org.tinfour.common

Class LinearConstraint

java.lang.Object

org.tinfour.common.PolyLineConstraintAdapter

org.tinfour.common.LinearConstraint

All Implemented Interfaces:

Iterable<Vertex>, IConstraint, IPolyline

public class LinearConstraint
extends PolyLineConstraintAdapter
implements IConstraint

An implementation of the IConstraint interface intended to store constraints comprised of a chain of connected line segments. Constraint chains must be non-self-intersecting (except at segment endpoints). The chain must never "fold back" on itself. All segments in the chain must be non-zero-length.

Do not use this class for closed polygons.

Field Summary

Fields inherited from class org.tinfour.common.PolyLineConstraintAdapter

applicationData, constraintIndex, constraintLinkingEdge, isComplete, length, list, maintainingTin

Constructor Summary

Constructors

Constructor and Description
LinearConstraint() The standard constructor
LinearConstraint(List<Vertex> vList) Constructs a constraint with the specified vertices.
LinearConstraint(Vertex v0, Vertex v1) A convience constructor intended for the frequently occurring case in which an application wishes to define a constraint as a single line segment.

Method Summary

Modifier and Type	Method and Description
void	complete() Called to indicate that the feature is complete and that no further vertices will be added to it.
boolean	definesConstrainedRegion() Indicates whether the constraint defines a data area.
LinearConstraint	getConstraintWithNewGeometry(List<Vertex> geometry) Gets a new constraint that has the attributes of this constraint and the specified geometry.
double	getNominalPointSpacing() Get the average distance between points for the feature.
Path2D	getPath2D(AffineTransform transform) Gets a Java Path2D based on the geometry of the constraint mapped through an optional affine transform.
boolean	isPolygon() Indicates whether the instance represents a polygon.
boolean	isValid() Indicates that sufficient information has been stored in the polyline to establish a valid geometry.
LinearConstraint	refactor(Iterable<Vertex> geometry) Creates a new polyline feature with the specified geometry and transfers any data elements defined by the implementing class from the current object to the newly created one.

Methods inherited from class org.tinfour.common.PolyLineConstraintAdapter

add, getApplicationData, getBounds, getConstraintIndex, getConstraintLinkingEdge, getLength, getManagingTin, getVertices, isPointInsideConstraint, iterator, setApplicationData, setConstraintIndex, setConstraintLinkingEdge

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.tinfour.common.IConstraint

getApplicationData, getConstraintIndex, getConstraintLinkingEdge, getManagingTin, isPointInsideConstraint, setApplicationData, setConstraintIndex, setConstraintLinkingEdge

Methods inherited from interface org.tinfour.common.IPolyline

add, getBounds, getLength, getVertices

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Constructor Detail

LinearConstraint

public LinearConstraint()

The standard constructor

LinearConstraint

public LinearConstraint(Vertex v0,
                        Vertex v1)

A convience constructor intended for the frequently occurring case in which an application wishes to define a constraint as a single line segment.

Parameters:

v0 - the initial vertex of the edge

v1 - the final vertex of the edge

LinearConstraint

public LinearConstraint(List<Vertex> vList)

Constructs a constraint with the specified vertices. This approach is generally faster than adding the vertices one at a time.

Parameters:

vList - a valid list containing at least 2 distinct points.

Method Detail

complete

public final void complete()

Description copied from interface: IPolyline

Called to indicate that the feature is complete and that no further vertices will be added to it. Some implementing classes may perform lightweight sanity checking on the feature instance.

Multiple calls to complete are benign and will be ignored. If vertices are added after complete is called, the behavior is undefined.

Specified by:

complete in interface IPolyline

isPolygon

public boolean isPolygon()

Description copied from interface: IPolyline

Indicates whether the instance represents a polygon. Some implementations may define a constant value for this method, others may determine it dynamically.

Specified by:

isPolygon in interface IPolyline

Returns:

true if the instance is a polygon; otherwise, false.

definesConstrainedRegion

public boolean definesConstrainedRegion()

Indicates whether the constraint defines a data area. Because linear constraints cannot define an area, this method always returns false.

Specified by:

definesConstrainedRegion in interface IConstraint

Returns:

always false for linear constraints.

getNominalPointSpacing

public double getNominalPointSpacing()

Description copied from interface: IPolyline

Get the average distance between points for the feature.

Specified by:

getNominalPointSpacing in interface IPolyline

Returns:

if the feature contains more than one point, a floating point value greater than zero; otherwise a NaN.

getConstraintWithNewGeometry

public LinearConstraint getConstraintWithNewGeometry(List<Vertex> geometry)

Description copied from interface: IConstraint

Gets a new constraint that has the attributes of this constraint and the specified geometry. This method is primarily used in cases where a geometry is very similar (or identical) to the input but either simplified or with replacement vertices.

Specified by:

getConstraintWithNewGeometry in interface IConstraint

Parameters:

geometry - a valid set of vertices.

Returns:

a new constraint.

refactor

public LinearConstraint refactor(Iterable<Vertex> geometry)

Description copied from interface: IPolyline

Creates a new polyline feature with the specified geometry and transfers any data elements defined by the implementing class from the current object to the newly created one.

This method is intended to be used in cases where application code performs some kind of transformation on the geometry of the existing object and produces a new object. In doing so, the application code treats the existing object on a read-only basis, but is free to transfer any implementation-specific data from the old object to the new. Examples of possible transformations include an implementation of a point-reduction technique such as Visvalingam's algorithm or point-addition techniques such as curve smoothing.

Specified by:

refactor in interface IPolyline

Parameters:

geometry - a list or other iterable instance that can be used as a source of vertices.

Returns:

if successful, a new instance of the implementing class.

isValid

public boolean isValid()

Description copied from interface: IPolyline

Indicates that sufficient information has been stored in the polyline to establish a valid geometry.

Specified by:

isValid in interface IPolyline

Returns:

true if the polyline has a valid geometry; otherwise, false.

getPath2D

public Path2D getPath2D(AffineTransform transform)

Gets a Java Path2D based on the geometry of the constraint mapped through an optional affine transform.

Specified by:

getPath2D in interface IConstraint

Parameters:

transform - a valid transform, or the null to use the identity transform.

Returns:

a valid instance of a Java Path2D