X-Git-Url: https://gitweb.fperrin.net/?a=blobdiff_plain;f=tim%2Fprune%2Fdata%2FDistance.java;h=d12d98817d5c7fce86d687f12f566940a03dbbd7;hb=112bb0c9b46894adca9a33ed8c99ea712b253185;hp=61afdca0dd5f3ae1514c76f8ccca60fb7e19b5b9;hpb=312fec956e43f5d0a38617da5d0add9c62563e2c;p=GpsPrune.git

diff --git a/tim/prune/data/Distance.java b/tim/prune/data/Distance.java
index 61afdca..d12d988 100644
--- a/tim/prune/data/Distance.java
+++ b/tim/prune/data/Distance.java
@@ -5,32 +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;
+	}
 }