Implementation-Dependent Features

Although an ISO standard, GKS still includes some features which vary from implementation to implementation or device to device. The principle features to watch are text fonts and fill area hatch styles. GKSGRAL supports 11 stroke-precision Latin text fonts plus Greek

and a solid filled font. These are illustrated in . The fonts are available both in italic and non-italic scripts, as well as proportionally and non-proportionally spaced. The font indices are given in Appendix on Page .

At CERN, GKSGRAL has been modified to provide 24 Fill Area Hatch Styles (indices -101 to -124), and these should produce the same result on all workstations (see ). Other parameters with which the package has currently been configured are:

Workstations

10 simultaneously open workstations (6 on VM)

Segments

2000 segments, names in range 1-32763

Normalization Transformations

21 (0 to 20)

Viewing Transformations

21 (0 to 20)

Fill Area

The number of points in a Fill Area primitive is limited to 300.

Polyline

If the number of points in a Polyline is larger than 300 then they will be split into several primitives.

The actual values of these and other parameters may be inquired at run-time by calling the routines:

CALL GQWKM(ERRIND, MXOPWK, MXACWK, MXWKAS)
 
CALL GQMNTN(ERRIND, MAXTNR)
 
CALL GQLWK(WTYPE, ERRIND, MPLBTE, MPMBTE, MTXBTE, MFABTE, MPAI, MCOLI)
    or
CALL GQLWK3(WTYPE, ERRIND, MPLBTE, MPMBTE, MTXBTE, MFABTE, MPAI,
             MEDBTE, MCOLI, MVTE)
 
CALL GQSGP(WTYPE, ERRIND, NSGP)

WTYPE

workstation type (input parameter)

ERRIND

error number

MXOPWK

maximum number of simultaneously open workstations

MXACWK

maximum number of simultaneously active workstations

MXWKAS

maximum number of workstations associated with a segment

MAXTNR

maximum normalization transformation number

MPLBTE

maximum number of polyline bundle table entries

MPMBTE

maximum number of polymarker bundle table entries

MTXBTE

maximum number of text bundle table entries

MFABTE

maximum number of fill area bundle table entries

MPAI

maximum number of pattern indices

MEDBTE

maximum number of edge bundle table entries

MCOLI

maximum number of colour indices

MVTE

maximum number of view table entries

NSGP

maximum number of segment priorities

picture name=FONTS$$S

Figure: GTS-GRAL italic, proportionally-spaced fonts

picture name=HATCH$$S

Figure: CERN-defined hatch patterns