Abstract
We explore an extension to rectilinear convexity of the classic problem of computing the convex hull of a collection of line segments. Namely, we solve the problem of computing and maintaining the rectilinear convex hull of a set of n line segments, while we simultaneously rotate the coordinate axes by an angle that goes from 0 to \(2\pi \).
We describe an algorithm that runs in optimal \(\varTheta (n\log n)\) time and \(\varTheta (n\alpha (n))\) space for segments that are non-necessarily disjoint, where \(\alpha (n)\) is the inverse of the Ackermann’s function. If instead the line segments form a simple polygonal chain, the algorithm can be adapted so as to improve the time and space complexities to \(\varTheta (n)\).
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Notes
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- 2.
See the definition of the maximal r-convex hull in [15].
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- 4.
We remark that, since the set \(\mathcal {O}\) is formed by two orthogonal lines parallel to the coordinate axis, in this paper \(\mathcal {O}\)-convexity is equivalent to Orthogonal Convexity.
References
Alegría, C., Orden, D., Seara, C., Urrutia, J.: Separating bichromatic point sets in the plane by restricted orientation convex hulls maintenance of maxima of 2D point sets. J. Global Optim. 85, 1–34 (2022). https://doi.org/10.1007/s10898-022-01238-9
Biedl, T., Genç, B.: Reconstructing orthogonal Polyhedra from putative vertex sets. Comput. Geomet. Theor. Appl. 44(8), 409–417 (2011). https://doi.org/10.1016/j.comgeo.2011.04.002
Chazelle, B.: An optimal convex hull algorithm in any fixed dimension. Discr. Comput. Geom. 10(4), 377–409 (1993). https://doi.org/10.1007/bf02573985
Davari, M.J., Edalat, A., Lieutier, A.: The convex hull of finitely generable subsets and its predicate transformer. In: 2019 34th Annual ACM/IEEE Symposium on Logic in Computer Science (LICS). IEEE (2019). https://doi.org/10.1109/lics.2019.8785680
Devillers, O., Golin, M.J.: Incremental algorithms for finding the convex hulls of circles and the lower envelopes of parabolas. Inf. Process. Lett. 56(3), 157–164 (1995). https://doi.org/10.1016/0020-0190(95)00132-V
Díaz-Bañez, J.M., López, M.A., Mora, M., Seara, C., Ventura, I.: Fitting a two-joint orthogonal chain to a point set. Comput. Geom. 44(3), 135–147 (2011). https://doi.org/10.1016/j.comgeo.2010.07.005
Fink, E., Wood, D.: Restricted-orientation Convexity. Monographs in Theoretical Computer Science (An EATCS Series). 1st Edn. Springer, Heidelberg (2004). https://doi.org/10.1007/978-3-642-18849-7
Franěk, V.: On algorithmic characterization of functional \(D\)-convex hulls, Ph. D. thesis, Faculty of Mathematics and Physics, Charles University in Prague (2008)
Franěk, V., Matoušek, J.: Computing \(D\)-convex hulls in the plane. Comput. Geomet. Theor. Appl. 42(1), 81–89 (2009). https://doi.org/10.1016/j.comgeo.2008.03.003
Hershberger, J.: Finding the upper envelope of \(n\) line segments in \({O}(n\log n)\) time. Inf. Process. Lett. 33, 169–174 (1989). https://doi.org/10.1016/0020-0190(89)90136-1
Kedem, K., Livne, R., Pach, J., Sharir, M.: On the union of Jordan regions and collision-free translational motion amidst polygonal obstacles. Discr. Comput. Geomet. 1(1), 59–71 (1986). https://doi.org/10.1007/BF02187683
Melkman, A.A.: On-line construction of the convex hull of a simple polyline. Inf. Process. Lett. 25(1), 11–12 (1987). https://doi.org/10.1016/0020-0190(87)90086-X
Metelskii, N.N., Martynchik, V.N.: Partial convexity. Math. Notes 60(3), 300–305 (1996). https://doi.org/10.1007/BF02320367
Nicholl, T.M., Lee, D.T., Liao, Y.Z., Wong, C.K.: On the X-Y convex hull of a set of X-Y polygons. BIT Numer. Math. 23(4), 456–471 (1983). https://doi.org/10.1007/BF01933620
Ottmann, T., Soisalon-Soininen, E., Wood, D.: On the definition and computation of rectilinear convex hulls. Inf. Sci. 33(3), 157–171 (1984). https://doi.org/10.1016/0020-0255(84)90025-2
Pérez-Lantero, P., Seara, C., Urrutia, J.: A fitting problem in three dimension. In: Book of Abstracts of the XX Spanish Meeting on Computational Geometry, pp. 21–24. EGC 2023 (2023)
Preparata, F.P., Shamos, M.I.: Computational geometry: an introduction. Text and Monographs in Computer Science. 1st Edn. Springer, NY (1985). https://doi.org/10.1007/978-1-4612-1098-6
Rawlins, G.J.E.: Explorations in restricted-orientation geometry, Ph. D. thesis, School of Computer Science, University of Waterloo (1987)
Rawlins, G.J., Wood, D.: Ortho-convexity and its generalizations. In: Toussaint, G.T. (ed.) Computational Morphology, Machine Intelligence and Pattern Recognition, vol. 6, pp. 137–152. North-Holland (1988). https://doi.org/10.1016/B978-0-444-70467-2.50015-1
Schuierer, S., Wood, D.: Restricted-orientation visibility. Tech. Rep. 40, Institut für Informatik, Universität Freiburg (1991)
Sharir, M., Agarwal, P.K.: Davenport-Schinzel Sequences and Their Geometric Applications. Cambridge University Press (1995)
Wang, C., Zhou, R.G.: A quantum search algorithm of two-dimensional convex hull. Commun. Theoret. Phys. 73(11), 115102 (2021). https://doi.org/10.1088/1572-9494/ac1da0
Wiernik, A., Sharir, M.: Planar realizations of nonlinear Davenport-Schinzel sequences by segments. Discr. Comput. Geomet. 3(1), 15–47 (1988). https://doi.org/10.1007/BF02187894
Acknowledgements
Justin Dallant is supported by the French Community of Belgium via the funding of a FRIA grant. Pablo Pérez-Lantero was partially supported by project DICYT 042332PL Vicerrectoría de Investigación, Desarrollo e Innovación USACH (Chile). Carlos Seara is supported by Project PID2019-104129GB-I00/AEI/10.13039/501100011033 of the Spanish Ministry of Science and Innovation.
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Alegría, C., Dallant, J., Pérez-Lantero, P., Seara, C. (2023). The Rectilinear Convex Hull of Line Segments. In: Fernau, H., Jansen, K. (eds) Fundamentals of Computation Theory. FCT 2023. Lecture Notes in Computer Science, vol 14292. Springer, Cham. https://doi.org/10.1007/978-3-031-43587-4_3
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