public void Insert(TPoint2D point)
{
var count = Points.Size;
//always insert first two points
if (count != 1)
{
var farRight = point.X > RightMost.X;
var farLeft = point.X < LeftMost.X;
var withinBounds = !farRight && !farLeft;
//don't insert when point lies inside the range of the convex hull but on the wrong side
if (withinBounds)
{
var orientation = Geometry2D.Orient(LeftMost.AsVector(), RightMost.AsVector(), point.AsVector());
var pointLiesAbove = orientation == 1;
if (pointLiesAbove != IsUpper)
{
return;
}
}
TPoint2D startPoint, endPoint;
Points.TryFind(p => UpdatePredicate(point, p, true), out startPoint);
Points.TryFind(p => UpdatePredicate(point, p, false), out endPoint);
//point outside of hull
if (startPoint != null || endPoint != null)
{
if (startPoint != RightMost && endPoint != LeftMost)
{
SearchPredicate <TPoint2D> inRangePredicate = p =>
{
if (startPoint != null && p.X <= startPoint.X)
{
return(1);
}
if (endPoint != null && p.X >= endPoint.X)
{
return(-1);
}
return(0);
};
//delete everything after start up to end
TPoint2D element;
Points.TryFind(inRangePredicate, out element);
while (element != null)
{
Points.Delete(element);
Points.TryFind(inRangePredicate, out element);
}
}
}
//point inside of hull
else
{
return;
}
}
Points.Insert(point, pointWithSameX =>
{
if (IsUpper)
{
return(point.Y > pointWithSameX.Y);
}
return(point.Y < pointWithSameX.Y);
});
}
