Added unit tests for Mercator projection class.

- changed its methods to static
- add some documentation for its methods

#story[928]

src/main/java/seng302/models/map/Boundary.java

@@ -9,36 +9,36 @@ package seng302.models.map;
  */
 public class Boundary {
 
-	private double north, east, south, west;
+	private double northLat, eastLng, southLat, westLng;
 
-	public Boundary(double north, double east, double south, double west) {
-		this.north = north;
-		this.east = east;
-		this.south = south;
-		this.west = west;
+	public Boundary(double northLat, double eastLng, double southLat, double westLng) {
+		this.northLat = northLat;
+		this.eastLng = eastLng;
+		this.southLat = southLat;
+		this.westLng = westLng;
 	}
 
 	public double getCentreLat() {
-		return (north + south) / 2;
+		return (northLat + southLat) / 2;
 	}
 
 	public double getCentreLng() {
-		return (east + west) / 2;
+		return (eastLng + westLng) / 2;
 	}
 
-	public double getNorth() {
-		return north;
+	public double getNorthLat() {
+		return northLat;
 	}
 
-	public double getEast() {
-		return east;
+	public double getEastLng() {
+		return eastLng;
 	}
 
-	public double getSouth() {
-		return south;
+	public double getSouthLat() {
+		return southLat;
 	}
 
-	public double getWest() {
-		return west;
+	public double getWestLng() {
+		return westLng;
 	}
 }

src/main/java/seng302/models/map/MercatorProjection.java

@@ -2,21 +2,16 @@ package seng302.models.map;
 
 public class MercatorProjection {
 
-	private double MERCATOR_RANGE = 256;
-	private double pixelsPerLngDegree, pixelsPerLngRadian;
-
-
-	public MercatorProjection() {
-		pixelsPerLngDegree = MERCATOR_RANGE / 360.0;
-		pixelsPerLngRadian = MERCATOR_RANGE / (2 * Math.PI);
-	}
+	private static final double MERCATOR_RANGE = 256;
+	private static final double pixelsPerLngDegree = MERCATOR_RANGE / 360.0;
+	private static final double pixelsPerLngRadian = MERCATOR_RANGE / (2 * Math.PI);
 
 	/**
 	 * A help function keeps the value in bound between -0.9999 and 0.9999.
 	 * @param value in bound value
 	 * @return the value in bound
 	 */
-	private double bound(double value) {
+	private static double bound(double value) {
 		return Math.min(Math.max(value, -0.9999), 0.9999);
 	}
 
@@ -25,7 +20,7 @@ public class MercatorProjection {
 	 * @param geo MapGeo (lat, lng) location to be projected
 	 * @return the projection GeoPoint (x, y) on planar
 	 */
-	public MapPoint toMapPoint(MapGeo geo) {
+	public static MapPoint toMapPoint(MapGeo geo) {
 		MapPoint point = new MapPoint(0, 0);
 		MapPoint origin = new MapPoint(MERCATOR_RANGE / 2.0, MERCATOR_RANGE / 2.0);
 		point.setX(origin.getX() + geo.getLng() * pixelsPerLngDegree);
@@ -42,7 +37,7 @@ public class MercatorProjection {
 	 * @param point MapPoint (x, y) to be converted back
 	 * @return the original Geo location converted from the given projection point
 	 */
-	public MapGeo toMapGeo(MapPoint point) {
+	public static MapGeo toMapGeo(MapPoint point) {
 		MapPoint origin = new MapPoint(MERCATOR_RANGE / 2.0, MERCATOR_RANGE / 2.0);
 		double lng = (point.getX() - origin.getX()) / pixelsPerLngDegree;
 		double latRadians = (point.getY() - origin.getY()) / (-pixelsPerLngRadian);