Version 8, September 2009

[GpsPrune.git] / tim / prune / data / Distance.java

diff --git a/tim/prune/data/Distance.java b/tim/prune/data/Distance.java
index 5425873102aa752833c9953c91e967705d0ad75b..d12d98817d5c7fce86d687f12f566940a03dbbd7 100644 (file)
--- a/tim/prune/data/Distance.java
+++ b/tim/prune/data/Distance.java
@@ -5,30 +5,66 @@ package tim.prune.data;
  */
 public abstract class Distance
 {
-       // distance formats
-       public static final int UNITS_KILOMETRES = 1;
-       public static final int UNITS_MILES      = 2;
+       /** distance units */
+       public enum Units
+       {
+               /** Kilometres */
+               KILOMETRES,
+               /** Miles */
+               MILES,
+               /** Metres */
+               METRES,
+               /** Feet */
+               FEET
+       }
 
        // Geographical constants
        private static final double EARTH_RADIUS_KM = 6372.795;
-       private static final double EARTH_RADIUS_MILES = 3959.8712255;
        // Conversion constants
-       //private static final double CONVERT_KM_TO_MILES = 1.609344;
-       //private static final double CONVERT_MILES_TO_KM = 0.621371192;
+       private static final double CONVERT_KM_TO_MILES = 0.621371192;
 
 
        /**
         * Convert the given angle in radians into a distance
         * @param inAngDist angular distance in radians
-        * @param inUnits desired units, miles or km
+        * @param inUnits desired units, eg miles or km
         * @return distance in specified format
         */
-       public static double convertRadians(double inAngDist, int inUnits)
+       public static double convertRadiansToDistance(double inAngDist, Units inUnits)
        {
                // Multiply by appropriate factor
-               if (inUnits == UNITS_MILES)
-                       return inAngDist * EARTH_RADIUS_MILES;
+               if (inUnits == Units.MILES)
+                       return inAngDist * EARTH_RADIUS_KM * CONVERT_KM_TO_MILES;
+               else if (inUnits == Units.METRES)
+                       return inAngDist * EARTH_RADIUS_KM * 1000;
+               // default kilometres
                return inAngDist * EARTH_RADIUS_KM;
        }
 
+       /**
+        * Convert the given distance into an angle in radians
+        * @param inDist distance to convert
+        * @param inUnits units, eg miles or km
+        * @return angular distance in radians
+        */
+       public static double convertDistanceToRadians(double inDist, Units inUnits)
+       {
+               // Divide by appropriate factor
+               if (inUnits == Units.MILES)
+                       return inDist / EARTH_RADIUS_KM / CONVERT_KM_TO_MILES;
+               else if (inUnits == Units.METRES)
+                       return inDist / EARTH_RADIUS_KM / 1000;
+               // default kilometres
+               return inDist / EARTH_RADIUS_KM;
+       }
+
+       /**
+        * Convert the given distance from metres to miles
+        * @param inMetres number of metres
+        * @return number of miles
+        */
+       public static double convertMetresToMiles(double inMetres)
+       {
+               return inMetres / 1000.0 * CONVERT_KM_TO_MILES;
+       }
 }