Reset collision tag on visualiser boat after displaying collision

- Modified View3D to index subjects rather than shapes by source ID
- Enforced one collision per boat on server to reduce rendering load
- Changed collision radius to less than bounce radius
- Fixed game-breaking null command bug

#story[1195]

racevisionGame/src/main/java/mock/model/MockRace.java

@@ -366,10 +366,8 @@ public class MockRace extends RaceState {
         //Checks if the current boat has finished the race or not.
         boolean finish = this.isLastLeg(boat.getCurrentLeg());
 
-        if (!finish && totalElapsedMilliseconds >= updatePeriodMilliseconds) {
-
-            if(boat.isVelocityDefault()) setBoatSpeed(boat);
-
+        if (!finish && totalElapsedMilliseconds >= updatePeriodMilliseconds && boat.isVelocityDefault()) {
+            setBoatSpeed(boat);
             //Calculates the distance travelled, in meters, in the current timeslice.
             double distanceTravelledMeters = boat.calculateMetersTravelled(updatePeriodMilliseconds) * this.scaleFactor;
 

racevisionGame/src/main/java/mock/model/collider/Collider.java

@@ -24,7 +24,8 @@ public abstract class Collider extends Observable implements Locatable {
         // Direction of collider from heading
         Bearing relative = Bearing.fromDegrees(absolute.degrees() - boat.getBearing().degrees());
 
-        if(actualDistance <= distance) {
+        if(!boat.isColliding() && actualDistance <= distance) {
+            boat.setColliding(true);
             Collision collision = new Collision(boat, relative, distance);
             // Notify object of collision
             onCollisionEnter(collision);

racevisionGame/src/main/java/mock/model/commandFactory/CollisionCommand.java

@@ -29,17 +29,18 @@ public class CollisionCommand extends ObserverCommand {
     public void execute() {
         this.azimuth = Azimuth.fromDegrees(boat.getBearing().degrees() - 180d);
         this.startingPosition = boat.getPosition();
-        this.distance = 30;
+        this.distance = 60;
         boat.setVelocityDefault(false);
     }
 
     @Override
     public void update(Observable o, Object arg) {
         if(GPSCoordinate.calculateDistanceMeters(boat.getPosition(), startingPosition) < distance) {
-            boat.setPosition(GPSCoordinate.calculateNewPosition(boat.getPosition(), 2, azimuth));
+            boat.setPosition(GPSCoordinate.calculateNewPosition(boat.getPosition(), 3, azimuth));
         } else {
             race.deleteObserver(this);
             boat.setVelocityDefault(true);
+            boat.setColliding(false);
         }
     }
 }