/* -*-c++-*- */
/* osgEarth - Dynamic map generation toolkit for OpenSceneGraph
* Copyright 2008-2010 Pelican Mapping
* http://osgearth.org
*
* osgEarth is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program.  If not, see <http://www.gnu.org/licenses/>
*/

#ifndef OSGEARTH_ENGINE_OSGTERRAIN_TILE_FACTORY_H
#define OSGEARTH_ENGINE_OSGTERRAIN_TILE_FACTORY_H 1

#include "OSGTerrainOptions"
#include "TransparentLayer"

#include <osgEarth/Map>
#include <osgEarth/TileSource>
#include <osgEarth/ImageLayer>
#include <osgEarth/ElevationLayer>
#include <osgEarth/Locators>

#include <osgDB/ReaderWriter>
#include <osg/CoordinateSystemNode>
#include <osg/ClusterCullingCallback>
#include <vector>

using namespace osgEarth;
using namespace osgEarth::Drivers;

class Terrain;
class StreamingTerrain;
class Tile;
class StreamingTile;

/**
* TileFactory is the main workhorse - it generates osg Nodes for TileKeys.
*/
class OSGTileFactory : public osg::Referenced
{
public:
    OSGTileFactory(
        unsigned                 engineId,
        const MapFrame&          cull_thread_mapf,
        const OSGTerrainOptions& props =OSGTerrainOptions() );

public:
    /**
    * Creates a node graph containing four tiles that correspond to the four
    * subkeys of the provided TileKey.
    */
    osg::Node* createSubTiles(
        const MapFrame&  mapf,
        Terrain*         terrain,
        const TileKey&   key,
        bool             populateLayers );

    /**
    * Creates a single terrain tile corresponding to the provided TileKey.
    */
    osg::Node* createTile(
        const MapFrame&  mapf,
        Terrain*         terrain,
        const TileKey&   key,
        bool             populateLayers,
        bool             wrapInPagedLOD,
        bool             fallback,
        bool&            out_validData);


    CustomColorLayerRef* createImageLayer(
        const MapInfo&    mapInfo,
        ImageLayer*       layer,
        const TileKey&    key,
        ProgressCallback* progress);

    osgTerrain::HeightFieldLayer* createHeightFieldLayer(
        const MapFrame& mapf,
        const TileKey&  key,
        bool            exactOnly );

    /**
    * Gets the properties that customize how this engine renders tile data.
    */
    const OSGTerrainOptions& getTerrainOptions() const;

    /**
    * Gets a pagedLOD child URI given a tile key.
    */
    std::string createURI( unsigned int id, const TileKey& key );

    /**
     * Wraps a tile in a paged LOD and setup up all its parameters
     */
    osg::Node* prepareTile( 
        Tile*            tile, 
        Terrain*         terrain,
        const MapInfo&   mapInfo,
        bool             wrapInPagedLOD );

    bool createValidGeoImage(
        ImageLayer*       layer,
        const TileKey&    key,
        GeoImage&         out_image,
        TileKey&          out_actualTileKey,
        ProgressCallback* progress  = 0);

    osg::Matrixd getTransformFromExtents(double minX, double minY, double maxX, double maxY) const;

    // checks whether more data exists below the specified key's level of detail
    bool hasMoreLevels( Map* map, const TileKey& key );

    static osg::HeightField* createEmptyHeightField(
        const TileKey& key,
        int            numCols =8,
        int            numRows =8 );

    osgTerrain::HeightFieldLayer* createPlaceholderHeightfieldLayer(
        osg::HeightField* ancestorHF,
        const TileKey&    ancestorKey,
        const TileKey&    key,
        GeoLocator*       locator );

protected:

    osg::Node* createPlaceholderTile(
        const MapFrame&   mapf,
        StreamingTerrain* terrain,
        const TileKey&    key );

    osg::Node* createPopulatedTile(
        const MapFrame&  mapf,
        Terrain*         terrain,
        const TileKey&   key,
        bool             wrapInPagedLOD,
        bool             fallback,
        bool&            out_validData);

    void addPlaceholderImageLayers( Tile* tile, Tile* ancestorTile );

    void addPlaceholderHeightfieldLayer(
        StreamingTile* tile,
        StreamingTile* ancestorTile,
        GeoLocator*    defaultLocator,
        const TileKey& key,
        const TileKey& ancestorKey );

    osg::ClusterCullingCallback* createClusterCullingCallback(
        Tile*                tile,
        osg::EllipsoidModel* et );

    void init();

protected:

    unsigned          _engineId;
    const MapFrame&   _cull_thread_mapf;
    OSGTerrainOptions _terrainOptions;
};

#endif // OSGEARTH_ENGINE_OSGTERRAIN_TILE_FACTORY_H
