Interface ICoordinateSequenceFilter
An interface for classes which process the coordinates in a CoordinateSequence.
A filter can either record information about each coordinate,
or change the value of the coordinate.
Filters can be
used to implement operations such as coordinate transformations, centroid and
envelope computation, and many other functions.
Geometry classes support the concept of applying a
CoordinateSequenceFilter to each
CoordinateSequences they contain.
For maximum efficiency, the execution of filters can be short-circuited by using the Done property.
Namespace: NetTopologySuite.Geometries
Assembly: NetTopologySuite.dll
Syntax
public interface ICoordinateSequenceFilterRemarks
CoordinateSequenceFilter is an example of the Gang-of-Four Visitor pattern.
Note: In general, it is preferable to treat Geometrys as immutable. Mutation should be performed by creating a new Geometry object (see GeometryEditor and GeometryTransformer for convenient ways to do this). An exception to this rule is when a new Geometry has been created via Copy(). In this case mutating the Geometry will not cause aliasing issues, and a filter is a convenient way to implement coordinate transformation.
Properties
| Improve this Doc View SourceDone
Reports whether the application of this filter can be terminated.
Declaration
bool Done { get; }Property Value
| Type | Description |
|---|---|
| Boolean |
Remarks
Once this method returns true, it must
continue to return true on every subsequent call.
GeometryChanged
Reports whether the execution of this filter has modified the coordinates of the geometry. If so, GeometryChanged() will be executed after this filter has finished being executed.
Declaration
bool GeometryChanged { get; }Property Value
| Type | Description |
|---|---|
| Boolean |
Remarks
Most filters can simply return a constant value reflecting whether they are able to change the coordinates.
Methods
| Improve this Doc View SourceFilter(CoordinateSequence, Int32)
Performs an operation on a coordinate in a CoordinateSequence.
Declaration
void Filter(CoordinateSequence seq, int i)Parameters
| Type | Name | Description |
|---|---|---|
| CoordinateSequence | seq | the |
| Int32 | i | i the index of the coordinate to apply the filter to |