hull_for.rb

def hull_for(min_distance, max_distance)
  client = TrackPoint.mongo_client
  points = []
  client.command({geoNear: 'track_points', near: [20.459423, 50.799929] , spherical: true, num: 15000, minDistance: min_distance, maxDistance: max_distance, distanceMultiplier: EARTH_RADIUS}).each { |document|
    document['results'].each do |point|
      points << point['obj']['location']
    end
  }
  result = []
  if points.empty?
    Rails.logger.warn 'no hull for no points - returning empty hull[]'
  else
    hull_polygon = HullCalc.convex_hull points
    Rails.logger.info "calculated hull polygon with #{hull_polygon.size} points from a total of #{points.size} points"
    result = hull_polygon
  end
  result
end