ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1987.tb00536.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractOnly the diehards want to develop applications using basic window system facilities. The preferred approach is a higher‐level “toolkit” of user interface components, such as menus and scroll bars. Experience with current toolkits shows the need for an object‐oriented interface to these components.NeWS, the Network/extensible Window System, allows user interface components to be programmed in PostScript. Fortunately, object‐oriented interfaces are natural in PostScript, and they have been used to create a toolkit with some novel properties. Among these are the use of concurrent processing and run‐time inheritance of component methods.“Postscript is the future of words on paper.”

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1987.tb00537.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractAn extended model and calculus, called RasterCalc, is presented for operations on discrete graphics rasters, including their colour functions. The operations are separated into two main categories: operations on domains, and operations on colour functions. The operations are further classified as local and remote, depending on the correspondence between destination and source pixels. The new raster element or pixel can be a function of a single element from one or more rasters, a function of a small area from other rasters, or a function of entire rasters. Local operations have their main applications in computer graphics, while remote operations are more oriented towards image processing. A mathematically oriented notation is used to define and represent the operations included. RasterCalc has been implemented as a procedure package in Pascal, to be used on a powerful, yet expensive display. Recently a C version has been completed for a personal colour computer with a special chip for raster operations.The work reported in this paper is partially supplied by the Dutch Technical Sciences Foundation, under project number LWI 14.0130: “Facilities for raster graphics in programming language

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1987.tb00538.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThe fill area primitive is one of the most powerful primitives of GKS and its derivatives (GKS‐3D, PHIGS etc.). Since its specrfication is extremely general, it is important to explore new approaches to achieve higher performance in its implementation. In this paper fast algorithms are presented for special situations, which can be included, together with appropriate tests, into a complete GKS output pipeline. As a result, a speed improvement With a factor of two may be achieved in important practical case

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1987.tb00539.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractIn Computer‐Aided Design applications there is often a need to compute the union, intersection and Merence of two polygons or polyhedra. The sequential algorithms for this problem are characterized by poor speed of response and large computational complexity. In order to remove these defects, an algorithm amenable to implementation on a parallel architecture is proposed. The parallel architecture designed is a systolic one which forms a dedicated subsystem to perform set‐theoretic operations on polygons. The improvement in speed gained by using the systolic array as compared to a uniprocessor has been evaluated using simulation techniques. Extensions of this architecture to perform the same operations on polyhedra are also discus

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1987.tb00540.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractAspects of a prototype binding of GKS to the C++ programming language are presented. The binding makes use of classes and derived classes to define GKS concepts such as segments and workstations. Operator overloading is used for some GKS Functions.

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1987.tb00541.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThe Graphical Kernel System (GKS) has become an international standard in graphics programming and attempts are now being made to integrate it with multiprocessing, possibly in distributed systems. It is therefore necessary to consider new programming languages able to support distributed implementations of GKS. Among them, Ada and Nil are considered here, since they are particularly suitable for concurrent programming. They are compared and evaluated in those specific tools which may provide data safety, system reconfigurability, and availability to distributed programming. The structural philosophies of the two languages are emphasized and reconfigurable implementation schemata for GKS in both of them are then suggested.

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1987.tb00542.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1987.tb00543.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1987.tb00544.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0167-7055    

DOI:10.1111/j.1467-8659.1987.tb00545.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY