Package org.locationtech.spatial4j.shape.jts

Class JtsGeometry

java.lang.Object

org.locationtech.spatial4j.shape.BaseShape<JtsSpatialContext>

org.locationtech.spatial4j.shape.jts.JtsGeometry

All Implemented Interfaces:

Shape

public class JtsGeometry
extends BaseShape<JtsSpatialContext>

Wraps a JTS Geometry (i.e. may be a polygon or basically anything). JTS does a great deal of the hard work, but there is work here in handling dateline (aka anti-meridian) wrap.

Field Summary

Fields

Modifier and Type	Field	Description
private Rectangle	bbox
private org.locationtech.jts.geom.Geometry	geom
private boolean	hasArea
protected org.locationtech.jts.geom.prep.PreparedGeometry	preparedGeometry
static java.lang.String	SYSPROP_ASSERT_VALIDATE	System property boolean that can disable auto validation in an assert.
protected boolean	validated

Fields inherited from class org.locationtech.spatial4j.shape.BaseShape

ctx

Constructor Summary

Constructors

Constructor	Description
JtsGeometry(org.locationtech.jts.geom.Geometry geom, JtsSpatialContext ctx, boolean dateline180Check, boolean allowMultiOverlap)

Method Summary

Modifier and Type	Method	Description
private boolean	assertValidate()	called via assertion
protected Rectangle	computeGeoBBox(org.locationtech.jts.geom.Geometry geoms)	Given geoms which has already been checked for being in world bounds, return the minimal longitude range of the bounding box.
private static org.locationtech.jts.geom.Geometry	cutUnwrappedGeomInto360(org.locationtech.jts.geom.Geometry geom)	This "pages" through standard geo boundaries offset by multiples of 360 longitudinally that intersect geom, and the intersecting results of a page and the geom are shifted into the standard -180 to +180 and added to a new geometry that is returned.
boolean	equals(java.lang.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.
JtsGeometry	getBuffered(double distance, SpatialContext ctx)	Returns a buffered version of this shape.
JtsPoint	getCenter()	Returns the center point of this shape.
org.locationtech.jts.geom.Geometry	getGeom()
boolean	hasArea()	Does the shape have area? This will be false for points and lines.
int	hashCode()
void	index()	Adds an index to this class internally to compute spatial relations faster.
static SpatialRelation	intersectionMatrixToSpatialRelation(org.locationtech.jts.geom.IntersectionMatrix matrix)
boolean	isEmpty()	Shapes can be "empty", which is to say it exists nowhere.
(package private) boolean	isIndexed()	Determines if the shape has been indexed.
private org.locationtech.jts.geom.Geometry	narrowCollectionIfPossible(org.locationtech.jts.geom.GeometryCollection gc)	Attempts to retype a geometry collection under the following circumstances, returning null if the collection can not be retyped.
protected SpatialRelation	relate(org.locationtech.jts.geom.Geometry oGeom)
SpatialRelation	relate(Circle circle)
SpatialRelation	relate(JtsGeometry jtsGeometry)
SpatialRelation	relate(Point pt)
SpatialRelation	relate(Rectangle rectangle)
SpatialRelation	relate(Shape other)	Describe the relationship between the two objects.
private static void	shiftGeomByX(org.locationtech.jts.geom.Geometry geom, int xShift)
java.lang.String	toString()
private static org.locationtech.jts.geom.Geometry	unionGeometryCollection(org.locationtech.jts.geom.Geometry geom)
private static org.locationtech.jts.geom.Geometry	unwrapDateline(org.locationtech.jts.geom.Geometry geom)	If geom spans the dateline (aka anti-meridian), then this modifies it to be a valid JTS geometry that extends to the right of the standard -180 to +180 width such that some points are greater than +180 but some remain less.
private static int	unwrapDateline(org.locationtech.jts.geom.LineString lineString)	See unwrapDateline(Geometry).
private static int	unwrapDateline(org.locationtech.jts.geom.Polygon poly)	See unwrapDateline(Geometry).
void	validate()	Validates the shape, throwing a descriptive error if it isn't valid.

Methods inherited from class org.locationtech.spatial4j.shape.BaseShape

getContext

Methods inherited from class java.lang.Object

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

Field Detail

SYSPROP_ASSERT_VALIDATE

public static final java.lang.String SYSPROP_ASSERT_VALIDATE

System property boolean that can disable auto validation in an assert.

See Also:

Constant Field Values

geom

private final org.locationtech.jts.geom.Geometry geom

hasArea

private final boolean hasArea

bbox

private final Rectangle bbox

preparedGeometry

protected org.locationtech.jts.geom.prep.PreparedGeometry preparedGeometry

validated

protected boolean validated

Constructor Detail

JtsGeometry

public JtsGeometry(org.locationtech.jts.geom.Geometry geom,
                   JtsSpatialContext ctx,
                   boolean dateline180Check,
                   boolean allowMultiOverlap)

Method Detail

narrowCollectionIfPossible

private org.locationtech.jts.geom.Geometry narrowCollectionIfPossible(org.locationtech.jts.geom.GeometryCollection gc)

Attempts to retype a geometry collection under the following circumstances, returning null if the collection can not be retyped.

• Single object collections are collapsed down to the object.
• Homogenous collections are recast as the appropriate subclass.

See Also:

GeometryFactory.buildGeometry(Collection)

assertValidate

private boolean assertValidate()

called via assertion

validate

public void validate()
              throws InvalidShapeException

Validates the shape, throwing a descriptive error if it isn't valid. Note that this is usually called automatically by default, but that can be disabled.

Throws:

InvalidShapeException - with descriptive error if the shape isn't valid

isIndexed

boolean isIndexed()

Determines if the shape has been indexed.

index

public void index()

Adds an index to this class internally to compute spatial relations faster. In JTS this is called a PreparedGeometry. This isn't done by default because it takes some time to do the optimization, and it uses more memory. Calling this method isn't thread-safe so be careful when this is done. If it was already indexed then nothing happens.

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.

computeGeoBBox

protected Rectangle computeGeoBBox(org.locationtech.jts.geom.Geometry geoms)

Given geoms which has already been checked for being in world bounds, return the minimal longitude range of the bounding box.

getBuffered

public JtsGeometry 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.

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).

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.

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

getCenter

public JtsPoint 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

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.

relate

public SpatialRelation relate(Point pt)

relate

public SpatialRelation relate(Rectangle rectangle)

relate

public SpatialRelation relate(Circle circle)

relate

public SpatialRelation relate(JtsGeometry jtsGeometry)

relate

protected SpatialRelation relate(org.locationtech.jts.geom.Geometry oGeom)

intersectionMatrixToSpatialRelation

public static SpatialRelation intersectionMatrixToSpatialRelation(org.locationtech.jts.geom.IntersectionMatrix matrix)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

equals

public boolean equals(java.lang.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 java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

getGeom

public org.locationtech.jts.geom.Geometry getGeom()

unwrapDateline

private static org.locationtech.jts.geom.Geometry unwrapDateline(org.locationtech.jts.geom.Geometry geom)

If geom spans the dateline (aka anti-meridian), then this modifies it to be a valid JTS geometry that extends to the right of the standard -180 to +180 width such that some points are greater than +180 but some remain less.

Returns:

The same geometry or a new one if it was unwrapped

unwrapDateline

private static int unwrapDateline(org.locationtech.jts.geom.Polygon poly)

See unwrapDateline(Geometry).

unwrapDateline

private static int unwrapDateline(org.locationtech.jts.geom.LineString lineString)

See unwrapDateline(Geometry).

shiftGeomByX

private static void shiftGeomByX(org.locationtech.jts.geom.Geometry geom,
                                 int xShift)

unionGeometryCollection

private static org.locationtech.jts.geom.Geometry unionGeometryCollection(org.locationtech.jts.geom.Geometry geom)

cutUnwrappedGeomInto360

private static org.locationtech.jts.geom.Geometry cutUnwrappedGeomInto360(org.locationtech.jts.geom.Geometry geom)

This "pages" through standard geo boundaries offset by multiples of 360 longitudinally that intersect geom, and the intersecting results of a page and the geom are shifted into the standard -180 to +180 and added to a new geometry that is returned.