com.vividsolutions.jts.geom
Interface CoordinateSequence

All Superinterfaces:
java.lang.Cloneable
All Known Implementing Classes:
CoordinateArraySequence, PackedCoordinateSequence

public interface CoordinateSequence
extends java.lang.Cloneable

The internal representation of a list of coordinates inside a Geometry.

There are some cases in which you might want Geometries to store their points using something other than the JTS Coordinate class. For example, you may want to experiment with another implementation, such as an array of x's and an array of y's. Or you might want to use your own coordinate class, one that supports extra attributes like M-values.

You can do this by implementing the CoordinateSequence and CoordinateSequenceFactory interfaces. You would then create a GeometryFactory parameterized by your CoordinateSequenceFactory, and use this GeometryFactory to create new Geometries. All of these new Geometries will use your CoordinateSequence implementation.

For an example, see the code for com.vividsolutions.jtsexample.geom.TwoArrayCoordinateSequenceExample.

Version:
1.7
See Also:
DefaultCoordinateSequenceFactory, TwoArrayCoordinateSequenceFactory

Field Summary
static int M
           
static int X
          Standard ordinate index values
static int Y
           
static int Z
           
 
Method Summary
 java.lang.Object clone()
          Returns a deep copy of this collection.
 Envelope expandEnvelope(Envelope env)
          Expands the given Envelope to include the coordinates in the sequence.
 Coordinate getCoordinate(int i)
          Returns (possibly a copy of) the i'th coordinate in this sequence.
 void getCoordinate(int index, Coordinate coord)
          Copies the i'th coordinate in the sequence to the supplied Coordinate.
 Coordinate getCoordinateCopy(int i)
          Returns a copy of the i'th coordinate in this sequence.
 int getDimension()
          Returns the dimension (number of ordinates in each coordinate) for this sequence.
 double getOrdinate(int index, int ordinateIndex)
          Returns the ordinate of a coordinate in this sequence.
 double getX(int index)
          Returns ordinate X (0) of the specified coordinate.
 double getY(int index)
          Returns ordinate Y (1) of the specified coordinate.
 void setOrdinate(int index, int ordinateIndex, double value)
          Sets the value for a given ordinate of a coordinate in this sequence.
 int size()
          Returns the number of coordinates in this sequence.
 Coordinate[] toCoordinateArray()
          Returns (possibly copies of) the Coordinates in this collection.
 

Field Detail

X

public static final int X
Standard ordinate index values

See Also:
Constant Field Values

Y

public static final int Y
See Also:
Constant Field Values

Z

public static final int Z
See Also:
Constant Field Values

M

public static final int M
See Also:
Constant Field Values
Method Detail

getDimension

public int getDimension()
Returns the dimension (number of ordinates in each coordinate) for this sequence.

Returns:
the dimension of the sequence.

getCoordinate

public Coordinate getCoordinate(int i)
Returns (possibly a copy of) the i'th coordinate in this sequence. Whether or not the Coordinate returned is the actual underlying Coordinate or merely a copy depends on the implementation.

Note that in the future the semantics of this method may change to guarantee that the Coordinate returned is always a copy. Callers should not to assume that they can modify a CoordinateSequence by modifying the object returned by this method.

Parameters:
i - the index of the coordinate to retrieve
Returns:
the i'th coordinate in the sequence

getCoordinateCopy

public Coordinate getCoordinateCopy(int i)
Returns a copy of the i'th coordinate in this sequence. This method optimizes the situation where the caller is going to make a copy anyway - if the implementation has already created a new Coordinate object, no further copy is needed.

Parameters:
i - the index of the coordinate to retrieve
Returns:
a copy of the i'th coordinate in the sequence

getCoordinate

public void getCoordinate(int index,
                          Coordinate coord)
Copies the i'th coordinate in the sequence to the supplied Coordinate. Only the first two dimensions are copied.

Parameters:
index - the index of the coordinate to copy
coord - a Coordinate to receive the value

getX

public double getX(int index)
Returns ordinate X (0) of the specified coordinate.

Parameters:
index -
Returns:
the value of the X ordinate in the index'th coordinate

getY

public double getY(int index)
Returns ordinate Y (1) of the specified coordinate.

Parameters:
index -
Returns:
the value of the Y ordinate in the index'th coordinate

getOrdinate

public double getOrdinate(int index,
                          int ordinateIndex)
Returns the ordinate of a coordinate in this sequence. Ordinate indices 0 and 1 are assumed to be X and Y. Ordinates indices greater than 1 have user-defined semantics (for instance, they may contain other dimensions or measure values).

Parameters:
index - the coordinate index in the sequence
ordinateIndex - the ordinate index in the coordinate (in range [0, dimension-1])

size

public int size()
Returns the number of coordinates in this sequence.

Returns:
the size of the sequence

setOrdinate

public void setOrdinate(int index,
                        int ordinateIndex,
                        double value)
Sets the value for a given ordinate of a coordinate in this sequence.

Parameters:
index - the coordinate index in the sequence
ordinateIndex - the ordinate index in the coordinate (in range [0, dimension-1])
value - the new ordinate value

toCoordinateArray

public Coordinate[] toCoordinateArray()
Returns (possibly copies of) the Coordinates in this collection. Whether or not the Coordinates returned are the actual underlying Coordinates or merely copies depends on the implementation. Note that if this implementation does not store its data as an array of Coordinates, this method will incur a performance penalty because the array needs to be built from scratch.

Returns:
a array of coordinates containing the point values in this sequence

expandEnvelope

public Envelope expandEnvelope(Envelope env)
Expands the given Envelope to include the coordinates in the sequence. Allows implementing classes to optimize access to coordinate values.

Parameters:
env - the envelope to expand
Returns:
a ref to the expanded envelope

clone

public java.lang.Object clone()
Returns a deep copy of this collection. Called by Geometry#clone.

Returns:
a copy of the coordinate sequence containing copies of all points