ComGraphix Data Exchange Format (CGDEF) Reader/Writer

FME provides reader and writer access to MapGrafix import and export files. The ComGrafix Data Exchange Format (CGDEF) is a published ASCII format that can be used by the MapGrafix product for input and output.

ComGraphix Data Exchange Format Files are often called CGDEF files.


MapGraphix is a two-dimensional (2D) system with no provision for storing user-defined attributes with the geometric data. The CGDEF reader and writer support symbols (point), lines (vector), polylines, arcs (arc, ovalarc, and polyarc), ellipses (oval, circle), polygons, and text geometric data.

Some geometric entities may have display properties such as pen and brush width
(lineweight), pattern, and color.

CGDEF files are ASCII format, and use a system of keywords and values to define map parameters, overlay (layer) structure, element definitions and graphic attributes. All CGDEF map and vector geometric data is contained in a single file with the .cgdef extension.

Note: FME does not support the import and export of TIFF files with the CGDEF. TIFF files operate on the image layer, which is something that FME does not support.

Reader Overview

The CGDEF reader first opens CGDEF file defined in the workspace. The CGDEF reader then extracts map parameters, followed by overlay definitions, and all the features from the file. Options are provided for returning symbols as single points, or exploded into their component pieces.

Writer Overview

The CGDEF writer creates and writes feature data to the CGDEF file specified by writer dataset. The folder where the file is created must exist before the translation occurs, and if there is an old CGDEF file with the same filename in the folder, it will be overwritten with the new feature data.

Before actually writing out features, the writer first scans the prototype/template file (defined in the writer parameters) to extract all the header information required by CGDEF.