87 lines
2.1 KiB
C++
87 lines
2.1 KiB
C++
|
// file plugin
|
||
|
|
#include "hello_datasource.hpp"
|
||
|
|
#include "hello_featureset.hpp"
|
||
|
|
|
||
|
|
using mapnik::datasource;
|
||
|
|
using mapnik::parameters;
|
||
|
|
|
||
|
|
DATASOURCE_PLUGIN(hello_datasource)
|
||
|
|
|
||
|
|
hello_datasource::hello_datasource(parameters const& params, bool bind)
|
||
|
|
: datasource(params),
|
||
|
|
type_(datasource::Vector),
|
||
|
|
desc_(*params_.get<std::string>("type"), *params_.get<std::string>("encoding","utf-8")),
|
||
|
|
extent_()
|
||
|
|
{
|
||
|
|
if (bind)
|
||
|
|
{
|
||
|
|
this->bind();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void hello_datasource::bind() const
|
||
|
|
{
|
||
|
|
if (is_bound_) return;
|
||
|
|
|
||
|
|
// 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);
|
||
|
|
|
||
|
|
is_bound_ = true;
|
||
|
|
}
|
||
|
|
|
||
|
|
hello_datasource::~hello_datasource() { }
|
||
|
|
|
||
|
|
// This name must match the plugin filename, eg 'hello.input'
|
||
|
|
std::string const hello_datasource::name_="hello";
|
||
|
|
|
||
|
|
std::string hello_datasource::name()
|
||
|
|
{
|
||
|
|
return name_;
|
||
|
|
}
|
||
|
|
|
||
|
|
int hello_datasource::type() const
|
||
|
|
{
|
||
|
|
return type_;
|
||
|
|
}
|
||
|
|
|
||
|
|
mapnik::box2d<double> hello_datasource::envelope() const
|
||
|
|
{
|
||
|
|
if (!is_bound_) bind();
|
||
|
|
|
||
|
|
return extent_;
|
||
|
|
}
|
||
|
|
|
||
|
|
mapnik::layer_descriptor hello_datasource::get_descriptor() const
|
||
|
|
{
|
||
|
|
if (!is_bound_) bind();
|
||
|
|
|
||
|
|
return desc_;
|
||
|
|
}
|
||
|
|
|
||
|
|
mapnik::featureset_ptr hello_datasource::features(mapnik::query const& q) const
|
||
|
|
{
|
||
|
|
if (!is_bound_) bind();
|
||
|
|
|
||
|
|
// if the query box intersects our world extent then query for features
|
||
|
|
if (extent_.intersects(q.get_bbox()))
|
||
|
|
{
|
||
|
|
return mapnik::featureset_ptr(new 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) const
|
||
|
|
{
|
||
|
|
if (!is_bound_) bind();
|
||
|
|
|
||
|
|
// features_at_point is rarely used - only by custom applications,
|
||
|
|
// so for this sample plugin let's do nothing...
|
||
|
|
return mapnik::featureset_ptr();
|
||
|
|
}
|