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Esri GIS software has included polygon overlay since the first release of ARC/INFO in 1982. [15] Each generation of Esri software (ARC/INFO, ArcGIS, ArcGIS Pro) has included a set of separate tools for each of the overlay operators (Intersect, Union, Clip, etc.).
It can be used for line or line-segment clipping against a rectangular window, as well as against a convex polygon. The algorithm is based on classifying a vertex of the clipping window against a half-space given by a line p: ax + by + c = 0. The result of the classification determines the edges intersected by the line p. The algorithm is ...
Matthias Kramm's gfxpoly, a free C library for 2D polygons (BSD license). Klaas Holwerda's Boolean, a C++ library for 2D polygons. David Kennison's Polypack, a FORTRAN library based on the Vatti algorithm. Klamer Schutte's Clippoly, a polygon clipper written in C++. Michael Leonov's poly_Boolean, a C++ library, which extends the Schutte algorithm.
Sliver polygons are typically created when polygons are automatically generated from lines that should be coincident (e.g., an international boundary following a river de jure, or two adjacent counties) but are not, due to the natural discrepancies that arise from manual or automated digitization. This can occur when a single layer is digitized ...
It is developed and regulated by Esri as a mostly open specification for data interoperability among Esri and other GIS software products. [1] The shapefile format can spatially describe vector features: points, lines, and polygons, representing, for example, water wells, rivers, and lakes.
GIS software distinguishes the interior and the exterior by requiring that the line be ordered counter-clockwise, so the interior is always on the left side of the boundary. In nearly every format, a polygon can have "holes" (e.g., an island in a lake) by including interior rings, each in clockwise order (so the interior is still on the left).
Merge or dissolve the rectangles and circles into a single polygon. Software implementations of the buffer operation typically use alterations of this strategy to process more efficiently and accurately. In Mathematics, GIS Buffer operation is a Minkowski Sum (or difference) of a geometry and a disk. Other terms used: Offsetting a Polygon. [5]
Clipping is defined as the interaction of subject and clip polygons. While clipping usually involves finding the intersections (regions of overlap) of subject and clip polygons, clipping algorithms can also be applied with other boolean clipping operations: difference, where the clipping polygons remove overlapping regions from the subject; union, where clipping returns the regions covered by ...