Class OverlayOp
java.lang.Object
org.locationtech.jts.operation.GeometryGraphOperation
org.locationtech.jts.operation.overlay.OverlayOp
Computes the geometric overlay of two
Geometry
s. The overlay
can be used to determine any boolean combination of the geometries.- Version:
- 1.7
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final int
The code for the Difference overlay operation.static final int
The code for the Intersection overlay operation.static final int
The code for the Symmetric Difference overlay operation.static final int
The code for the Union overlay operation.Fields inherited from class org.locationtech.jts.operation.GeometryGraphOperation
arg, li, resultPrecisionModel
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionstatic Geometry
createEmptyResult
(int overlayOpCode, Geometry a, Geometry b, GeometryFactory geomFact) Creates an empty result geometry of the appropriate dimension, based on the given overlay operation and the dimensions of the inputs.getGraph()
Gets the graph constructed to compute the overlay.getResultGeometry
(int overlayOpCode) Gets the result of the overlay for a given overlay operation.protected void
Insert an edge from one of the noded input graphs.boolean
isCoveredByA
(Coordinate coord) Tests if an L edge should be included in the result or not.boolean
isCoveredByLA
(Coordinate coord) Tests if a point node should be included in the result or not.static boolean
isResultOfOp
(int loc0, int loc1, int overlayOpCode) Tests whether a point with givenLocation
s relative to two geometries is contained in the result of overlaying the geometries using a given overlay operation.static boolean
isResultOfOp
(Label label, int opCode) Tests whether a point with a given topologicalLabel
relative to two geometries is contained in the result of overlaying the geometries using a given overlay operation.static Geometry
Computes an overlay operation for the given geometry arguments.Methods inherited from class org.locationtech.jts.operation.GeometryGraphOperation
getArgGeometry, setComputationPrecision
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Field Details
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INTERSECTION
public static final int INTERSECTIONThe code for the Intersection overlay operation.- See Also:
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UNION
public static final int UNIONThe code for the Union overlay operation.- See Also:
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DIFFERENCE
public static final int DIFFERENCEThe code for the Difference overlay operation.- See Also:
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SYMDIFFERENCE
public static final int SYMDIFFERENCEThe code for the Symmetric Difference overlay operation.- See Also:
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Constructor Details
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OverlayOp
Constructs an instance to compute a single overlay operation for the given geometries.- Parameters:
g0
- the first geometry argumentg1
- the second geometry argument
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Method Details
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overlayOp
Computes an overlay operation for the given geometry arguments.- Parameters:
geom0
- the first geometry argumentgeom1
- the second geometry argumentopCode
- the code for the desired overlay operation- Returns:
- the result of the overlay operation
- Throws:
TopologyException
- if a robustness problem is encountered
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isResultOfOp
Tests whether a point with a given topologicalLabel
relative to two geometries is contained in the result of overlaying the geometries using a given overlay operation.The method handles arguments of
Location.NONE
correctly- Parameters:
label
- the topological label of the pointopCode
- the code for the overlay operation to test- Returns:
- true if the label locations correspond to the overlayOpCode
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isResultOfOp
public static boolean isResultOfOp(int loc0, int loc1, int overlayOpCode) Tests whether a point with givenLocation
s relative to two geometries is contained in the result of overlaying the geometries using a given overlay operation.The method handles arguments of
Location.NONE
correctly- Parameters:
loc0
- the code for the location in the first geometryloc1
- the code for the location in the second geometryoverlayOpCode
- the code for the overlay operation to test- Returns:
- true if the locations correspond to the overlayOpCode
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getResultGeometry
Gets the result of the overlay for a given overlay operation.Note: this method can be called once only.
- Parameters:
overlayOpCode
- the overlay operation to perform- Returns:
- the compute result geometry
- Throws:
TopologyException
- if a robustness problem is encountered
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getGraph
Gets the graph constructed to compute the overlay.- Returns:
- the overlay graph
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insertUniqueEdge
Insert an edge from one of the noded input graphs. Checks edges that are inserted to see if an identical edge already exists. If so, the edge is not inserted, but its label is merged with the existing edge. -
isCoveredByLA
Tests if a point node should be included in the result or not.- Parameters:
coord
- the point coordinate- Returns:
- true if the coordinate point is covered by a result Line or Area geometry
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isCoveredByA
Tests if an L edge should be included in the result or not.- Parameters:
coord
- the point coordinate- Returns:
- true if the coordinate point is covered by a result Area geometry
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createEmptyResult
public static Geometry createEmptyResult(int overlayOpCode, Geometry a, Geometry b, GeometryFactory geomFact) Creates an empty result geometry of the appropriate dimension, based on the given overlay operation and the dimensions of the inputs. The created geometry is always an atomic geometry, not a collection.The empty result is constructed using the following rules:
INTERSECTION
- result has the dimension of the lowest input dimensionUNION
- result has the dimension of the highest input dimensionDIFFERENCE
- result has the dimension of the left-hand inputSYMDIFFERENCE
- result has the dimension of the highest input dimension (since the symmetric Difference is the union of the differences).
- Parameters:
overlayOpCode
- the code for the overlay operation being performeda
- an input geometryb
- an input geometrygeomFact
- the geometry factory being used for the operation- Returns:
- an empty atomic geometry of the appropriate dimension
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