/*
* Copyright (c) 2016 Vivid Solutions.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Eclipse Distribution License v. 1.0 which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
*
* http://www.eclipse.org/org/documents/edl-v10.php.
*/
package org.locationtech.jts.geom;
import org.locationtech.jts.geom.impl.CoordinateArraySequenceFactory;
import org.locationtech.jts.geom.impl.PackedCoordinateSequenceFactory;
/**
* The internal representation of a list of coordinates inside a Geometry.
* <p>
* This allows Geometries to store their
* points using something other than the JTS {@link Coordinate} class.
* For example, a storage-efficient implementation
* might store coordinate sequences as an array of x's
* and an array of y's.
* Or a custom coordinate class might support extra attributes like M-values.
* <p>
* Implementing a custom coordinate storage structure
* requires implementing the {@link CoordinateSequence} and
* {@link CoordinateSequenceFactory} interfaces.
* To use the custom CoordinateSequence, create a
* new {@link GeometryFactory} parameterized by the CoordinateSequenceFactory
* The {@link GeometryFactory} can then be used to create new {@link Geometry}s.
* The new Geometries
* will use the custom CoordinateSequence implementation.
* <p>
* For an example, see the code for
* {@link ExtendedCoordinateExample}.
*
* @see CoordinateArraySequenceFactory
* @see PackedCoordinateSequenceFactory
* @see ExtendedCoordinateExample
*
* @version 1.7
*/
public interface CoordinateSequence
extends Cloneable
{
/**
* Standard ordinate index values
*/
int X = 0;
int Y = 1;
int Z = 2;
int M = 3;
/**
* Returns the dimension (number of ordinates in each coordinate)
* for this sequence.
*
* @return the dimension of the sequence.
*/
int getDimension();
/**
* 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.
* <p>
* 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.
*
* @param i the index of the coordinate to retrieve
* @return the i'th coordinate in the sequence
*/
Coordinate getCoordinate(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.
*
* @param i the index of the coordinate to retrieve
* @return a copy of the i'th coordinate in the sequence
*/
Coordinate getCoordinateCopy(int i);
/**
* Copies the i'th coordinate in the sequence to the supplied
* {@link Coordinate}. Only the first two dimensions are copied.
*
* @param index the index of the coordinate to copy
* @param coord a {@link Coordinate} to receive the value
*/
void getCoordinate(int index, Coordinate coord);
/**
* Returns ordinate X (0) of the specified coordinate.
*
* @param index
* @return the value of the X ordinate in the index'th coordinate
*/
double getX(int index);
/**
* Returns ordinate Y (1) of the specified coordinate.
*
* @param index
* @return the value of the Y ordinate in the index'th coordinate
*/
double getY(int index);
/**
* 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).
*
* @param index the coordinate index in the sequence
* @param ordinateIndex the ordinate index in the coordinate (in range [0, dimension-1])
*/
double getOrdinate(int index, int ordinateIndex);
/**
* Returns the number of coordinates in this sequence.
* @return the size of the sequence
*/
int size();
/**
* Sets the value for a given ordinate of a coordinate in this sequence.
*
* @param index the coordinate index in the sequence
* @param ordinateIndex the ordinate index in the coordinate (in range [0, dimension-1])
* @param value the new ordinate value
*/
void setOrdinate(int index, int ordinateIndex, double value);
/**
* 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.
*
* @return a array of coordinates containing the point values in this sequence
*/
Coordinate[] toCoordinateArray();
/**
* Expands the given {@link Envelope} to include the coordinates in the sequence.
* Allows implementing classes to optimize access to coordinate values.
*
* @param env the envelope to expand
* @return a ref to the expanded envelope
*/
Envelope expandEnvelope(Envelope env);
/**
* Returns a deep copy of this collection.
* Called by Geometry#clone.
*
* @return a copy of the coordinate sequence containing copies of all points
*/
Object clone();
}