public static IEnumerable <Rhino.Geometry.Curve> Offset(IEnumerable <Rhino.Geometry.Curve> curves, double distance, JoinType joinType, EndType endType, double miter, double arcTolerance, Plane?plane)
{
var curveList = curves as IList <Rhino.Geometry.Curve> ?? curves.ToList();
plane = GetPlane(curveList, plane);
var polylines2D = curveList.Select(o => Polyline2D.FromCurve(o, plane.Value))
.Where(o => o != null)
.ToList();
double unit;
Point2d center;
CalculateUnit(polylines2D, miter * distance, out unit, out center);
var polylinesInt = polylines2D.Select(o => PolylineInt.FromPolyline2D(o, center, unit))
.ToList();
var clipper = new ClipperOffset(miter, arcTolerance / unit);
foreach (var polygon in polylinesInt)
{
clipper.AddPath(polygon, joinType, polygon.Closed ? EndType.etClosedPolygon : endType);
}
var solution = new List <List <IntPoint> >();
clipper.Execute(ref solution, distance / unit);
return(solution.Select(o => o.ToCurve(plane.Value, center, unit)));
}