protected PointOfInterest standingOrder(Point2D whereIAm) {
Point2D target =
new Point2D.Double(
whereIAm.getX() + (spiralHeading.getDx() * MOVEMENT_LENGTH),
whereIAm.getY() + (spiralHeading.getDy() * MOVEMENT_LENGTH));
while (!StaticDiver.pointIsOnBoard(target.getX(), target.getY(), boardRadius)) {
switch (spiralHeading) {
case N:
spiralHeading = Direction.W;
break;
case E:
spiralHeading = Direction.N;
break;
case S:
spiralHeading = Direction.E;
break;
case W:
spiralHeading = Direction.S;
break;
}
target =
new Point2D.Double(
whereIAm.getX() + (spiralHeading.getDx() * MOVEMENT_LENGTH),
whereIAm.getY() + (spiralHeading.getDy() * MOVEMENT_LENGTH));
}
return new PointOfInterest(target);
}
/*Should only be called once*/
private void findDanger() {
for (Observation o : whatYouSee) {
// logger.trace("What I see: " + o.getName() + "\t\tIs it dangerous? " + o.isDangerous());
if (!o.isDangerous()) continue;
Point2D predictedLocation;
int speed = 0;
int happy = 0; // can't use o.happiness() because that is 0 when you are on boat!
for (SeaLifePrototype life : seaLifePossibilities) {
if (life.getName().equals(o.getName())) {
speed = life.getSpeed();
happy = life.getHappiness();
break;
}
}
// Get the location and distance based on predicted location
// (taking into account whether creature is stationary or moving).
if (speed == 0 || o.getDirection() == null) {
predictedLocation = o.getLocation();
} else {
// predict where it will be
Point2D loc =
new Point2D.Double(
// o.getLocation().getX() + (o.getDirection().getDx() *
// (o.getDirection().isDiag() ? 3 : 2)),
// o.getLocation().getY() + (o.getDirection().getDy() *
// (o.getDirection().isDiag() ? 3 : 2))
o.getLocation().getX() + (o.getDirection().getDx()),
o.getLocation().getY() + (o.getDirection().getDy()));
if (ourBoard.inBounds((int) loc.getX(), (int) loc.getY())) {
predictedLocation = loc;
} else {
predictedLocation = o.getLocation();
}
}
// For each Direction that diver can move, calculate the sum of danger from all creatures
// affecting it.
// The danger is scaled based on distance (decreases by a factor of radius).
for (Direction d : Direction.values()) {
Point2D nextPosition =
new Point2D.Double(myPosition.getX() + d.getDx(), myPosition.getY() + d.getDy());
if (!ourBoard.inBounds((int) nextPosition.getX(), (int) nextPosition.getY())) continue;
double distanceToCreature = Math.max(1.0, nextPosition.distance(predictedLocation));
// logger.debug("Direction:"+d+" distanceToCreature = " + distanceToCreature);
// Only consider dangerous creatures if:
// 1. They are stationary and affect cells next to the candidate cell, OR
// 2. They are moving and affect cells within DANGER_MAX_DISTANCE of the candidate cell.
if (o.isDangerous()
&& ((speed == 0 && distanceToCreature <= STATIONARY_DANGER_DISTANCE)
|| (speed > 0 && distanceToCreature <= DANGER_MAX_DISTANCE))) {
double formerDirectionDanger = 0;
if (directionDanger.containsKey(d)) {
formerDirectionDanger = directionDanger.get(d);
// logger.debug("formerDirectionDanger = " + formerDirectionDanger);
}
directionDanger.put(
d,
new Double(
formerDirectionDanger
+ (Math.abs(happy * DANGER_MULTIPLIER) / Math.pow(distanceToCreature, 2))));
}
}
}
}
public Direction findSafestDirection(
Point2D myPosition,
Point2D myPreviousPosition,
Set<Observation> whatYouSee,
Direction preferredDirection,
boolean shouldReturnToBoat) {
updateCoordinates(myPosition, myPreviousPosition, whatYouSee);
findDanger();
// if we are at boat, reset the tracked helper state
if (myPosition.equals(new Point2D.Double(0, 0))) {
backtrackLocations.clear();
}
// logger.debug("in find safest direction");
double minDanger = Integer.MAX_VALUE;
ArrayList<DirectionAndDanger> directionsSafeToDangerous = new ArrayList<DirectionAndDanger>();
ArrayList<Direction> safestDirections = new ArrayList<Direction>();
// First, find the minimum danger. Create an equivalence class of directions sharing this value.
for (Direction d : Direction.values()) {
double curDanger;
if (directionDanger.containsKey(d)) {
curDanger = Math.abs(directionDanger.get(d));
// logger.trace("directionDanger.get("+d+") = "+curDanger);
} else {
curDanger = 0;
}
Point2D nextPosition =
new Point2D.Double(myPosition.getX() + d.getDx(), myPosition.getY() + d.getDy());
// Do not consider directions that take us too close to the walls
if (ourBoard.isNearBoundary(
nextPosition, Math.max(WALL_MAX_DISTANCE, (double) r / Math.sqrt(2.0) - 1.0))) {
continue;
}
// Do not consider directions that put us in backtracked locations
// i.e. we are trying to go around danger, so don't go backwards
if (backtrackLocations.contains(nextPosition)) {
continue;
}
// logger.debug("current danger in direction " + d + ":" + curDanger);
if (curDanger < minDanger) {
safestDirections.clear();
safestDirections.add(d);
// logger.debug("Min Danger so far in Direction: " + d);
minDanger = curDanger;
} else if (curDanger == minDanger) {
safestDirections.add(d);
}
directionsSafeToDangerous.add(new DirectionAndDanger(d, curDanger));
}
// Sort from least dangerous to most dangerous
Collections.sort(directionsSafeToDangerous);
mySafestDirection = null;
if (shouldReturnToBoat) {
// If returning to boat, always head in preferredDirection if it is among the safest
if (preferredDirection == null) {
mySafestDirection = null;
} else if (safestDirections.contains(preferredDirection)) {
mySafestDirection = preferredDirection;
} else {
// Prioritize the directions closer to the safest
// And de-prioritize the previous location
Direction previousDirection = OurBoard.getDirectionTowards(myPosition, myPreviousPosition);
for (Direction d : DirectionUtil.getClosestDirections(preferredDirection)) {
if (safestDirections.contains(d) && !d.equals(previousDirection)) {
mySafestDirection = d;
break;
}
}
// We excluded previous direction in above loop.
// If mySafestDirection == null, that means safest is previous direction.
if (mySafestDirection == null) {
if (!directionsSafeToDangerous.isEmpty()) {
mySafestDirection = directionsSafeToDangerous.get(0).getDirection();
} else {
// just go back towards boat...
mySafestDirection = OurBoard.getDirectionTowards(myPosition, new Point2D.Double(0, 0));
}
}
// we did not pick preferredDirection, so next time make sure we don't come back
backtrackLocations.add(myPreviousPosition);
}
} else {
// 80% of the time, continue in preferredDirection if it is among the safest
if (preferredDirection != null
&& safestDirections.contains(preferredDirection)
&& random.nextDouble() <= 0.80) {
mySafestDirection = preferredDirection;
} else {
List<Direction> closestDirections = DirectionUtil.getClosestDirections(preferredDirection);
// Try to pick the safest direction out of [forward-left, forward-right, left, right]
List<Direction> firstTwo = closestDirections.subList(0, 2);
List<Direction> nextTwo = closestDirections.subList(2, 4);
// Look at the top 3 safest directions
if (directionsSafeToDangerous.size() >= 3) {
for (DirectionAndDanger dad : directionsSafeToDangerous.subList(0, 3)) {
// skip the one going backwards
if (dad.equals(OurBoard.getDirectionTowards(myPosition, myPreviousPosition))) {
continue;
}
if (firstTwo.contains(dad.getDirection())) {
mySafestDirection = dad.getDirection();
break;
} else if (nextTwo.contains(dad.getDirection())) {
mySafestDirection = dad.getDirection();
break;
}
}
}
if (mySafestDirection == null) {
if (!safestDirections.isEmpty()) {
Collections.shuffle(safestDirections);
mySafestDirection = safestDirections.get(0);
} else {
// no safe directions?? return to boat then...
mySafestDirection = OurBoard.getDirectionTowards(myPosition, new Point2D.Double(0, 0));
}
}
// we did not pick preferredDirection, so next time make sure we don't come back
backtrackLocations.add(myPreviousPosition);
}
}
// if we end up going in preferredDirection, no need to avoid backtrack areas anymore
backtrackLocations.clear();
// logger.debug("Safest direction: " + mySafestDirection + " (from among " +
// safestDirections.toString() + ")");
return mySafestDirection;
}