Ejemplo n.º 1
0
    public Point2D.Double getDirectionFor(Task task) {
      Point2D.Double loc = task.ownerLoc;
      Point2D.Double tLoc = task.targetLoc;
      Point2D.Double tVel = task.target.getVelocity();
      double tSpeed = tVel == null ? 0 : tVel.distance(0, 0);
      Point2D.Double diff = new Point2D.Double(tLoc.x - loc.x, tLoc.y - loc.y);

      if (tSpeed == 0 || task.owner.par.topSpeed < tSpeed * 1.0001)
        return PlanarMathUtils.normalize(diff);

      // In this algorithm, the capture point is assumed to be where the pursuer would first be able
      // to overtake the evader if the evader kept heading
      // in its current direction... this is where the ratio of speeds is equal to the ratio of
      // distances to this hypothetical point.
      // The evader's distance to this point is dE, and the pursuer heads toward the evader's
      // position plus its heading times dE*leadFactor.
      double mu =
          task.owner.par.topSpeed / tSpeed; // ratio of speeds is used several times in the formula
      double dcosth =
          (tVel.x * diff.x + tVel.y * diff.y)
              / tSpeed; // basic dot product formula for cosine... provides ||diff|| * cos of angle
                        // between diff and tVel
      double dE =
          (Math.abs(dcosth) - Math.sqrt(dcosth * dcosth - (1 - mu * mu) * diff.distanceSq(0, 0)))
              / (1 - mu * mu);

      return unitVectorTo(
          loc,
          new Point2D.Double(
              tLoc.x + tVel.x * leadFactor * dE / tSpeed,
              tLoc.y + tVel.y * leadFactor * dE / tSpeed),
          task.type.multiplier);
    }
 public int compare(Point2D.Double a, Point2D.Double b) {
   return Double.compare(a.distanceSq(center), b.distanceSq(center));
 }