Classes | |
class | EdgeSetNoder |
Nodes a set of edges. More... | |
class | FuzzyPointLocator |
Finds the most likely Location of a point relative to the polygonal components of a geometry, using a tolerance value. More... | |
class | LineBuilder |
Forms JTS LineStrings out of a the graph of geomgraph::DirectedEdge created by an OverlayOp. More... | |
class | MaximalEdgeRing |
A ring of edges 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 | OffsetPointGenerator |
Generates points offset from both sides of all segments in a geometry. 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 overlay of two Geometry. More... | |
struct | overlayOp |
OverlayOp::overlayOp Adapter for use with geom::BinaryOp. More... | |
class | OverlayResultValidator |
Validates that the result of an overlay operation is geometrically correct within a given tolerance. 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... |
The Overlay Algorithm is used in spatial analysis methods for computing set-theoretic 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 set-theoretic spatial analysis method has the following steps: