/// <summary>
/// Calculates the scaling factor of a route as well as x/y offset for correct points positioning
/// </summary>
private static void CalculateFactorAndOffset()
{
GpsPoint firstGpsPoint = new GpsPoint(_params.GpsStartPoint.Lon, _params.GpsStartPoint.Lat, null);
firstGpsPoint = TransposePoint(firstGpsPoint);
GpsPoint lastGpsPoint = new GpsPoint (_params.GpsEndPoint.Lon, _params.GpsEndPoint.Lat, null);
lastGpsPoint = TransposePoint(lastGpsPoint);
_scalingFactorX = Math.Abs(_params.ImgStartPoint.X - _params.ImgEndPoint.X) / Math.Abs(firstGpsPoint.Lon - lastGpsPoint.Lon);
_scalingFactorY = Math.Abs(_params.ImgStartPoint.Y - _params.ImgEndPoint.Y) / Math.Abs(firstGpsPoint.Lat - lastGpsPoint.Lat);
firstGpsPoint = DislocatePointByFactor(firstGpsPoint);
_offsetX = _params.ImgStartPoint.X > firstGpsPoint.Lon ? _params.ImgStartPoint.X - firstGpsPoint.Lon : firstGpsPoint.Lon - _params.ImgStartPoint.X;
_offsetY = _params.ImgStartPoint.Y > firstGpsPoint.Lat ? _params.ImgStartPoint.Y - firstGpsPoint.Lat : firstGpsPoint.Lat - _params.ImgStartPoint.Y;
}
// pomnoži koordinate točke s koeficijentom za ispravnu veličinu rute (scaling)
/// <summary>
/// Corrects the position of the point by a calculated offset
/// </summary>
/// <param name="point">Input point</param>
/// <returns>Correctly positioned point after offset is applied</returns>
private static GpsPoint DislocatePointByFactor(GpsPoint point)
{
point.Lon *= _scalingFactorX;
point.Lat *= _scalingFactorY;
return point;
}
/// <summary>
/// Transposes a GPS point into a coordinate system point
/// </summary>
/// <param name="point">GPS point</param>
/// <returns>Transposed point for coordinate system</returns>
private static GpsPoint TransposePoint(GpsPoint point)
{
double factorX = _maxLng < 0 ? Math.Abs(_maxLng) : _maxLng * -1;
double factorY = _maxLat < 0 ? Math.Abs(_maxLat) : _maxLat * -1;
point.Lon += factorX;
point.Lat = Math.Abs(point.Lat + factorY);
return point;
}
public TransposerParams(ImgPoint imgA, ImgPoint imgB, GpsPoint gpsA, GpsPoint gpsB, int step)
{
_imgStartPoint = imgA;
_imgEndPoint = imgB;
_gpsStartPoint = gpsA;
_gpsEndPoint = gpsB;
_stepLength = step;
}
/// <summary>
/// Optimizes the distance between points so that too dense and too sparse areas of points are evened-out.
/// </summary>
private static void PointDistanceOptimization()
{
GpsPoint lastPushed = new GpsPoint();
GpsPoint current = new GpsPoint();
for(int i = 0; i < GpsPoints.Count; i++)
{
current = TransposePoint(GpsPoints[i]);
current = DislocatePointByFactor(current);
current.Lon = Math.Abs(current.Lon) + _offsetX;
current.Lat = Math.Abs(current.Lat) + _offsetY;
// check if this is the last point of the list to optimize, if yes then add it and break the loop
if (Math.Sqrt(Math.Pow(current.Lon - _params.ImgEndPoint.X, 2) + Math.Pow(current.Lat - _params.ImgEndPoint.Y, 2)) < _params.StepLength / 1000)
{
if (i == GpsPoints.Count - 1)
{
current.Lon = _params.ImgEndPoint.X;
current.Lat = _params.ImgEndPoint.Y;
_imgPoints.Add(new ImgPoint(current.Lon, current.Lat, current.Elev));
break;
}
}
if (i == 0)
{
lastPushed = current;
_imgPoints.Add(new ImgPoint(lastPushed.Lon, lastPushed.Lat, lastPushed.Elev));
}
else
{
double distPx = Math.Sqrt(Math.Pow(current.Lon - lastPushed.Lon, 2) + Math.Pow(current.Lat - lastPushed.Lat, 2)); // distance between the current and the preceeding point
double angle = Math.Acos(Math.Abs(current.Lon - lastPushed.Lon) / distPx); // angle between the current and the preceeding point
double distPxRnded = Math.Round(distPx * 1000);
double offsetX = Math.Cos(angle) * (_params.StepLength / 1000);
double offsetY = Math.Sin(angle) * (_params.StepLength / 1000);
GpsPoint filler = new GpsPoint();
if (distPxRnded >= _params.StepLength && distPxRnded < 2 * _params.StepLength)
{
// acceptable point distance, add the point to the list
lastPushed = current;
_imgPoints.Add(new ImgPoint(lastPushed.Lon, lastPushed.Lat, lastPushed.Elev));
}
else if (distPxRnded >= 2 * _params.StepLength)
{
// add additional points to fill up too scarse area of points
if (lastPushed.Lon == current.Lon) // if the points are on the same vertical line
{
filler.Lon = lastPushed.Lon;
filler.Lat = lastPushed.Lat < current.Lat ? lastPushed.Lat + _params.StepLength / 1000 : lastPushed.Lat - _params.StepLength / 1000;
filler.Elev = lastPushed.Elev;
lastPushed = filler;
_imgPoints.Add(new ImgPoint(lastPushed.Lon, lastPushed.Lat, lastPushed.Elev));
}
else if (lastPushed.Lat == current.Lat) // if the points are on the same horizontal line
{
filler.Lat = lastPushed.Lat;
filler.Lon = lastPushed.Lon < current.Lon ? lastPushed.Lon + _params.StepLength / 1000 : lastPushed.Lon - _params.StepLength / 1000;
filler.Elev = lastPushed.Elev;
lastPushed = filler;
_imgPoints.Add(new ImgPoint(lastPushed.Lon, lastPushed.Lat, lastPushed.Elev));
}
else
{
// calculate and add the "filler" point
do
{
filler.Lon = lastPushed.Lon < current.Lon ? lastPushed.Lon + offsetX : lastPushed.Lon - offsetX;
filler.Lat = lastPushed.Lat < current.Lat ? lastPushed.Lat + offsetY : lastPushed.Lat - offsetY;
filler.Elev = lastPushed.Elev;
lastPushed = filler;
_imgPoints.Add(new ImgPoint(lastPushed.Lon, lastPushed.Lat, lastPushed.Elev));
distPx = Math.Sqrt(Math.Pow(current.Lon - lastPushed.Lon, 2) + Math.Pow(current.Lat - lastPushed.Lat, 2));
distPxRnded = Math.Round(distPx * 1000);
} while (distPxRnded >= 2 * _params.StepLength);
}
}
}
}
}
