int QuickHullPartition(List <CGPoint> points, int low, int high)
{
int fp = CGUtils.LeftFarmostPointFromLine(points[low], points[high], points);
if (fp == -1)
{
return(-1);
}
CGPoint from = points[low];
low++;
high--;
points.Swap(low, fp);
CGPoint pivot = points[low];
while (low < high)
{
while (low < high && !CGUtils.ToLeft(from, pivot, points[high]))
{
high--;
}
points[low] = points[high];
while (low < high && CGUtils.ToLeft(from, pivot, points[high]))
{
low++;
}
points[high] = points[low];
}
points[low] = pivot;
return(low);
}