Пример #1
0
 /// <summary>
 /// See interface docs.
 /// </summary>
 public void ResetCoordinates()
 {
     lock (this) {
         LatestCoordinateTime = default(DateTime);
         FullCoordinates.Clear();
         ShortCoordinates.Clear();
         FirstCoordinateChanged = 0;
         LastCoordinateChanged  = 0;
     }
 }
Пример #2
0
        /// <summary>
        /// See interface docs.
        /// </summary>
        /// <param name="utcNow"></param>
        /// <param name="shortCoordinateSeconds"></param>
        public void UpdateCoordinates(DateTime utcNow, int shortCoordinateSeconds)
        {
            if (Latitude != null && Longitude != null)
            {
                var nowTick = utcNow.Ticks;

                var lastFullCoordinate       = FullCoordinates.Count == 0 ? null : FullCoordinates[FullCoordinates.Count - 1];
                var secondLastFullCoordinate = FullCoordinates.Count < 2 ? null : FullCoordinates[FullCoordinates.Count - 2];
                if (lastFullCoordinate == null || Latitude != lastFullCoordinate.Latitude || Longitude != lastFullCoordinate.Longitude)
                {
                    PositionTime = utcNow;

                    // Check to see whether the aircraft appears to be moving impossibly fast and, if it is, reset its trail. Do this even if
                    // the gap between this message and the last is below the threshold for adding to the trails.
                    if (lastFullCoordinate != null)
                    {
                        var distance = GreatCircleMaths.Distance(lastFullCoordinate.Latitude, lastFullCoordinate.Longitude, Latitude, Longitude);
                        if (distance > _ResetCoordinatesDistance)
                        {
                            var fastestTime = _ResetCoordinatesTime * (distance / _ResetCoordinatesDistance);
                            if (nowTick - lastFullCoordinate.Tick < fastestTime)
                            {
                                ResetCoordinates();
                            }
                        }
                    }

                    // Only update the trails if more than one second has elapsed since the last position update
                    long lastUpdateTick = lastFullCoordinate == null ? 0 : lastFullCoordinate.Tick;
                    if (nowTick - lastUpdateTick >= TicksPerSecond)
                    {
                        var coordinate = new Coordinate(DataVersion, nowTick, (float)Latitude, (float)Longitude, Track);

                        if (FullCoordinates.Count > 1 &&
                            (int)(lastFullCoordinate.Heading.GetValueOrDefault() + 0.5f) == (int)(Track.GetValueOrDefault() + 0.5f) &&
                            (int)(secondLastFullCoordinate.Heading.GetValueOrDefault() + 0.5f) == (int)(Track.GetValueOrDefault() + 0.5f))
                        {
                            FullCoordinates[FullCoordinates.Count - 1] = coordinate;
                        }
                        else
                        {
                            FullCoordinates.Add(coordinate);
                        }

                        long earliestAllowable   = nowTick - (TicksPerSecond * shortCoordinateSeconds);
                        var  firstAllowableIndex = ShortCoordinates.FindIndex(c => c.Tick >= earliestAllowable);
                        if (firstAllowableIndex == -1)
                        {
                            ShortCoordinates.Clear();
                        }
                        else if (firstAllowableIndex > 0)
                        {
                            ShortCoordinates.RemoveRange(0, firstAllowableIndex);
                        }
                        ShortCoordinates.Add(coordinate);

                        if (FirstCoordinateChanged == 0)
                        {
                            FirstCoordinateChanged = DataVersion;
                        }
                        LastCoordinateChanged = DataVersion;
                        LatestCoordinateTime  = utcNow;
                    }
                }
            }
        }