Graphic Technologies, Inc. (GTI) GTViewer Reader/Writer

Licensing options for this format begin with FME Desktop Professional Edition.

Note: For more information on this format, please visit the Graphic Technologies, Inc. website at www.gti-us.com.

The GTI GTViewer Reader and Writer modules provide FME with access to Graphic Technologies, Inc.’s (GTI’s) GTViewer Format.

The GTViewer format is used by several of GTI’s products including GTViewer, Pocket GTViewer, GTVx, GTWeb, GTRead, GTCreate, GTViewer .NET Control, Pocket GTViewer .NET Control, GT/Field, and GTData.

Overview

The GTViewer format stores both geometry and attribute information for spatially organized features.

The GTViewer format is packaged in two different forms: Unextracted and Extracted. The Unextracted format is the main format used by GTViewer and consists of a .GTM file (GTViewer Manager File) plus a collection of files that are referenced by the .GTM file including graphics files, index files, query files, tabular data files, color files, fonts, linestyles, etc.

The Extracted format in the form of a .GTX file is a single file derived from a .GTM file and its dependencies. The Extracted file format is used by Pocket GTViewer, but is also a valid format for GTViewer, GTVx, GTWeb, and GTRead, and the .NET Controls. A .GTX Extract file can contain an entire dataset or only a specific area (defined by a polygon).

File Extension	Contents	Module Support
.GTM	Unextracted Data File	Write
.GTX	Extracted Data File	Read (session graphics only)
.GTG	Graphic File/Export file	Read and Write (as part of .GTM output).

The Unextracted Data managed by a .GTM file consists of a variety of file types. A summary of these file types is shown below:

File Type	Contents
.GTG Graphics File (Binary File)	Contains GTViewer Graphics elements and any embedded data for a single GTViewer category. Can be imported and exported by GTViewer, GTVx, Pocket GTViewer, and the .NET Controls. All geometry information is stored in this file type. Can be read directly by the Reader module and can be created by the Writer module.
.GTN Spatial Index File (Binary File)	Spatial index for a single .GTG file or GTViewer category. Used to increase rendering performance. Generated by the Writer module.
.DFN Font Definition file (Binary File)	Contains font information for one GTViewer text or symbol font. Used by the Reader module to get specific origin information for symbols.
Color.txt Color Definition File (ASCII File)	Maps color ID values to RGB component color values. Used by the Reader module to get color information for each element. Created or updated by the Writer module.
Filter#.FLT Display Filter Definition Files (ASCII File)	Contains default display settings (display status, min display threshold, max display threshold, select-ability, snap-ability) for each Filter ID in a single GTViewer category. Created or updated by the Writer module.
Range.txt Range Definition File (ASCII File)	Contains the default data set range for a dataset. Created by the Writer module.
Data.txt Tabular Data File (ASCII File)	Pipe delimited tabular data values with table schema. Contains one or more tables. Created by the Writer module.
Data.tab Tabular Data Definition File (ASCII File)	Schema Definition for all tables contained in the Tabular Data File. Includes all alternate names, display priorities for tables and attributes. Created by the Writer module.
Data.idx Tabular Data Index file (Binary File)	Index file for Tabular Data File. Indexes records in Tabular Data File by primary key(s). Created by the Writer module.

The Extracted Data in a .GTX file is a composite of the information in an Unextracted Data’s .GTM file and all of the files it references, producing an equivalent data representation in a single file for the entire dataset or a specific region (as defined by a polygon) in a dataset.