void DrawQuadrangle(CGPoint p0, CGPoint p1, CGPoint p2, CGPoint p3, CALayer layer, RTRResultStabilityStatus progress)
{
var area = new CAShapeLayer();
var recognizedAreaPath = new UIBezierPath();
recognizedAreaPath.MoveTo(p0);
recognizedAreaPath.AddLineTo(p1);
recognizedAreaPath.AddLineTo(p2);
recognizedAreaPath.AddLineTo(p3);
recognizedAreaPath.ClosePath();
area.Path = recognizedAreaPath.CGPath;
area.StrokeColor = ProgressColor(progress).CGColor;
area.FillColor = UIColor.Clear.CGColor;
layer.AddSublayer(area);
}