We propose two different methods for generating random orthogonal polygons with a given number of vertices. One is a polynomial time algorithm and it is supported by a technique we developed to obtain polygons with an increasing number of vertices starting from a unit square. The other follows a constraint programming approach and gives great control on the generated polygons. In particular, it...

Morphing is a process of shape transformation between two objects. This paper focuses on morphing of simple polygons. In general, the key part of most morphing methods is to find correspondence between vertices of both objects. We present a new algorithm trying to avoid this step. Using an idea of intersection of two polygons (called core) the problem of morphing polygons is decomposed to sever...

We describe the first algorithm to compute the outer common tangents of two disjoint simple polygons using linear time and only constant workspace. A tangent of a polygon is a line touching the polygon such that all of the polygon lies on the same side of the line. An outer common tangent of two polygons is a tangent of both polygons such that the polygons lie on the same side of the tangent. E...

Several algorithms for computing the Minkowski sum of two polygons in the plane begin by decomposing each polygon into convex subpolygons. We examine diierent methods for decomposing polygons by their suitability for eecient construction of Minkowski sums. We study and experiment with various well-known decompositions as well as with several new decomposition schemes. We report on our experimen...

The oriented strip packing problem is very important to manufacturing industries: given a strip of xed width and a set of many (> 100) nonconvex polygons with 1, 2, 4, or 8 orientations permitted for each polygon, nd a set of translations and orientations for the polygons that places them without overlapping into the strip of minimum length. Heuristics are given for two versions of strip packin...

Ice-wedge polygons and related microtopographic variations are ubiquitous to landscapes underlain by permafrost. Highand low-centered polygons are typical but surprisingly, their role on hydrologic fluxes and stocks is not well quantified. We performed hydrologic modeling analyses using the physically-based model WaSiM-ETH that was forced by data from the Biocomplexity Experiment, Barrow, Alask...

In 1949 Horn and Valentine [HV] showed that if each pair of points a,b in a simple polygon P could be connected by a polygonal path of length two lying in P (such polygons are termed L-convex polygons) then through each point x in P there exists a line segment L(x) lying in P such that for every point y in P there exists a point z in L(x) with the property that the segment yz lies in P. Since t...

Practical GIS generalisation using existing Arc/Info operations invariably follows a simple, generic generalisation algorithm. Typically the algorithm consists of dissolving adjacent polygons with the same attribute value, line generalisation, selection of all polygons of small area, and elimination of selected polygons by merging with the neighbouring polygon of largest area. This paper addres...

In a proportional contact representation of a planar graph, each vertex is represented by a simple polygon with area proportional to a given weight, and edges are represented by adjacencies between the corresponding pairs of polygons. In this paper we study proportional contact representations that use rectilinear polygons without wasted areas (white space). In this setting, the best known algo...

In this paper, we investigate the problem of Boolean operation on circular-arc polygons. We present a concise and efficient method, in which the concept of related edges is introduced. Given two circular-arc polygons with M and N edges, respectively, the proposed method only takes O((l+k)∗ log l+M +N) time, where k is the number of intersection points, l is the number of related edges. The prop...