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EDITORIAL

Computer Graphics F o m 6(3) comes to you in time for the EUROGRAPHICS '87 Conference and brings some innovations, some regular features and the usual good crop of refereed papers. The issue starts with a paper from Densmore and Rosenthal, which formed the basis of Rosenthal's invited keynote paper at the EUROGRAPHICS(UK) conference at the University of East Anglia in Norwich in April. The paper describes some very interesting developments in UIMS tools in the NeWS environment. The second paper by van der Bos addresses some important topics which have been stretching the minds of the standards groups recently, particularly the one involved with the development of the Computer Graphics Interface. The paper is concerned with the types of operations which should be supported in a colour raster environment and describes some operations suitable both for graphics and image processing applications. These are defined in a mathematically oriented notation called RasterCalc and implemented in Pascal and C programming environments.

The GKS Fill Area primitive continues to attract interest and the paper by Herman and Reviczky addresses the need to ensure an efficient implementation of the primitive while conforming to the GKS definition of a very general polygon filler. They have devised a number of tests to ensure that simpler polygons can be detected and f led very quickly, only resorting to the more general and computationally expensive methods when r d y necessary (a minority of cases in most applications). The rapid handling of areas is also the subject of the next paper, by Krishnan and Patnadc, which also extends the interest to polyhedra and examines the requirements for a systolic architecture for boolean operations on polygons and polyhedra. They have demonstrated the speed gains achievable using the proposed algorithms and architecture which continue, in simulations, to gain speed while adding processors up to the 128 max- imum that they have used. Suggestions as to how to turn their asymptotic speedup into a linear relation would, I am sure, be appreciated!

Two papers examining the realisation of GKS in Herent programming languages complete the refereed papers in this issue. The first, by John Richards, looks at the appropriate way on binding GKS to C+ +, and the second, by Milanese, compares the Nil and ADA language systems for a distributed implementation.

In the reports section we have what we hope will become a regular feature of Computer Gruphics Forum, the literature review by Jon Owen, our Book Reviews Editor. We thank him once more for the enormous amount of work that goes into such an exercise and hope our readers fmd the survey useful. Anyone who is interested in helping Jon with the work of book reviews is invited to write to him at the address inside the back cover, indicating the subject areas and levels of books they fell most competent to review.

One new feature in this issue is our iirst EUROGRAPHICS Competition Crossword. Prizes will be awarded for both the simple and cryptic clue versions, so have a go and send your entries in on time.

The issue also contains a number of important announcements, including the details, and call for papers, for the EUROGRAPHICS '88 Conference in Nice. Also m o u n d are a new category of EUROGRAPHICS member, a new national chapter in Spain and several new working groups. Your attention is particularly drawn to the request for the ordinary membership to make sure they put in nomi- nations for the EUROGRAPHICS Executive Committee elections.

AU in all a pleasing issue to have edited and one which clearly demonstrates the vitality of the Association as it matures in its second quinquennium. .

David Arnold Bkbr de Ruiter