Chapter 13. Utility Subroutines

The subroutines in this category provide convenient mechanisms for modifying data or performing calculations.

Some subroutines perform transformations on matrixes; others let your application alter the viewing characteristics in the Viewing Coordinate (VC) system. In addition, the Pack Data Record utility provides a convenient mechanism for the construction of data records used by input device initialization subroutines.

The Convert Data utility allows you to convert data to a form known by a target application when two or more application processes are communicating.

GPCCV - Convert Coordinate Values

Purpose

Use GPCCV to convert coordinate values in a window system from one coordinate system to another. Only workstations which use the facilities of a window system (e.g., X-Windows) support this procedure.

This subroutine converts Normalized Projection Coordinates (NPC), Device Coordinates (DC) or Window Units (WU).

The conversion type (ctype) parameter specifies the type of conversion to be performed. The point type (ptype) parameter specifies the organization of the input values, either as an array of two-dimentional points (1=POINT_2D ) or as an array of three-dimensional points (2=POINT_3D ) The number parameter specifies the number of two-dimensional or three-dimensional points in the input list (ilist) parameter to convert. The array of the output list (olist) is the same size as the ilist

This subroutine is assigned escape identifier 1015.

Note:

This subroutine is an escape subroutine, and therefore, may not be available on all workstations. Use the Inquire List of Available Escape Subroutines (GPQES) to determine if this subroutine is supported by a specified workstation.

Parameters