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Further reading □ Overview □ Contents □ Preface □ Notation □ 1. Introduction □ 2. Graphical output □ 3. Coordinates □ 4. Segments and Attributes □ 5. Input devices □ 6. Interaction styles □ 7. Workstations □ 8. Environment □ 9. Input control □ 10. Segment storage □ 11. Metafiles □ 12. Further facilities □ 13. Individual attributes □ A. Abbreviations □ B. Language binding □ C. Complete program □ Index
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⟶ ACD ⟶ Literature ⟶ Books ⟶ GKS
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Further reading ⇓

□ Overview □ Contents □ Preface □ Notation □ 1. Introduction □ 2. Graphical output □ 3. Coordinates □ 4. Segments and Attributes □ 5. Input devices □ 6. Interaction styles □ 7. Workstations □ 8. Environment □ 9. Input control □ 10. Segment storage □ 11. Metafiles □ 12. Further facilities □ 13. Individual attributes □ A. Abbreviations □ B. Language binding □ C. Complete program □ Index

Notation

It is inevitable, in a technical work such as this, that a number of abbreviations are used. The more important ones are defined as they are introduced but, for completeness, all the abbreviations are defined in Appendix A.

GKS, itself, is defined independently of a programming language. Before it can be used from a particular language, a language binding must be defined for that language. In this book, GKS is presented in terms of the Draft International Standard FORTRAN language binding (FORTRAN 77), details of which are listed in Appendix B.

Since a language binding must obey the conventions of a language, all the subroutine names in the FORTRAN 77 language binding are restricted to be at most six characters. To make this book more readable, each subroutine name has been replaced by the full function name from the GKS document (ISO 7942). Both names are listed in Appendix B. For example, the name of the subroutine for line drawing is GPL but in this book we use the GKS name POLYLINE.

The examples in this book are given in a dialect of FORTRAN 77. In the interests of illustrating the subject matter, some liberties have been taken. In particular, no restrictions are placed on the length of identifiers and the word CALL is omitted from CALL statements.

Thus, using the example above. in FORTRAN 77 we would use:

      CALL GPL(N, X, Y)

to draw a line but here this is written as:

      POLYLINE(N, X, Y)

INTEGER and REAL values are mixed indiscriminately (for example, where a subroutine requires a REAL parameter, an INTEGER or REAL actual parameter may be used). Parameters specifying one of a number of options, which in Pascal would be of enumeration type, are written as variable names, with the assumption that the appropriate settings have been made elsewhere. For example, the GKS function to specify the CLIP (rather than NOCLIP) option for the clipping indicator will be written as:

      SET CLIPPING INDICATOR(CLIP)

In the FORTRAN 77 language binding, names have been defined for these values. These should be made available, by means of PARAMETER or DATA statements, for inclusion in application programs (in an installation dependent manner). Thus to set the clipping indicator to CLIP requires:

      CALL GSCLIP(GCLIP)
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