Class GeometryFixer

Fixes a geometry to be a valid geometry, while preserving as much as possible of the shape and location of the input. Validity is determined according to IsValid.

Input geometries are always processed, so even valid inputs may have some minor alterations.The output is always a new geometry object.

Semantic Rules

1. Vertices with non-finite X or Y ordinates are removed (as per IsValid)
2. Repeated points are reduced to a single point
3. Empty atomic geometries are valid and are returned unchanged
4. Empty elements are removed from collections
5. Point: keep valid coordinate, or EMPTY
6. LineString: coordinates are fixed
7. LinearRing: coordinates are feixed, keep valid ring or else convert into LineString
8. Polygon: transform into a valid polygon, preserving as much of the extent and vertices as possible.
   • Rings are fixed to ensure they are valid
   • Holes intersection the shell are subtracted from the shell
   • Holes outside the shell are converted into polygons
9. MultiPolygon: each polygon is fixed, then result made non - overlapping (via union)
10. GeometryCollection: each element is fixed
11. Collapsed lines and polygons are handled as follows, depending on the keepCollapsed setting:
    • false: (default) collapses are converted to empty geometries (and removed if they are elements of collections)
    • true: collapses are converted to a valid geometry of lower dimension

Inheritance

Object

GeometryFixer

Inherited Members

Object.Equals(Object)

Object.Equals(Object, Object)

Object.GetHashCode()

Object.GetType()

Object.MemberwiseClone()

Object.ReferenceEquals(Object, Object)

Object.ToString()

Namespace: NetTopologySuite.Geometries.Utilities

Assembly: NetTopologySuite.dll

Syntax

public class GeometryFixer

Constructors

GeometryFixer(Geometry)

Creates a new instance to fix a given geometry

Declaration

public GeometryFixer(Geometry geom)

Parameters

Type	Name	Description
Geometry	geom	The geometry to be fixed

Properties

KeepCollapsed

Gets or sets a value indicating whether collapsed geometries are converted to empty, (which will be removed from collections), or to a valid geometry of lower dimension. The default is to convert collapses to empty geometries (false).

Declaration

public bool KeepCollapsed { get; set; }

Property Value

Type	Description
Boolean

KeepMulti

Gets or sets a value indicating whether collapsed geometries are converted to empty, (which will be removed from collections), or to a valid geometry of lower dimension. The default is to convert collapses to empty geometries (false).

Declaration

public bool KeepMulti { get; set; }

Property Value

Type	Description
Boolean

Methods

Fix(Geometry)

Fixes a geometry to be valid.

Declaration

public static Geometry Fix(Geometry geom)

Parameters

Type	Name	Description
Geometry	geom	The geometry to be fixed

Returns

Type	Description
Geometry	The valid fixed geometry

Fix(Geometry, Boolean)

Fixes a geometry to be valid, allowing to set a flag controlling how single item results from fixed MULTI geometries should be returned.

Declaration

public static Geometry Fix(Geometry geom, bool isKeepMulti)

Parameters

Type	Name	Description
Geometry	geom	The geometry to be fixed
Boolean	isKeepMulti	A flag indicating if MULTI geometries should not be converted to single instance types if they consist of only one item.

Returns

Type	Description
Geometry	The valid fixed geometry

GetResult()

Gets the fixed geometry.

Declaration

public Geometry GetResult()

Returns

Type	Description
Geometry	The fixed geometry

See Also

IsValid