wht_type: wht_polygon
WhiteStar polygon features contain either a single polygon or an aggregate of polygons. When reading a WhiteStar entity, the reader will aggregate all linear elements for a single entity into one POLYGON feature. Similarly, the writer will put all lines contained in a single POLYGON feature into one entity in the output WhiteStar file.
The “implied closure” flag of the entity header will always be reflected in the feature type of the feature representing the entity. If the flag is set to “1” in an input WhiteStar file, LINE features will be generated. Conversely, POLYGON entities are written with the “implied closure” flag in the entity header set to a value of “1”.