GKSPACK

GKSPACK contains routines which may be placed into several categories.

• One category of routines is intended to ease the use of GKS for those people with simple applications who do not need further GKS features, NAG graphics users for example. These routines are built on top of GKS and are not implementation dependant. They include routines to initialize and stop GKS (GCINIT, GCSTOP), to ask the user for input (GPRMPT), etc.
• The next category of routines provide facilities to allow applications which must run on several GKS implementations to obtain information about workstation types and connection identifiers from a data file. This avoids having to ask the user interactively to supply implementation dependant values. These routines include GCGIMP, GCGWTC, etc.
• Some routines provide access to GKS features which might be awkward to use, or which may be implementation dependant. For example, use of GDPs, or the construction of menus. GKSGRAL includes a large number of utility routines of this type starting with the sentinel characters GU, and GKSPACK contains CERN-written emulations of many of them for use with other GKS implementations.
• Another category of routines is for non-standard GKS utilities which allow the user to perform specific actions not foreseen by the GKS standard, and which may require internal knowledge of the GKS implementation. Thus, it may not be possible to implement these routines for GKS implementations other than the one from GTS-GRAL if access to the source code is not available. The principal examples of routines in this category, heavily used at CERN by PAW for instance, are GCATOG and GCGTOA. These are used to switch the graphics terminal between graphics and alphanumeric mode in order for applications to intermix graphics and Fortran I/O on the same device.

For various technical reasons it has been decided to include entry points for all routines in GKSPACK in the GTS-GRAL libraries maintained by CERN. This means that users of GKSGRAL do not need to link to a separate library in order to have access to GKSPACK routines, which is a change to the previous situation when it was necessary to link applications also with the CERN library 'NGRAFLIB'.

For users of other GKS implementations a PAM file, named GKSPACK, is available. Initially, apart from GKSGRAL, this has support only for DECGKS. The PAM file distributed by the CERN Program Library will be included also on the GTS-GRAL distribution tape, and is available at CERN as follows:

IBM:

via GIME CERNPAMS

VXCERN:

in CERN_ROOT:[PAM]GKSPACK.PAM

Apollo:

in /cern/pro/pam/gkspack.pam

UNIX:

in $CERN/pro/pam/gkspack.pam

VXCERN:

GKS_ROOT:[LIB]GKSPACK_DEC.OLB

As mentioned above, GKSPACK includes some routines for which it may not be possible to produce correctly working versions for implementations other than GKSGRAL. For example, this is the situation for GCATOG and GCGTOA with DECGKS. In these cases GKSPACK contains dummy routines with the correct calling sequences, but which write out an error message to a file named GKSPACK.ERR. In fact, for GCATOG and GCGTOA, calling the dummy routines when using a terminal actually stops the application program as well. This is because if the application mixes Fortran I/O and graphics without using correctly working versions of GCATOG and GCGTOA then probably the terminal will block and need to be re-set. (If used via VM/CMS this also can block the communications.)

The GKSPACK routines which provide access to the implementation dependant values for workstation types and connection identifiers require access to a data file. Examples of this file are distributed with GKSPACK, and at CERN are available as follows:

IBM

The file is called GKS$IMPL DAT. A GTS-GRAL GKS version is available on the 'Q' disk, but users may provide their own if they wish.

VAX

The file is available via the Logical Name GKS_IMPLEMENTATION. Both GTS-GRAL and DECGKS versions of the file exist, and users must assign the one they wish to use.

GKS_ROOT:[DAT]GKS_IMPLEM.GTS
GKS_ROOT:[DAT]GKS_IMPLEM.DEC

UNIX

The file is accessed via $GKS_IMPLEM, which must be defined as an environment variable. A GTS-GRAL GKS version called gks_implem.gts is available in $gkshome, or in /cern/gks/pro/dat.

DECGKS
NB WKTYPES    5
 
PSTSCR            61     9
T4107             82     0
VT340             17     0
VXUIS             41     0
WISS               5     1

• List of routines
• GKSPACK Error Messages
• GKSPACK Example Program