PHIGS is the latest of the computer graphics standards. It builds on the earlier standards, GKS and GKS-3D, with the main emphasis on providing a 2D and 3D graphics standard aimed at the person producing highly structured computer graphics or the person who needs to interact with the graphics in a complex way. It has become extremely popular in a short period due to the number of implementations that have been made available on workstations.
This book aims at providing a basic understanding of PHIGS concentrating on those parts which are the most novel, the structure store and the viewing model. It is not an exhaustive description of all the facilities in PHIGS. However, by the end of the book, readers should be capable of writing a wide range of PHIGS programs.
Examples have been written in pseudo-Fortran 77 using the PHIGS names for functions rather than the constrained Fortran 6-character names. The necessary information is provided to convert the examples into genuine Fortran programs. Two major examples, a 2D desk and a 3D object, are used throughout the book. The necessary data is provided to allow the reader to implement these himself and try out further variants of the examples.
Chapters 1 to 4 introduce the PHIGS structure store and the output primitives using mainly 20 examples. Chapter 5 concentrates on the hierarchical structure facilities showing how they can be used to manipulate objects in complex ways.
Chapters 6 to 8 describes the viewing facilities available particularly in 3D. Chapters 9 and 10 discuss the input facilities and how interactive programs are written in PHIGS.
The remaining chapters concentrate on the aspects of PHIGS dependent on the environment in which it is used and the less important features.
While being written as an introductory text, it is hoped that it can also act as a reference guide to the main facilities in PHIGS.
Much of David Duce's contribution to this book was written in Ward 6 of Chapel Allerton Hospital, Leeds, whilst his father was a patient there. The book is dedicated to George Duce, who provides a shining example of what can be achieved by patient determination, and to the doctors, physiotherapists, speech therapists and nursing staff for their skill and loving care.
The examples have been tested, where possible, using the SUN PHIGS implementation and many of the diagrams have been produced using its CGM workstation. We would like to thank Predrag Popovic for the use of his software for converting CGM to POSTSCRIPT.
We would also like to thank the Yugoslavian Computer Graphics Society whose invitation to give a 2-day PHIGS Tutorial in Dubrovnik in 1990 was the catalyst for the writing of this book.
