/**
* 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 );
}
}
}
// 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;
}
FilterContext push(FeatureList& input, FilterContext& context)
{
if (_featureSource.valid())
{
// Get any features that intersect this query.
FeatureList boundaries;
getFeatures(context.extent().get(), boundaries );
// The list of output features
FeatureList output;
if (boundaries.empty())
{
// No intersecting features. If contains is false, then just the output to the input.
if (contains() == false)
{
output = input;
}
}
else
{
// Transform the boundaries into the coordinate system of the features
for (FeatureList::iterator itr = boundaries.begin(); itr != boundaries.end(); ++itr)
{
itr->get()->transform( context.profile()->getSRS() );
}
for(FeatureList::const_iterator f = input.begin(); f != input.end(); ++f)
{
Feature* feature = f->get();
if ( feature && feature->getGeometry() )
{
osg::Vec2d c = feature->getGeometry()->getBounds().center2d();
if ( contains() == true )
{
// coarsest:
if (_featureSource->getFeatureProfile()->getExtent().contains(GeoPoint(feature->getSRS(), c.x(), c.y())))
{
for (FeatureList::iterator itr = boundaries.begin(); itr != boundaries.end(); ++itr)
{
Ring* ring = dynamic_cast< Ring*>(itr->get()->getGeometry());
if (ring && ring->contains2D(c.x(), c.y()))
{
output.push_back( feature );
}
}
}
}
else
{
bool contained = false;
// coarsest:
if (_featureSource->getFeatureProfile()->getExtent().contains(GeoPoint(feature->getSRS(), c.x(), c.y())))
{
for (FeatureList::iterator itr = boundaries.begin(); itr != boundaries.end(); ++itr)
{
Ring* ring = dynamic_cast< Ring*>(itr->get()->getGeometry());
if (ring && ring->contains2D(c.x(), c.y()))
{
contained = true;
break;
}
}
}
if ( !contained )
{
output.push_back( feature );
}
}
}
}
}
OE_INFO << LC << "Allowed " << output.size() << " out of " << input.size() << " features\n";
input = output;
}
return context;
}
