/// <summary>
/// Reverses the order of the knot vector.
/// </summary>
/// <param name="knots">Knot vectors to be reversed.</param>
/// <returns>Reversed knot vectors.</returns>
public static KnotVector Reverse(KnotVector knots)
{
KnotVector reversedKnots = new KnotVector {
knots[0]
};
for (int i = 1; i < knots.Count; i++)
{
reversedKnots.Add(reversedKnots[i - 1] + (knots[knots.Count - i] - knots[knots.Count - i - 1]));
}
return(reversedKnots);
}
/// <summary>
/// Normalizes knot vectors of all curves to the same domain.
/// </summary>
internal static IList <NurbsBase> NormalizedKnots(IList <NurbsBase> curves)
{
// Unify knots, normalized them.
curves = curves
.Select(curve => curve.Knots.GetDomain(curve.Degree).Length > 1
? new NurbsCurve(curve.Degree, curve.Knots.Normalize(), curve.ControlPoints)
: curve).ToList();
// Unify curves by knots.
KnotVector combinedKnots = curves.First().Knots.Copy();
foreach (NurbsBase curve in curves.Skip(1))
{
combinedKnots.AddRange(curve.Knots.Where(k => !combinedKnots.Contains(k)).ToList());
}
curves = (from curve in curves
let knotToInsert = combinedKnots.OrderBy(k => k).Where(k => !curve.Knots.Contains(k)).ToKnot()
select KnotVector.Refine(curve, knotToInsert)).ToList();
return(curves);
}