public static VCircleEvent CircleCheckDataNode(VDataNode n, double ys)
{
var l = LeftDataNode(n);
var r = RightDataNode(n);
if (l == null || r == null || l.DataPoint.Equals(r.DataPoint) || l.DataPoint.Equals(n.DataPoint) || n.DataPoint.Equals(r.DataPoint))
{
return(null);
}
if (Fortune.Ccw(l.DataPoint[0], l.DataPoint[1], n.DataPoint[0], n.DataPoint[1], r.DataPoint[0], r.DataPoint[1], false) <= 0)
{
return(null);
}
var center = Fortune.CircumCircleCenter(l.DataPoint, n.DataPoint, r.DataPoint);
var vc = new VCircleEvent {
NodeN = n, NodeL = l, NodeR = r, CenterX = center[0], CenterY = center[1], Valid = true
};
if (vc.Y > ys || Math.Abs(vc.Y - ys) < 1e-10)
{
return(vc);
}
return(null);
}