gov/nasa/worldwind/geom/Position.java

   1 /*
   2 Copyright (C) 2001, 2006 United States Government
   3 as represented by the Administrator of the
   4 National Aeronautics and Space Administration.
   5 All Rights Reserved.
   6 */
   7 package gov.nasa.worldwind.geom;
   8
   9 import gov.nasa.worldwind.util.Logging;
  10
  11 /**
  12  * @author tag
  13  * @version $Id: Position.java 2568 2007-08-16 22:28:18Z tgaskins $
  14  */
  15 public class Position
  16 {
  17     private final Angle latitude;
  18     private final Angle longitude;
  19     private final double elevation;
  20
  21     public static final Position ZERO = new Position(Angle.ZERO, Angle.ZERO, 0d);
  22
  23     public static Position fromRadians(double latitude, double longitude, double elevation)
  24     {
  25         return new Position(Angle.fromRadians(latitude), Angle.fromRadians(longitude), elevation);
  26     }
  27
  28     public static Position fromDegrees(double latitude, double longitude, double elevation)
  29     {
  30         return new Position(Angle.fromDegrees(latitude), Angle.fromDegrees(longitude), elevation);
  31     }
  32
  33     public Position(Angle latitude, Angle longitude, double elevation)
  34     {
  35         if (latitude == null || longitude == null)
  36         {
  37             String message = Logging.getMessage("nullValue.LatitudeOrLongitudeIsNull");
  38             Logging.logger().severe(message);
  39             throw new IllegalArgumentException(message);
  40         }
  41
  42         this.latitude = latitude;
  43         this.longitude = longitude;
  44         this.elevation = elevation;
  45     }
  46
  47     public Position(LatLon latLon, double elevation)
  48     {
  49         if (latLon == null)
  50         {
  51             String message = Logging.getMessage("nullValue.LatLonIsNull");
  52             Logging.logger().severe(message);
  53             throw new IllegalArgumentException(message);
  54         }
  55
  56         this.latitude = latLon.getLatitude();
  57         this.longitude = latLon.getLongitude();
  58         this.elevation = elevation;
  59     }
  60
  61     /**
  62      * Obtains the latitude of this position
  63      *
  64      * @return this position's latitude
  65      */
  66     public final Angle getLatitude()
  67     {
  68         return this.latitude;
  69     }
  70
  71     /**
  72      * Obtains the longitude of this position
  73      *
  74      * @return this position's longitude
  75      */
  76     public final Angle getLongitude()
  77     {
  78         return this.longitude;
  79     }
  80
  81     public LatLon getLatLon()
  82     {
  83         return new LatLon(this.getLatitude(), this.getLongitude());
  84     }
  85
  86     public Position add(Position that)
  87     {
  88         Angle lat = Angle.normalizedLatitude(this.latitude.add(that.latitude));
  89         Angle lon = Angle.normalizedLongitude(this.longitude.add(that.longitude));
  90
  91         return new Position(lat, lon, this.elevation + that.elevation);
  92     }
  93
  94     public Position subtract(Position that)
  95     {
  96         Angle lat = Angle.normalizedLatitude(this.latitude.subtract(that.latitude));
  97         Angle lon = Angle.normalizedLongitude(this.longitude.subtract(that.longitude));
  98
  99         return new Position(lat, lon, this.elevation - that.elevation);
 100     }
 101
 102     public static boolean positionsCrossLongitudeBoundary(Iterable<Position> positions)
 103     {
 104         if (positions == null)
 105         {
 106             String msg = Logging.getMessage("nullValue.PositionsListIsNull");
 107             Logging.logger().severe(msg);
 108             throw new IllegalArgumentException(msg);
 109         }
 110
 111         Position pos = null;
 112         for (Position posNext : positions)
 113         {
 114             if (pos != null)
 115             {
 116                 // A segment cross the line if end pos have different longitude signs
 117                 // and are more than 180 degress longitude apart
 118                 if (Math.signum(pos.getLongitude().degrees) != Math.signum(posNext.getLongitude().degrees))
 119                 {
 120                     if (Math.abs(pos.getLongitude().degrees - posNext.getLongitude().degrees) > 180)
 121                         return true;
 122                 }
 123             }
 124             pos = posNext;
 125         }
 126
 127         return false;
 128     }
 129
 130     /**
 131      * Obtains the elevation of this position
 132      *
 133      * @return this position's elevation
 134      */
 135     public final double getElevation()
 136     {
 137         return this.elevation;
 138     }
 139
 140     public String toString()
 141     {
 142         return "(" + this.latitude.toString() + ", " + this.longitude.toString() + ", " + this.elevation + ")";
 143     }
 144
 145     public static boolean positionsCrossLongitudeBoundary(Position p1, Position p2)
 146     {
 147         if (p1 == null || p2 == null)
 148         {
 149             String msg = Logging.getMessage("nullValue.PositionsListIsNull");
 150             Logging.logger().severe(msg);
 151             throw new IllegalArgumentException(msg);
 152         }
 153
 154         // A segment cross the line if end pos have different longitude signs
 155         // and are more than 180 degress longitude apart
 156         if (Math.signum(p1.getLongitude().degrees) != Math.signum(p2.getLongitude().degrees))
 157         {
 158             if (Math.abs(p1.getLongitude().degrees - p2.getLongitude().degrees) > 180)
 159                 return true;
 160         }
 161
 162         return false;
 163     }
 164 }