Пример #1
0
    static bool detect_extent(boost::shared_ptr<sqlite_connection> ds,
                              bool has_spatial_index,
                              mapnik::box2d<double> & extent,
                              std::string const& index_table,
                              std::string const& metadata,
                              std::string const& geometry_field,
                              std::string const& geometry_table,
                              std::string const& key_field,
                              std::string const& table
        )
    {
        if (has_spatial_index)
        {
            std::ostringstream s;
            s << "SELECT MIN(xmin), MIN(ymin), MAX(xmax), MAX(ymax) FROM "
              << index_table;

            boost::shared_ptr<sqlite_resultset> rs(ds->execute_query(s.str()));
            if (rs->is_valid() && rs->step_next())
            {
                if (! rs->column_isnull(0))
                {
                    double xmin = rs->column_double(0);
                    double ymin = rs->column_double(1);
                    double xmax = rs->column_double(2);
                    double ymax = rs->column_double(3);
                    extent.init (xmin, ymin, xmax, ymax);
                    return true;
                }
            }
        }
        else if (! metadata.empty())
        {
            std::ostringstream s;
            s << "SELECT xmin, ymin, xmax, ymax FROM " << metadata;
            s << " WHERE LOWER(f_table_name) = LOWER('" << geometry_table << "')";
            boost::shared_ptr<sqlite_resultset> rs(ds->execute_query(s.str()));
            if (rs->is_valid() && rs->step_next())
            {
                double xmin = rs->column_double(0);
                double ymin = rs->column_double(1);
                double xmax = rs->column_double(2);
                double ymax = rs->column_double(3);
                extent.init (xmin, ymin, xmax, ymax);
                return true;
            }
        }
        else if (! key_field.empty())
        {
            std::ostringstream s;
            s << "SELECT " << geometry_field << "," << key_field
              << " FROM (" << table << ")";
            boost::shared_ptr<sqlite_resultset> rs(ds->execute_query(s.str()));
            sqlite_utils::query_extent(rs,extent);
            return true;
        }
        return false;
    }
Пример #2
0
void shape_io::read_bbox(shape_file::record_type & record, mapnik::box2d<double> & bbox)
{
    double lox = record.read_double();
    double loy = record.read_double();
    double hix = record.read_double();
    double hiy = record.read_double();
    bbox.init(lox, loy, hix, hiy);
}