuint _fbo;
    };

    /**
     * Provides \class Tiles with the chunk index rendered as text onto its tiles.
     */
    class ChunkIndexTileProvider : public TextTileProvider {
    public:
        virtual void renderText(const FontRenderer& fontRenderer, const ChunkIndex& chunkIndex) const;
    };


    class SizeReferenceTileProvider : public TextTileProvider {
    public:
        SizeReferenceTileProvider(const ghoul::Dictionary& dictionary);

        virtual void renderText(const FontRenderer& fontRenderer, const ChunkIndex& chunkIndex) const;
        virtual Tile backgroundTile(const ChunkIndex& chunkIndex) const;

        virtual ChunkHashKey toHash(const ChunkIndex& chunkIndex) const;


    private:

        int roundedLongitudalLength(const ChunkIndex& chunkIndex) const;

        Ellipsoid _ellipsoid;
        Tile _backgroundTile;
    };

}  // namespace openspace




#endif  // __TEXT_TILE_PROVIDER_H__