IsSimpleOp class

Tests whether a Geometry is simple. In general, the SFS specification of simplicity follows the rule:

  • A Geometry is simple if and only if the only self-intersections are at boundary points.

Simplicity is defined for each {@link Geometry} type as follows:

  • Polygonal geometries are simple by definition, so isSimple trivially returns true. (Note: this means that isSimple cannot be used to test for (invalid) self-intersections in Polygons. In order to check if a Polygonal geometry has self-intersections, use {@link Geometry#isValid()}).
  • Linear geometries are simple iff they do not self-intersect at interior points (i.e. points other than boundary points). This is equivalent to saying that no two linear components satisfy the SFS {@link Geometry#touches(Geometry)} predicate.
  • Zero-dimensional (point) geometries are simple if and only if they have no repeated points.
  • Empty geometries are always simple, by definition
For {@link Lineal} geometries the evaluation of simplicity can be customized by supplying a {@link BoundaryNodeRule} to define how boundary points are determined. The default is the SFS-standard {@link BoundaryNodeRule#MOD2_BOUNDARY_RULE}. Note that under the Mod-2 rule, closed LineStrings (rings) will never satisfy the touches predicate at their endpoints, since these are interior points, not boundary points. If it is required to test whether a set of LineStrings touch only at their endpoints, use IsSimpleOp with {@link BoundaryNodeRule#ENDPOINT_BOUNDARY_RULE}. For example, this can be used to validate that a set of lines form a topologically valid linear network.

@see BoundaryNodeRule

@version 1.7

Constructors

IsSimpleOp.withGeom(Geometry inputGeom)
Creates a simplicity checker using the default SFS Mod-2 Boundary Node Rule
IsSimpleOp.withGeomAndRule(Geometry inputGeom, BoundaryNodeRule boundaryNodeRule)
Creates a simplicity checker using a given {@link BoundaryNodeRule}

Properties

hashCode → int
The hash code for this object.
no setterinherited
inputGeom ↔ Geometry
getter/setter pair
isClosedEndpointsInInterior ↔ bool
getter/setter pair
nonSimpleLocation ↔ Coordinate?
getter/setter pair
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

addEndpoint(Map endPoints, Coordinate p, bool isClosed) → void
Add an endpoint to the map, creating an entry for it if none exists
computeSimple(Geometry geom) → bool
getNonSimpleLocation() → Coordinate?
Gets a coordinate for the location where the geometry fails to be simple. (i.e. where it has a non-boundary self-intersection). {@link #isSimple} must be called before this method is called.
hasClosedEndpointIntersection(GeometryGraph graph) → bool
Tests that no edge intersection is the endpoint of a closed line. This ensures that closed lines are not touched at their endpoint, which is an interior point according to the Mod-2 rule To check this we compute the degree of each endpoint. The degree of endpoints of closed lines must be exactly 2.
hasNonEndpointIntersection(GeometryGraph graph) → bool
For all edges, check if there are any intersections which are NOT at an endpoint. The Geometry is not simple if there are intersections not at endpoints.
isSimple() → bool
Tests whether the geometry is simple.
isSimpleGeometryCollection(Geometry geom) → bool
Semantics for GeometryCollection is simple iff all components are simple.
isSimpleLine(LineString geom) → bool
Reports whether a {@link LineString} is simple.
isSimpleLinearGeometry(Geometry geom) → bool
isSimpleMultiLine(MultiLineString geom) → bool
Reports whether a {@link MultiLineString} geometry is simple.
isSimpleMultiPoint(MultiPoint mp) → bool
A MultiPoint is simple iff it has no repeated points @deprecated use isSimple()
isSimpleMultiPoint_(MultiPoint mp) → bool
isSimplePolygonal(Geometry geom) → bool
Computes simplicity for polygonal geometries. Polygonal geometries are simple if and only if all of their component rings are simple.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited