Implemented wake visualisation for each boat

- Added and tested wake calculation for BoatInRace
- Draws boat in canvas between start and entering Finish leg
- Allow boat velocity to be set after initialisation for testing
#story [21]

src/test/java/seng302/Model/BoatInRaceTest.java

@@ -1,6 +1,7 @@
 package seng302.Model;
 
 import javafx.scene.paint.Color;
+import org.junit.Assert;
 import org.junit.Ignore;
 import org.junit.Test;
 import seng302.GPSCoordinate;
@@ -111,4 +112,43 @@ public class BoatInRaceTest {
         assertEquals(testBoat.getVelocity(), 20.0);
     }
 
+
+    @Test
+    public void getWakeAtProperHeading() throws Exception {
+        BoatInRace boat = new BoatInRace("Test", 1, Color.ALICEBLUE, "tt");
+
+        // Construct leg of 0 degrees
+        GPSCoordinate startPoint = new GPSCoordinate(0, 0);
+        GPSCoordinate endPoint = new GPSCoordinate(50, 0);
+        Leg leg0deg = new Leg("Start", startPoint, endPoint, 0);
+        boat.setCurrentLeg(leg0deg);
+        boat.setCurrentPosition(new GPSCoordinate(0,0));
+
+        assertEquals(0, boat.calculateHeading(), 1e-8);
+
+        // Construct leg from wake - heading should be 180 degrees
+        Leg leg180deg = new Leg("Start", startPoint, boat.getWake(), 0);
+        boat.setCurrentLeg(leg180deg);
+
+        assertEquals(180, boat.calculateHeading(), 1e-8);
+    }
+
+    @Test
+    public void getWakeProportionalToVelocity() throws Exception {
+        BoatInRace boat = new BoatInRace("Test", 10, Color.ALICEBLUE, "tt");
+
+        // Construct leg of 0 degrees at 0 N
+        GPSCoordinate startPoint = new GPSCoordinate(0, 0);
+        GPSCoordinate endPoint = new GPSCoordinate(50, 0);
+        Leg leg0deg = new Leg("Start", startPoint, endPoint, 0);
+        boat.setCurrentLeg(leg0deg);
+        boat.setCurrentPosition(new GPSCoordinate(0,0));
+
+        // Get latitude of endpoint of wake at 10 kn (longitude is 0)
+        double endpointAt10Kn = boat.getWake().getLatitude();
+
+        // Latitude of endpoint at 20 kn should be twice endpoint at 10 kn
+        boat.setVelocity(20);
+        assertEquals(2*endpointAt10Kn, boat.getWake().getLatitude(), 1e-8);
+    }
 }