Added document and unit tests for GeoUtility class.

- three methods in GeoUtility have been tested and passed.

#story[828]

src/main/java/seng302/App.java

@@ -24,6 +24,4 @@ public class App extends Application
         new Thread(new Simulator(1000)).run();
         launch(args);
     }
-}
+}
-
-

src/main/java/seng302/server/simulator/GeoUtility.java

@@ -33,8 +33,14 @@ public class GeoUtility {
 	 *
 	 * @param p1 the first geographical position, start point
 	 * @param p2 the second geographical position, end point
-	 * @return the bearing in degree from p1 to p2, value range (0 ~ 360 deg.).
+	 * @return the initial bearing in degree from p1 to p2, value range (0 ~ 360 deg.).
 	 * vertical up is 0 deg. horizontal right is 90 deg.
+	 *
+	 * NOTE:
+	 * The final bearing will differ from the initial bearing by varying degrees
+	 * according to distance and latitude (if you were to go from say 35°N,45°E
+	 * (≈ Baghdad) to 35°N,135°E (≈ Osaka), you would start on a heading of 60°
+	 * and end up on a heading of 120°
 	 */
 	public static Double getBearing(Position p1, Position p2) {
 

src/test/java/seng302/server/simulator/GeoUtilityTest.java

@@ -0,0 +1,75 @@
+package seng302.server.simulator;
+
+import org.junit.Test;
+import seng302.server.simulator.mark.Position;
+
+import static org.junit.Assert.*;
+
+/**
+ * To test methods in GeoUtility.
+ * Created by Haoming on 28/04/17.
+ */
+public class GeoUtilityTest {
+
+	private Position p1 = new Position(57.670333, 11.827833);
+	private Position p2 = new Position(57.671524, 11.844495);
+	private Position p3 = new Position(57.670822, 11.843392);
+	private Position p4 = new Position(25.694829, 98.392049);
+
+	private double toleranceRate = 0.01;
+
+	@Test
+	public void getDistance() throws Exception {
+		double expected, actual;
+
+		actual = GeoUtility.getDistance(p1, p2);
+		expected = 1000;
+		assertEquals(expected, actual, expected * toleranceRate);
+
+		actual = GeoUtility.getDistance(p1, p3);
+		expected = 927;
+		assertEquals(expected, actual, expected * toleranceRate);
+
+		actual = GeoUtility.getDistance(p2, p4);
+		expected = 7430180;
+		assertEquals(expected, actual, expected * toleranceRate);
+	}
+
+	@Test
+	public void getBearing() throws Exception {
+		double expected, actual;
+
+		actual = GeoUtility.getBearing(p1, p2);
+		expected = 82;
+		assertEquals(expected, actual, expected * toleranceRate);
+
+		actual = GeoUtility.getBearing(p1, p3);
+		expected = 86;
+		assertEquals(expected, actual, expected * toleranceRate);
+
+		actual = GeoUtility.getBearing(p2, p4);
+		expected = 78;
+		assertEquals(expected, actual, expected * toleranceRate);
+	}
+
+	@Test
+	public void getGeoCoordinate() throws Exception {
+		Position expected, actual;
+
+		actual = GeoUtility.getGeoCoordinate(p1, 82.0, 1000.0);
+		expected = p2;
+		assertEquals(expected.getLat(), actual.getLat(), expected.getLat() * toleranceRate);
+		assertEquals(expected.getLng(), actual.getLng(), expected.getLng() * toleranceRate);
+
+		actual = GeoUtility.getGeoCoordinate(p1, 86.0, 927.0);
+		expected = p3;
+		assertEquals(expected.getLat(), actual.getLat(), expected.getLat() * toleranceRate);
+		assertEquals(expected.getLng(), actual.getLng(), expected.getLng() * toleranceRate);
+
+		actual = GeoUtility.getGeoCoordinate(p2, 78.0, 7430180.0);
+		expected = p4;
+		assertEquals(expected.getLat(), actual.getLat(), expected.getLat() * toleranceRate);
+		assertEquals(expected.getLng(), actual.getLng(), expected.getLng() * toleranceRate);
+	}
+
+}