/** Updates graph: finds closest station to each actor in world. Does not occur at every frame. */
public void update() {
if (frames_since_update++ < UPDATE_AFTER_FRAMES) return;
frames_since_update = 0;
// For each vehicle in the world, determine which station is the closest.
Actor[] actors = world.getActors();
for (Actor actor : actors) {
if (!(actor instanceof Vehicle)) continue;
Vehicle vehicle = (Vehicle) actor;
// Iterate over each station until the closest one is found.
Station closest_station = null;
float closest_station_distance = Float.MAX_VALUE;
for (Station station : stations) {
if (station == null) continue;
float new_distance = vehicle.distance(station);
if (new_distance < closest_station_distance) {
closest_station = station;
closest_station_distance = new_distance;
}
}
vehicle.setClosestStation(closest_station);
}
}
