Area entities are represented in the CCOGIF file as an Area Fixed-Length Record (AFLR) and optionally, as an Area Variable-Length Record (AVLR). The FME combines the contents of these two records into a single feature – the area entity feature.
The geometry of FME's area entity feature is the coordinates of a point inside the area, as defined in the AFLR. A Z-value of -9999 represents an undefined values so any AFLRs that have a Z-value of -9999 are translated as an (x,y) coordinate instead of an (x,y,z) coordinate. Note that the area entity feature itself does not contain any polygonal geometry. Instead, it contains a list of attributes pointing to the identifiers of the lines that make up the boundary of the area. To form a polygon from CCOGIF data it is necessary to use the ReferenceFactory, or a similar factory, in the mapping file to associate the area feature with its polygonal boundaries.
In addition to the geometry and the attributes common to all entity features (listed in the previous section), area entity features have the following attributes defined:
|
Attribute Name |
Description |
Type |
| ccogif_record_code | Record code, constant AFLR. | char(4) |
| ccogif_area_id | Area ID number. | int(16) |
| ccogif_num_bnd_lines | Number of lines that form the boundaries of this polygon (n>=0). | int(16) |
| ccogif_line_id{n} | Line identifier of nth boundary line for this area. | int(16) |