public static IEnumerable <DB.Curve> ToCurveMany(this NurbsCurve value, double factor)
{
if (value.Degree == 1)
{
var curvePoints = value.Points;
int pointCount = curvePoints.Count;
if (pointCount > 1)
{
DB.XYZ end, start = curvePoints[0].Location.ToXYZ(factor);
for (int p = 1; p < pointCount; start = end, ++p)
{
end = curvePoints[p].Location.ToXYZ(factor);
yield return(DB.Line.CreateBound(start, end));
}
}
}
else if (value.Degree == 2)
{
for (int s = 0; s < value.SpanCount; ++s)
{
var segment = value.Trim(value.SpanDomain(s)) as NurbsCurve;
yield return(NurbsSplineEncoder.ToNurbsSpline(segment, factor));
}
}
else if (value.IsClosed(Revit.ShortCurveTolerance * 1.01))
{
var segments = value.DuplicateSegments();
if (segments.Length == 1)
{
if
(
value.NormalizedLengthParameter(0.5, out var mid) &&
value.Split(mid) is Curve[] half
)
{
yield return(NurbsSplineEncoder.ToNurbsSpline(half[0] as NurbsCurve, factor));
yield return(NurbsSplineEncoder.ToNurbsSpline(half[1] as NurbsCurve, factor));
}
else
{
throw new ConversionException("Failed to Split closed Edge");
}
}
else
{
foreach (var segment in segments)
{
yield return(NurbsSplineEncoder.ToNurbsSpline(segment as NurbsCurve, factor));
}
}
}
else
{
yield return(NurbsSplineEncoder.ToNurbsSpline(value, factor));
}
}
public static DB.Curve ToCurve(this NurbsCurve value, double factor)
{
if (value.TryGetEllipse(out var ellipse, out var interval, Revit.VertexTolerance * factor))
{
return(ellipse.ToCurve(interval, factor));
}
var gap = Revit.ShortCurveTolerance * 1.01;
if (value.IsClosed(gap * factor))
{
var length = value.GetLength();
if
(
length > gap &&
value.LengthParameter((gap / 2.0), out var t0) &&
value.LengthParameter(length - (gap / 2.0), out var t1)
)
{
var segments = value.Split(new double[] { t0, t1 });
value = segments[0] as NurbsCurve ?? value;
}
else
{
throw new ConversionException($"Failed to Split closed NurbsCurve, Length = {length}");
}
}
if (value.Degree < 3 && value.SpanCount > 1)
{
value = value.DuplicateCurve() as NurbsCurve;
value.IncreaseDegree(3);
}
return(NurbsSplineEncoder.ToNurbsSpline(value, factor));
}