GESC(3NCARG)

NAME
gesc - Provide "Escape" for non-standard GKS features

DESCRIPTION
GESC (Escape) - provides a standard way of implementing nonstandard GKS features. NCAR GKS has only two user-accessible escape functions defined: one for changing the name of a metafile and another for pausing in an X window.

SYNOPSIS
CALL GESC (FCTID, LIDR, IDR, MXODR, LODR, ODR)

C-BINDING SYNOPSIS
#include <ncarg/gks.h>

void gescape(Gint func_id, const Gescape_in_data *in_data, Gstore *store_data,Gescape_out_data **out_data);

DESCRIPTION

FCTID
    (Integer, Input) - A function identifier specifying the requested activity. The legal values for FCTID are "-1391" for changing a metafile name and "-1396" for effecting a pause in an X window.

LIDR
    (Integer, Input) - Dimension of the IDR input data record array (for IDR, see below).

IDR (Character * 80 Array, Input) - Input data record. For calls to GESC with FCTID equal to -1391 the input data record should contain the desired metafile name left justified and blank filled; for calls to GESC with FCTID equal to -1396 the input data record should contain the workstation identifier encoded as a five character number.

MXODR
    (Integer, Input) - Maximum length of the ODR output data record array (for ODR, see below).

LODR
    (Integer, Output) - Dimension of the ODR output data record array.

ODR (MXODR)
    (Character * 80 Array, Output) - Output data record.

USAGE
LIDR, MXODR, and LODR must always be at least "1" in value.

EXAMPLES
GESC can be used to dynamically change the name of an output metafile and to do so one should use the calls GOPKS and GOPWK instead of OPNGKS. If you are using OPNGKS, see the man page for SETUSV for changing the name of the metafile.

To change the name of the output metafile inside your program, you should make a call similar to the following:

       CHARACTER*80 MFNAME

       CALL GOPKS (6,IDUM)
       MFNAME = 'new.cgm.name'
       CALL GESC(-1391,1,MFNAME,1,1,CDUM)

The call to GESC to change the metafile name must always occur just before the call to GOPWK that opens a CGM workstation. Setting the environment variable NCARG_GKS_OUTPUT overrides any attempt to change the name of an output metafile via a GESC call.

See the "User's Guide for NCAR GKS-0A Graphics" for a more complete example of changing metafile names from within a code.

Here is an example of a code that will create an X window, draw a line, and then pause waiting for a mouse click or a key click.

       CHARACTER*80 IREC,ODUM
       CALL GOPKS(6,0)
       CALL GOPWK(3,0,8)
       CALL GACWK(3)
       CALL LINE(0.,0.,1.,1.)
       CALL SFLUSH
       IREC = '    3'
       CALL GESC(-1396,1,IREC,1,1,ODUM)
       CALL GDAWK(3)
       CALL GCLWK(3)
       CALL GCLKS
       STOP
       END

The functions FRAME and NGPICT are in general much easier to use and more flexible than the direct ESCAPE call for pausing in an X window. It is suggested that those functions be used.

ACCESS
To use GKS routines, load the NCAR GKS-0A library ncarg_gks.

SEE ALSO
Online: SETUSV, FRAME, NGPICT, gescape

Hardcopy: User's Guide for NCAR GKS-0A Graphics; NCAR Graphics Fundamentals, UNIX Version

COPYRIGHT
Copyright (C) 1987-2009
University Corporation for Atmospheric Research
The use of this Software is governed by a License Agreement.