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This paper discusses the hidden-surface problem from tile point of view of sorting. The various surfaces of an object to be shown in hidden-surface or hidden-line form must be sorted to find out which ones are visible at various places on the screen. Surfaces may be sorted by lateral position in the picture (X I'), by depth (Z), or by other criteria. The paper shows that the order of sorting and the types of sorting used form differences among the existing hidden-surface algorithms. To reduce the work of sorting, each algorithm capitalizes on some coherence property of the objects represented. ‘Scan-line coherence,’ the fact that one TV scan line of output is likely to be nearly the same as the previous TV scan line, is one commonly used kind of coherence. ‘Frame coherence,’ the fact that the entire picture does not change very much between successive frames of a motion picture can be very helpful if it is applicable. By systematically looking for additional kinds of coherence and untried sorting orders and sorting types, the paper is able to suggest two promising new approaches to the hidden-surface problem. The first, a combination of three existing algorithms, is promising because it would capitalize on both frame and scan-line coherence. The second new approach would sort in the order Y, Z, X, … the only sorting order for which an existing algorithm could not be found. [ABSTRACT FROM AUTHOR]

Binary search trees are an important technique for organizing large files because they are efficient for both random and sequential access of records, and for modification of a file. Because of this, they have received a great deal of attention in recent years, and their properties are now better understood than those of most other file organization methods. This paper surveys the main results which have been obtained. [ABSTRACT FROM AUTHOR]

The proliferation of programming languages has raised many issues of language design, definition, and implementation. This paper presents a series of ten mini-languages, each of which exposes salient features found in existing programming languages. The value of the mini-languages lies in their brevity of description and the isolation of important linguistic features: in particular, the notions of assignment, transfer of control, functions, parameter passing, type checking, data structures, string manipulation, and input/output. The mini-languages may serve a variety of uses: notably, as a pedagogical tool for teaching programming languages, as a subject of study for the design of programming languages, and as a set of test cases for methods of language implementation or formal definition. [ABSTRACT FROM AUTHOR]

This paper surveys the use of the computer in the humanities and fine arts, and indicates the relevance of available hardware and software for those applications areas. The first section covers (a) pattern recognition and analysis in art, architecture, music, and literature (with an emphasis upon the latter), and (b) pattern construction, or synthesis, in art, architecture, music, and language. In the second section, data representation and manipulation are described with reference to: first, transformation of the artifact into a form suitable for the computer; second, internal data storage and manipulation; and, third, output. The three types of artifacts dealt with are: aural, or auditory; visual, including both nonalphameric and alphameric forms; tactile. A discussion of data structures and of data manipulation occupies the subsection on internal data storage and manipulation, and the brief commentary on output concentrates on aural and visual modes. [ABSTRACT FROM AUTHOR]