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java.lang.Object com.vividsolutions.jts.geom.Geometry
public abstract class Geometry
A representation of a planar, linear vector geometry.
GeometryCollection
s would be useful, GeometryCollection
s are not supported as arguments to binary predicates or the relate
method. Point
, LineString
, or Polygon
will be returned if the result contains a single element; otherwise, a MultiPoint
, MultiLineString
, or MultiPolygon
will be returned. If the result is heterogeneous a GeometryCollection
will be returned. Because it is not clear at this time what semantics for set-theoretic methods involving GeometryCollection
s would be useful, GeometryCollections
are not supported as arguments to the set-theoretic methods.
Geometry
. The SFS does not specify an unambiguous representation of a given point set returned from a spatial analysis method. One goal of JTS is to make this specification precise and unambiguous. JTS will use a canonical form for Geometry
s returned from spatial analysis methods. The canonical form is a Geometry
which is simple and noded:
isSimple
. LineString
s. It means that all intersection points on LineString
s will be present as endpoints of LineString
s in the result. Geometry
s. These new points arise from intersections between line segments in the edges of the input Geometry
s. In the general case it is not possible to represent constructed points exactly. This is due to the fact that the coordinates of an intersection point may contain twice as many bits of precision as the coordinates of the input line segments. In order to represent these constructed points explicitly, JTS must truncate them to fit the PrecisionModel
. Unfortunately, truncating coordinates moves them slightly. Line segments which would not be coincident in the exact result may become coincident in the truncated representation. This in turn leads to "topology collapses" -- situations where a computed element has a lower dimension than it would in the exact result.
When JTS detects topology collapses during the computation of spatial analysis methods, it will throw an exception. If possible the exception will report the location of the collapse.
equalsExact(Geometry)
method. This implements a comparison based on exact, structural pointwise equality. The equals(Object)
is a synonym for this method, to provide structural equality semantics for use in Java collections. It is important to note that structural pointwise equality is easily affected by things like ring order and component order. In many situations it will be desirable to normalize geometries before comparing them (using the norm()
or normalize()
methods). equalsNorm(Geometry)
is provided as a convenience method to compute equality over normalized geometries, but it is expensive to use. Finally, equalsExact(Geometry, double)
allows using a tolerance value for point comparison. equalsTopo(Geometry)
method. It implements the SFS definition of point-set equality defined in terms of the DE-9IM matrix. To support the SFS naming convention, the method equals(Geometry)
is also provided as a synonym. However, due to the potential for confusion with equals(Object)
its use is discouraged. Since equals(Object)
and hashCode()
are overridden, Geometries can be used effectively in Java collections.
Field Summary | |
---|---|
protected Envelope | envelope The bounding box of this Geometry . |
protected GeometryFactory | factory The GeometryFactory used to create this Geometry |
protected int | SRID The ID of the Spatial Reference System used by this Geometry |
Constructor Summary | |
---|---|
Geometry(GeometryFactory factory) Creates a new Geometry via the specified GeometryFactory. |
Method Summary | |
---|---|
abstract void | apply(CoordinateFilter filter) Performs an operation with or on this Geometry 's coordinates. |
abstract void | apply(CoordinateSequenceFilter filter) Performs an operation on the coordinates in this Geometry 's CoordinateSequence s. |
abstract void | apply(GeometryComponentFilter filter) Performs an operation with or on this Geometry and its component Geometry's. |
abstract void | apply(GeometryFilter filter) Performs an operation with or on this Geometry and its subelement Geometry s (if any). |
Geometry | buffer(double distance) Computes a buffer area around this geometry having the given width. |
Geometry | buffer(double distance, int quadrantSegments) Computes a buffer area around this geometry having the given width and with a specified accuracy of approximation for circular arcs. |
Geometry | buffer(double distance, int quadrantSegments, int endCapStyle) Computes a buffer area around this geometry having the given width and with a specified accuracy of approximation for circular arcs, and using a specified end cap style. |
protected void | checkNotGeometryCollection(Geometry g) Throws an exception if g 's class is GeometryCollection . |
Object | clone() Creates and returns a full copy of this Geometry object (including all coordinates contained by it). |
protected int | compare(Collection a, Collection b) Returns the first non-zero result of compareTo encountered as the two Collection s are iterated over. |
int | compareTo(Object o) Returns whether this Geometry is greater than, equal to, or less than another Geometry . |
int | compareTo(Object o, CoordinateSequenceComparator comp) Returns whether this Geometry is greater than, equal to, or less than another Geometry , using the given CoordinateSequenceComparator . |
protected abstract int | compareToSameClass(Object o) Returns whether this Geometry is greater than, equal to, or less than another Geometry having the same class. |
protected abstract int | compareToSameClass(Object o, CoordinateSequenceComparator comp) Returns whether this Geometry is greater than, equal to, or less than another Geometry of the same class. |
protected abstract Envelope | computeEnvelopeInternal() Returns the minimum and maximum x and y values in this Geometry , or a null Envelope if this Geometry is empty. |
boolean | contains(Geometry g) Tests whether this geometry contains the argument geometry. |
Geometry | convexHull() Computes the smallest convex Polygon that contains all the points in the Geometry . |
boolean | coveredBy(Geometry g) Tests whether this geometry is covered by the argument geometry. |
boolean | covers(Geometry g) Tests whether this geometry covers the argument geometry. |
boolean | crosses(Geometry g) Tests whether this geometry crosses the argument geometry. |
Geometry | difference(Geometry other) Computes a Geometry representing the closure of the point-set of the points contained in this Geometry that are not contained in the other Geometry. |
boolean | disjoint(Geometry g) Tests whether this geometry is disjoint from the argument geometry. |
double | distance(Geometry g) Returns the minimum distance between this Geometry and another Geometry . |
protected boolean | equal(Coordinate a, Coordinate b, double tolerance) |
boolean | equals(Geometry g) Tests whether this geometry is topologically equal to the argument geometry. |
boolean | equals(Object o) Tests whether this geometry is structurally and numerically equal to a given Object . |
boolean | equalsExact(Geometry other) Returns true if the two Geometry s are exactly equal. |
abstract boolean | equalsExact(Geometry other, double tolerance) Returns true if the two Geometry s are exactly equal, up to a specified distance tolerance. |
boolean | equalsNorm(Geometry g) Tests whether two geometries are exactly equal in their normalized forms. |
boolean | equalsTopo(Geometry g) Tests whether this geometry is topologically equal to the argument geometry as defined by the SFS equals predicate. |
void | geometryChanged() Notifies this geometry that its coordinates have been changed by an external party (for example, via a CoordinateFilter ). |
protected void | geometryChangedAction() Notifies this Geometry that its Coordinates have been changed by an external party. |
double | getArea() Returns the area of this Geometry . |
abstract Geometry | getBoundary() Returns the boundary, or an empty geometry of appropriate dimension if this Geometry is empty. |
abstract int | getBoundaryDimension() Returns the dimension of this Geometry s inherent boundary. |
Point | getCentroid() Computes the centroid of this Geometry . |
abstract Coordinate | getCoordinate() Returns a vertex of this Geometry (usually, but not necessarily, the first one). |
abstract Coordinate[] | getCoordinates() Returns an array containing the values of all the vertices for this geometry. |
abstract int | getDimension() Returns the dimension of this geometry. |
Geometry | getEnvelope() Gets a Geometry representing the envelope (bounding box) of this Geometry . |
Envelope | getEnvelopeInternal() Gets an Envelope containing the minimum and maximum x and y values in this Geometry . |
GeometryFactory | getFactory() Gets the factory which contains the context in which this geometry was created. |
Geometry | getGeometryN(int n) Returns an element Geometry from a GeometryCollection (or this , if the geometry is not a collection). |
abstract String | getGeometryType() Returns the name of this Geometry's actual class. |
Point | getInteriorPoint() Computes an interior point of this Geometry . |
double | getLength() Returns the length of this Geometry . |
int | getNumGeometries() Returns the number of Geometry s in a GeometryCollection (or 1, if the geometry is not a collection). |
abstract int | getNumPoints() Returns the count of this Geometry s vertices. |
PrecisionModel | getPrecisionModel() Returns the PrecisionModel used by the Geometry . |
int | getSRID() Returns the ID of the Spatial Reference System used by the Geometry . |
Object | getUserData() Gets the user data object for this geometry, if any. |
int | hashCode() Gets a hash code for the Geometry. |
protected static boolean | hasNonEmptyElements(Geometry[] geometries) Returns true if the array contains any non-empty Geometry s. |
protected static boolean | hasNullElements(Object[] array) Returns true if the array contains any null elements. |
Geometry | intersection(Geometry other) Computes a Geometry representing the point-set which is common to both this Geometry and the other Geometry. |
boolean | intersects(Geometry g) Tests whether this geometry intersects the argument geometry. |
abstract boolean | isEmpty() Tests whether the set of points covered by this Geometry is empty. |
protected boolean | isEquivalentClass(Geometry other) Returns whether the two Geometry s are equal, from the point of view of the equalsExact method. |
protected boolean | isGeometryCollection() Tests whether this is an instance of a general GeometryCollection , rather than a homogeneous subclass. |
boolean | isRectangle() |
boolean | isSimple() Tests whether this Geometry is simple. |
boolean | isValid() Tests whether this Geometry is topologically valid, according to the OGC SFS specification. |
boolean | isWithinDistance(Geometry geom, double distance) Tests whether the distance from this Geometry to another is less than or equal to a specified value. |
Geometry | norm() Creates a new Geometry which is a normalized copy of this Geometry. |
abstract void | normalize() Converts this Geometry to normal form (or canonical form ). |
boolean | overlaps(Geometry g) Tests whether this geometry overlaps the specified geometry. |
IntersectionMatrix | relate(Geometry g) Returns the DE-9IM IntersectionMatrix for the two Geometry s. |
boolean | relate(Geometry g, String intersectionPattern) Tests whether the elements in the DE-9IM IntersectionMatrix for the two Geometry s match the elements in intersectionPattern . |
abstract Geometry | reverse() Computes a new geometry which has all component coordinate sequences in reverse order (opposite orientation) to this one. |
void | setSRID(int SRID) Sets the ID of the Spatial Reference System used by the Geometry . |
void | setUserData(Object userData) A simple scheme for applications to add their own custom data to a Geometry. |
Geometry | symDifference(Geometry other) Computes a Geometry which are not contained in the other Geometry, with the points in the other Geometry not contained in this Geometry . |
String | toString() |
String | toText() Returns the Well-known Text representation of this Geometry . |
boolean | touches(Geometry g) Tests whether this geometry touches the argument geometry. |
Geometry | union() Computes the union of all the elements of this geometry. |
Geometry | union(Geometry other) Computes a Geometry representing the point-set which is contained in both this Geometry and the other Geometry. |
boolean | within(Geometry g) Tests whether this geometry is within the specified geometry. |
Methods inherited from class java.lang.Object |
---|
finalize, getClass, notify, notifyAll, wait, wait, wait |
Field Detail |
---|
protected Envelope envelope
Geometry
.protected final GeometryFactory factory
GeometryFactory
used to create this Geometryprotected int SRID
Geometry
Constructor Detail |
---|
public Geometry(GeometryFactory factory)
Geometry
via the specified GeometryFactory.factory
- Method Detail |
---|
public abstract String getGeometryType()
Geometry
s actual classprotected static boolean hasNonEmptyElements(Geometry[] geometries)
Geometry
s.geometries
- an array of Geometry
s; no elements may be null
true
if any of the Geometry
s isEmpty
methods return false
protected static boolean hasNullElements(Object[] array)
null
elements.array
- an array to validatetrue
if any of array
s elements are null
public int getSRID()
Geometry
. JTS supports Spatial Reference System information in the simple way defined in the SFS. A Spatial Reference System ID (SRID) is present in each Geometry
object. Geometry
provides basic accessor operations for this field, but no others. The SRID is represented as an integer.
Geometry
is defined.public void setSRID(int SRID)
Geometry
. NOTE: This method should only be used for exceptional circumstances or for backwards compatibility. Normally the SRID should be set on the GeometryFactory
used to create the geometry. SRIDs set using this method will not be propagated to geometries returned by constructive methods.
GeometryFactory
public GeometryFactory getFactory()
public Object getUserData()
null
if none setpublic int getNumGeometries()
Geometry
s in a GeometryCollection
(or 1, if the geometry is not a collection).public Geometry getGeometryN(int n)
Geometry
from a GeometryCollection
(or this
, if the geometry is not a collection).n
- the index of the geometry elementpublic void setUserData(Object userData)
Note that user data objects are not present in geometries created by construction methods.
userData
- an object, the semantics for which are defined by the application using this Geometrypublic PrecisionModel getPrecisionModel()
PrecisionModel
used by the Geometry
.Geometry
and all other Geometry
spublic abstract Coordinate getCoordinate()
Geometry
(usually, but not necessarily, the first one). The returned coordinate should not be assumed to be an actual Coordinate object used in the internal representation.Coordinate
which is a vertex of this Geometry
.public abstract Coordinate[] getCoordinates()
In general, the array cannot be assumed to be the actual internal storage for the vertices. Thus modifying the array may not modify the geometry itself. Use the CoordinateSequence.setOrdinate(int, int, double)
method (possibly on the components) to modify the underlying data. If the coordinates are modified, geometryChanged()
must be called afterwards.
Geometry
geometryChanged()
, CoordinateSequence.setOrdinate(int, int, double)
public abstract int getNumPoints()
Geometry
s vertices. The Geometry
s contained by composite Geometry
s must be Geometry's; that is, they must implement getNumPoints
Geometry
public boolean isSimple()
Geometry
is simple. The SFS definition of simplicity follows the general rule that a Geometry is simple if it has no points of self-tangency, self-intersection or other anomalous points. Simplicity is defined for each Geometry
subclass as follows:
isSimple
tests for this condition and reports false
if it is not met. (This is a looser test than checking for validity). Geometry
s are always simple. true
if this Geometry
is simpleisValid()
public boolean isValid()
Geometry
is topologically valid, according to the OGC SFS specification. For validity rules see the Javadoc for the specific Geometry subclass.
true
if this Geometry
is validIsValidOp
public abstract boolean isEmpty()
Geometry
is empty.true
if this Geometry
does not cover any pointspublic double distance(Geometry g)
Geometry
and another Geometry
.g
- the Geometry
from which to compute the distanceIllegalArgumentException
- if g is nullpublic boolean isWithinDistance(Geometry geom, double distance)
Geometry
to another is less than or equal to a specified value.geom
- the Geometry to check the distance todistance
- the distance value to comparetrue
if the geometries are less than distance
apart.public boolean isRectangle()
public double getArea()
Geometry
. Areal Geometries have a non-zero area. They override this function to compute the area. Others return 0.0public double getLength()
Geometry
. Linear geometries return their length. Areal geometries return their perimeter. They override this function to compute the area. Others return 0.0public Point getCentroid()
Geometry
. The centroid is equal to the centroid of the set of component Geometries of highest dimension (since the lower-dimension geometries contribute zero "weight" to the centroid). The centroid of an empty geometry is POINT EMPTY
.
Point
which is the centroid of this Geometrypublic Point getInteriorPoint()
Geometry
. An interior point is guaranteed to lie in the interior of the Geometry, if it possible to calculate such a point exactly. Otherwise, the point may lie on the boundary of the geometry. The interior point of an empty geometry is POINT EMPTY
.
Point
which is in the interior of this Geometrypublic abstract int getDimension()
Note that this is a different concept to the dimension of the vertex Coordinate
s. The geometry dimension can never be greater than the coordinate dimension. For example, a 0-dimensional geometry (e.g. a Point) may have a coordinate dimension of 3 (X,Y,Z).
public abstract Geometry getBoundary()
Geometry
is empty. (In the case of zero-dimensional geometries, ' an empty GeometryCollection is returned.) For a discussion of this function, see the OpenGIS Simple Features Specification. As stated in SFS Section 2.1.13.1, "the boundary of a Geometry is a set of Geometries of the next lower dimension."Geometry
public abstract int getBoundaryDimension()
Geometry
s inherent boundary.Dimension.FALSE
if the boundary is the empty geometry.public Geometry getEnvelope()
Geometry
. If this Geometry
is:
Point
. Point
. LineString
Polygon
whose vertices are (minx miny, maxx miny, maxx maxy, minx maxy, minx miny). GeometryFactory.toGeometry(Envelope)
public Envelope getEnvelopeInternal()
Envelope
containing the minimum and maximum x and y values in this Geometry
. If the geometry is empty, an empty Envelope
is returned. The returned object is a copy of the one maintained internally, to avoid aliasing issues. For best performance, clients which access this envelope frequently should cache the return value.
Geometry
.public void geometryChanged()
CoordinateFilter
). When this method is called the geometry will flush and/or update any derived information it has cached (such as its Envelope
). The operation is applied to all component Geometries.protected void geometryChangedAction()
apply(GeometryComponentFilter)
public boolean disjoint(Geometry g)
The disjoint
predicate has the following equivalent definitions:
[FF*FF****]
! g.intersects(this) = true
disjoint
is the inverse of intersects
) g
- the Geometry
with which to compare this Geometry
true
if the two Geometry
s are disjointintersects(com.vividsolutions.jts.geom.Geometry)
public boolean touches(Geometry g)
The touches
predicate has the following equivalent definitions:
[FT*******]
[F**T*****]
[F***T****]
false
.g
- the Geometry
with which to compare this Geometry
true
if the two Geometry
s touch; Returns false
if both Geometry
s are pointspublic boolean intersects(Geometry g)
The intersects
predicate has the following equivalent definitions:
[T********]
[*T*******]
[***T*****]
[****T****]
! g.disjoint(this) = true
intersects
is the inverse of disjoint
) g
- the Geometry
with which to compare this Geometry
true
if the two Geometry
s intersectdisjoint(com.vividsolutions.jts.geom.Geometry)
public boolean crosses(Geometry g)
The crosses
predicate has the following equivalent definitions:
[T*T******]
(for P/L, P/A, and L/A situations) [T*****T**]
(for L/P, A/P, and A/L situations) [0********]
(for L/L situations) false
. The SFS defined this predicate only for P/L, P/A, L/L, and L/A situations. In order to make the relation symmetric, JTS extends the definition to apply to L/P, A/P and A/L situations as well.
g
- the Geometry
with which to compare this Geometry
true
if the two Geometry
s cross.public boolean within(Geometry g)
The within
predicate has the following equivalent definitions:
[T*F**F***]
g.contains(this) = true
within
is the converse of contains(com.vividsolutions.jts.geom.Geometry)
) A.within(B) = false
(As a concrete example, take A to be a LineString which lies in the boundary of a Polygon B.) For a predicate with similar behaviour but avoiding this subtle limitation, see coveredBy(com.vividsolutions.jts.geom.Geometry)
.g
- the Geometry
with which to compare this Geometry
true
if this Geometry
is within g
contains(com.vividsolutions.jts.geom.Geometry)
, coveredBy(com.vividsolutions.jts.geom.Geometry)
public boolean contains(Geometry g)
The contains
predicate has the following equivalent definitions:
[T*****FF*]
g.within(this) = true
contains
is the converse of within(com.vividsolutions.jts.geom.Geometry)
) B.contains(A) = false
. (As a concrete example, take A to be a LineString which lies in the boundary of a Polygon B.) For a predicate with similar behaviour but avoiding this subtle limitation, see covers(com.vividsolutions.jts.geom.Geometry)
.g
- the Geometry
with which to compare this Geometry
true
if this Geometry
contains g
within(com.vividsolutions.jts.geom.Geometry)
, covers(com.vividsolutions.jts.geom.Geometry)
public boolean overlaps(Geometry g)
The overlaps
predicate has the following equivalent definitions:
[T*T***T**]
(for two points or two surfaces) or [1*T***T**]
(for two curves) false
.g
- the Geometry
with which to compare this Geometry
true
if the two Geometry
s overlap.public boolean covers(Geometry g)
The covers
predicate has the following equivalent definitions:
[T*****FF*]
[*T****FF*]
[***T**FF*]
[****T*FF*]
g.coveredBy(this) = true
covers
is the converse of coveredBy(com.vividsolutions.jts.geom.Geometry)
) false
. This predicate is similar to contains(com.vividsolutions.jts.geom.Geometry)
, but is more inclusive (i.e. returns true
for more cases). In particular, unlike contains
it does not distinguish between points in the boundary and in the interior of geometries. For most situations, covers
should be used in preference to contains
. As an added benefit, covers
is more amenable to optimization, and hence should be more performant.
g
- the Geometry
with which to compare this Geometry
true
if this Geometry
covers g
contains(com.vividsolutions.jts.geom.Geometry)
, coveredBy(com.vividsolutions.jts.geom.Geometry)
public boolean coveredBy(Geometry g)
The coveredBy
predicate has the following equivalent definitions:
[T*F**F***]
[*TF**F***]
[**FT*F***]
[**F*TF***]
g.covers(this) = true
coveredBy
is the converse of covers(com.vividsolutions.jts.geom.Geometry)
) false
. This predicate is similar to within(com.vividsolutions.jts.geom.Geometry)
, but is more inclusive (i.e. returns true
for more cases).
g
- the Geometry
with which to compare this Geometry
true
if this Geometry
is covered by g
within(com.vividsolutions.jts.geom.Geometry)
, covers(com.vividsolutions.jts.geom.Geometry)
public boolean relate(Geometry g, String intersectionPattern)
IntersectionMatrix
for the two Geometry
s match the elements in intersectionPattern
. The pattern is a 9-character string, with symbols drawn from the following set: g
- the Geometry
with which to compare this Geometry
intersectionPattern
- the pattern against which to check the intersection matrix for the two Geometry
strue
if the DE-9IM intersection matrix for the two Geometry
s match intersectionPattern
IntersectionMatrix
public IntersectionMatrix relate(Geometry g)
IntersectionMatrix
for the two Geometry
s.g
- the Geometry
with which to compare this Geometry
IntersectionMatrix
describing the intersections of the interiors, boundaries and exteriors of the two Geometry
spublic boolean equals(Geometry g)
This method is included for backward compatibility reasons. It has been superseded by the equalsTopo(Geometry)
method, which has been named to clearly denote its functionality.
This method should NOT be confused with the method equals(Object)
, which implements an exact equality comparison.
g
- the Geometry
with which to compare this Geometry
Geometry
s are topologically equalequalsTopo(Geometry)
public boolean equalsTopo(Geometry g)
equals
predicate. The SFS equals
predicate has the following equivalent definitions:
T*F**FFF*
T*F **F FF*
equalsExact(Geometry)
.g
- the Geometry
with which to compare this Geometry
true
if the two Geometry
s are topologically equalequalsExact(Geometry)
public boolean equals(Object o)
Object
. If the argument Object
is not a Geometry
, the result is false
. Otherwise, the result is computed using equalsExact(Geometry)
. This method is provided to fulfill the Java contract for value-based object equality. In conjunction with hashCode()
it provides semantics which are most useful for using Geometry
s as keys and values in Java collections.
Note that to produce the expected result the input geometries should be in normal form. It is the caller's responsibility to perform this where required (using Geometry#norm() or {@link #normalize()} as appropriate).
o
- the Object to compareequalsExact(Geometry)
, hashCode()
, norm()
, normalize()
public int hashCode()
public String toString()
public String toText()
Geometry
. For a definition of the Well-known Text format, see the OpenGIS Simple Features Specification.Geometry
public Geometry buffer(double distance)
abs(distance)
. Mathematically-exact buffer area boundaries can contain circular arcs. To represent these arcs using linear geometry they must be approximated with line segments. The buffer geometry is constructed using 8 segments per quadrant to approximate the circular arcs. The end cap style is CAP_ROUND
.
The buffer operation always returns a polygonal result. The negative or zero-distance buffer of lines and points is always an empty Polygon
. This is also the result for the buffers of degenerate (zero-area) polygons.
distance
- the width of the buffer (may be positive, negative or 0)TopologyException
- if a robustness error occursbuffer(double, int)
, buffer(double, int, int)
public Geometry buffer(double distance, int quadrantSegments)
Mathematically-exact buffer area boundaries can contain circular arcs. To represent these arcs using linear geometry they must be approximated with line segments. The quadrantSegments
argument allows controlling the accuracy of the approximation by specifying the number of line segments used to represent a quadrant of a circle
The buffer operation always returns a polygonal result. The negative or zero-distance buffer of lines and points is always an empty Polygon
. This is also the result for the buffers of degenerate (zero-area) polygons.
distance
- the width of the buffer (may be positive, negative or 0)quadrantSegments
- the number of line segments used to represent a quadrant of a circleTopologyException
- if a robustness error occursbuffer(double)
, buffer(double, int, int)
public Geometry buffer(double distance, int quadrantSegments, int endCapStyle)
Mathematically-exact buffer area boundaries can contain circular arcs. To represent these arcs using linear geometry they must be approximated with line segments. The quadrantSegments
argument allows controlling the accuracy of the approximation by specifying the number of line segments used to represent a quadrant of a circle
The end cap style specifies the buffer geometry that will be created at the ends of linestrings. The styles provided are:
BufferOp.CAP_ROUND
- (default) a semi-circle BufferOp.CAP_BUTT
- a straight line perpendicular to the end segment BufferOp.CAP_SQUARE
- a half-square The buffer operation always returns a polygonal result. The negative or zero-distance buffer of lines and points is always an empty Polygon
. This is also the result for the buffers of degenerate (zero-area) polygons.
distance
- the width of the buffer (may be positive, negative or 0)quadrantSegments
- the number of line segments used to represent a quadrant of a circleendCapStyle
- the end cap style to useTopologyException
- if a robustness error occursbuffer(double)
, buffer(double, int)
, BufferOp
public Geometry convexHull()
Polygon
that contains all the points in the Geometry
. This obviously applies only to Geometry
s which contain 3 or more points; the results for degenerate cases are specified as follows: Number of Point s in argument Geometry | Geometry class of result |
---|---|
0 | empty GeometryCollection |
1 | Point |
2 | LineString |
3 or more | Polygon |
Geometry
' s pointspublic abstract Geometry reverse()
public Geometry intersection(Geometry other)
Geometry
representing the point-set which is common to both this Geometry
and the other
Geometry. The intersection of two geometries of different dimension produces a result geometry of dimension less than or equal to the minimum dimension of the input geometries. The result geometry may be a heterogenous GeometryCollection
. If the result is empty, it is an atomic geometry with the dimension of the lowest input dimension.
Intersection of GeometryCollection
s is supported only for homogeneous collection types.
Non-empty heterogeneous GeometryCollection
arguments are not supported.
other
- the Geometry
with which to compute the intersectionGeometry
sTopologyException
- if a robustness error occursIllegalArgumentException
- if the argument is a non-empty heterogeneous GeometryCollection
public Geometry union(Geometry other)
Geometry
representing the point-set which is contained in both this Geometry
and the other
Geometry. The union of two geometries of different dimension produces a result geometry of dimension equal to the maximum dimension of the input geometries. The result geometry may be a heterogenous GeometryCollection
. If the result is empty, it is an atomic geometry with the dimension of the highest input dimension.
Unioning LineString
s has the effect of noding and dissolving the input linework. In this context "noding" means that there will be a node or endpoint in the result for every endpoint or line segment crossing in the input. "Dissolving" means that any duplicate (i.e. coincident) line segments or portions of line segments will be reduced to a single line segment in the result. If merged linework is required, the LineMerger
class can be used.
Non-empty GeometryCollection
arguments are not supported.
other
- the Geometry
with which to compute the unionGeometry
and the points of other
TopologyException
- if a robustness error occursIllegalArgumentException
- if either input is a non-empty GeometryCollectionLineMerger
public Geometry difference(Geometry other)
Geometry
representing the closure of the point-set of the points contained in this Geometry
that are not contained in the other
Geometry. If the result is empty, it is an atomic geometry with the dimension of the left-hand input.
Non-empty GeometryCollection
arguments are not supported.
other
- the Geometry
with which to compute the differenceGeometry
with other
TopologyException
- if a robustness error occursIllegalArgumentException
- if either input is a non-empty GeometryCollectionpublic Geometry symDifference(Geometry other)
Geometry
which are not contained in the other
Geometry, with the points in the other
Geometry not contained in this Geometry
. If the result is empty, it is an atomic geometry with the dimension of the highest input dimension. Non-empty GeometryCollection
arguments are not supported.
other
- the Geometry
with which to compute the symmetric differenceGeometry
with other
TopologyException
- if a robustness error occursIllegalArgumentException
- if either input is a non-empty GeometryCollectionpublic Geometry union()
union()
supports GeometryCollection
s (which the other overlay operations currently do not).
The result obeys the following contract:
LineString
s has the effect of fully noding and dissolving the linework. Polygon
s will always return a Polygonal
geometry (unlike union(Geometry)
, which may return geometrys of lower dimension if a topology collapse occurred. TopologyException
- if a robustness error occursUnaryUnionOp
public abstract boolean equalsExact(Geometry other, double tolerance)
Geometry
s are exactly equal, up to a specified distance tolerance. Two Geometries are exactly equal within a distance tolerance if and only if: GeometryFactory
, the SRID
, or the userData
fields. To properly test equality between different geometries, it is usually necessary to normalize()
them first.
other
- the Geometry
with which to compare this Geometry
tolerance
- distance at or below which two Coordinate
s are considered equaltrue
if this and the other Geometry
have identical structure and point values, up to the distance tolerance.equalsExact(Geometry)
, normalize()
, norm()
public boolean equalsExact(Geometry other)
Geometry
s are exactly equal. Two Geometries are exactly equal iff: equalsTopo(Geometry)
, which is more useful in certain situations (such as using geometries as keys in collections). This method does not test the values of the GeometryFactory
, the SRID
, or the userData
fields.
To properly test equality between different geometries, it is usually necessary to normalize()
them first.
other
- the Geometry
with which to compare this Geometry
true
if this and the other Geometry
have identical structure and point values.equalsExact(Geometry, double)
, normalize()
, norm()
public boolean equalsNorm(Geometry g)
equalsExact(Geometry)
. This method is relatively expensive to compute. For maximum performance, the client should instead perform normalization on the individual geometries at an appropriate point during processing.
g
- a Geometrypublic abstract void apply(CoordinateFilter filter)
Geometry
's coordinates. If this method modifies any coordinate values, geometryChanged()
must be called to update the geometry state. Note that you cannot use this method to modify this Geometry if its underlying CoordinateSequence's #get method returns a copy of the Coordinate, rather than the actual Coordinate stored (if it even stores Coordinate objects at all).filter
- the filter to apply to this Geometry
's coordinatespublic abstract void apply(CoordinateSequenceFilter filter)
Geometry
's CoordinateSequence
s. If the filter reports that a coordinate value has been changed, geometryChanged()
will be called automatically.filter
- the filter to applypublic abstract void apply(GeometryFilter filter)
Geometry
and its subelement Geometry
s (if any). Only GeometryCollections and subclasses have subelement Geometry's.filter
- the filter to apply to this Geometry
(and its children, if it is a GeometryCollection
).public abstract void apply(GeometryComponentFilter filter)
filter
- the filter to apply to this Geometry
.public Object clone()
Geometry
object (including all coordinates contained by it). Subclasses are responsible for overriding this method and copying their internal data. Overrides should call this method first.public abstract void normalize()
Geometry
to normal form (or canonical form ). Normal form is a unique representation for Geometry
s. It can be used to test whether two Geometry
s are equal in a way that is independent of the ordering of the coordinates within them. Normal form equality is a stronger condition than topological equality, but weaker than pointwise equality. The definitions for normal form use the standard lexicographical ordering for coordinates. "Sorted in order of coordinates" means the obvious extension of this ordering to sequences of coordinates. NOTE that this method mutates the value of this geometry in-place. If this is not safe and/or wanted, the geometry should be cloned prior to normalization.
public Geometry norm()
normalize()
public int compareTo(Object o)
Geometry
is greater than, equal to, or less than another Geometry
. If their classes are different, they are compared using the following ordering:
Geometry
s have the same class, their first elements are compared. If those are the same, the second elements are compared, etc.compareTo
in interface Comparable
o
- a Geometry
with which to compare this Geometry
o
, as defined in "Normal Form For Geometry" in the JTS Technical Specificationspublic int compareTo(Object o, CoordinateSequenceComparator comp)
Geometry
is greater than, equal to, or less than another Geometry
, using the given CoordinateSequenceComparator
. If their classes are different, they are compared using the following ordering:
Geometry
s have the same class, their first elements are compared. If those are the same, the second elements are compared, etc.o
- a Geometry
with which to compare this Geometry
comp
- a CoordinateSequenceComparator
o
, as defined in "Normal Form For Geometry" in the JTS Technical Specificationsprotected boolean isEquivalentClass(Geometry other)
Geometry
s are equal, from the point of view of the equalsExact
method. Called by equalsExact
. In general, two Geometry
classes are considered to be "equivalent" only if they are the same class. An exception is LineString
, which is considered to be equivalent to its subclasses.other
- the Geometry
with which to compare this Geometry
for equalitytrue
if the classes of the two Geometry
s are considered to be equal by the equalsExact
method.protected void checkNotGeometryCollection(Geometry g)
g
's class is GeometryCollection
. (Its subclasses do not trigger an exception).g
- the Geometry
to checkIllegalArgumentException
- if g
is a GeometryCollection
but not one of its subclassesprotected boolean isGeometryCollection()
GeometryCollection
, rather than a homogeneous subclass.protected abstract Envelope computeEnvelopeInternal()
Geometry
, or a null Envelope
if this Geometry
is empty. Unlike getEnvelopeInternal
, this method calculates the Envelope
each time it is called; getEnvelopeInternal
caches the result of this method.Geometry
s bounding box; if the Geometry
is empty, Envelope#isNull
will return true
protected abstract int compareToSameClass(Object o)
Geometry
is greater than, equal to, or less than another Geometry
having the same class.o
- a Geometry
having the same class as this Geometry
o
, as defined in "Normal Form For Geometry" in the JTS Technical Specificationsprotected abstract int compareToSameClass(Object o, CoordinateSequenceComparator comp)
Geometry
is greater than, equal to, or less than another Geometry
of the same class. using the given CoordinateSequenceComparator
.o
- a Geometry
having the same class as this Geometry
comp
- a CoordinateSequenceComparator
o
, as defined in "Normal Form For Geometry" in the JTS Technical Specificationsprotected int compare(Collection a, Collection b)
compareTo
encountered as the two Collection
s are iterated over. If, by the time one of the iterations is complete, no non-zero result has been encountered, returns 0 if the other iteration is also complete. If b
completes before a
, a positive number is returned; if a before b, a negative number.a
- a Collection
of Comparable
sb
- a Collection
of Comparable
scompareTo
result, if any; otherwise, zeroprotected boolean equal(Coordinate a, Coordinate b, double tolerance)
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