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.*;
  10
  11 /**
  12  * @author tag
  13  * @version $Id: Position.java 2233 2007-07-06 23:56:34Z 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 = WorldWind.retrieveErrMsg("nullValue.LatitudeOrLongitudeIsNull");
  38             WorldWind.logger().log(java.util.logging.Level.FINE, 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 = WorldWind.retrieveErrMsg("nullValue.LatLonIsNull");
  52             WorldWind.logger().log(java.util.logging.Level.FINE, 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 Position add(Position that)
  82     {
  83         Angle lat = Angle.normalizedLatitude(this.latitude.add(that.latitude));
  84         Angle lon = Angle.normalizedLongitude(this.longitude.add(that.longitude));
  85
  86         return new Position(lat, lon, this.elevation + that.elevation);
  87     }
  88
  89     public Position subtract(Position that)
  90     {
  91         Angle lat = Angle.normalizedLatitude(this.latitude.subtract(that.latitude));
  92         Angle lon = Angle.normalizedLongitude(this.longitude.subtract(that.longitude));
  93
  94         return new Position(lat, lon, this.elevation - that.elevation);
  95     }
  96
  97     public static boolean positionsCrossLongitudeBoundary(Iterable<Position> positions)
  98     {
  99         if (positions == null)
 100         {
 101             String msg = WorldWind.retrieveErrMsg("nullValue.PositionsListIsNull");
 102             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
 103             throw new IllegalArgumentException(msg);
 104         }
 105
 106         Position pos = null;
 107         for (Position posNext : positions)
 108         {
 109             if (pos != null)
 110             {
 111                 // A segment cross the line if end pos have different longitude signs
 112                 // and are more than 180 degress longitude apart
 113                 if (Math.signum(pos.getLongitude().degrees) != Math.signum(posNext.getLongitude().degrees))
 114                 {
 115                     if (Math.abs(pos.getLongitude().degrees - posNext.getLongitude().degrees) > 180)
 116                         return true;
 117                 }
 118             }
 119             pos = posNext;
 120         }
 121
 122         return false;
 123     }
 124
 125     /**
 126      * Obtains the elevation of this position
 127      *
 128      * @return this position's elevation
 129      */
 130     public final double getElevation()
 131     {
 132         return this.elevation;
 133     }
 134
 135     public String toString()
 136     {
 137         return "(" + this.latitude.toString() + ", " + this.longitude.toString() + ", " + this.elevation;
 138     }
 139 }