com.spatial4j.core.shape.impl

Class BufferedLineString

java.lang.Object

com.spatial4j.core.shape.BaseShape<SpatialContext>

com.spatial4j.core.shape.impl.BufferedLineString

All Implemented Interfaces:

Shape

public class BufferedLineString
extends BaseShape<SpatialContext>

A BufferedLineString is a collection of BufferedLine shapes, resulting in what some call a "Track" or "Polyline" (ESRI terminology). The buffer can be 0. Note that BufferedLine isn't yet aware of geodesics (e.g. the dateline).

Field Summary

Fields inherited from class com.spatial4j.core.shape.BaseShape

ctx

Constructor Summary

Constructors

Constructor and Description
BufferedLineString(List<Point> points, double buf, boolean expandBufForLongitudeSkew, SpatialContext ctx)
BufferedLineString(List<Point> points, double buf, SpatialContext ctx) Needs at least 1 point, usually more than that.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object o) The sub-classes of Shape generally implement the same contract for Object.equals(Object) and Object.hashCode() amongst the same sub-interface type.
double	getArea(SpatialContext ctx) Calculates the area of the shape, in square-degrees.
Rectangle	getBoundingBox() Get the bounding box for this Shape.
double	getBuf()
Shape	getBuffered(double distance, SpatialContext ctx) Returns a buffered version of this shape.
Point	getCenter() Returns the center point of this shape.
List<Point>	getPoints()
ShapeCollection<BufferedLine>	getSegments()
boolean	hasArea() Does the shape have area? This will be false for points and lines.
int	hashCode()
boolean	isEmpty() Shapes can be "empty", which is to say it exists nowhere.
SpatialRelation	relate(Shape other) Describe the relationship between the two objects.
String	toString()

Methods inherited from class com.spatial4j.core.shape.BaseShape

getContext

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

BufferedLineString

public BufferedLineString(List<Point> points,
                  double buf,
                  SpatialContext ctx)

Needs at least 1 point, usually more than that. If just one then it's internally treated like 2 points.

BufferedLineString

public BufferedLineString(List<Point> points,
                  double buf,
                  boolean expandBufForLongitudeSkew,
                  SpatialContext ctx)

Parameters:

points - ordered control points. If empty then this shape is empty.

buf - Buffer >= 0

expandBufForLongitudeSkew - See #expandBufForLongitudeSkew(com.spatial4j.core.shape.Point, com.spatial4j.core.shape.Point, double). If true then the buffer for each segment is computed.

ctx -

Method Detail

isEmpty

public boolean isEmpty()

Description copied from interface: Shape

Shapes can be "empty", which is to say it exists nowhere. The underlying coordinates are typically NaN.

getBuffered

public Shape getBuffered(double distance,
                SpatialContext ctx)

Description copied from interface: Shape

Returns a buffered version of this shape. The buffer is usually a rounded-corner buffer, although some shapes might buffer differently. This is an optional operation.

Returns:

Not null, and the returned shape should contain the current shape.

getSegments

public ShapeCollection<BufferedLine> getSegments()

getBuf

public double getBuf()

getArea

public double getArea(SpatialContext ctx)

Description copied from interface: Shape

Calculates the area of the shape, in square-degrees. If ctx is null then simple Euclidean calculations will be used. This figure can be an estimate.

relate

public SpatialRelation relate(Shape other)

Description copied from interface: Shape

Describe the relationship between the two objects. For example

• this is WITHIN other
• this CONTAINS other
• this is DISJOINT other
• this INTERSECTS other

Note that a Shape implementation may choose to return INTERSECTS when the true answer is WITHIN or CONTAINS for performance reasons. If a shape does this then it must document when it does. Ideally the shape will not do this approximation in all circumstances, just sometimes.

If the shapes are equal then the result is CONTAINS (preferred) or WITHIN.

hasArea

public boolean hasArea()

Description copied from interface: Shape

Does the shape have area? This will be false for points and lines. It will also be false for shapes that normally have area but are constructed in a degenerate case as to not have area (e.g. a circle with 0 radius or rectangle with no height or no width).

getCenter

public Point getCenter()

Description copied from interface: Shape

Returns the center point of this shape. This is usually the same as getBoundingBox().getCenter() but it doesn't have to be.

Postcondition: this.relate(this.getCenter()) == CONTAINS

getBoundingBox

public Rectangle getBoundingBox()

Description copied from interface: Shape

Get the bounding box for this Shape. This means the shape is within the bounding box and that it touches each side of the rectangle.

Postcondition: this.getBoundingBox().relate(this) == CONTAINS

toString

public String toString()

Overrides:

toString in class Object

getPoints

public List<Point> getPoints()

equals

public boolean equals(Object o)

Description copied from interface: Shape

The sub-classes of Shape generally implement the same contract for Object.equals(Object) and Object.hashCode() amongst the same sub-interface type. This means, for example, that multiple Point implementations of different classes are equal if they share the same x & y.

Specified by:

equals in interface Shape

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object