“School of Computer Science”

Back to Papers Home
Back to Papers of School of Computer Science

Paper   IPM / Computer Science / 11137
School of Computer Science
  Title:   Efficient Computation of Query Point Visibility in Polygon with Holes
  Author(s): 
1.  A. Zarei
2.  M. Ghodsi
  Status:   In Proceedings
  Proceeding:
  Year:  2005
  Pages:   314 - 320
  Publisher(s):   ACM
  Supported by:  IPM
  Abstract:
In this paper, we consider the problem of computing the visibility of a query point inside polygons with holes. The goal is to perform this computation efficiently per query with more cost in the preprocessing phase. Our algorithm is based on solutions in [13] and [2] proposed for simple polygons. In our solution, the preprocessing is done in time O(n3 log(n)) to construct a data structure of size O(n3). It is then possible to report the visibility polygon of any query point q in time O((1+h') log n+ - V(q) - ), in which n and h are the number of the vertices and holes of the polygon respectively, - V(q) - is the size of the visibility polygon of q, and h' is an output and preprocessing sensitive parameter of at most min(h, - V(q) - ). This is claimed to be the best query-time result on this problem so far.

Download TeX format
back to top
scroll left or right