C++ TileSource类代码示例

GeoImage
ImageLayer::createImageFromTileSource(const TileKey&    key,
                                      ProgressCallback* progress)
{
    TileSource* source = getTileSource();
    if ( !source )
        return GeoImage::INVALID;

    // If the profiles are different, use a compositing method to assemble the tile.
    if ( !key.getProfile()->isHorizEquivalentTo( getProfile() ) )
    {
        return assembleImage( key, progress );
    }

    // Good to go, ask the tile source for an image:
    osg::ref_ptr<TileSource::ImageOperation> op = getOrCreatePreCacheOp();

    // Fail is the image is blacklisted.
    if ( source->getBlacklist()->contains(key) )
    {
        OE_DEBUG << LC << "createImageFromTileSource: blacklisted(" << key.str() << ")" << std::endl;
        return GeoImage::INVALID;
    }

    if (!mayHaveData(key))
    {
        OE_DEBUG << LC << "createImageFromTileSource: mayHaveData(" << key.str() << ") == false" << std::endl;
        return GeoImage::INVALID;
    }

    //if ( !source->hasData( key ) )
    //{
    //    OE_DEBUG << LC << "createImageFromTileSource: hasData(" << key.str() << ") == false" << std::endl;
    //    return GeoImage::INVALID;
    //}

    // create an image from the tile source.
    osg::ref_ptr<osg::Image> result = source->createImage( key, op.get(), progress );   

    // Process images with full alpha to properly support MP blending.    
    if (result.valid() && 
        options().featherPixels() == true)
    {
        ImageUtils::featherAlphaRegions( result.get() );
    }    
    
    // If image creation failed (but was not intentionally canceled and 
    // didn't time out or end for any other recoverable reason), then
    // blacklist this tile for future requests.
    if (result == 0L)
    {
        if ( progress == 0L ||
             ( !progress->isCanceled() && !progress->needsRetry() ) )
        {
            source->getBlacklist()->add( key );
        }
    }

    return GeoImage(result.get(), key.getExtent());
}

TileSource*
TileSourceFactory::create( const TileSourceOptions& options )
{
    TileSource* result = 0L;

    std::string driver = options.getDriver();
    if ( driver.empty() )
    {
        OE_WARN << "ILLEGAL- no driver set for tile source" << std::endl;
        return 0L;
    }

    osg::ref_ptr<osgDB::Options> rwopt = Registry::instance()->cloneOrCreateOptions();
    rwopt->setPluginData( TILESOURCEOPTIONS_TAG, (void*)&options );

    std::string driverExt = std::string( ".osgearth_" ) + driver;
    result = dynamic_cast<TileSource*>( osgDB::readObjectFile( driverExt, rwopt.get() ) );
    if ( !result )
    {
        OE_WARN << "WARNING: Failed to load TileSource driver for \"" << driver << "\"" << std::endl;
    }

    // apply an Override Profile if provided.
    if ( result && options.profile().isSet() )
    {
        const Profile* profile = Profile::create(*options.profile());
        if ( profile )
        {
            result->setProfile( profile );
        }
    }

    return result;
}

bool CacheTileHandler::hasData( const TileKey& key ) const
{
    TileSource* ts = _layer->getTileSource();
    if (ts)
    {
        return ts->hasData(key);
    }
    return true;
}

GeoImage
ImageLayer::createImageFromTileSource(const TileKey&    key,
                                      ProgressCallback* progress)
{
    TileSource* source = getTileSource();
    if ( !source )
        return GeoImage::INVALID;

    // If the profiles are different, use a compositing method to assemble the tile.
    if ( !key.getProfile()->isHorizEquivalentTo( getProfile() ) )
    {
        return assembleImageFromTileSource( key, progress );
    }

    // Good to go, ask the tile source for an image:
    osg::ref_ptr<TileSource::ImageOperation> op = _preCacheOp;

    // Fail is the image is blacklisted.
    if ( source->getBlacklist()->contains(key) )
    {
        OE_DEBUG << LC << "createImageFromTileSource: blacklisted(" << key.str() << ")" << std::endl;
        return GeoImage::INVALID;
    }
    
    if ( !source->hasData( key ) )
    {
        OE_DEBUG << LC << "createImageFromTileSource: hasData(" << key.str() << ") == false" << std::endl;
        return GeoImage::INVALID;
    }

    // create an image from the tile source.
    osg::ref_ptr<osg::Image> result = source->createImage( key, op.get(), progress );

    // Process images with full alpha to properly support MP blending.    
    if ( result.valid() && *_runtimeOptions.featherPixels())
    {
        ImageUtils::featherAlphaRegions( result.get() );
    }    
    
    // If image creation failed (but was not intentionally canceled),
    // blacklist this tile for future requests.
    if ( result == 0L && (!progress || !progress->isCanceled()) )
    {
        source->getBlacklist()->add( key );
    }

    return GeoImage(result.get(), key.getExtent());
}

unsigned int
TerrainLayer::getMaxDataLevel() const
{
    //Try the setting first

    if ( _runtimeOptions->maxDataLevel().isSet() )
    {
        return _runtimeOptions->maxDataLevel().get();
    }

    //Try the TileSource
    TileSource* ts = getTileSource();
    if ( ts )
    {
        return ts->getMaxDataLevel();
    }

    //Just default
    return 20;
}

unsigned int
TerrainLayer::getMaxDataLevel() const
{
    const TerrainLayerOptions& opt = getTerrainLayerOptions();
    //Try the setting first
    if (opt.maxDataLevel().isSet())
    {
        return opt.maxDataLevel().get();
    }

    //Try the TileSource
	TileSource* ts = getTileSource();
	if (ts)
	{
		return ts->getMaxDataLevel();
	}

    //Just default
	return 20;
}

std::shared_ptr<Tile> TileBuilder::build(TileID _tileID, const TileData& _tileData, const TileSource& _source) {

    m_selectionFeatures.clear();

    auto tile = std::make_shared<Tile>(_tileID, *m_scene->mapProjection(), &_source);

    tile->initGeometry(m_scene->styles().size());

    m_styleContext.setKeywordZoom(_tileID.s);

    for (auto& builder : m_styleBuilder) {
        if (builder.second)
            builder.second->setup(*tile);
    }

    for (const auto& datalayer : m_scene->layers()) {

        if (datalayer.source() != _source.name()) { continue; }

        for (const auto& collection : _tileData.layers) {

            if (!collection.name.empty()) {
                const auto& dlc = datalayer.collections();
                bool layerContainsCollection =
                    std::find(dlc.begin(), dlc.end(), collection.name) != dlc.end();

                if (!layerContainsCollection) { continue; }
            }

            for (const auto& feat : collection.features) {
                applyStyling(feat, datalayer);
            }
        }
    }

    for (auto& builder : m_styleBuilder) {

        builder.second->addLayoutItems(m_labelLayout);
    }

    float tileSize = m_scene->mapProjection()->TileSize() * m_scene->pixelScale();

    m_labelLayout.process(_tileID, tile->getInverseScale(), tileSize);

    for (auto& builder : m_styleBuilder) {
        tile->setMesh(builder.second->style(), builder.second->build());
    }

    tile->setSelectionFeatures(m_selectionFeatures);

    return tile;
}

void
CompositeTileSource::initialize( const std::string& referenceURI, const Profile* overrideProfile )
{
    osg::ref_ptr<const Profile> profile = overrideProfile;

    for(CompositeTileSourceOptions::ComponentVector::iterator i = _options._components.begin();
        i != _options._components.end();
        ++i)
    {
        TileSource* source = i->_tileSourceInstance.get();
        if ( source )
        {
            osg::ref_ptr<const Profile> localOverrideProfile = overrideProfile;

            const TileSourceOptions& opt = source->getOptions();
            if ( opt.profile().isSet() )
                localOverrideProfile = Profile::create( opt.profile().value() );

            source->initialize( referenceURI, localOverrideProfile.get() );

            if ( !profile.valid() )
            {
                // assume the profile of the first source to be the overall profile.
                profile = source->getProfile();
            }
            else if ( !profile->isEquivalentTo( source->getProfile() ) )
            {
                // if sub-sources have different profiles, print a warning because this is
                // not supported!
                OE_WARN << LC << "Components with differing profiles are not supported. " 
                    << "Visual anomalies may result." << std::endl;
            }
            
            _dynamic = _dynamic || source->isDynamic();

            // gather extents
            const DataExtentList& extents = source->getDataExtents();
            for( DataExtentList::const_iterator j = extents.begin(); j != extents.end(); ++j )
            {
                getDataExtents().push_back( *j );
            }
        }
    }

    setProfile( profile.get() );

    _initialized = true;
}

void CableRenderer::render(const TilePos& pos, Tile* tile, TileTessellator* tess) {
	int x = pos.x, y = pos.y, z = pos.z;
	TileSource* ts = tess->region;
	
	bool front = ts->getTile(x + 1, y, z) == tile->id;
	bool back = ts->getTile(x - 1, y, z) == tile->id;
	bool left = ts->getTile(x, y, z + 1) == tile->id;
	bool right = ts->getTile(x, y, z - 1) == tile->id;
	bool bottom = ts->getTile(x, y - 1, z) == tile->id;
	bool top = ts->getTile(x, y + 1, z) == tile->id;
	
	tess->useForcedUV = true;
	tess->forcedUV = tile->getTexture(0, 0);
	
	tess->setRenderBounds(0.4, 0.4, 0.4, 0.6, 0.6, 0.6);
	tess->tessellateBlockInWorld(tile, {x, y, z});
	
	if(front) {
		tess->setRenderBounds(0.6, 0.4, 0.4, 1, 0.6, 0.6);
		tess->tessellateBlockInWorld(tile, {x, y, z});
	}
	
	if(back) {
		tess->setRenderBounds(0, 0.4, 0.4, 0.4, 0.6, 0.6);
		tess->tessellateBlockInWorld(tile, {x, y, z});
	}
	
	if(left) {
		tess->setRenderBounds(0.4, 0.4, 0.6, 0.6, 0.6, 1);
		tess->tessellateBlockInWorld(tile, {x, y, z});
	}
	
	if(right) {
		tess->setRenderBounds(0.4, 0.4, 0, 0.6, 0.6, 0.4);
		tess->tessellateBlockInWorld(tile, {x, y, z});
	}
	
	if(bottom) {
		tess->setRenderBounds(0.4, 0, 0.4, 0.6, 0.4, 0.6);
		tess->tessellateBlockInWorld(tile, {x, y, z});
	}
	
	if(top) {
		tess->setRenderBounds(0.4, 0.6, 0.4, 0.6, 1, 0.6);
		tess->tessellateBlockInWorld(tile, {x, y, z});
	}
	tess->useForcedUV = false;
}

bool PistonArmTile::addCollisionShapes(TileSource& region, int x, int y, int z, AABB const* posAABB, std::vector<AABB, std::allocator<AABB>>& pool) {
	int data = region.getData(x, y, z);
	float var9 = 0.25F;
	float var10 = 0.375F;
	float var11 = 0.625F;
	float var12 = 0.25F;
	float var13 = 0.75F;

	switch(getRotation(data)) {
    	case 0:
    	    addAABB(AABB(0.0F, 0.0F, 0.0F, 1.0F, 0.25F, 1.0F).move(x, y, z), posAABB, pool);
    	    addAABB(AABB(0.375F, 0.25F, 0.375F, 0.625F, 1.0F, 0.625F).move(x, y, z), posAABB, pool);
    	    break;
    	case 1:
    	    addAABB(AABB(0.0F, 0.75F, 0.0F, 1.0F, 1.0F, 1.0F).move(x, y, z), posAABB, pool);
    	    addAABB(AABB(0.375F, 0.0F, 0.375F, 0.625F, 0.75F, 0.625F).move(x, y, z), posAABB, pool);
    	    break;
    	case 2:
    	    addAABB(AABB(0.0F, 0.0F, 0.0F, 1.0F, 1.0F, 0.25F).move(x, y, z), posAABB, pool);
    	    addAABB(AABB(0.25F, 0.375F, 0.25F, 0.75F, 0.625F, 1.0F).move(x, y, z), posAABB, pool);
    	    break;
    	case 3:
    	    addAABB(AABB(0.0F, 0.0F, 0.75F, 1.0F, 1.0F, 1.0F).move(x, y, z), posAABB, pool);
    	    addAABB(AABB(0.25F, 0.375F, 0.0F, 0.75F, 0.625F, 0.75F).move(x, y, z), posAABB, pool);
    	    break;
    	case 4:
    	    addAABB(AABB(0.0F, 0.0F, 0.0F, 0.25F, 1.0F, 1.0F).move(x, y, z), posAABB, pool);
    	    addAABB(AABB(0.375F, 0.25F, 0.25F, 0.625F, 0.75F, 1.0F).move(x, y, z), posAABB, pool);
    	    break;
    	case 5:
    	    addAABB(AABB(0.75F, 0.0F, 0.0F, 1.0F, 1.0F, 1.0F).move(x, y, z), posAABB, pool);
    	    addAABB(AABB(0.0F, 0.375F, 0.25F, 0.75F, 0.625F, 0.75F).move(x, y, z), posAABB, pool);
    	    break;
    }
	return true;
}

osg::Image*
CompositeTileSource::createImage( const TileKey& key, ProgressCallback* progress )
{
    ImageMixVector images;
    images.reserve( _options._components.size() );

    for(CompositeTileSourceOptions::ComponentVector::const_iterator i = _options._components.begin();
            i != _options._components.end();
            ++i )
    {
        if ( progress && progress->isCanceled() )
            return 0L;

        TileSource* source = i->_tileSourceInstance->get();
        if ( source )
        {

            //TODO:  This duplicates code in ImageLayer::isKeyValid.  Maybe should move that to TileSource::isKeyValid instead
            int minLevel = 0;
            int maxLevel = INT_MAX;
            if (i->_imageLayerOptions->minLevel().isSet())
            {
                minLevel = i->_imageLayerOptions->minLevel().value();
            }
            else if (i->_imageLayerOptions->minLevelResolution().isSet())
            {
                minLevel = source->getProfile()->getLevelOfDetailForHorizResolution( i->_imageLayerOptions->minLevelResolution().value(), source->getPixelsPerTile());
            }

            if (i->_imageLayerOptions->maxLevel().isSet())
            {
                maxLevel = i->_imageLayerOptions->maxLevel().value();
            }
            else if (i->_imageLayerOptions->maxLevelResolution().isSet())
            {
                maxLevel = source->getProfile()->getLevelOfDetailForHorizResolution( i->_imageLayerOptions->maxLevelResolution().value(), source->getPixelsPerTile());
            }




            // check that this source is within the level bounds:
            if (minLevel > key.getLevelOfDetail() ||
                    maxLevel < key.getLevelOfDetail() )
            {
                continue;
            }





            if ( !source->getBlacklist()->contains( key.getTileId() ) )
            {
                //Only try to get data if the source actually has data
                if ( source->hasData( key ) )
                {
                    osg::ref_ptr< ImageLayerPreCacheOperation > preCacheOp;
                    if ( i->_imageLayerOptions.isSet() )
                    {
                        preCacheOp = new ImageLayerPreCacheOperation();
                        preCacheOp->_processor.init( i->_imageLayerOptions.value(), true );
                    }



                    ImageOpacityPair imagePair(
                        source->createImage( key, preCacheOp.get(), progress ),
                        1.0f );

                    //If the image is not valid and the progress was not cancelled, blacklist
                    if (!imagePair.first.valid() && (!progress || !progress->isCanceled()))
                    {
                        //Add the tile to the blacklist
                        OE_DEBUG << LC << "Adding tile " << key.str() << " to the blacklist" << std::endl;
                        source->getBlacklist()->add( key.getTileId() );
                    }

                    if ( imagePair.first.valid() )
                    {
                        // check for opacity:
                        imagePair.second = i->_imageLayerOptions.isSet() ? i->_imageLayerOptions->opacity().value() : 1.0f;

                        images.push_back( imagePair );
                    }
                }
                else
                {
                    OE_DEBUG << LC << "Source has no data at " << key.str() << std::endl;
                }
            }
            else
            {
                OE_DEBUG << LC << "Tile " << key.str() << " is blacklisted, not checking" << std::endl;
            }
        }
    }

    if ( progress && progress->isCanceled() )
    {
//.........这里部分代码省略.........

Status
CompositeTileSource::initialize(const osgDB::Options* dbOptions)
{
    _dbOptions = Registry::instance()->cloneOrCreateOptions(dbOptions);

    osg::ref_ptr<const Profile> profile = getProfile();

    for(CompositeTileSourceOptions::ComponentVector::iterator i = _options._components.begin();
        i != _options._components.end(); )
    {        
        if ( i->_imageLayerOptions.isSet() && !i->_layer.valid() )
        {
            // Disable the l2 cache for composite layers so that we don't get run out of memory on very large datasets.
            i->_imageLayerOptions->driver()->L2CacheSize() = 0;

            osg::ref_ptr< ImageLayer > layer = new ImageLayer(*i->_imageLayerOptions);
            layer->setReadOptions(_dbOptions.get());
            Status status = layer->open();
            if (status.isOK())
            {
                i->_layer = layer;
                _imageLayers.push_back( layer );
                OE_INFO << LC << " .. added image layer " << layer->getName() << " (" << i->_imageLayerOptions->driver()->getDriver() << ")\n";
            }
            else
            {
                OE_WARN << LC << "Could not open image layer (" << layer->getName() << ") ... " << status.message() << std::endl;
            }            
        }
        else if (i->_elevationLayerOptions.isSet() && !i->_layer.valid())
        {
            // Disable the l2 cache for composite layers so that we don't get run out of memory on very large datasets.
            i->_elevationLayerOptions->driver()->L2CacheSize() = 0;

            osg::ref_ptr< ElevationLayer > layer = new ElevationLayer(*i->_elevationLayerOptions);   
            layer->setReadOptions(_dbOptions.get());
            Status status = layer->open();
            if (status.isOK())
            {
                i->_layer = layer;
                _elevationLayers.push_back( layer.get() );                
            }
            else
            {
                OE_WARN << LC << "Could not open elevation layer (" << layer->getName() << ") ... " << status.message() << std::endl;
            }
        }

        if ( !i->_layer.valid() )
        {
            OE_WARN << LC << "A component has no valid TerrainLayer ... removing." << std::endl;
            i = _options._components.erase( i );
        }
        else
        {            
            TileSource* source = i->_layer->getTileSource();

            // If no profile is specified assume they want to use the profile of the first layer in the list.
            if (!profile.valid())
            {
                profile = source->getProfile();
            }

            _dynamic = _dynamic || source->isDynamic();
            
            // gather extents                        
            const DataExtentList& extents = source->getDataExtents();            
            for( DataExtentList::const_iterator j = extents.begin(); j != extents.end(); ++j )
            {                
                // Convert the data extent to the profile that is actually used by this TileSource
                DataExtent dataExtent = *j;                
                GeoExtent ext = dataExtent.transform(profile->getSRS());
                unsigned int minLevel = 0;
                unsigned int maxLevel = profile->getEquivalentLOD( source->getProfile(), *dataExtent.maxLevel() );                                        
                dataExtent = DataExtent(ext, minLevel, maxLevel);                                
                getDataExtents().push_back( dataExtent );
            }          
        }

        ++i;
    }

    // set the new profile that was derived from the components
    setProfile( profile.get() );

    _initialized = true;
    return STATUS_OK;
}

osg::Image*
CompositeTileSource::createImage( const TileKey& key, ProgressCallback* progress )
{
    ImageMixVector images;
    images.reserve( _options._components.size() );

    for(CompositeTileSourceOptions::ComponentVector::const_iterator i = _options._components.begin();
        i != _options._components.end();
        ++i )
    {
        if ( progress && progress->isCanceled() )
            return 0L;

        // check that this source is within the level bounds:
        if (i->_imageLayerOptions->minLevel().value() > key.getLevelOfDetail() ||
            i->_imageLayerOptions->maxLevel().value() < key.getLevelOfDetail() )
        {
            continue;
        }

        TileSource* source = i->_tileSourceInstance->get();
        if ( source )
        {
            if ( !source->getBlacklist()->contains( key.getTileId() ) )
            {
                //Only try to get data if the source actually has data
                if ( source->hasData( key ) )
                {
                    ImageOpacityPair imagePair(
                        source->createImage( key, _preCacheOp.get(), progress ),
                        1.0f );

                    //If the image is not valid and the progress was not cancelled, blacklist
                    if (!imagePair.first.valid() && (!progress || !progress->isCanceled()))
                    {
                        //Add the tile to the blacklist
                        OE_DEBUG << LC << "Adding tile " << key.str() << " to the blacklist" << std::endl;
                        source->getBlacklist()->add( key.getTileId() );
                    }

                    if ( imagePair.first.valid() )
                    {
                        // check for opacity:
                        imagePair.second = i->_imageLayerOptions.isSet() ? i->_imageLayerOptions->opacity().value() : 1.0f;

                        images.push_back( imagePair );
                    }
                }
                else
                {
                    OE_DEBUG << LC << "Source has no data at " << key.str() << std::endl;
                }
            }
            else
            {
                OE_DEBUG << LC << "Tile " << key.str() << " is blacklisted, not checking" << std::endl;
            }
        }
    }

    if ( progress && progress->isCanceled() )
    {
        return 0L;
    }
    else if ( images.size() == 0 )
    {
        return 0L;
    }
    else if ( images.size() == 1 )
    {
        return images[0].first.release();
    }
    else
    {
        osg::Image* result = new osg::Image( *images[0].first.get() );
        for( unsigned int i=1; i<images.size(); ++i )
        {
            ImageOpacityPair& pair = images[i];
            if ( pair.first.valid() )
            {
                ImageUtils::mix( result, pair.first.get(), pair.second );
            }
        }
        return result;
    }
}

osg::Image*
CompositeTileSource::createImage(const TileKey&    key,
                                 ProgressCallback* progress )
{
    ImageMixVector images;
    images.reserve( _options._components.size() );

    for(CompositeTileSourceOptions::ComponentVector::const_iterator i = _options._components.begin();
        i != _options._components.end();
        ++i )
    {
        if ( progress && progress->isCanceled() )
            return 0L;

        ImageInfo imageInfo;
        imageInfo.dataInExtents = false;



        TileSource* source = i->_tileSourceInstance.get();
        if ( source )
        {
            //TODO:  This duplicates code in ImageLayer::isKeyValid.  Maybe should move that to TileSource::isKeyValid instead
            int minLevel = 0;
            int maxLevel = INT_MAX;
            if (i->_imageLayerOptions->minLevel().isSet())
            {
                minLevel = i->_imageLayerOptions->minLevel().value();
            }
            else if (i->_imageLayerOptions->minResolution().isSet())
            {
                minLevel = source->getProfile()->getLevelOfDetailForHorizResolution( 
                    i->_imageLayerOptions->minResolution().value(), 
                    source->getPixelsPerTile());
            }

            if (i->_imageLayerOptions->maxLevel().isSet())
            {
                maxLevel = i->_imageLayerOptions->maxLevel().value();
            }
            else if (i->_imageLayerOptions->maxResolution().isSet())
            {
                maxLevel = source->getProfile()->getLevelOfDetailForHorizResolution( 
                    i->_imageLayerOptions->maxResolution().value(), 
                    source->getPixelsPerTile());
            }

            // check that this source is within the level bounds:
            if (minLevel > (int)key.getLevelOfDetail() ||
                maxLevel < (int)key.getLevelOfDetail() )
            {
                continue;
            }
            
                //Only try to get data if the source actually has data                
                if (source->hasDataInExtent( key.getExtent() ) )
                {
                    //We have data within these extents
                    imageInfo.dataInExtents = true;

                    if ( !source->getBlacklist()->contains( key.getTileId() ) )
                    {                        
                        osg::ref_ptr< ImageLayerPreCacheOperation > preCacheOp;
                        if ( i->_imageLayerOptions.isSet() )
                        {
                            preCacheOp = new ImageLayerPreCacheOperation();
                            preCacheOp->_processor.init( i->_imageLayerOptions.value(), _dbOptions.get(), true );                        
                        }

                        imageInfo.image = source->createImage( key, preCacheOp.get(), progress );
                        imageInfo.opacity = 1.0f;

                        //If the image is not valid and the progress was not cancelled, blacklist
                        if (!imageInfo.image.valid() && (!progress || !progress->isCanceled()))
                        {
                            //Add the tile to the blacklist
                            OE_DEBUG << LC << "Adding tile " << key.str() << " to the blacklist" << std::endl;
                            source->getBlacklist()->add( key.getTileId() );
                        }
                        imageInfo.opacity = i->_imageLayerOptions.isSet() ? i->_imageLayerOptions->opacity().value() : 1.0f;
                    }
                }
                else
                {
                    OE_DEBUG << LC << "Source has no data at " << key.str() << std::endl;
                }
        }

        //Add the ImageInfo to the list
        images.push_back( imageInfo );
    }

    unsigned numValidImages = 0;
    osg::Vec2s textureSize;
    for (unsigned int i = 0; i < images.size(); i++)
    {
        ImageInfo& info = images[i];
        if (info.image.valid())
        {
            if (numValidImages == 0)
//.........这里部分代码省略.........

TileSource::Status
CompositeTileSource::initialize(const osgDB::Options* dbOptions)
{
    _dbOptions = Registry::instance()->cloneOrCreateOptions(dbOptions);

    osg::ref_ptr<const Profile> profile = getProfile();

    for(CompositeTileSourceOptions::ComponentVector::iterator i = _options._components.begin();
        i != _options._components.end(); )
    {
        if ( i->_imageLayerOptions.isSet() )
        {
            if ( !i->_tileSourceInstance.valid() )
            {
                i->_tileSourceInstance = TileSourceFactory::create( i->_imageLayerOptions->driver().value() );
            
                if ( !i->_tileSourceInstance.valid() )
                {
                    OE_WARN << LC << "Could not find a TileSource for driver [" << i->_imageLayerOptions->driver()->getDriver() << "]" << std::endl;
                }
            }
        }

        if ( !i->_tileSourceInstance.valid() )
        {
            OE_WARN << LC << "A component has no valid TileSource ... removing." << std::endl;
            i = _options._components.erase( i );
        }
        else
        {
            TileSource* source = i->_tileSourceInstance.get();
            if ( source )
            {
                osg::ref_ptr<const Profile> localOverrideProfile = profile.get();

                const TileSourceOptions& opt = source->getOptions();
                if ( opt.profile().isSet() )
                {
                    localOverrideProfile = Profile::create( opt.profile().value() );
                    source->setProfile( localOverrideProfile.get() );
                }

                // initialize the component tile source:
                TileSource::Status compStatus = source->startup( _dbOptions.get() );

                if ( compStatus == TileSource::STATUS_OK )
                {
                    if ( !profile.valid() )
                    {
                        // assume the profile of the first source to be the overall profile.
                        profile = source->getProfile();
                    }
                    else if ( !profile->isEquivalentTo( source->getProfile() ) )
                    {
                        // if sub-sources have different profiles, print a warning because this is
                        // not supported!
                        OE_WARN << LC << "Components with differing profiles are not supported. " 
                            << "Visual anomalies may result." << std::endl;
                    }
                
                    _dynamic = _dynamic || source->isDynamic();

                    // gather extents
                    const DataExtentList& extents = source->getDataExtents();
                    for( DataExtentList::const_iterator j = extents.begin(); j != extents.end(); ++j )
                    {
                        getDataExtents().push_back( *j );
                    }
                }

                else
                {
                    // if even one of the components fails to initialize, the entire
                    // composite tile source is invalid.
                    return Status::Error("At least one component is invalid");
                }
            }
        }

        ++i;
    }

    // set the new profile that was derived from the components
    setProfile( profile.get() );

    _initialized = true;
    return STATUS_OK;
}