org.locationtech.jts.algorithm

Interface BoundaryNodeRule

All Known Implementing Classes:

BoundaryNodeRule.EndPointBoundaryNodeRule, BoundaryNodeRule.Mod2BoundaryNodeRule, BoundaryNodeRule.MonoValentEndPointBoundaryNodeRule, BoundaryNodeRule.MultiValentEndPointBoundaryNodeRule

public interface BoundaryNodeRule

An interface for rules which determine whether node points which are in boundaries of Lineal geometry components are in the boundary of the parent geometry collection. The SFS specifies a single kind of boundary node rule, the BoundaryNodeRule.Mod2BoundaryNodeRule rule. However, other kinds of Boundary Node Rules are appropriate in specific situations (for instance, linear network topology usually follows the BoundaryNodeRule.EndPointBoundaryNodeRule.) Some JTS operations (such as RelateOp, BoundaryOp and IsSimpleOp) allow the BoundaryNodeRule to be specified, and respect the supplied rule when computing the results of the operation.

An example use case for a non-SFS-standard Boundary Node Rule is that of checking that a set of LineStrings have valid linear network topology, when turn-arounds are represented as closed rings. In this situation, the entry road to the turn-around is only valid when it touches the turn-around ring at the single (common) endpoint. This is equivalent to requiring the set of LineStrings to be simple under the BoundaryNodeRule.EndPointBoundaryNodeRule. The SFS-standard BoundaryNodeRule.Mod2BoundaryNodeRule is not sufficient to perform this test, since it states that closed rings have no boundary points.

This interface and its subclasses follow the Strategy design pattern.

Version:

1.7

Author:

Martin Davis

See Also:

RelateOp, BoundaryOp, IsSimpleOp, PointLocator

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	BoundaryNodeRule.EndPointBoundaryNodeRule A BoundaryNodeRule which specifies that any points which are endpoints of lineal components are in the boundary of the parent geometry.
static class	BoundaryNodeRule.Mod2BoundaryNodeRule A BoundaryNodeRule specifies that points are in the boundary of a lineal geometry iff the point lies on the boundary of an odd number of components.
static class	BoundaryNodeRule.MonoValentEndPointBoundaryNodeRule A BoundaryNodeRule which determines that only endpoints with valency of exactly 1 are on the boundary.
static class	BoundaryNodeRule.MultiValentEndPointBoundaryNodeRule A BoundaryNodeRule which determines that only endpoints with valency greater than 1 are on the boundary.

Field Summary

Fields

Modifier and Type	Field and Description
static BoundaryNodeRule	ENDPOINT_BOUNDARY_RULE The Endpoint Boundary Node Rule.
static BoundaryNodeRule	MOD2_BOUNDARY_RULE The Mod-2 Boundary Node Rule (which is the rule specified in the OGC SFS).
static BoundaryNodeRule	MONOVALENT_ENDPOINT_BOUNDARY_RULE The Monovalent Endpoint Boundary Node Rule.
static BoundaryNodeRule	MULTIVALENT_ENDPOINT_BOUNDARY_RULE The MultiValent Endpoint Boundary Node Rule.
static BoundaryNodeRule	OGC_SFS_BOUNDARY_RULE The Boundary Node Rule specified by the OGC Simple Features Specification, which is the same as the Mod-2 rule.

Method Summary

Modifier and Type	Method and Description
boolean	isInBoundary(int boundaryCount) Tests whether a point that lies in boundaryCount geometry component boundaries is considered to form part of the boundary of the parent geometry.

Field Detail

MOD2_BOUNDARY_RULE

static final BoundaryNodeRule MOD2_BOUNDARY_RULE

The Mod-2 Boundary Node Rule (which is the rule specified in the OGC SFS).

See Also:

BoundaryNodeRule.Mod2BoundaryNodeRule

ENDPOINT_BOUNDARY_RULE

static final BoundaryNodeRule ENDPOINT_BOUNDARY_RULE

The Endpoint Boundary Node Rule.

See Also:

BoundaryNodeRule.EndPointBoundaryNodeRule

MULTIVALENT_ENDPOINT_BOUNDARY_RULE

static final BoundaryNodeRule MULTIVALENT_ENDPOINT_BOUNDARY_RULE

The MultiValent Endpoint Boundary Node Rule.

See Also:

BoundaryNodeRule.MultiValentEndPointBoundaryNodeRule

MONOVALENT_ENDPOINT_BOUNDARY_RULE

static final BoundaryNodeRule MONOVALENT_ENDPOINT_BOUNDARY_RULE

The Monovalent Endpoint Boundary Node Rule.

See Also:

BoundaryNodeRule.MonoValentEndPointBoundaryNodeRule

OGC_SFS_BOUNDARY_RULE

static final BoundaryNodeRule OGC_SFS_BOUNDARY_RULE

The Boundary Node Rule specified by the OGC Simple Features Specification, which is the same as the Mod-2 rule.

See Also:

BoundaryNodeRule.Mod2BoundaryNodeRule

Method Detail

isInBoundary

boolean isInBoundary(int boundaryCount)

Tests whether a point that lies in boundaryCount geometry component boundaries is considered to form part of the boundary of the parent geometry.

Parameters:

boundaryCount - the number of component boundaries that this point occurs in

Returns:

true if points in this number of boundaries lie in the parent boundary