Research and Advances

Representation of many-sided polygons and polygonal lines for rapid processing

A representation for polygons and polygonal lines is described which allows sets of consecutive sides to be collectively examined. The set of sides are arranged in a binary tree hierarchy by inclusion. A fast algorithm for testing the inclusion of a point in a many-sided polygon is given. The speed of the algorithm is discussed for both ideal and practical examples. It is shown that the points of intersection of two polygonal lines can be located by what is essentially a binary tree search. The algorithm and a practical example are discussed. The representation overcomes many of the disadvantages associated with the various fixed-grid methods for representing curves and regions.

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Research and Advances

A buddy system variation for disk storage allocation

A generalization of the buddy system for storage allocation is described. The set of permitted block sizes {SIZEi}ni=0 must satisfy the condition SIZEi = SIZEi-1 + SIZEi-k(i) where k may be any meaningful integral-valued function. This makes it possible to force logical storage blocks to coincide with physical storage blocks, such as tracks and cylinders.

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