Namespace NetTopologySuite.Geometries.Utilities

Provides classes that parse and modify Geometry objects.

Classes

AffineTransformation

Represents an affine transformation on the 2D Cartesian plane.

AffineTransformationBuilder

Builds an AffineTransformation defined by a set of control vectors.

AffineTransformationFactory

Supports creating AffineTransformations defined by various kinds of inputs and transformation mapping rules.

ComponentCoordinateExtracter

Extracts a representative Coordinate from each connected component of a Geometry.

EnvelopeCombiner

Utility to combine just the Envelopes of a list of geometries.

GeometryCollectionMapper

Maps the members of a GeometryCollection into another GeometryCollection via a defined mapping function.

GeometryCombiner

Combines Geometrys to produce a GeometryCollection of the most appropriate type.

GeometryEditor

A class which supports creating new Geometrys which are modifications of existing ones, maintaining the same type structure.

GeometryEditor.CoordinateOperation

A GeometryEditorOperation which edits the coordinate list of a Geometry. Operates on Geometry subclasses which contains a single coordinate list.

GeometryEditor.CoordinateSequenceOperation

A GeometryEditor.IGeometryEditorOperation which edits the CoordinateSequence of a Geometry.

Operates on Geometry subclasses which contains a single coordinate list.

GeometryEditor.NoOpGeometryOperation

A GeometryEditorOperation which does not modify the input geometry. This can be used for simple changes of GeometryFactory (including PrecisionModel and SRID).

GeometryExtracter

Extracts the components of a given type from a Geometry.

GeometryExtracter<T>

Extracts the components of type T from a Geometry.

GeometryExtracterByTypeName

Extracts the components of type T from a Geometry.

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

GeometryMapper

Methods to map various collections of Geometrys via defined mapping functions.

GeometryMapper.MapOp

Standard implementation of a geometry mapping

GeometryTransformer

A framework for processes which transform an input Geometry into an output Geometry, possibly changing its structure and type(s).

LinearComponentExtracter

Extracts all the 1-dimensional (LineString) components from a Geometry. For polygonal geometries, this will extract all the component LinearRings. If desired, LinearRings can be forced to be returned as LineStrings.

LineStringExtracter

Extracts all the LineString elements from a Geometry.

Matrix

Implements some 2D matrix operations (in particular, solving systems of linear equations).

NoninvertibleTransformationException

Indicates that an AffineTransformation is non-invertible.

PointExtracter

Extracts all the 0-dimensional (Point) components from a Geometry.

PolygonExtracter

Extracts all the Polygon elements from a Geometry.

ShortCircuitedGeometryVisitor

A visitor to Geometry elements which components, which allows short-circuiting when a defined condition holds.

SineStarFactory

Creates geometries which are shaped like multi-armed stars with each arm shaped like a sine wave. These kinds of geometries are useful as a more complex geometry for testing algorithms.

Interfaces

GeometryEditor.IGeometryEditorOperation

A interface which specifies an edit operation for Geometries.

GeometryMapper.IMapOp

An interface for geometry functions used for mapping.