std::unique_ptr<OGRPoint> centroid(const osmium::Way& way) {
std::unique_ptr<OGRLineString> ogr_linestring = m_factory.create_linestring(way);
OGRPolygon polygon;
polygon.addRing(static_cast<OGRLinearRing*>(ogr_linestring.get()));
std::unique_ptr<OGRPoint> centroid(new OGRPoint);
int ret = polygon.Centroid(centroid.get());
if (ret != OGRERR_NONE) {
std::cerr << "Couldn't calculate centroid of way = " << way.id() << ".\n";
osmium::geometry_error e(std::string("Couldn't calculate centroid of way = ") + std::to_string(way.id()) + std::string(".\n"));
throw e;
return nullptr;
} else {
return centroid;
}
return nullptr;
}
bool MapWidget::loadCountyShapes()
{
OGRRegisterAll();
std::string filename = g_dataDirectory + "/counties/tl_2009_48_county00.shp";
OGRDataSource * dataSource = OGRSFDriverRegistrar::Open(filename.c_str(), false);
if(dataSource == NULL)
{
put_flog(LOG_ERROR, "could not open %s", filename.c_str());
return false;
}
OGRLayer * layer = dataSource->GetLayerByName("tl_2009_48_county00");
layer->ResetReading();
OGRFeature * feature;
while((feature = layer->GetNextFeature()) != NULL)
{
// get county FIPS code
int nodeId = feature->GetFieldAsInteger("COUNTYFP00");
if(nodeId == 0)
{
put_flog(LOG_WARN, "invalid county");
}
// add a new county to the counties map corresponding to this nodeId
boost::shared_ptr<MapShape> county(new MapShape());
counties_[nodeId] = county;
OGRGeometry * geometry = feature->GetGeometryRef();
if(geometry != NULL && geometry->getGeometryType() == wkbPolygon)
{
OGRPolygon * polygon = (OGRPolygon *)geometry;
OGRLinearRing * ring = polygon->getExteriorRing();
for(int i=0; i<ring->getNumPoints(); i++)
{
// x is longitude, y latitude
county->addVertex(ring->getY(i), ring->getX(i));
}
// set the centroid
OGRPoint centroidPoint;
if(polygon->Centroid(¢roidPoint) == OGRERR_NONE)
{
county->setCentroid(centroidPoint.getY(), centroidPoint.getX());
}
else
{
put_flog(LOG_WARN, "no polygon centroid");
}
}
else
{
put_flog(LOG_WARN, "no polygon geometry");
}
OGRFeature::DestroyFeature(feature);
}
OGRDataSource::DestroyDataSource(dataSource);
return true;
}