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geos::operation::valid::ConsistentAreaTester Class Reference

Checks that a geomgraph::GeometryGraph representing an area (a Polygon or MultiPolygon ) is consistent with the OGC-SFS semantics for area geometries. Checks that a geomgraph::GeometryGraph representing an area (a geom::Polygon or geom::MultiPolygon) has consistent semantics for area geometries. This check is required for any reasonable polygonal model (including the OGC-SFS model, as well as models which allow ring self-intersection at single points). More...

#include <ConsistentAreaTester.h>

List of all members.

Public Member Functions

 ConsistentAreaTester (geomgraph::GeometryGraph *newGeomGraph)
geom::CoordinategetInvalidPoint ()
bool isNodeConsistentArea ()
 Check all nodes to see if their labels are consistent with area topology.
bool hasDuplicateRings ()


Detailed Description

Checks that a geomgraph::GeometryGraph representing an area (a Polygon or MultiPolygon ) is consistent with the OGC-SFS semantics for area geometries. Checks that a geomgraph::GeometryGraph representing an area (a geom::Polygon or geom::MultiPolygon) has consistent semantics for area geometries. This check is required for any reasonable polygonal model (including the OGC-SFS model, as well as models which allow ring self-intersection at single points).

Checks include:

If an inconsistency is found the location of the problem is recorded and is available to the caller.


Constructor & Destructor Documentation

geos::operation::valid::ConsistentAreaTester::ConsistentAreaTester geomgraph::GeometryGraph *  newGeomGraph  ) 
 

Creates a new tester for consistent areas.

Parameters:
geomGraph the topology graph of the area geometry. Caller keeps responsibility for its deletion


Member Function Documentation

geom::Coordinate& geos::operation::valid::ConsistentAreaTester::getInvalidPoint  ) 
 

Returns:
the intersection point, or null if none was found

bool geos::operation::valid::ConsistentAreaTester::hasDuplicateRings  ) 
 

Checks for two duplicate rings in an area. Duplicate rings are rings that are topologically equal (that is, which have the same sequence of points up to point order). If the area is topologically consistent (determined by calling the isNodeConsistentArea, duplicate rings can be found by checking for EdgeBundles which contain more than one geomgraph::EdgeEnd. (This is because topologically consistent areas cannot have two rings sharing the same line segment, unless the rings are equal). The start point of one of the equal rings will be placed in invalidPoint.

Returns:
true if this area Geometry is topologically consistent but has two duplicate rings

bool geos::operation::valid::ConsistentAreaTester::isNodeConsistentArea  ) 
 

Check all nodes to see if their labels are consistent with area topology.

Returns:
true if this area has a consistent node labelling


The documentation for this class was generated from the following file:
Generated on Thu Jun 11 06:17:03 2009 for GEOS by  doxygen 1.4.4