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// file plugin
#include "hello_datasource.hpp"
#include "hello_featureset.hpp"
// boost
#include <boost/make_shared.hpp>
using mapnik::datasource;
using mapnik::parameters;
DATASOURCE_PLUGIN(hello_datasource)
hello_datasource::hello_datasource(parameters const& params)
: datasource(params),
desc_(*params.get<std::string>("type"), *params.get<std::string>("encoding","utf-8")),
extent_()
{
this->init(params);
}
void hello_datasource::init(mapnik::parameters const& params)
{
// every datasource must have some way of reporting its extent
// in this case we are not actually reading from any data so for fun
// let's just create a world extent in Mapnik's default srs:
// '+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs' (equivalent to +init=epsg:4326)
// see http://spatialreference.org/ref/epsg/4326/ for more details
extent_.init(-180,-90,180,90);
}
hello_datasource::~hello_datasource() { }
// This name must match the plugin filename, eg 'hello.input'
const char * hello_datasource::name()
{
return "hello";
}
mapnik::datasource::datasource_t hello_datasource::type() const
{
return datasource::Vector;
}
mapnik::box2d<double> hello_datasource::envelope() const
{
return extent_;
}
boost::optional<mapnik::datasource::geometry_t> hello_datasource::get_geometry_type() const
{
return mapnik::datasource::Point;
}
mapnik::layer_descriptor hello_datasource::get_descriptor() const
{
return desc_;
}
mapnik::featureset_ptr hello_datasource::features(mapnik::query const& q) const
{
// if the query box intersects our world extent then query for features
if (extent_.intersects(q.get_bbox()))
{
return boost::make_shared<hello_featureset>(q.get_bbox(),desc_.get_encoding());
}
// otherwise return an empty featureset pointer
return mapnik::featureset_ptr();
}
mapnik::featureset_ptr hello_datasource::features_at_point(mapnik::coord2d const& pt, double tol) const
{
// features_at_point is rarely used - only by custom applications,
// so for this sample plugin let's do nothing...
return mapnik::featureset_ptr();
}
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