GEOS
3.9.0dev

Contains classes that perform a topological overlay to compute boolean spatial functions. More...
Classes  
class  EdgeSetNoder 
Nodes a set of edges. More...  
class  LineBuilder 
Forms JTS LineStrings out of a the graph of geomgraph::DirectedEdge created by an OverlayOp. More...  
class  MaximalEdgeRing 
A ring of DirectedEdges which may contain nodes of degree > 2. More...  
class  MinimalEdgeRing 
A ring of Edges with the property that no node has degree greater than 2. More...  
class  OverlayNodeFactory 
Creates nodes for use in the geomgraph::PlanarGraph constructed during overlay operations. NOTE: also used by operation::valid. More...  
class  OverlayOp 
Computes the geometric overlay of two Geometry. More...  
class  PointBuilder 
Constructs geom::Point s from the nodes of an overlay graph. More...  
class  PolygonBuilder 
Forms Polygon out of a graph of geomgraph::DirectedEdge. More...  
Contains classes that perform a topological overlay to compute boolean spatial functions.
The Overlay Algorithm is used in spatial analysis methods for computing settheoretic operations (boolean combinations) of input Geometrys. The algorithm for computing the overlay uses the intersection operations supported by topology graphs. To compute an overlay it is necessary to explicitly compute the resultant graph formed by the computed intersections.
The algorithm to compute a settheoretic spatial analysis method has the following steps: