private PlaceOfInterest FindPivot(List <PlaceOfInterest> points)
{
PlaceOfInterest lowestLeftPoint = points[0];
for (int i = 1; i < points.Count; i++)
{
if (points[i].LongitudeX == lowestLeftPoint.LongitudeX)
{
if (points[i].LatitudeY < lowestLeftPoint.LatitudeY)
{
lowestLeftPoint = points[i];
}
}
else if (points[i].LongitudeX < lowestLeftPoint.LongitudeX)
{
lowestLeftPoint = points[i];
}
}
//return _points.First(c => c.Y == _points.Max(x => x.Y));
return(lowestLeftPoint);
}
private List <PlaceOfInterest> ConvexHull(PlaceOfInterest pivot, List <PlaceOfInterest> points)
{
List <PlaceOfInterest> Hull = new List <PlaceOfInterest>();
points.Remove(pivot);
var s = new RadioSort(pivot);
points.Sort(s);
Hull.Add(pivot); // first point
Hull.Add(points[0]); // second point
points.RemoveAt(0);
Hull.Add(points[0]); // third point
points.RemoveAt(0);
while (points.Count != 0)
{
long value = s.SignedArea(Hull[Hull.Count - 2], Hull[Hull.Count - 1], points[0]);
if (value < 0)
{
Hull.Add(points[0]);
points.RemoveAt(0);
}
else if (value == 0)
{
Hull.RemoveAt(Hull.Count - 1);
Hull.Add(points[0]);
points.RemoveAt(0);
}
else
{
Hull.RemoveAt(Hull.Count - 1);
//Hull.Add(points[0]);
// points.RemoveAt(0);
}
}
return(Hull);
}
