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arXiv · 1111.3584

Computing a visibility polygon using few variables

Luis Barba·Matias Korman·Stefan Langerman·Rodrigo I. Silveira
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Abstract

We present several algorithms for computing the visibility polygon of a simple polygon $P$ from a viewpoint inside the polygon, when the polygon resides in read-only memory and only few working variables can be used. The first algorithm uses a constant number of variables, and outputs the vertices of the visibility polygon in $O(n\Rout)$ time, where $\Rout$ denotes the number of reflex vertices of $P$ that are part of the output. The next two algorithms use $O(\log \Rin)$ variables, and output the visibility polygon in $O(n\log \Rin)$ randomized expected time or $O(n\log^2 \Rin)$ deterministic time, where $\Rin$ is the number of reflex vertices of $P$.

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Luis Barba, Matias Korman, Stefan Langerman, Rodrigo I. Silveira. 2011-11-15. Computing a visibility polygon using few variables. https://arxiv.org/abs/1111.3584

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