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) {
+	public Boundary(double northLat, double eastLng, double southLat, double westLng) {
-		this.north = north;
+		this.northLat = northLat;
-		this.east = east;
+		this.eastLng = eastLng;
-		this.south = south;
+		this.southLat = southLat;
-		this.west = west;
+		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() {
+	public double getNorthLat() {
-		return north;
+		return northLat;
 	}
 
-	public double getEast() {
+	public double getEastLng() {
-		return east;
+		return eastLng;
 	}
 
-	public double getSouth() {
+	public double getSouthLat() {
-		return south;
+		return southLat;
 	}
 
-	public double getWest() {
+	public double getWestLng() {
-		return west;
+		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 static final double MERCATOR_RANGE = 256;
-	private double pixelsPerLngDegree, pixelsPerLngRadian;
+	private static final double pixelsPerLngDegree = MERCATOR_RANGE / 360.0;
-
+	private static final double pixelsPerLngRadian = MERCATOR_RANGE / (2 * Math.PI);
-
-	public MercatorProjection() {
-		pixelsPerLngDegree = MERCATOR_RANGE / 360.0;
-		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);

src/test/java/seng302/models/map/MercatorProjectionTest.java

@@ -0,0 +1,42 @@
+package seng302.models.map;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Unit test for Mercator Project class.
+ * Created by hyi25 on 15/05/17.
+ */
+public class MercatorProjectionTest {
+	@Test
+	public void toMapPoint() throws Exception {
+		MapGeo geo1 = new MapGeo(12.485394, 19.38947);
+		MapPoint actualPoint1 = MercatorProjection.toMapPoint(geo1);
+		MapPoint expectedPoint1 = new MapPoint(141.78806755555556, 119.0503853635612);
+		assertEquals(expectedPoint1.getX(), actualPoint1.getX(), 0.0001);
+		assertEquals(expectedPoint1.getY(), actualPoint1.getY(), 0.0001);
+
+		MapGeo geo2 = new MapGeo(77.456432, -23.456462);
+		MapPoint actualPoint2 = MercatorProjection.toMapPoint(geo2);
+		MapPoint expectedPoint2 = new MapPoint(111.31984924444444, 38.03143323746788);
+		assertEquals(expectedPoint2.getX(), actualPoint2.getX(), 0.0001);
+		assertEquals(expectedPoint2.getY(), actualPoint2.getY(), 0.0001);
+	}
+
+	@Test
+	public void toMapGeo() throws Exception {
+		MapPoint point1 = new MapPoint(123.1234, 25.4565);
+		MapGeo actualGeo1 = MercatorProjection.toMapGeo(point1);
+		MapGeo expectedGeo1 = new MapGeo(80.77043127275441, -6.857718749999995);
+		assertEquals(expectedGeo1.getLat(), actualGeo1.getLat(), 0.0001);
+		assertEquals(expectedGeo1.getLng(), actualGeo1.getLng(), 0.0001);
+
+		MapPoint point2 = new MapPoint(1.235, 255.4565);
+		MapGeo actualGeo2 = MercatorProjection.toMapGeo(point2);
+		MapGeo expectedGeo2 = new MapGeo(-84.98475532898011, -178.26328125);
+		assertEquals(expectedGeo2.getLat(), actualGeo2.getLat(), 0.0001);
+		assertEquals(expectedGeo2.getLng(), actualGeo2.getLng(), 0.0001);
+	}
+
+}