Interface Geometry

 All Superinterfaces:
TransfiniteSet
 All Known Subinterfaces:
Aggregate
,Boundary
,Complex
,ComplexBoundary
,Composite
,CompositeCurve
,CompositePoint
,CompositeSolid
,CompositeSurface
,Curve
,CurveBoundary
,MultiCurve
,MultiPoint
,MultiPrimitive
,MultiSurface
,OrientableCurve
,OrientablePrimitive
,OrientableSurface
,Point
,PolyhedralSurface
,Primitive
,PrimitiveBoundary
,Ring
,Shell
,Solid
,SolidBoundary
,Surface
,SurfaceBoundary
,Tin
,TriangulatedSurface
@UML(identifier="GM_Object", specification=ISO_19107) public interface Geometry extends TransfiniteSet
Root class of the geometric object taxonomy.Geometry
supports interfaces common to all geographically referenced geometric objects.Geometry
instances are sets of direct positions in a particular coordinate reference system. AGeometry
can be regarded as an infinite set of points that satisfies the set operation interfaces for a set of direct positions,TransfiniteSet<DirectPosition>
. Since:
 GeoAPI 1.0
 Author:
 Martin Desruisseaux (IRD)


Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description Geometry
clone()
Returns a clone of this geometry with deep copy semantic.double
distance(Geometry geometry)
Returns the distance between thisGeometry
and anotherGeometry
.Boundary
getBoundary()
Returns a finite set ofGeometry
s containing all of the direct positions on the boundary of thisGeometry
.Geometry
getBuffer(double distance)
Returns aGeometry
containing all points whose distance from thisGeometry
is less than or equal to the distance passed as a parameter.DirectPosition
getCentroid()
Returns the mathematical centroid for thisGeometry
.Complex
getClosure()
Returns a finite set ofGeometry
s containing all of the points on the boundary of thisGeometry
and this object (the union of the object and its boundary).Geometry
getConvexHull()
Returns aGeometry
that represents the convex hull of thisGeometry
.int
getCoordinateDimension()
Returns the dimension of the coordinates that define thisGeometry
, which must be the same as the coordinate dimension of the coordinate reference system for thisGeometry
.CoordinateReferenceSystem
getCoordinateReferenceSystem()
Returns the coordinate reference system used in direct position coordinates.int
getDimension(DirectPosition point)
Returns the inherent dimension of thisGeometry
, which shall be less than or equal to the coordinate dimension.Envelope
getEnvelope()
Returns the minimum bounding box for thisGeometry
.Set<? extends Complex>
getMaximalComplex()
Returns the set of maximal complexes within which thisGeometry
is contained.Geometry
getMbRegion()
Returns a region in the coordinate reference system that contains thisGeometry
.Precision
getPrecision()
Returns the precision model used to guide the accuracy of topology operations.DirectPosition
getRepresentativePoint()
Returns a point value that is guaranteed to be on thisGeometry
.boolean
isCycle()
Returnstrue
if thisGeometry
has an empty boundary after topological simplification (removal of overlaps between components in nonstructured aggregates, such as subclasses ofAggregate
).boolean
isMutable()
Returnsfalse
if this geometry is immutable.boolean
isSimple()
Returnstrue
if thisGeometry
has no interior point of selfintersection or selftangency.Geometry
toImmutable()
Returns an immutable copy of this geometry.Geometry
transform(CoordinateReferenceSystem newCRS)
Returns a newGeometry
that is the coordinate transformation of thisGeometry
into the passed coordinate reference system within the accuracy of the transformation.Geometry
transform(CoordinateReferenceSystem newCRS, MathTransform transform)
Returns a newGeometry
that is the coordinate transformation of thisGeometry
into the passed coordinate reference system, using the specified transform.
Methods inherited from interface TransfiniteSet
contains, contains, difference, equals, intersection, intersects, symmetricDifference, union




Method Detail

getCoordinateReferenceSystem
@UML(identifier="CRS", obligation=MANDATORY, specification=ISO_19107) CoordinateReferenceSystem getCoordinateReferenceSystem()
Returns the coordinate reference system used in direct position coordinates. Ifnull
, then thisGeometry
uses the coordinate reference system from anotherGeometry
in which it is contained.The most common example where the coordinate reference system is
null
is the elements and subcomplexes of a maximal complex. The complex can carry the coordinate reference system for all primitive elements and for allComplex
subcomplexes.This association is only navigable from
Geometry
to coordinate reference system. This means that the coordinate reference system objects in a data set do not keep a list ofGeometry
s that use them. Returns:
 The coordinate reference system used in direct position coordinates.
 See Also:
getCoordinateDimension()

getPrecision
Precision getPrecision()
Returns the precision model used to guide the accuracy of topology operations. Returns:
 the precision model used for topological operations.

getMbRegion
@UML(identifier="mbRegion", obligation=MANDATORY, specification=ISO_19107) Geometry getMbRegion()
Returns a region in the coordinate reference system that contains thisGeometry
. The default shall be to return an instance of an appropriateGeometry
subclass that represents the same spatial set returned fromgetEnvelope()
. The most common use ofmbRegion
will be to support indexing methods that use extents other than minimum bounding rectangles (MBR or envelopes). This does not restrict the returnedGeometry
from being a nonvector geometric representation, although those types are not defined within this specification. Returns:
 The minimum bounding region.
 See Also:
getEnvelope()
,getBoundary()

getRepresentativePoint
@UML(identifier="representativePoint", obligation=MANDATORY, specification=ISO_19107) DirectPosition getRepresentativePoint()
Returns a point value that is guaranteed to be on thisGeometry
. The default logic may be to use the direct position of the point returned bygetCentroid()
if that point is on the object. Another use of representative point may be for the placement of labels in systems based on graphic presentation. Returns:
 The representative point.
 See Also:
getCentroid()

getBoundary
@UML(identifier="boundary", obligation=MANDATORY, specification=ISO_19107) Boundary getBoundary()
Returns a finite set ofGeometry
s containing all of the direct positions on the boundary of thisGeometry
. These object collections shall have further internal structure where appropriate. The finite set ofGeometry
s returned shall be in the same coordinate reference system as thisGeometry
. If theGeometry
is in a complex, then the boundaryGeometry
s returned shall be in the same complex. If theGeometry
is not in any complex, then the boundaryGeometry
s returned may have been constructed in response to the operation. The elements of a boundary shall be smaller in dimension than the original element. Returns:
 The sets of positions on the boundary.
 See Also:
getMbRegion()
,getClosure()
,getBuffer(double)
,#getDistance

getClosure
@UML(identifier="closure", obligation=MANDATORY, specification=ISO_19107) Complex getClosure()
Returns a finite set ofGeometry
s containing all of the points on the boundary of thisGeometry
and this object (the union of the object and its boundary). These object collections shall have further internal structure where appropriate. The finite set ofGeometry
s returned shall be in the same coordinate reference system as thisGeometry
. If theGeometry
is in a complex, then the boundaryGeometry
s returned shall be in the same complex. If theGeometry
is not in any complex, then the boundaryGeometry
s returned may have been constructed in response to the operation. Returns:
 The sets of points on the union of this object and its boundary.
 See Also:
getBoundary()

isSimple
@UML(identifier="isSimple", obligation=MANDATORY, specification=ISO_19107) boolean isSimple()
Returnstrue
if thisGeometry
has no interior point of selfintersection or selftangency. In mathematical formalisms, this means that every point in the interior of the object must have a metric neighborhood whose intersection with the object is isomorphic to an nsphere, where n is the dimension of thisGeometry
.Since most coordinate geometries are represented, either directly or indirectly by functions from regions in Euclidean space of their topological dimension, the easiest test for simplicity to require that a function exist that is onetoone and bicontinuous (continuous in both directions). Such a function is a topological isomorphism. This test does not work for "closed" objects (that is, objects for which
isCycle()
returnstrue
). Returns:
true
if this object has no interior point of selfintersection or selftangency. See Also:
isCycle()

isCycle
@UML(identifier="isCycle", obligation=MANDATORY, specification=ISO_19107) boolean isCycle()
Returnstrue
if thisGeometry
has an empty boundary after topological simplification (removal of overlaps between components in nonstructured aggregates, such as subclasses ofAggregate
). This condition is alternatively referred to as being "closed" as in a "closed curve." This creates some confusion since there are two distinct and incompatible definitions for the word "closed". The use of the word cycle is rarer (generally restricted to the field of algebraic topology), but leads to less confusion. Essentially, an object is a cycle if it is isomorphic to a geometric object that is the boundary of a region in some Euclidean space. Thus a curve is a cycle if it is isomorphic to a circle (has the same start and end point). A surface is a cycle if it isomorphic to the surface of a sphere, or some torus. A solid, with finite size, in a space of dimension 3 is never a cycle. Returns:
true
if thisGeometry
has an empty boundary after topological simplification. See Also:
isSimple()

distance
@UML(identifier="distance", obligation=MANDATORY, specification=ISO_19107) double distance(Geometry geometry)
Returns the distance between thisGeometry
and anotherGeometry
. This distance is defined to be the greatest lower bound of the set of distances between all pairs of points that include one each from each of the twoGeometry
s. A "distance" value shall be a positive number associated to a distance unit such as meter or standard foot. If necessary, the second geometric object shall be transformed into the same coordinate reference system as the first before the distance is calculated.If the geometric objects overlap, or touch, then their distance apart shall be zero. Some current implementations use a "negative" distance for such cases, but the approach is neither consistent between implementations, nor theoretically viable.
NOTE: The role of the reference system in distance calculations is important. Generally, there are at least three types of distances that may be defined between points (and therefore between geometric objects): map distance, geodesic distance, and terrain distance.
 Map distance is the distance between the points as defined by their positions in a coordinate projection (such as on a map when scale is taken into account). Map distance is usually accurate for small areas where scale functions have wellbehaved derivatives.
 Geodesic distance is the length of the shortest curve between those two points along the surface of the earth model being used by the coordinate reference system. Geodesic distance behaves well for wide areas of coverage, and takes the earth's curvature into account. It is especially handy for air and sea navigation, although care should be taken to distinguish between rhumb line (curves of constant bearing) and geodesic curve distance.
 Terrain distance takes into account the local vertical displacements (hypsography). Terrain distance can be based either on a geodesic distance or a map distance.
 Parameters:
geometry
 The other object. Returns:
 The distance between the two objects.
 Since:
 GeoAPI 2.1
 See Also:
getBoundary()
,getBuffer(double)
,CoordinateSystem.getAxis(int)

getDimension
@UML(identifier="dimension", obligation=MANDATORY, specification=ISO_19107) int getDimension(DirectPosition point)
Returns the inherent dimension of thisGeometry
, which shall be less than or equal to the coordinate dimension. The dimension of a collection of geometric objects shall be the largest dimension of any of its pieces. Points are 0dimensional, curves are 1dimensional, surfaces are 2dimensional, and solids are 3dimensional. Locally, the dimension of a geometric object at a point is the dimension of a local neighborhood of the point  that is the dimension of any coordinate neighborhood of the point. Dimension is unambiguously defined only for direct positions interior to thisGeometry
. If the passed direct position isnull
, then the operation shall return the largest possible dimension for any direct position in thisGeometry
. Parameters:
point
 The point where to evaluate the dimension, ornull
. Returns:
 The inherent dimension.
 See Also:
getCoordinateDimension()

getCoordinateDimension
@UML(identifier="coordinateDimension", obligation=MANDATORY, specification=ISO_19107) int getCoordinateDimension()
Returns the dimension of the coordinates that define thisGeometry
, which must be the same as the coordinate dimension of the coordinate reference system for thisGeometry
. Returns:
 The coordinate dimension.
 See Also:
getDimension(org.opengis.geometry.DirectPosition)
,getCoordinateReferenceSystem()

getMaximalComplex
@UML(identifier="maximalComplex", obligation=MANDATORY, specification=ISO_19107) Set<? extends Complex> getMaximalComplex()
Returns the set of maximal complexes within which thisGeometry
is contained. As a set of primitives, a complex may be contained as a set in another larger complex, referred to as a "super complex" of the original. A complex is maximal if there is no such larger super complex. Returns:
 The set of maximal complexes within which this
Geometry
is contained.

transform
@UML(identifier="transform", obligation=MANDATORY, specification=ISO_19107) Geometry transform(CoordinateReferenceSystem newCRS) throws TransformException
Returns a newGeometry
that is the coordinate transformation of thisGeometry
into the passed coordinate reference system within the accuracy of the transformation. Parameters:
newCRS
 The new coordinate reference system. Returns:
 The transformed
Geometry
.  Throws:
TransformException
 if the transformation failed.

transform
@Extension Geometry transform(CoordinateReferenceSystem newCRS, MathTransform transform) throws TransformException
Returns a newGeometry
that is the coordinate transformation of thisGeometry
into the passed coordinate reference system, using the specified transform. It is the user responsability to ensure that the supplied transform is appropriate for this geometry. Parameters:
newCRS
 The new coordinate reference system.transform
 The transform from the existing coordinate reference system to the new coordinate reference system. Returns:
 The transformed
Geometry
.  Throws:
TransformException
 if the transformation failed.

getEnvelope
@UML(identifier="envelope", obligation=MANDATORY, specification=ISO_19107) Envelope getEnvelope()
Returns the minimum bounding box for thisGeometry
. This shall be the coordinate region spanning the minimum and maximum value for each ordinate taken on by direct positions in thisGeometry
. The simplest representation for an envelope consists of two direct positions, the first one containing all the minimums for each ordinate, and second one containing all the maximums. However, there are cases for which these two positions would be outside the domain of validity of the object's coordinate reference system. Returns:
 The envelope.
 See Also:
getMbRegion()

getCentroid
@UML(identifier="centroid", obligation=MANDATORY, specification=ISO_19107) DirectPosition getCentroid()
Returns the mathematical centroid for thisGeometry
. The result is not guaranteed to be on the object. For heterogeneous collections of primitives, the centroid only takes into account those of the largest dimension. For example, when calculating the centroid of surfaces, an average is taken weighted by area. Since curves have no area they do not contribute to the average. Returns:
 The centroid.
 See Also:
getRepresentativePoint()

getConvexHull
@UML(identifier="convexHull", obligation=MANDATORY, specification=ISO_19107) Geometry getConvexHull()
Returns aGeometry
that represents the convex hull of thisGeometry
. Convexity requires the use of "lines" or "curves of shortest length" and the use of different coordinate systems may result in different versions of the convex hull of an object. Each implementation shall decide on an appropriate solution to this ambiguity. For two reasonable coordinate systems, a convex hull of an object in one will be very closely approximated by the transformed image of the convex hull of the same object in the other. Returns:
 The convex hull.

getBuffer
@UML(identifier="buffer", obligation=MANDATORY, specification=ISO_19107) Geometry getBuffer(double distance)
Returns aGeometry
containing all points whose distance from thisGeometry
is less than or equal to the distance passed as a parameter. TheGeometry
returned is in the same reference system as this originalGeometry
. The dimension of the returnedGeometry
is normally the same as the coordinate dimension  a collection of surfaces in 2D space and a collection of solids in 3D space, but this may be application defined. Parameters:
distance
 The distance. Returns:
 A geometry containing all points whose distance from this
Geometry
is less than or equal to the specified distance.  See Also:
getBoundary()
,#getDistance
,CoordinateSystem.getAxis(int)

isMutable
@Extension boolean isMutable()
Returnsfalse
if this geometry is immutable. Immutable geometries are guarantee to never change their state, neither directly (through a change in this object) or indirectly (through a change in an other object this geometry depends upon). Immutable geometries avoid the need for cloning them. More specifically:
If
false
, then this geometry is immutable. It is guarantee that a call to anysetFoo(...)
method will throws anUnmodifiableGeometryException
(that said, immutable geometries are necessarily unmodifiable. The converse is not true, see next point below). This geometry will never change its state, and there is no need for cloning it. 
If
true
, then this geometry is mutable. Note that mutable geometry is not synonymous of modifiable geometry. The nuance lays in whatever the geometry may changes its state directly (as of user request) or indirectly:
This geometry may be modifiable, in which case invoking
setFoo(...)
methods is legal and will not throws exception. 
This geometry may still unmodifiable. User is not allowed to modify it himself and invoking any
setFoo(...)
method will throws anUnmodifiableGeometryException
. However, the implementation may change the geometry itself (for example a timevarying geometry).

 Returns:
true
if this geometry is mutable.


toImmutable
@Extension Geometry toImmutable()
Returns an immutable copy of this geometry. The returned Geometry is guaranteed to have anisMutable()
value of false. Moreover, as per the contract ofisMutable()
, its values will never change. Any attempts to change the values of the returned object will result in aUnmodifiableGeometryException
.Implementors are free to return
this
if this object is already immutable. Returns:
 An immutable copy of this geometry.

clone
Geometry clone() throws CloneNotSupportedException
Returns a clone of this geometry with deep copy semantic. Any change on this object will have no impact on the returned clone, and conversely. For big geometries, implementations are encouraged to share as much internal data as possible (as opposed to performing a real copy of the data), while preserving the deep copy semantic.Special cases:

If this geometry is immutable (
isMutable() == false
), then there is no need for cloning this object. This method may returnthis
or returns a modifiable copy of this object, at implementation choice. 
If a deep copy semantic is not possible at a reasonable cost (for example for some database backend), then this method throws a
CloneNotSupportedException
. 
If a deep cloning is possible for all case (i.e. if this method never throws
CloneNotSupportedException
), then the implementation should implements theCloneable
interface.
 Returns:
 A clone of this geometry, which may or may not be mutable.
 Throws:
CloneNotSupportedException
 if this object do not support clone. This exception is never throws if this object implementsCloneable
. See Also:
Cloneable
,isMutable()


