public void act(BucketbotBase self) {
alphabetsoup.framework.Map map = SimulationWorldSimpleExample.getSimulationWorld().getMap();
float cur_speed = getSpeed(); // called once for code efficiency (since getSpeed does a sqrt)
// find distance to be covered before next planned update
getNextEventTime(curTime);
double time_interval = Math.max(getMinUntil() - curTime, 0.001);
float distance_to_be_covered =
(float) (Math.max(cur_speed, getTargetSpeed()) * time_interval);
distance_to_be_covered +=
2 * getRadius(); // count its radius and the radius of another object
// make sure see at least a minimal distance regardless of speed
float min_visible_distance = 3 * getRadius();
distance_to_be_covered = Math.max(distance_to_be_covered, min_visible_distance);
// get visible objects within the distance of the next planned update
Collection<Circle> visible_objects =
map.getBucketbotsWithinDistance(getX(), getY(), distance_to_be_covered);
if (self.getBucket() != null)
visible_objects.addAll(
map.getBucketsWithinDistance(getX(), getY(), distance_to_be_covered));
// don't want to do anything yet,
// unless something is now visible that wasn't before,
// a collision occured (speed == 0)
// timer is ready to do something else
if (((getBucket() == null && visible_objects.size() == 1)
|| (getBucket() != null && visible_objects.size() == 2))
&& cur_speed > 0.0f
&& curTime < cruiseUntil) return;
// if something other than bucketbot (and bucket if applicable) is near, evade
if ((getBucket() == null && visible_objects.size() > 1)
|| (getBucket() != null && visible_objects.size() > 2)) {
// find closest object
float min_dist2 = Float.POSITIVE_INFINITY; // minimum distance squared
for (Circle c : visible_objects) {
if (c == self || c == self.getBucket()) continue;
// see if infront of bucketbot
float object_direction = (float) Math.atan2(c.getY() - getY(), c.getX() - getX());
float relative_direction = angleDifference(object_direction, getDirection());
if (Math.abs(relative_direction)
> Math.PI / 4 + 0.5) // just beyond 1/4 circle, to make sure they don't get stuck
continue;
// see if it's closer than any other
float dist2 =
(getX() - c.getX()) * (getX() - c.getX()) + (getY() - c.getY()) * (getY() - c.getY());
if (dist2 < min_dist2) min_dist2 = dist2;
}
// if anything is closer than this constant value, then evade...
if (min_dist2 < min_visible_distance * min_visible_distance) {
float new_direction = getBestEvadeDirection(min_visible_distance);
if (getDirection() != new_direction) setDirection(new_direction);
setTargetSpeed(getMaxVelocity());
cruiseUntil = curTime + 0.25f;
frustration = 0.0f;
stateQueue.add(0, bucketbotEvade);
return;
}
}
// if trying to move, but can't try evading
if (cur_speed > 0.0f) {
stuckCount = 0;
} else { // not moving...
stuckCount++;
if (stuckCount > 3) {
frustration = 0.0f;
stateQueue.add(0, bucketbotEvade);
return;
}
}
// find distance to goal
float goal_distance = getDistance(moveToX, moveToY);
// make sure tolerance is less than the map's tolerance/3 to make sure that if it sets a
// bucket down,
// the next one bucketbot will be able to pick it up (and could also be tolerance/3 away)
// better fudge factor than tolerance / 2 (which is the minimum that will work)
float tolerance = map.getTolerance() / 3;
// if close enough to goal and stopped moving, then do next action
if (goal_distance < tolerance && cur_speed == 0.0f) {
frustration = 0.0f;
stateQueue.remove(0);
if (stateQueue.size() > 0) stateQueue.get(0).act(self);
return;
}
// if not facing the right way (within tolerance), or heading outside of the map, turn so it
// is a good direction
double projected_x = getX() + goal_distance * Math.cos(getDirection());
double projected_y = getY() + goal_distance * Math.sin(getDirection());
if ((projected_x - moveToX) * (projected_x - moveToX)
+ (projected_y - moveToY) * (projected_y - moveToY)
>= tolerance * tolerance
|| projected_x + getRadius() > map.getWidth()
|| projected_x - getRadius() < 0.0
|| projected_y + getRadius() > map.getHeight()
|| projected_y - getRadius() < 0.0) {
setDirection((float) Math.atan2(moveToY - getY(), moveToX - getX()));
if (cur_speed > 0) setTargetSpeed(0.0f);
cruiseUntil = getAccelerateUntil();
return;
}
// going the right direction -now figure out speed
// if too close to stop, then stop as fast as possible
float decel_time = cur_speed / getMaxAcceleration();
float decel_distance = getMaxAcceleration() / 2 * decel_time * decel_time;
if (cur_speed > 0.0f && decel_distance > goal_distance) {
setTargetSpeed(0.0f);
cruiseUntil = getAccelerateUntil();
frustration = (frustration + 1.0f) / 2;
return;
}
// get new velocity based on frustration
float cur_vel = getMaxVelocity() * Math.max(1.0f - frustration, 0.0078125f);
setTargetSpeed(cur_vel);
// see if have room to accelerate to full speed and still decelerate
float accel_time = getTargetSpeedDifference() / getMaxAcceleration();
float accel_distance =
cur_speed * accel_time + getMaxAcceleration() / 2 * accel_time * accel_time;
decel_time = cur_vel / getMaxAcceleration();
decel_distance = getMaxAcceleration() / 2 * accel_time * accel_time;
// if enough room to fully accelerate, do so
if (accel_distance + decel_distance <= goal_distance) cruiseUntil = getAccelerateUntil();
else { // don't have time to fully accelerate
// having this code spread out with sub-steps dramatically helps the java compiler have
// better performance
double cos_dir = Math.cos(getDirection());
double sin_dir = Math.sin(getDirection());
double x_accel = getMaxAcceleration() * cos_dir;
double y_accel = getMaxAcceleration() * sin_dir;
if (Math.abs(x_accel) > Math.abs(y_accel)) {
double x_goal = goal_distance * cos_dir;
cruiseUntil =
curTime
+ sqrt2
* (Math.sqrt(2 * x_accel * x_goal + getXVelocity() * getXVelocity())
- sqrt2 * getXVelocity())
/ (2 * x_accel);
} else {
double y_goal = goal_distance * sin_dir;
cruiseUntil =
curTime
+ sqrt2
* (Math.sqrt(2 * y_accel * y_goal + getYVelocity() * getYVelocity())
- sqrt2 * getYVelocity())
/ (2 * y_accel);
}
}
} // act()
/**
* getBestEvadeDirection returns the largest approximate gap to escape. This gap is approximated
* by finding the gaps between all potential collideable objects around the Bucketbot, and
* weighting them positively by size and weighting them inversely by both distance and gapsize.
* The direction bisecting the largest of these weighted gaps is returned.
*
* @param visible_distance how far the Bucketbot can see
* @return best direction to evade
*/
public float getBestEvadeDirection(float visible_distance) {
alphabetsoup.framework.Map map = SimulationWorldSimpleExample.getSimulationWorld().getMap();
// get visible objects within the distance of the next planned update
Collection<Circle> visible_objects =
map.getBucketbotsWithinDistance(getX(), getY(), visible_distance);
if (getBucket() != null)
visible_objects.addAll(map.getBucketsWithinDistance(getX(), getY(), visible_distance));
// if nothing other than bucketbot (and bucket if applicable), keep going in same direction
if ((getBucket() == null && visible_objects.size() <= 1)
|| (getBucket() != null && visible_objects.size() <= 2)) return getDirection();
List<CollideableObject> objects = new ArrayList<CollideableObject>();
// get object distances and directions
for (Circle c : visible_objects) {
if (c == this || c == getBucket()) continue;
float object_direction = (float) Math.atan2(c.getY() - getY(), c.getX() - getX());
objects.add(
new CollideableObject(
2 * c.getRadius(), getDistance(c.getX(), c.getY()), object_direction));
}
// add 4 walls
if (getX() < visible_distance)
objects.add(
new CollideableObject(
(float) (2 * Math.sqrt(visible_distance * visible_distance - getX() * getX())),
getX(),
(float) Math.PI));
if (map.getWidth() - getX() < visible_distance)
objects.add(
new CollideableObject(
(float)
(2
* Math.sqrt(
visible_distance * visible_distance
- (map.getWidth() - getX()) * (map.getWidth() - getX()))),
map.getWidth() - getX(),
0.0f));
if (getY() < visible_distance)
objects.add(
new CollideableObject(
(float) (2 * Math.sqrt(visible_distance * visible_distance - getY() * getY())),
getY(),
(float) (3 * Math.PI / 2)));
if (map.getHeight() - getY() < visible_distance)
objects.add(
new CollideableObject(
(float)
(2
* Math.sqrt(
visible_distance * visible_distance
- (map.getHeight() - getY()) * (map.getHeight() - getY()))),
map.getHeight() - getY(),
(float) Math.PI / 2));
// if no objects, then nothing to collide with
if (objects.size() == 0) return getDirection();
// sort objects by direction, so between each two objects is the smallest real gaps
Collections.sort(objects, objects.get(0));
// add beginning one again
objects.add(
new CollideableObject(
objects.get(0).size,
objects.get(0).distance,
(float) (objects.get(0).direction + 2 * Math.PI)));
// find maximal gap
// start with first gap
float evade_direction = (objects.get(0).direction + objects.get(1).direction) / 2;
double weight =
((objects.get(0).size + objects.get(1).size) / 2)
/ (((objects.get(0).distance + objects.get(1).distance) / 2)
* (objects.get(1).direction - objects.get(0).direction));
// for all after the first gap
for (int i = 1; i < objects.size() - 1; i++) {
// get weight (a heuristic for speed)
float w =
((objects.get(i).size + objects.get(i + 1).size) / 2)
/ (((objects.get(i).distance + objects.get(i + 1).distance) / 2)
* (objects.get(i + 1).direction - objects.get(i).direction));
// if better direction, then choose direction bisecting the two objects
if (w < weight) {
weight = w;
evade_direction = (objects.get(i).direction + objects.get(i + 1).direction) / 2;
}
}
return evade_direction;
}
