public double icpStep(
      DoubleOrientedPoint pret, IGMap map, DoubleOrientedPoint p, double[] readings) {
    int angleIndex = initialBeamsSkip;
    DoubleOrientedPoint lp = new DoubleOrientedPoint(p.x, p.y, p.theta);

    lp.x += Math.cos(p.theta) * laserPose.x - Math.sin(p.theta) * laserPose.y;
    lp.y += Math.sin(p.theta) * laserPose.x + Math.cos(p.theta) * laserPose.y;
    lp.theta += laserPose.theta;
    int skip = 0;
    double freeDelta = map.getDelta() * freeCellRatio;
    List<DoublePointPair> pairs = new ArrayList<DoublePointPair>();

    for (int rIndex = initialBeamsSkip; rIndex < readings.length; rIndex++, angleIndex++) {
      skip++;
      skip = skip > likelihoodSkip ? 0 : skip;
      if (readings[rIndex] > usableRange || readings[rIndex] == 0.0) continue;
      if (skip != 0) continue;
      DoublePoint phit = new DoublePoint(lp.x, lp.y);

      phit.x += readings[rIndex] * Math.cos(lp.theta + laserAngles[angleIndex]);
      phit.y += readings[rIndex] * Math.sin(lp.theta + laserAngles[angleIndex]);
      IntPoint iphit = map.world2map(phit);

      DoublePoint pfree = new DoublePoint(lp.x, lp.y);
      pfree.x +=
          (readings[rIndex] - map.getDelta() * freeDelta)
              * Math.cos(lp.theta + laserAngles[angleIndex]);
      pfree.y +=
          (readings[rIndex] - map.getDelta() * freeDelta)
              * Math.sin(lp.theta + laserAngles[angleIndex]);
      pfree.x = pfree.x - phit.x;
      pfree.y = pfree.y - phit.y;

      IntPoint ipfree = map.world2map(pfree);
      boolean found = false;
      DoublePoint bestMu = new DoublePoint(0., 0.);
      DoublePoint bestCell = new DoublePoint(0., 0.);
      for (int xx = -kernelSize; xx <= kernelSize; xx++)
        for (int yy = -kernelSize; yy <= kernelSize; yy++) {
          IntPoint pr = new IntPoint(iphit.x + xx, iphit.y + yy);
          IntPoint pf = new IntPoint(pr.x + ipfree.x, pr.y + ipfree.y);
          PointAccumulator cell = (PointAccumulator) map.cell(pr, true);
          PointAccumulator fcell = (PointAccumulator) map.cell(pf, true);

          if (cell.doubleValue() > fullnessThreshold && fcell.doubleValue() < fullnessThreshold) {
            DoublePoint mu = DoublePoint.minus(phit, cell.mean());
            if (!found) {
              bestMu = mu;
              bestCell = cell.mean();
              found = true;
            } else if (DoublePoint.mulD(mu, mu) < DoublePoint.mulD(bestMu, bestMu)) {
              bestMu = mu;
              bestCell = cell.mean();
            }
          }
        }
      if (found) {
        pairs.add(new DoublePointPair(phit, bestCell));
      }
    }

    DoubleOrientedPoint result = new DoubleOrientedPoint(0.0, 0.0, 0.0);
    LOG.error("result(" + pairs.size() + ")=" + result.x + " " + result.y + " " + result.theta);
    pret.x = p.x + result.x;
    pret.y = p.y + result.y;
    pret.theta = p.theta + result.theta;
    pret.theta = Math.atan2(Math.sin(pret.theta), Math.cos(pret.theta));
    return score(map, p, readings);
  }
  double score(IGMap map, DoubleOrientedPoint p, double[] readings) {
    double s = 0;
    int angleIndex = initialBeamsSkip;
    DoubleOrientedPoint lp = new DoubleOrientedPoint(p.x, p.y, p.theta);
    lp.x += Math.cos(p.theta) * laserPose.x - Math.sin(p.theta) * laserPose.y;
    lp.y += Math.sin(p.theta) * laserPose.x + Math.cos(p.theta) * laserPose.y;
    lp.theta += laserPose.theta;
    int skip = 0;
    double freeDelta = map.getDelta() * freeCellRatio;
    for (int rIndex = initialBeamsSkip; rIndex < readings.length; rIndex++, angleIndex++) {
      skip++;
      skip = skip > likelihoodSkip ? 0 : skip;
      if (skip != 0 || readings[rIndex] > usableRange || readings[rIndex] == 0.0) continue;
      DoublePoint phit = new DoublePoint(lp.x, lp.y);
      phit.x += readings[rIndex] * Math.cos(Utils.theta(lp.theta + laserAngles[angleIndex]));
      phit.y += readings[rIndex] * Math.sin(Utils.theta(lp.theta + laserAngles[angleIndex]));
      IntPoint iphit = map.world2map(phit);
      DoublePoint pfree = new DoublePoint(lp.x, lp.y);
      pfree.x +=
          (readings[rIndex] - map.getDelta() * freeDelta)
              * Math.cos(Utils.theta(lp.theta + laserAngles[angleIndex]));
      pfree.y +=
          (readings[rIndex] - map.getDelta() * freeDelta)
              * Math.sin(Utils.theta(lp.theta + laserAngles[angleIndex]));
      pfree.x = pfree.x - phit.x;
      pfree.y = pfree.y - phit.y;

      IntPoint ipfree = map.world2map(pfree);
      boolean found = false;
      DoublePoint bestMu = new DoublePoint(0., 0.);
      for (int xx = -kernelSize; xx <= kernelSize; xx++) {
        for (int yy = -kernelSize; yy <= kernelSize; yy++) {
          IntPoint pr = new IntPoint(iphit.x + xx, iphit.y + yy);
          IntPoint pf = new IntPoint(pr.x + ipfree.x, pr.y + ipfree.y);
          // int ss = map.getStorage().cellState(pr);
          //                    if ((ss) > 0) {
          PointAccumulator cell = (PointAccumulator) map.cell(pr, true);
          PointAccumulator fcell = (PointAccumulator) map.cell(pf, true);
          if (cell != null && fcell != null) {
            if (cell.doubleValue() > fullnessThreshold && fcell.doubleValue() < fullnessThreshold) {
              DoublePoint mu = DoublePoint.minus(phit, cell.mean());
              if (!found) {
                bestMu = mu;
                found = true;
              } else {
                bestMu = DoublePoint.mulD(mu, mu) < DoublePoint.mulD(bestMu, bestMu) ? mu : bestMu;
              }
            }
          }
          //                    }
        }
      }
      if (found) {
        s += Math.exp(-1. / (gaussianSigma * DoublePoint.mulD(bestMu, bestMu)));
      }
    }
    return s;
  }
  public void computeActiveArea(IGMap map, DoubleOrientedPoint p, double[] readings) {
    if (m_activeAreaComputed) return;
    // Set<IntPoint> activeArea = new HashSet<IntPoint>();
    DoubleOrientedPoint lp = new DoubleOrientedPoint(p.x, p.y, p.theta);
    lp.x += Math.cos(p.theta) * laserPose.x - Math.sin(p.theta) * laserPose.y;
    lp.y += Math.sin(p.theta) * laserPose.x + Math.cos(p.theta) * laserPose.y;
    lp.theta += laserPose.theta;
    //        IntPoint p0 = map.world2map(lp);

    DoublePoint min = map.map2world(new IntPoint(0, 0));
    DoublePoint max = map.map2world(new IntPoint(map.getMapSizeX() - 1, map.getMapSizeY() - 1));

    if (lp.x < min.x) min.x = lp.x;
    if (lp.y < min.y) min.y = lp.y;
    if (lp.x > max.x) max.x = lp.x;
    if (lp.y > max.y) max.y = lp.y;
    int readingIndex;
    int angleIndex = initialBeamsSkip;
    for (readingIndex = initialBeamsSkip; readingIndex < laserBeams; readingIndex++, angleIndex++) {
      double r = readings[readingIndex];
      double angle = laserAngles[angleIndex];

      if (r > laserMaxRange || r == 0.0 || r > Double.MAX_VALUE) continue;
      double d = r > usableRange ? usableRange : r;
      //            DoublePoint phit = new DoublePoint(lp.x, lp.y);
      double phitx = lp.x, phity = lp.y;
      phitx += d * Math.cos(lp.theta + angle);
      phity += d * Math.sin(lp.theta + angle);
      if (phitx < min.x) min.x = phitx;
      if (phity < min.y) min.y = phity;
      if (phitx > max.x) max.x = phitx;
      if (phity > max.y) max.y = phity;
    }

    if (!map.isInsideD(min) || !map.isInsideD(max)) {
      DoublePoint lmin = map.map2world(new IntPoint(0, 0));
      DoublePoint lmax = map.map2world(new IntPoint(map.getMapSizeX() - 1, map.getMapSizeY() - 1));
      min.x = (min.x >= lmin.x) ? lmin.x : min.x - enlargeStep;
      max.x = (max.x <= lmax.x) ? lmax.x : max.x + enlargeStep;
      min.y = (min.y >= lmin.y) ? lmin.y : min.y - enlargeStep;
      max.y = (max.y <= lmax.y) ? lmax.y : max.y + enlargeStep;
      map.resize(min.x, min.y, max.x, max.y);
    }

    //        readingIndex = initialBeamsSkip;
    //        angleIndex = initialBeamsSkip;
    //        for (readingIndex = initialBeamsSkip; readingIndex < laserBeams; readingIndex++,
    // angleIndex++) {
    //            if (generateMap) {
    //                double d = readings[readingIndex];
    //                if (d > laserMaxRange || d == 0.0 || d > Double.MAX_VALUE)
    //                    continue;
    //                if (d > usableRange)
    //                    d = usableRange;
    //
    //                DoublePoint phit = new DoublePoint(d * Math.cos(lp.theta +
    // laserAngles[angleIndex]) + lp.x, d * Math.sin(lp.theta + laserAngles[angleIndex]) + lp.y);
    //                p0 = map.world2map(lp);
    //                IntPoint p1 = map.world2map(phit);
    //
    //                d += map.getDelta();
    //                GridLineTraversalLine line = new GridLineTraversalLine();
    //                line.points = m_linePoints;
    //                GridLineTraversalLine.gridLine(p0, p1, line);
    //                for (int i = 0; i < line.numPoints - 1; i++) {
    //                    IntPoint patch = (m_linePoints[i]);
    //                    activeArea.add(patch);
    //                }
    //                if (d <= usableRange) {
    //                    IntPoint patch = (p1);
    //                    activeArea.add(patch);
    //                }
    //            } else {
    //                double r = readings[readingIndex];
    //                double angle = laserAngles[angleIndex];
    //                if (readings[readingIndex] > laserMaxRange || readings[readingIndex] >
    // usableRange) {
    //                    continue;
    //                }
    ////                DoublePoint phit = new DoublePoint(lp.x, lp.y);
    //                double phitx = lp.x;
    //                double phity = lp.y;
    //                phitx += r * Math.cos(lp.theta + angle);
    //                phity += r * Math.sin(lp.theta + angle);
    //
    //                IntPoint p1 = map.world2map(phitx, phity);
    //                assert (p1.x >= 0 && p1.y >= 0);
    //                IntPoint cp = (p1);
    //                assert (cp.x >= 0 && cp.y >= 0);
    //                activeArea.add(cp);
    //            }
    //        }
    // this allocates the unallocated cells in the active area of the map
    // map.setActiveArea(activeArea, false);
    m_activeAreaComputed = true;
  }