org.opentripplanner.graph_builder.module.map.LinearIterator Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of otp Show documentation
Show all versions of otp Show documentation
The OpenTripPlanner multimodal journey planning system
package org.opentripplanner.graph_builder.module.map;
import java.util.Iterator;
import org.locationtech.jts.geom.*;
import org.locationtech.jts.linearref.LinearLocation;
/**
* I copied this class from JTS but made a few changes.
*
* The JTS version of this class has several design decisions that don't work for me. In particular,
* hasNext() in the original should be "isValid", and if we start mid-segment, we should continue at
* the end of this segment rather than the end of the next segment.
*/
public class LinearIterator implements Iterable {
private Geometry linearGeom;
private final int numLines;
/**
* Invariant: currentLine <> null if the iterator is pointing at a valid coordinate
*
* @throws IllegalArgumentException if linearGeom is not lineal
*/
private LineString currentLine;
private int componentIndex = 0;
private int vertexIndex = 0;
private double segmentFraction;
/**
* Creates an iterator initialized to the start of a linear {@link Geometry}
*
* @param linear the linear geometry to iterate over
* @throws IllegalArgumentException if linearGeom is not lineal
*/
public LinearIterator(Geometry linear) {
this(linear, 0, 0);
}
/**
* Creates an iterator starting at a {@link LinearLocation} on a linear {@link Geometry}
*
* @param linear the linear geometry to iterate over
* @param start the location to start at
* @throws IllegalArgumentException if linearGeom is not lineal
*/
public LinearIterator(Geometry linear, LinearLocation start) {
this(linear, start.getComponentIndex(), start.getSegmentIndex());
this.segmentFraction = start.getSegmentFraction();
}
/**
* Creates an iterator starting at a specified component and vertex in a linear {@link Geometry}
*
* @param linearGeom the linear geometry to iterate over
* @param componentIndex the component to start at
* @param vertexIndex the vertex to start at
* @throws IllegalArgumentException if linearGeom is not lineal
*/
public LinearIterator(Geometry linearGeom, int componentIndex, int vertexIndex) {
if (!(linearGeom instanceof Lineal))
throw new IllegalArgumentException("Lineal geometry is required");
this.linearGeom = linearGeom;
numLines = linearGeom.getNumGeometries();
this.componentIndex = componentIndex;
this.vertexIndex = vertexIndex;
loadCurrentLine();
}
private void loadCurrentLine() {
if (componentIndex >= numLines) {
currentLine = null;
return;
}
currentLine = (LineString) linearGeom.getGeometryN(componentIndex);
}
/**
* Tests whether there are any vertices left to iterator over.
*
* @return true if there are more vertices to scan
*/
public boolean hasNext() {
if (componentIndex >= numLines)
return false;
if (componentIndex == numLines - 1 && vertexIndex >= currentLine.getNumPoints() - 1)
return false;
return true;
}
public boolean isValidIndex() {
if (componentIndex >= numLines)
return false;
if (componentIndex == numLines - 1 && vertexIndex >= currentLine.getNumPoints())
return false;
return true;
}
/**
* Moves the iterator ahead to the next vertex and (possibly) linear component.
*/
public void next() {
if (!hasNext())
return;
segmentFraction = 0.0;
vertexIndex++;
if (vertexIndex >= currentLine.getNumPoints()) {
componentIndex++;
if (componentIndex < linearGeom.getNumGeometries() - 1) {
loadCurrentLine();
vertexIndex = 0;
}
}
}
/**
* Checks whether the iterator cursor is pointing to the endpoint of a linestring.
*
* @return true if the iterator is at an endpoint
*/
public boolean isEndOfLine() {
if (componentIndex >= numLines)
return false;
// LineString currentLine = (LineString) linear.getGeometryN(componentIndex);
if (vertexIndex < currentLine.getNumPoints() - 1)
return false;
return true;
}
/**
* The component index of the vertex the iterator is currently at.
*
* @return the current component index
*/
public int getComponentIndex() {
return componentIndex;
}
/**
* The vertex index of the vertex the iterator is currently at.
*
* @return the current vertex index
*/
public int getVertexIndex() {
return vertexIndex;
}
/**
* Gets the {@link LineString} component the iterator is current at.
*
* @return a linestring
*/
public LineString getLine() {
return currentLine;
}
/**
* Gets the first {@link Coordinate} of the current segment. (the coordinate of the current
* vertex).
*
* @return a {@link Coordinate}
*/
public Coordinate getSegmentStart() {
return currentLine.getCoordinateN(vertexIndex);
}
/**
* Gets the second {@link Coordinate} of the current segment. (the coordinate of the next
* vertex). If the iterator is at the end of a line, null is returned.
*
* @return a {@link Coordinate} or null
*/
public Coordinate getSegmentEnd() {
if (vertexIndex < getLine().getNumPoints() - 1)
return currentLine.getCoordinateN(vertexIndex + 1);
return null;
}
public LinearLocation getLocation() {
return new LinearLocation(componentIndex, vertexIndex, segmentFraction);
}
class LinearIteratorIterator implements Iterator {
@Override
public boolean hasNext() {
return LinearIterator.this.hasNext();
}
@Override
public LinearLocation next() {
LinearLocation result = getLocation();
LinearIterator.this.next();
return result;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
}
@Override
public Iterator iterator() {
return new LinearIteratorIterator();
}
public static LinearLocation getEndLocation(Geometry linear) {
//the version in LinearLocation is broken
int lastComponentIndex = linear.getNumGeometries() - 1;
LineString lastLine = (LineString) linear.getGeometryN(lastComponentIndex);
int lastSegmentIndex = lastLine.getNumPoints() - 1;
return new LinearLocation(lastComponentIndex, lastSegmentIndex, 0.0);
}
}