com.vividsolutions.jts.geomgraph.index.SweepLineEvent Maven / Gradle / Ivy
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/*
* 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.vividsolutions.jts.geomgraph.index;
/**
* @version 1.7
*/
public class SweepLineEvent
implements Comparable
{
private static final int INSERT = 1;
private static final int DELETE = 2;
private Object label; // used for red-blue intersection detection
private double xValue;
private int eventType;
private SweepLineEvent insertEvent = null; // null if this is an INSERT event
private int deleteEventIndex;
private Object obj;
/**
* Creates an INSERT event.
*
* @param label the edge set label for this object
* @param x the event location
* @param obj the object being inserted
*/
public SweepLineEvent(Object label, double x, Object obj)
{
this.eventType = INSERT;
this.label = label;
xValue = x;
this.obj = obj;
}
/**
* Creates a DELETE event.
*
* @param x the event location
* @param insertEvent the corresponding INSERT event
*/
public SweepLineEvent(double x, SweepLineEvent insertEvent)
{
eventType = DELETE;
xValue = x;
this.insertEvent = insertEvent;
}
public boolean isInsert() { return eventType == INSERT; }
public boolean isDelete() { return eventType == DELETE; }
public SweepLineEvent getInsertEvent() { return insertEvent; }
public int getDeleteEventIndex() { return deleteEventIndex; }
public void setDeleteEventIndex(int deleteEventIndex) { this.deleteEventIndex = deleteEventIndex; }
public Object getObject() { return obj; }
public boolean isSameLabel(SweepLineEvent ev)
{
// no label set indicates single group
if (label == null) return false;
return label == ev.label;
}
/**
* Events are ordered first by their x-value, and then by their eventType.
* Insert events are sorted before Delete events, so that
* items whose Insert and Delete events occur at the same x-value will be
* correctly handled.
*/
public int compareTo(Object o) {
SweepLineEvent pe = (SweepLineEvent) o;
if (xValue < pe.xValue) return -1;
if (xValue > pe.xValue) return 1;
if (eventType < pe.eventType) return -1;
if (eventType > pe.eventType) return 1;
return 0;
}
}