static internal IEnumerable <Autodesk.Revit.DB.Curve> ToHost(this Rhino.Geometry.Curve curve, double curveTolerance = double.PositiveInfinity)
{
curveTolerance = Math.Min(Revit.ShortCurveTolerance, Math.Abs(curveTolerance));
Debug.Assert(!curve.IsShort(curveTolerance));
var simplifiedCurve = curve.Simplify(CurveSimplifyOptions.SplitAtFullyMultipleKnots, curveTolerance, Revit.AngleTolerance);
if (simplifiedCurve != null)
{
curve = simplifiedCurve;
}
switch (curve)
{
case Rhino.Geometry.LineCurve line:
yield return(Autodesk.Revit.DB.Line.CreateBound(line.PointAtStart.ToHost(), line.PointAtEnd.ToHost()));
break;
case Rhino.Geometry.PolylineCurve polyline:
for (int p = 1; p < polyline.PointCount; ++p)
{
yield return(Autodesk.Revit.DB.Line.CreateBound(polyline.Point(p - 1).ToHost(), polyline.Point(p).ToHost()));
}
break;
case Rhino.Geometry.ArcCurve arc:
if (arc.IsClosed)
{
yield return(Autodesk.Revit.DB.Arc.Create(arc.Arc.Plane.ToHost(), arc.Arc.Radius, 0.0, (2.0 * Math.PI) - 2e-8));
}
else
{
yield return(Autodesk.Revit.DB.Arc.Create(arc.Arc.StartPoint.ToHost(), arc.Arc.EndPoint.ToHost(), arc.Arc.MidPoint.ToHost()));
}
break;
case Rhino.Geometry.PolyCurve polyCurve:
polyCurve.RemoveNesting();
polyCurve.RemoveShortSegments(curveTolerance);
for (int s = 0; s < polyCurve.SegmentCount; ++s)
{
foreach (var segment in polyCurve.SegmentCurve(s).ToHost())
{
yield return(segment);
}
}
break;
case Rhino.Geometry.NurbsCurve nurbsCurve:
if (nurbsCurve.IsLinear(Revit.VertexTolerance))
{
yield return(Autodesk.Revit.DB.Line.CreateBound(nurbsCurve.PointAtStart.ToHost(), nurbsCurve.PointAtEnd.ToHost()));
yield break;
}
if (nurbsCurve.TryGetPolyline(out var polylineSegment))
{
polylineSegment.ReduceSegments(curveTolerance);
foreach (var segment in polylineSegment.GetSegments())
{
yield return(Autodesk.Revit.DB.Line.CreateBound(segment.From.ToHost(), segment.To.ToHost()));
}
yield break;
}
if (nurbsCurve.TryGetArc(out var arcSegment, Revit.VertexTolerance))
{
yield return(Autodesk.Revit.DB.Arc.Create(arcSegment.StartPoint.ToHost(), arcSegment.EndPoint.ToHost(), arcSegment.MidPoint.ToHost()));
yield break;
}
if (nurbsCurve.IsClosed)
{
if (nurbsCurve.TryGetCircle(out var circle, Revit.VertexTolerance))
{
yield return(Autodesk.Revit.DB.Arc.Create(circle.Plane.ToHost(), circle.Radius, 0.0, 2.0 * (2.0 * Math.PI) - 2e-8));
yield break;
}
if (nurbsCurve.TryGetEllipse(out var ellipse, Revit.VertexTolerance))
{
yield return(Autodesk.Revit.DB.Ellipse.CreateCurve(ellipse.Plane.Origin.ToHost(), ellipse.Radius1, ellipse.Radius2, ellipse.Plane.XAxis.ToHost(), ellipse.Plane.YAxis.ToHost(), 0.0, (2.0 * Math.PI) - 2e-8));
yield break;
}
foreach (var segment in nurbsCurve.Split(nurbsCurve.Domain.Mid))
{
foreach (var c in segment.ToHost())
{
yield return(c);
}
}
}
else
{
nurbsCurve.Knots.RemoveMultipleKnots(1, nurbsCurve.Degree, Revit.VertexTolerance);
var degree = nurbsCurve.Degree;
var knots = nurbsCurve.Knots.ToHost();
var controlPoints = nurbsCurve.Points.ToHost();
Debug.Assert(degree >= 1);
Debug.Assert(controlPoints.Count > nurbsCurve.Degree);
Debug.Assert(knots.Count == nurbsCurve.Degree + controlPoints.Count + 1);
Autodesk.Revit.DB.Curve nurbSpline = null;
try
{
if (nurbsCurve.IsRational)
{
var weights = new List <double>(controlPoints.Count);
foreach (var p in nurbsCurve.Points)
{
Debug.Assert(p.Weight > 0.0);
weights.Add(p.Weight);
}
Debug.Assert(weights.Count == controlPoints.Count);
nurbSpline = NurbSpline.CreateCurve(nurbsCurve.Degree, knots, controlPoints, weights);
}
else
{
nurbSpline = NurbSpline.CreateCurve(nurbsCurve.Degree, knots, controlPoints);
}
}
catch (Autodesk.Revit.Exceptions.ApplicationException e)
{
Debug.Fail(e.Source, e.Message);
}
yield return(nurbSpline);
}
break;
default:
foreach (var c in curve.ToNurbsCurve().ToHost())
{
yield return(c);
}
break;
}
}