private static FsTaskScoreParams CalcScoreParams(Task t, ScoreFormulaGAP sfg, Participant[] ps)
{
  FsTaskScoreParams sp = new FsTaskScoreParams();
  double min_dist = sfg.Min_dist;
  double task_distance = t.DistanceExact; // http://fs.fai.org/ticket/103
  sp.Task_distance = task_distance;
  sp.Ss_distance = t.Ss_distance;

  double[] times = new double[ps.Length];
  int i = 0;
  foreach (Participant p in ps)
  {
    // present
    sp.No_of_pilots_present++;

    // flying
    if (p._flew) sp.No_of_pilots_flying++;

    // sum dist over task min dist
    if (p._distance > min_dist) sp.Sum_dist_over_min += p._distance - min_dist;

    // no pilots landing out
    if (p._flew && (p._distance < task_distance || task_distance == 0)) sp.No_of_pilots_LO++;
    //if (p._flew && p._finished_ss == null) sp.No_of_pilots_LO++;

    // no pilots reaching ES
    if (p._flew && p._finished_ss != null) sp.No_of_pilots_reaching_ES++;

    if (p._flew && p._distance >= task_distance && task_distance > 0) sp.No_of_pilots_reaching_goal++;  // not used?

    // best distance
    if (p._distance > sp.Best_dist)
    {
      // ERDAL20090907 in response to http://fs.fai.org/ticket/198
      if (t.DistanceExact > 0 && p._distance > t.DistanceExact) sp.Best_dist = t.DistanceExact;
      else sp.Best_dist = p._distance;
      //if (t.Distance > 0 && p._distance > t.Distance) sp.Best_dist = t.Distance;
      //else sp.Best_dist = p._distance;
    }

    // those reaching end of speedsection ...
    double time = p.Result.Ss_Time_Dec_Hours;
    if (time > 0)
    {
      // http://fs.fai.org/ticket/35
      if (sp.First_start_time == null || p.Result.Started_ss.Utc_time < sp.First_start_time.Utc_time)
        sp.First_start_time = p.Result.Started_ss;

      // http://fs.fai.org/ticket/16
      // store time (will sort ascending to use later for time validity calculations)
      // (not using Best_time anymore)
      times[i++] = time;

      // best time (given time)
      if (time < sp.Best_time || sp.Best_time == 0) sp.Best_time = time;

      // first finish time
      Time finishedTaskSs = p.Result.Finished_ss;
      if (sp.First_finish_time == null || finishedTaskSs.Utc_time < sp.First_finish_time.Utc_time)
        sp.First_finish_time = finishedTaskSs;
    }
  }

  // http://fs.fai.org/ticket/16
  // time_validity_based_on_pilot_with_speed_rank
  // default is time of first pilot at ES
  // time_validity_based_on_pilot_with_speed_rank = 1 if not specified in the scoring formula params.
  Array.Sort<double>(times);
  i = 0;
  while (i < times.Length && times[i] == 0) i++;
  i += sfg.Time_validity_based_on_pilot_no - 1;
  double time_validity_time = 0; // if no one at ES time used is 0
  if (i < times.Length) time_validity_time = times[i]; // pilot no x reached ES so we use that time
  else if (times.Length > 0) time_validity_time = times[times.Length - 1]; // pilot no x did not reach ES so we use the last one to reach ES.

  double time_validity = CalcTimeValidity(time_validity_time, sfg.Nom_time, sp.Best_dist, sfg.Nom_dist);
  double launch_validity = CalcLaunchValidity(sp.No_of_pilots_flying, sp.No_of_pilots_present);
  double distance_validity = CalcDistanceValidity(sp.Sum_dist_over_min, sp.No_of_pilots_flying, sfg.Nom_goal, sfg.Nom_dist, sfg.Min_dist, sp.Best_dist);
  double day_quality = CalcDayQuality(time_validity, launch_validity, distance_validity);

  sp.Time_validity = time_validity;
  sp.Launch_validity = launch_validity;
  sp.Distance_validity = distance_validity;
  sp.Day_quality = day_quality;

  //ERDAL20090517
  if (sfg.Day_quality > 0)
  {
    //sp.Time_validity = 0;
    //sp.Launch_validity = 0;
    //sp.Distance_validity = 0;
    sp.Day_quality = sfg.Day_quality;
  }

  // Distance points (depends, among other things, on ratio of pilots at ES and flying)
  if (sfg.Use_distance_points)
  {
    sp.K = 0; // if not using time points: K=0 giving Distance_weight=0.9
    if (sp.Best_time > 0 && sfg.Use_time_points)
    {
      sp.Max_time_to_get_time_points = sp.Best_time + Math.Sqrt(sp.Best_time);
      foreach (Participant p in ps)
      {
        double time = p.Result.Ss_Time_Dec_Hours;
        if (time > 0 && time < sp.Max_time_to_get_time_points)
          sp.No_of_pilots_with_time_points++;
      }
      sp.K = sp.No_of_pilots_with_time_points * 1.0 / sp.No_of_pilots_flying;
    }
    sp.Distance_weight = 0.9 - 1.665 * sp.K + 1.713 * Math.Pow(sp.K, 2) - 0.587 * Math.Pow(sp.K, 3);
  }

  double dummy_arr_weight = 0;
  // Arrival time points (OzGAP2005)
  if (sfg.Use_arrival_time_points)
  {
    // a quart of what's left after distance got it's share
    dummy_arr_weight = (1.0 - sp.Distance_weight) / 4.0;
    if (sfg.If_use_arrival_time_points_div_by != 0) // ERDAL20090529 adapted to PWC2009. Note probably an error by Ulric ... probably missed the diff. btw. modOzGap2005.bas and modGAP.bas
      dummy_arr_weight = dummy_arr_weight / sfg.If_use_arrival_time_points_div_by;
  }
  // or Arrival position points (Normal <= GAP2002)
  // ERDAL20090513 http://fs.fai.org/ticket/179
  else // if (sfg.Use_arrival_position_points)
  {
    // an eight of what's left after distance got it's share
    dummy_arr_weight = (1.0 - sp.Distance_weight) / 8.0;
  }

  // Arrival (time or pos) and Departure points only if someone reached ES
  if (sp.No_of_pilots_reaching_ES > 0)
  {
    if (sfg.Use_arrival_time_points || sfg.Use_arrival_position_points)
    {
      sp.Arrival_weight = dummy_arr_weight;
    }

    // Departure points based on time enroute
    if (sfg.Use_departure_points)
    {
      sp.Departure_weight = dummy_arr_weight * 1.4;
    }
    // or Leading Out points based on area of time/distance graph
    else if (sfg.Use_leading_points)
    {
      sp.Leading_weight = dummy_arr_weight * 1.4;
      // ERDAL20110417 PWC2010... http://fs.fai.org/ticket/219  if not using arrival points put them into leading points instead of time points
      if (!sfg.Use_arrival_time_points && !sfg.Use_arrival_position_points) sp.Leading_weight += dummy_arr_weight;
    }

    // Time points
    if (sfg.Use_time_points)
    {
      sp.Time_weight
        = (1 - sp.Distance_weight)
        - sp.Arrival_weight
        - sp.Departure_weight
        - sp.Leading_weight;
    }
  }
  else // no one reaching end of speedsection,
  // hence no allocation of time, arrival, nor departure points (based on time enroute)
  // Only distance points and leading points make sense here.
  {
    // Leading points
    if (sfg.Use_leading_points)
    {
      sp.Leading_weight = dummy_arr_weight * 1.4; // http://fs.fai.org/ticket/88
    }
  }

  // now sum of all weights should be 1.
  // if it is less than 1 we add to distance weight
  // ERDAL20090701 restored this again but set default value to true so it is not in user interface (yet) but can be set directly in fsdb
  // ERDAL20090518 http://fs.fai.org/ticket/180 TODO: remove option all together (unless reaction is that it is needed)
  if (sfg.Use_1000_points_for_max_day_quality)
    sp.Distance_weight = 1 - sp.Time_weight - sp.Leading_weight - sp.Departure_weight - sp.Arrival_weight;

  // adjust for day quality
  sp.Available_points_distance = 1000 * sp.Day_quality * sp.Distance_weight;
  sp.Available_points_arrival = 1000 * sp.Day_quality * sp.Arrival_weight;
  sp.Available_points_departure = 1000 * sp.Day_quality * sp.Departure_weight;
  sp.Available_points_leading = 1000 * sp.Day_quality * sp.Leading_weight;
  sp.Available_points_time = 1000 * sp.Day_quality * sp.Time_weight;

  // smallest_leading_coefficient
  if (sfg.Use_departure_points
    || sfg.Use_leading_points)
  {
    // smallest leading coefficient
    sp.Smallest_leading_coefficient = 0;
    double smallest_leading_coefficient = double.MaxValue;
    if (sfg.Use_departure_points && sp.No_of_pilots_reaching_ES > 0)
    {
      foreach (Participant p in ps)
      {
        double lc = Gap.LcUsingDeparturePoints(p, t, sp);
        if (lc > 0 && lc < smallest_leading_coefficient) smallest_leading_coefficient = lc;
      }
    }
    else if (sfg.Use_leading_points)
    {
      foreach (Participant p in ps)
      {
        if (p._lc > 0 && (p._lc < smallest_leading_coefficient || smallest_leading_coefficient == 0))
        {
          smallest_leading_coefficient = p._lc;
        }
      }
    }
    if (smallest_leading_coefficient != double.MaxValue)
      sp.Smallest_leading_coefficient = smallest_leading_coefficient;
  } // -- smallest_leading_coefficient

  return sp;
}



private static DistanseScoreData100m[] CreateDistanceScoreData100mArray(Task t, FsTaskScoreParams sp, ScoreFormulaGAP sfg, Participant[] ps)
{
  // Save info for every 100 meters of the task

  DistanseScoreData100m[] da = null;

  double best_dist = sp.Best_dist;
  if (best_dist < sfg.Min_dist) best_dist = sfg.Min_dist;
  if (best_dist == 0) return da;
  int best_dist_kmx10 = (int)(best_dist * 10);
  int best_dist_kmx10r = (best_dist_kmx10 + 10) / 10 * 10; // eg if kmx10 = 517, best_dist_kmx10r = 520
  da = new DistanseScoreData100m[best_dist_kmx10r + 1];

  // For each 100m of task count no of landed pilots
  foreach (Participant p in ps)
  {
    // ERDAL20090907 in response to http://fs.fai.org/ticket/198
    //double dist = p._distance;
    //if (dist < sfg.Min_dist) dist = sfg.Min_dist;
    //else if (t.Distance > 0 && dist > t.Distance) dist = t.Distance;
    //// if landed out (ERDAL20080303-1940: not counting those in goal!!)  http://fs.fai.org/ticket/60
    //if (p._flew && dist < t.Distance) da[(int)(dist * 10)]._landed++;
    //// TODO: check ... for open dist. tasks it is vital that t.Distance is set to distance of the best pilot + 1 meter.!!!

    double dist = p._distance;
    if (dist < sfg.Min_dist) dist = sfg.Min_dist;
    else if (t.DistanceExact > 0 && dist > t.DistanceExact) dist = t.DistanceExact;
    if (p._flew && dist < t.DistanceExact) da[(int)(dist * 10)]._landed++;
  }

  // For each kilometer of the task find no of pilots having landed in the past kilometer
  int j = 0;
  for (int i = 0; i <= best_dist_kmx10r; i++)
  {
    // add up pilots having landed for each 100 meters
    j += da[i]._landed;
    // if a whole km is reached
    if (Math.IEEERemainder(i, 10) == 0)
    {
      // pilots having landed in the past kilometer
      da[i]._landed_full_km = j;
      // start over for the next kilometer
      j = 0;
    }
  }

  // Compute difficulty for each 100 meters of the task:
  // find no of landed pilots up ahead ...
  // 100 pilots landing out in 100km -> we look at the next 3 km.
  // 10 pilots landing out in 100km -> we look at the next 30 km.
  int look_ahead_dist_kmx10 = 30;  // look at least 3km ahead
  if (sp.No_of_pilots_LO > 0 && best_dist > sp.No_of_pilots_LO)
    look_ahead_dist_kmx10
      = (int)Math.Round(look_ahead_dist_kmx10 * best_dist / sp.No_of_pilots_LO,
        MidpointRounding.AwayFromZero);
  for (int i = 0; i <= best_dist_kmx10; i++)
    for (j = i; j < i + look_ahead_dist_kmx10 && j <= best_dist_kmx10; j++)
      da[i]._difficulty += da[j]._landed;

  // sum of all difficulty
  double sum_difficulty = 0;
  for (int i = 0; i <= best_dist_kmx10; i++)
    sum_difficulty += da[i]._difficulty;

  // Difficulty relative to sum of all difficulty
  if (sum_difficulty > 0)
  {
    for (int i = 0; i <= best_dist_kmx10; i++)
    {
      da[i]._rel_diff = da[i]._difficulty / (2.0 * sum_difficulty);
    }
  }

  // Compute distance score %
  // accumulated relative difficulty per 100 meters.
  double sum_rel_difficulty = 0;
  for (int i = 0; i <= best_dist_kmx10; i++)
  {
    sum_rel_difficulty += da[i]._rel_diff;
    da[i]._score_percent = sum_rel_difficulty;
  }

  // ERDAL20090518 making sure we 0.5 (sum of _rel_diff can end up at 0.49999999999999978 or similar, should not make visible diff but...)
  for (int i = best_dist_kmx10; i <= best_dist_kmx10r; i++)
  {
    da[i]._score_percent = 0.5;
  }

  // set score to all distances below or equal minimum distance
  int min_dist_kmx10 = (int)(sfg.Min_dist * 10);
  if (min_dist_kmx10 < da.Length)
  {
    for (int i = 0; i <= min_dist_kmx10; i++)
    {
      da[i]._score_percent = da[min_dist_kmx10]._score_percent;
    }
  }
  return da;
}