C++ TileSource::hasDataInExtent方法代码示例

    void execute()
    {
        GeoImage geoImage;
        bool isFallbackData = false;

        bool useMercatorFastPath =
            _opt->enableMercatorFastPath() != false &&
            _mapInfo->isGeocentric()                &&
            _layer->getProfile()                    &&
            _layer->getProfile()->getSRS()->isSphericalMercator();

        // fetch the image from the layer, falling back on parent keys utils we are 
        // able to find one that works.

        bool autoFallback = _key.getLevelOfDetail() <= 1;

        TileKey imageKey( _key );
        TileSource* tileSource = _layer->getTileSource();
        const Profile* layerProfile = _layer->getProfile();

        //Only try to get data from the source if it actually intersects the key extent
        bool hasDataInExtent = true;
        if (tileSource && layerProfile)
        {
            GeoExtent ext = _key.getExtent();
            if (!layerProfile->getSRS()->isEquivalentTo( ext.getSRS()))
            {
                ext = layerProfile->clampAndTransformExtent( ext );
            }
            hasDataInExtent = ext.isValid() && tileSource->hasDataInExtent( ext );
        }        
        
        if (hasDataInExtent)
        {
            while( !geoImage.valid() && imageKey.valid() && _layer->isKeyValid(imageKey) )
            {
                if ( useMercatorFastPath )
                {
                    bool mercFallbackData = false;
                    geoImage = _layer->createImageInNativeProfile( imageKey, 0L, autoFallback, mercFallbackData );
                    if ( geoImage.valid() && mercFallbackData )
                    {
                        isFallbackData = true;
                    }
                }
                else
                {
                    geoImage = _layer->createImage( imageKey, 0L, autoFallback );
                }

                if ( !geoImage.valid() )
                {
                    imageKey = imageKey.createParentKey();
                    isFallbackData = true;
                }
            }
        }

        GeoLocator* locator = 0L;

        if ( !geoImage.valid() )
        {
            // no image found, so make an empty one (one pixel alpha).
            geoImage = GeoImage( ImageUtils::createEmptyImage(), _key.getExtent() );
            locator = GeoLocator::createForKey( _key, *_mapInfo );
            isFallbackData = true;
        }
        else
        {
            if ( useMercatorFastPath )
                locator = new MercatorLocator(geoImage.getExtent());
            else
                locator = GeoLocator::createForExtent(geoImage.getExtent(), *_mapInfo);
        }

        bool isStreaming = _opt->loadingPolicy()->mode() == LoadingPolicy::MODE_PREEMPTIVE || _opt->loadingPolicy()->mode() == LoadingPolicy::MODE_SEQUENTIAL;

        if (geoImage.getImage() && isStreaming)
        {
            // protected against multi threaded access. This is a requirement in sequential/preemptive mode, 
            // for example. This used to be in TextureCompositorTexArray::prepareImage.
            // TODO: review whether this affects performance.    
            geoImage.getImage()->setDataVariance( osg::Object::DYNAMIC );
        }

        // add the color layer to the repo.
        _repo->add( CustomColorLayer(
            _layer,
            geoImage.getImage(),
            locator,
            _key.getLevelOfDetail(),
            _key,
            isFallbackData ) );
    }

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.........

GeoImage
ImageLayer::createImageFromTileSource(const TileKey&    key,
                                      ProgressCallback* progress,
                                      bool              forceFallback,
                                      bool&             out_isFallback)
{
    // Results:
    // 
    // * return an osg::Image matching the key extent is all goes well;
    //
    // * return NULL to indicate that the key exceeds the maximum LOD of the source data,
    //   and that the engine may need to generate a "fallback" tile if necessary;
    //
    // deprecated:
    // * return an "empty image" if the LOD is valid BUT the key does not intersect the
    //   source's data extents.

    out_isFallback = false;

    TileSource* source = getTileSource();
    if ( !source )
        return GeoImage::INVALID;

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

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

    osg::ref_ptr<osg::Image> result;

    if ( forceFallback )
    {
        // check if the tile source has any data coverage for the requested key.
        // the LOD is ignore here and checked later
        if ( !source->hasDataInExtent( key.getExtent() ) )
        {
            OE_DEBUG << LC << "createImageFromTileSource: hasDataInExtent(" << key.str() << ") == false" << std::endl;
            return GeoImage::INVALID;
        }

        TileKey finalKey = key;
        while( !result.valid() && finalKey.valid() )
        {
            if ( !source->getBlacklist()->contains( finalKey.getTileId() ) &&
                source->hasDataForFallback(finalKey))
            {
                result = source->createImage( finalKey, op.get(), progress );
                if ( result.valid() )
                {
                    if ( finalKey.getLevelOfDetail() != key.getLevelOfDetail() )
                    {
                        // crop the fallback image to match the input key, and ensure that it remains the
                        // same pixel size; because chances are if we're requesting a fallback that we're
                        // planning to mosaic it later, and the mosaicer requires same-size images.
                        GeoImage raw( result.get(), finalKey.getExtent() );
                        GeoImage cropped = raw.crop( key.getExtent(), true, raw.getImage()->s(), raw.getImage()->t(), *_runtimeOptions.driver()->bilinearReprojection() );
                        result = cropped.takeImage();
                    }
                }
            }
            if ( !result.valid() )
            {
                finalKey = finalKey.createParentKey();
                out_isFallback = true;
            }
        }

        if ( !result.valid() )
        {
            result = 0L;
            //result = _emptyImage.get();
            finalKey = key;
        }
    }
    else
    {
        // Fail is the image is blacklisted.
        if ( source->getBlacklist()->contains( key.getTileId() ) )
        {
            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;
        }
        result = source->createImage( key, op.get(), progress );
    }

    // Process images with full alpha to properly support MP blending.    
    if ( result != 0L && *_runtimeOptions.featherPixels())
    {
        ImageUtils::featherAlphaRegions( result.get() );
    }    
//.........这里部分代码省略.........