/*
* The JTS Topology Suite is a collection of Java classes that
* implement the fundamental operations required to validate a given
* geo-spatial data set to a known topological specification.
*
* Copyright (C) 2001 Vivid Solutions
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* For more information, contact:
*
* Vivid Solutions
* Suite #1A
* 2328 Government Street
* Victoria BC V8T 5G5
* Canada
*
* (250)385-6040
* www.vividsolutions.com
*/
package com.revolsys.geometry.noding;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import com.revolsys.geometry.algorithm.LineIntersector;
import com.revolsys.geometry.model.GeometryFactory;
import com.revolsys.geometry.model.LineString;
import com.revolsys.geometry.model.Point;
/**
* Represents a list of contiguous line segments,
* and supports noding the segments.
* The line segments are represented by an array of {@link Coordinates}s.
* Intended to optimize the noding of contiguous segments by
* reducing the number of allocated objects.
* SegmentStrings can carry a context object, which is useful
* for preserving topological or parentage information.
* All noded substrings are initialized with the same context object.
*
* @version 1.7
*/
public class NodedSegmentString implements NodableSegmentString {
/**
*
*/
private static final long serialVersionUID = 1L;
/**
* Gets the {@link SegmentString}s which result from splitting this string at node points.
*
* @param segments a Collection of NodedSegmentStrings
* @return a Collection of NodedSegmentStrings representing the substrings
*/
public static List<NodedSegmentString> getNodedSubstrings(
final Collection<NodedSegmentString> segments) {
final List<NodedSegmentString> nodedSegments = new ArrayList<>();
for (final NodedSegmentString segmentString : segments) {
final SegmentNodeList nodeList = segmentString.getNodeList();
nodeList.addSplitEdges(nodedSegments);
}
return nodedSegments;
}
private Object data;
private final SegmentNodeList nodeList = new SegmentNodeList(this);
private final LineString line;
/**
* Creates a new segment string from a list of vertices.
*
* @param line the vertices of the segment string
* @param data the user-defined data of this segment string (may be null)
*/
public NodedSegmentString(final LineString line, final Object data) {
this.line = line;
this.data = data;
}
/**
* Add an SegmentNode for intersection intIndex.
* An intersection that falls exactly on a vertex
* of the SegmentString is normalized
* to use the higher of the two possible segmentIndexes
*/
public void addIntersection(final LineIntersector li, final int segmentIndex, final int geomIndex,
final int intIndex) {
final Point point = li.getIntersection(intIndex);
addIntersection(point, segmentIndex);
}
/**
* Adds an intersection node for a given point and segment to this segment string.
*
* @param point the location of the intersection
* @param segmentIndex the index of the segment containing the intersection
*/
@Override
public void addIntersection(final Point point, final int segmentIndex) {
addIntersectionNode(point, segmentIndex);
}
/**
* Adds an intersection node for a given point and segment to this segment string.
* If an intersection already exists for this exact location, the existing
* node will be returned.
*
* @param point the location of the intersection
* @param segmentIndex the index of the segment containing the intersection
* @return the intersection node for the point
*/
public SegmentNode addIntersectionNode(final Point point, final int segmentIndex) {
final double x = point.getX();
final double y = point.getY();
int normalizedSegmentIndex = segmentIndex;
// normalize the intersection point location
final int nextSegIndex = normalizedSegmentIndex + 1;
if (nextSegIndex < size()) {
// Normalize segment index if point falls on vertex
// The check for point equality is 2D only - Z values are ignored
if (this.line.equalsVertex(nextSegIndex, x, y)) {
normalizedSegmentIndex = nextSegIndex;
}
}
/**
* Add the intersection point to edge intersection list.
*/
final SegmentNode ei = this.nodeList.add(x, y, normalizedSegmentIndex);
return ei;
}
/**
* Adds EdgeIntersections for one or both
* intersections found for a segment of an edge to the edge intersection list.
*/
public void addIntersections(final LineIntersector li, final int segmentIndex,
final int geomIndex) {
for (int i = 0; i < li.getIntersectionCount(); i++) {
addIntersection(li, segmentIndex, geomIndex, i);
}
}
@Override
public SegmentString clone() {
return this;
}
@Override
public boolean equalsVertex2d(final int vertexIndex, final double x, final double y) {
final double x1 = this.line.getX(vertexIndex);
if (x1 == x) {
final double y1 = this.line.getY(vertexIndex);
if (y1 == y) {
return true;
}
}
return false;
}
@Override
public boolean equalsVertex2d(final int vertexIndex1, final int vertexIndex2) {
return this.line.equalsVertex2d(vertexIndex1, vertexIndex2);
}
@Override
public int getAxisCount() {
return this.line.getAxisCount();
}
@Override
public double getCoordinate(final int vertexIndex, final int axisIndex) {
return this.line.getCoordinate(vertexIndex, axisIndex);
}
@Override
public double[] getCoordinates() {
return this.line.getCoordinates();
}
/**
* Gets the user-defined data for this segment string.
*
* @return the user-defined data
*/
@Override
public Object getData() {
return this.data;
}
public SegmentNodeList getNodeList() {
return this.nodeList;
}
@Override
public Point getPoint(final int i) {
return this.line.getPoint(i);
}
@Override
public LineString getPoints() {
return this.line;
}
/**
* Gets the octant of the segment starting at vertex <code>index</code>.
*
* @param index the index of the vertex starting the segment. Must not be
* the last index in the vertex list
* @return the octant of the segment at the vertex
*/
public int getSegmentOctant(final int index) {
if (index == size() - 1) {
return -1;
} else {
final double x1 = getX(index);
final double y1 = getY(index);
final double x2 = getX(index + 1);
final double y2 = getY(index + 1);
return safeOctant(x1, y1, x2, y2);
}
}
@Override
public int getVertexCount() {
return this.line.getVertexCount();
}
@Override
public double getX(final int i) {
return this.line.getX(i);
}
@Override
public double getY(final int i) {
return this.line.getY(i);
}
@Override
public double getZ(final int vertextIndex) {
return this.line.getZ(vertextIndex);
}
@Override
public boolean isClosed() {
return this.line.equalsVertex2d(0, size() - 1);
}
private int safeOctant(final double x1, final double y1, final double x2, final double y2) {
if (x1 == x2 && y1 == y2) {
return 0;
} else {
return Octant.octant(x1, y1, x2, y2);
}
}
/**
* Sets the user-defined data for this segment string.
*
* @param data an Object containing user-defined data
*/
@Override
public void setData(final Object data) {
this.data = data;
}
@Override
public int size() {
return this.line.getVertexCount();
}
@Override
public String toString() {
if (this.line == null || this.line.getVertexCount() == 0) {
return "LINESTRING EMPTY\t" + this.data;
} else if (this.line.getVertexCount() < 2) {
return GeometryFactory.floating(0, 2).point(this.line) + "\t" + this.data;
} else {
return GeometryFactory.floating(0, 2).lineString(this.line) + "\t" + this.data;
}
}
}