10.1137/0215023
Herbert Edelsbrunner
Herbert
Edelsbrunner0000-0002-9823-6833
Guibas, Leonidas J
Leonidas
Guibas
Stolfi, Jorge
Jorge
Stolfi
Optimal point location in a monotone subdivision
SIAM
1986
2018-12-11T12:06:58Z
2019-04-26T07:22:40Z
journal_article
https://research-explorer.app.ist.ac.at/record/4104
https://research-explorer.app.ist.ac.at/record/4104.json
Point location, often known in graphics as “hit detection,” is one of the fundamental problems of computational geometry. In a point location query we want to identify which of a given collection of geometric objects contains a particular point. Let $\mathcal{S}$ denote a subdivision of the Euclidean plane into monotone regions by a straight-line graph of $m$ edges. In this paper we exhibit a substantial refinement of the technique of Lee and Preparata [SIAM J. Comput., 6 (1977), pp. 594–606] for locating a point in $\mathcal{S}$ based on separating chains. The new data structure, called a layered dag, can be built in $O(m)$ time, uses $O(m)$ storage, and makes possible point location in $O(\log m)$ time. Unlike previous structures that attain these optimal bounds, the layered dag can be implemented in a simple and practical way, and is extensible to subdivisions with edges more general than straight-line segments.
© 1986 Society for Industrial and Applied Mathematics