


/*
 * 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;

import com.vividsolutions.jts.geom.Coordinate;

/**
 * Represents a point on an
 * edge which intersects with another edge.
 * <p>
 * The intersection may either be a single point, or a line segment
 * (in which case this point is the start of the line segment)
 * The intersection point must be precise.
 *
 * @version 1.7
 */
public class EdgeIntersection
    implements Comparable
{

  public Coordinate coord;   // the point of intersection
  public int segmentIndex;   // the index of the containing line segment in the parent edge
  public double dist;        // the edge distance of this point along the containing line segment

  public EdgeIntersection(Coordinate coord, int segmentIndex, double dist) {
    this.coord = new Coordinate(coord);
    this.segmentIndex = segmentIndex;
    this.dist = dist;
  }

  public int compareTo(Object obj)
  {
    EdgeIntersection other = (EdgeIntersection) obj;
    return compare(other.segmentIndex, other.dist);
  }
  /**
   * @return -1 this EdgeIntersection is located before the argument location
   * @return 0 this EdgeIntersection is at the argument location
   * @return 1 this EdgeIntersection is located after the argument location
   */
  public int compare(int segmentIndex, double dist)
  {
    if (this.segmentIndex < segmentIndex) return -1;
    if (this.segmentIndex > segmentIndex) return 1;
    if (this.dist < dist) return -1;
    if (this.dist > dist) return 1;
    return 0;
  }

  public boolean isEndPoint(int maxSegmentIndex)
  {
    if (segmentIndex == 0 && dist == 0.0) return true;
    if (segmentIndex == maxSegmentIndex) return true;
    return false;
  }
}
