boost::optional<mapnik::datasource_geometry_t> ogr_datasource::get_geometry_type() const
{
boost::optional<mapnik::datasource_geometry_t> result;
if (dataset_ && layer_.is_valid())
{
OGRLayer* layer = layer_.layer();
// NOTE: wkbFlatten macro in ogr flattens 2.5d types into base 2d type
#if GDAL_VERSION_NUM < 1800
switch (wkbFlatten(layer->GetLayerDefn()->GetGeomType()))
#else
switch (wkbFlatten(layer->GetGeomType()))
#endif
{
case wkbPoint:
case wkbMultiPoint:
result.reset(mapnik::datasource_geometry_t::Point);
break;
case wkbLinearRing:
case wkbLineString:
case wkbMultiLineString:
result.reset(mapnik::datasource_geometry_t::LineString);
break;
case wkbPolygon:
case wkbMultiPolygon:
result.reset(mapnik::datasource_geometry_t::Polygon);
break;
case wkbGeometryCollection:
result.reset(mapnik::datasource_geometry_t::Collection);
break;
case wkbNone:
case wkbUnknown:
{
// fallback to inspecting first actual geometry
// TODO - csv and shapefile inspect first 4 features
if (dataset_ && layer_.is_valid())
{
layer = layer_.layer();
// only new either reset of setNext
//layer->ResetReading();
layer->SetNextByIndex(0);
OGRFeature *poFeature;
while ((poFeature = layer->GetNextFeature()) != nullptr)
{
OGRGeometry* geom = poFeature->GetGeometryRef();
if (geom && ! geom->IsEmpty())
{
switch (wkbFlatten(geom->getGeometryType()))
{
case wkbPoint:
case wkbMultiPoint:
result.reset(mapnik::datasource_geometry_t::Point);
break;
case wkbLinearRing:
case wkbLineString:
case wkbMultiLineString:
result.reset(mapnik::datasource_geometry_t::LineString);
break;
case wkbPolygon:
case wkbMultiPolygon:
result.reset(mapnik::datasource_geometry_t::Polygon);
break;
case wkbGeometryCollection:
result.reset(mapnik::datasource_geometry_t::Collection);
break;
default:
break;
}
}
OGRFeature::DestroyFeature( poFeature );
break;
}
}
break;
}
default:
break;
}
}
return result;
}
