Added Knots <-> MMperSec conversions to AC35UnitConverter.

Removed redundant/unused conversions.
Documented all of the conversions, and renamed them to pack/unpackX, to match the API spec.
Updated/added some tests in AC35UnitConverterTest.
RaceStatus now contains a Bearing instead of a packed int bearing.
RaceStatus now contains wind speed in knots, instead of MMperSec packed.
This means that only RaceStatus decoder/encoder need to care about the bits-over-wire packed values.
issue #35 #36
#story[1095]

racevisionGame/src/main/java/network/Utils/AC35UnitConverter.java

@@ -1,43 +1,88 @@
 package network.Utils;
 
+import shared.model.Constants;
+
 /**
- * Created by fwy13 on 28/04/17.
+ * Contains various unit conversion for encoding/decoding messages.
+ * Our program uses the "unpacked" units, and the over-the-wire format uses "packed" units (e.g., degrees stored as ints).
  */
 public class AC35UnitConverter {
 
-    public static double convertGPS(int value){
-        //converts latitude or longitue to angle
+
+    /**
+     * Converts a packed GPSCoordinate (latitude or longitude) into the unpacked unit.
+     * @param value Packed lat/long value.
+     * @return Unpacked lat/long angle, in degrees.
+     */
+    public static double unpackGPS(int value) {
         return (double) value * 180.0 / 2147483648.0;//2^31 = 2147483648
     }
 
-    public static int convertGPSToInt(double value){
-        //converts latitude or longitue to angle
+    /**
+     * Converts a latitude or longitude angle into a packed unit.
+     * @param value The lat/long angle, in degrees, to convert.
+     * @return The packed value.
+     */
+    public static int packGPS(double value) {
         return (int) (value * 2147483648.0/180.0);//2^31 = 2147483648
     }
 
-    public static double convertHeading(long value){
-        return (double) value * 360.0/65536.0;//2^15
+
+    /**
+     * Unpacks a heading from an int to an angle in degrees (this is a bearing).
+     * @param value The packed value to unpack.
+     * @return The unpacked value in degrees.
+     */
+    public static double unpackHeading(int value) {
+        return (value * 360.0 / 65536.0);//2^15
     }
 
-    public static double convertHeading(int value){
-        return (double) value * 360.0/65536.0;//2^15
-    }
-
-
-    public static double convertHeading(double value){
-        return value * 360.0/65536.0;//2^15
-    }
-
-    public static int encodeHeading(int value){
+    /**
+     * Packs a heading (this is a bearing), in degrees, to a packed int value.
+     * @param value The heading in degrees.
+     * @return The packed value.
+     */
+    public static int packHeading(double value) {
         return (int) (value / 360.0 * 65536.0);//2^15
     }
 
-    public static int encodeHeading(double value){
-        return (int) (value / 360.0 * 65536.0);//2^15
+
+    /**
+     * Unpacks a true wind angle from a short to an angle in degrees (this is an azimuth).
+     * @param value The packed value to unpack.
+     * @return The unpacked value in degrees.
+     */
+    public static double unpackTrueWindAngle(short value) {
+        return (value * 180.0 / 32768.0);//-2^15 to 2^15
     }
 
-    public static double convertTrueWindAngle(long value){
-        return (double) value * 180.0/32768.0;//-2^15 to 2^15
+    /**
+     * Packs a true wind angle (this is an azimuth) from an angle in degrees to a packed short value.
+     * @param value The unpacked value in degrees.
+     * @return The packed value.
+     */
+    public static short packTrueWindAngle(double value) {
+        return (short) (value / 180.0 * 32768.0);//-2^15 to 2^15
     }
 
+
+    /**
+     * Unpacks a speed, in millimeters per second, to a double, in knots.
+     * @param millimetersPerSec Speed in millimeters per second.
+     * @return Speed in knots.
+     */
+    public static double unpackMMperSecToKnots(int millimetersPerSec) {
+        return (millimetersPerSec / Constants.KnotsToMMPerSecond);
+    }
+
+    /**
+     * Packs a speed, in knots, into an int, in millimeters per second.
+     * @param speedKnots Speed in knots.
+     * @return Speed in millimeters per second.
+     */
+    public static int packKnotsToMMperSec(double speedKnots) {
+        return (int) (speedKnots * Constants.KnotsToMMPerSecond);
+    }
+
+
 }