X-Git-Url: http://gitweb.fperrin.net/?p=GpsPrune.git;a=blobdiff_plain;f=src%2Ftim%2Fprune%2Fdata%2FDistance.java;fp=src%2Ftim%2Fprune%2Fdata%2FDistance.java;h=83864a59e890216548957711513ae188c5ba8571;hp=0000000000000000000000000000000000000000;hb=ce6f2161b8596f7018d6a76bff79bc9e571f35fd;hpb=2d8cb72e84d5cc1089ce77baf1e34ea3ea2f8465

diff --git a/src/tim/prune/data/Distance.java b/src/tim/prune/data/Distance.java
new file mode 100644
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--- /dev/null
+++ b/src/tim/prune/data/Distance.java
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+package tim.prune.data;
+
+import tim.prune.config.Config;
+
+/**
+ * Class to provide distance constants and functions
+ */
+public abstract class Distance
+{
+	// Geographical constants
+	/** Earth radius in metres */
+	private static final double EARTH_RADIUS_M = 6372795.0;
+
+
+	/**
+	 * Convert the given angle in radians into a distance
+	 * @param inAngDist angular distance in radians
+	 * @return distance in currently configured distance units
+	 */
+	public static double convertRadiansToDistance(double inAngDist)
+	{
+		return convertRadiansToDistance(inAngDist, Config.getUnitSet().getDistanceUnit());
+	}
+
+	/**
+	 * Convert the given angle in radians into a distance
+	 * @param inAngDist angular distance in radians
+	 * @param inUnit distance units
+	 * @return distance in specified distance units
+	 */
+	public static double convertRadiansToDistance(double inAngDist, Unit inUnit)
+	{
+		// Multiply by appropriate factor
+		return inAngDist * EARTH_RADIUS_M * inUnit.getMultFactorFromStd();
+	}
+
+	/**
+	 * Convert the given distance into an angle in radians
+	 * @param inDist distance to convert in the current distance units
+	 * @return angular distance in radians
+	 */
+	public static double convertDistanceToRadians(double inDist)
+	{
+		return convertDistanceToRadians(inDist, Config.getUnitSet().getDistanceUnit());
+	}
+
+	/**
+	 * Convert the given distance into an angle in radians
+	 * @param inDist distance to convert in the current distance units
+	 * @param inUnit distance unit
+	 * @return angular distance in radians
+	 */
+	public static double convertDistanceToRadians(double inDist, Unit inUnit)
+	{
+		// Divide by appropriate factor
+		return inDist / EARTH_RADIUS_M / inUnit.getMultFactorFromStd();
+	}
+}