A space–time trade-off for computing the visibility polygon in the multi-pass model

Abstract

We study the problem of computing the visibility polygon of a simple polygon $${\mathcal {P}}$$ from a viewpoint inside it, when $${\mathcal {P}}$$ resides in a read-only memory without random accessibility. This model of stored data is called the multi-pass model in the literature. We present an algorithm to compute the visibility polygon in this model in $$O(nr/t + nt)$$ time, where n is the size of input data, r is the number of reflex vertices of input data, and t is the number of additional variables which we use to compute the visibility polygon where $$2<t<r$$.