// override
// Creates an image.
osg::Image* createImage(const TileKey& key,
ProgressCallback* progress )
{
if ( !_imageLayer.valid() || !_featureSource.valid() )
return 0L;
// fetch the image for this key:
GeoImage image = _imageLayer->createImage(key, progress);
if ( !image.valid() )
return 0L;
// fetch a set of features for this key. The features are in their
// own SRS, so we need to transform:
const SpatialReference* featureSRS = _featureSource->getFeatureProfile()->getSRS();
GeoExtent extentInFeatureSRS = key.getExtent().transform( featureSRS );
// assemble a spatial query. It helps if your features have a spatial index.
Query query;
query.bounds() = extentInFeatureSRS.bounds();
//query.expression() = ... // SQL expression compatible with data source
osg::ref_ptr<FeatureCursor> cursor = _featureSource->createFeatureCursor(query);
// create a new image to return.
osg::Image* output = new osg::Image();
//output->allocateImage(128, 128, 1, GL_RGB, GL_UNSIGNED_BYTE);
// do your magic here.
return output;
}
/**
* Gets all the features that intersect the extent
*/
void getFeatures(const GeoExtent& extent, FeatureList& features)
{
GeoExtent localExtent = extent.transform( _featureSource->getFeatureProfile()->getSRS() );
Query query;
query.bounds() = localExtent.bounds();
if (localExtent.intersects( _featureSource->getFeatureProfile()->getExtent()))
{
osg::ref_ptr< FeatureCursor > cursor = _featureSource->createFeatureCursor( query );
if (cursor)
{
cursor->fill( features );
}
}
}