GRAFPAK-CGM


You may download a copy of GRAFPAK-CGM for evaluation.


GRAFPAK-CGM
ANSI/ISO CGM Generation Library for Graphics Applications. Now Available with CALS, ATA and PIP Profiles. Use Existing HCBS Plot Code to Generate CALS-Compliant CGMs.


A C Library for Computer Graphics Metafile (CGM) Generation

GRAFPAK-CGM is a library that defines an Application Programming Interface (API) for the generation of Computer Graphics Metafiles (CGMs). The library is implemented in the C programming language. The API conforms to C language conventions, but could be used from any other language.

Use of this product in application development reduces programming time and resources required to support the output of CGMs from the application. In the absence of this product, independent development of code to generate CGMs will require expert knowledge of CGM encodings, as well as the various CGM profiles relevant in a given operating environment.

The CGM Standard

Computer Graphics Metafile (CGM) is an American (ANSI X3.122-1986, FIPS Publication 128) and international (ISO/IEC 8632-1987) standard for storage, transmission and archival of graphics information. The standard defines a rich set of graphical elements and attributes; specifying encodings as well as element representation and storage formats.

There are three metafile encodings: binary, character and clear text. Binary CGMs are compact and intended for fast generation and interpretation. Character encoding is intended for situations where binary transmission is not available. Clear Text CGMs are verbose and human-readable. They may be edited with normal text editing tools. GRAFPAK-CGM is capable of generating CGMs in any of the three encodings.

CALS, PIP and ATA Application Profiles

The CGM format has been adopted as a part of the U.S. Department of Defense CALS standard (MIL-D-28003A), in the form of a CALS CGM Profile. The profile is a narrower definition of the basic standard, with additional restrictions on conformance and limitations on the use of certain elements and attributes. Similarly, the PIP profile, adopted by the petroleum industry, and the ATA profile, adopted by aerospace manufacturers, also rigorously define and restrict certain aspects of CGM files. GRAFPAK-CGM supports the generation of CGMs conforming to any of these profiles.

Programming Model

GRAFPAK-CGM implements the picture representation model defined in the CGM standard. Verbose function names with ANSI C prototypes are provided - one for each CGM element.

User Coordinate Systems

The CGM standard is quite specific in requirements for the coordinate system used in defining a picture. Once defined, the same coordinate system must be used in the entire picture. This is a limitation for many applications, where different parts of a picture are more conveniently represented in separate user defined coordinate systems. GRAFPAK-CGM alleviates this limitation by supporting a set of higher-level routines that allow the definition of multiple normalization transformations, with the appropriate one being selected for use as convenient.

Reuse Existing HCBS Code

Calcomp Host Computer Basic Software (HCBS) has been a popular FORTRAN-based direct programming interface for large plotters for many years. A vast amount of graphics output is based on this interface. GRAFPAK-CGM supports an additional interface compatible with a subset of HCBS calls. Simply relink your existing software with this library in place of HCBS and instantly make your software capable of generating CGMs directly.

Many existing graphics applications have retro-fitted GRAFPAK-CGM to the application's HCBS back-end to output CGM files. This is often done to meet the requirements to generate CALS-compliant CGMs.

GRAFPAK-CGM Feature Set

Metafile Delimiter and Descriptor Elements

Picture Descriptor and Control Elements

Graphical Primitives

Attributes

Total CGM Solutions

ATC is fully committed to the CGM standard and offers a complete family of CGM products. Generate CGMs from your application using GRAFPAK-CGM. Use Metacheck to verify conformance of your CGMs to the standard, and to the CALS profile. Incorporate MDL/I into your application and read in element-level information from CGMs. Use CGM-Spooler to view the CGMs and generate hardcopy. By using CGM solutions from ATC, you will be in the company of leading CAD vendors who obtain CGM technology from ATC.

For more information on GRAFPAK-CGM or any of our other products, contact an ATC account representative today.



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