C++ TileNode::getLocator方法代码示例

//.........这里部分代码省略.........
    tileNode->setTileModel( model );
    tileNode->compile( _modelCompiler.get() );

    // assemble a URI for this tile's child group:
    std::string uri = Stringify() << model->_tileKey.str() << "." << _engineUID << ".osgearth_engine_mp_tile";

    osg::Node* result = 0L;

    // Only add the next tile if all the following are true:
    // 1. Either there's real tile data, or a minLOD is explicity set in the options;
    // 2. The tile isn't blacklisted; and
    // 3. We are still below the maximim LOD.
    bool wrapInPagedLOD =
        (tileHasRealData || (_options.minLOD().isSet() && model->_tileKey.getLOD() < *_options.minLOD())) &&
        !osgEarth::Registry::instance()->isBlacklisted( uri ) &&
        model->_tileKey.getLOD() < *_options.maxLOD();

    if ( wrapInPagedLOD )
    {
        osg::BoundingSphere bs = tileNode->getBound();
      
        float maxRange = FLT_MAX;
        
        //Compute the min range based on the 2D size of the tile
        GeoExtent extent = model->_tileKey.getExtent();
        GeoPoint lowerLeft(extent.getSRS(), extent.xMin(), extent.yMin(), 0.0, ALTMODE_ABSOLUTE);
        GeoPoint upperRight(extent.getSRS(), extent.xMax(), extent.yMax(), 0.0, ALTMODE_ABSOLUTE);
        osg::Vec3d ll, ur;
        lowerLeft.toWorld( ll );
        upperRight.toWorld( ur );
        double radius = (ur - ll).length() / 2.0;
        float minRange = (float)(radius * _options.minTileRangeFactor().value());

        
        // create a PLOD so we can keep subdividing:
        osg::PagedLOD* plod = new CustomPagedLOD( _liveTiles.get(), _deadTiles.get() );
        plod->setCenter( bs.center() );
        plod->addChild( tileNode );
        plod->setRangeMode( *_options.rangeMode() );
        plod->setFileName( 1, uri );
  

        if (plod->getRangeMode() == osg::LOD::PIXEL_SIZE_ON_SCREEN)
        {
            static const float sqrt2 = sqrt(2.0f);

            minRange = 0;
            maxRange = (*_options.tilePixelSize()) * sqrt2;
            plod->setRange( 0, minRange, maxRange  );
            plod->setRange( 1, maxRange, FLT_MAX );            
        }
        else
        {
            plod->setRange( 0, minRange, maxRange );                
            plod->setRange( 1, 0, minRange );        
        }        
                        

        plod->setUserData( new MapNode::TileRangeData(minRange, maxRange) );

#if USE_FILELOCATIONCALLBACK
        osgDB::Options* options = Registry::instance()->cloneOrCreateOptions();
        options->setFileLocationCallback( new FileLocationCallback() );
        plod->setDatabaseOptions( options );

#endif
        result = plod;
        
        if ( tileHasLodBlending )
        {
            // Make the LOD transition distance, and a measure of how
            // close the tile is to an LOD change, to shaders.
            result->addCullCallback(new LODFactorCallback);
        }
    }
    else
    {
        result = tileNode;
    }

    // this cull callback dynamically adjusts the LOD scale based on distance-to-camera:
    if ( _options.lodFallOff().isSet() && *_options.lodFallOff() > 0.0 )
    {
        result->addCullCallback( new DynamicLODScaleCallback(*_options.lodFallOff()) );
    }

    // this one rejects back-facing tiles:
    if ( _mapInfo.isGeocentric() && _options.clusterCulling() == true )
    {
        osg::HeightField* hf =
            model->_elevationData.getHFLayer()->getHeightField();

        result->addCullCallback( HeightFieldUtils::createClusterCullingCallback(
            hf,
            tileNode->getLocator()->getEllipsoidModel(),
            *_options.verticalScale() ) );
    }

    parent->addChild( result );
}