/// <summary>
/// Creates a curve by using the underlying polyline
/// </summary>
/// <returns></returns>
public Curve CreateCurve()
{
Curve curve = new Curve();
Site a = HeadSite; //the corner start
Site b; //the corner origin
Site c; //the corner other end
while (Curve.FindCorner(a, out b, out c))
{
CubicBezierSegment bezierSeg = CreateBezierSegOnSite(b);
if (curve.Segments.Count == 0)
{
if (!ApproximateComparer.Close(a.Point, bezierSeg.Start))
{
Curve.AddLineSegment(curve, a.Point, bezierSeg.Start);
}
}
else if (!ApproximateComparer.Close(curve.End, bezierSeg.Start))
{
Curve.ContinueWithLineSegment(curve, bezierSeg.Start);
}
curve.AddSegment(bezierSeg);
a = b;
}
System.Diagnostics.Debug.Assert(a.Next.Next == null);
if (curve.Segments.Count == 0)
{
if (!ApproximateComparer.Close(a.Point, a.Next.Point))
{
Curve.AddLineSegment(curve, a.Point, a.Next.Point);
}
else
{
double w = 5;
curve.Segments.Add(new CubicBezierSegment(a.Point, a.Point + new Point(w, w), a.Point + new Point(-w, w), b.Point));
}
}
else if (!ApproximateComparer.Close(curve.End, a.Next.Point))
{
Curve.ContinueWithLineSegment(curve, a.Next.Point);
}
return(curve);
}
internal static Polyline CreateConvexHullAsClosedPolyline(IEnumerable <Point> points)
{
var convexHull = new Polyline(CalculateConvexHull(points))
{
Closed = true
};
#if TEST_MSAGL
foreach (var point in points)
{
if (Curve.PointRelativeToCurveLocation(point, convexHull) == PointLocation.Outside)
{
var hullPoint = convexHull[convexHull.ClosestParameter(point)];
// This can be too restrictive if very close points are put into the hull. It is probably
// better to clean up in the caller before doing this, but this assert can also be relaxed.
Debug.Assert(ApproximateComparer.Close(point, hullPoint, ApproximateComparer.IntersectionEpsilon * 20), String.Format("not CloseIntersections: initial point {0}, hull point {1}", point, hullPoint));
}
}
#endif // TEST_MSAGL
return(convexHull);
}
/// <summary>
/// computes orientation of three vectors with a common source
/// (compare polar angles of v1 and v2 with respect to v0)
/// </summary>
/// <returns>
/// -1 if the orientation is v0 v1 v2
/// 1 if the orientation is v0 v2 v1
/// 0 if v1 and v2 are collinear and codirectinal
/// </returns>
static public int GetOrientationOf3Vectors(Point vector0, Point vector1, Point vector2)
{
const double multiplier = 1000; //TODO, need to fix it?
vector0 *= multiplier;
vector1 *= multiplier;
vector2 *= multiplier;
double xp2 = Point.CrossProduct(vector0, vector2);
double dotp2 = vector0 * vector2;
double xp1 = Point.CrossProduct(vector0, vector1);
double dotp1 = vector0 * vector1;
// v1 is collinear with v0
if (ApproximateComparer.Close(xp1, 0.0) && ApproximateComparer.GreaterOrEqual(dotp1, 0.0))
{
if (ApproximateComparer.Close(xp2, 0.0) && ApproximateComparer.GreaterOrEqual(dotp2, 0.0))
{
return(0);
}
return(1);
}
// v2 is collinear with v0
if (ApproximateComparer.Close(xp2, 0.0) && ApproximateComparer.GreaterOrEqual(dotp2, 0.0))
{
return(-1);
}
if (ApproximateComparer.Close(xp1, 0.0) || ApproximateComparer.Close(xp2, 0.0) || xp1 * xp2 > 0.0)
{
// both on same side of v0, compare to each other
return(ApproximateComparer.Compare(Point.CrossProduct(vector2, vector1), 0.0));
}
// vectors "less than" zero degrees are actually large, near 2 pi
return(-ApproximateComparer.Compare(Math.Sign(xp1), 0.0));
}