示例#1
0
	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;
	}
示例#2
0
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(&centroidPoint) == 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;
}