/// <summary>
/// Decompose a curve into a collection of bezier curves.<br/>
/// </summary>
/// <param name="curve">The curve object.</param>
/// <param name="normalize">Set as per default false, true normalize the knots between 0 to 1.</param>
/// <returns>Collection of curve objects, defined by degree, knots, and control points.</returns>
internal static List <NurbsBase> DecomposeIntoBeziers(NurbsBase curve, bool normalize = false)
{
int degree = curve.Degree;
List <Point4> controlPoints = curve.ControlPoints;
KnotVector knots = curve.Knots;
// Find all of the unique knot values and their multiplicity.
// For each, increase their multiplicity to degree + 1.
Dictionary <double, int> knotMultiplicities = knots.Multiplicities();
int reqMultiplicity = degree + 1;
// Insert the knots.
foreach (KeyValuePair <double, int> kvp in knotMultiplicities)
{
if (kvp.Value >= reqMultiplicity)
{
continue;
}
List <double> knotsToInsert = CollectionHelpers.RepeatData(kvp.Key, reqMultiplicity - kvp.Value);
NurbsBase curveTemp = new NurbsCurve(degree, knots, controlPoints);
NurbsBase curveResult = KnotRefine(curveTemp, knotsToInsert);
knots = curveResult.Knots;
controlPoints = curveResult.ControlPoints;
}
int crvKnotLength = reqMultiplicity * 2;
List <NurbsBase> curves = new List <NurbsBase>();
int i = 0;
while (i < controlPoints.Count)
{
KnotVector knotsRange = (normalize)
? knots.GetRange(i, crvKnotLength).ToKnot().Normalize()
: knots.GetRange(i, crvKnotLength).ToKnot();
List <Point4> ptsRange = controlPoints.GetRange(i, reqMultiplicity);
NurbsBase tempCrv = new NurbsCurve(degree, knotsRange, ptsRange);
curves.Add(tempCrv);
i += reqMultiplicity;
}
return(curves);
}
public void Multiplicities_Returns_A_Dictionary_Of_Knot_Values_And_Multiplicity()
{
// Arrange
double[] knotsValue = { 0, 1, 2, 3, 3.3, 4 };
int[] multiplicityResult = { 4, 2, 3, 1, 1, 3 };
int count = 0;
KnotVector knots = new KnotVector {
0, 0, 0, 0, 1, 1, 2, 2, 2, 3, 3.3, 4, 4, 4
};
// Act
Dictionary <double, int> multiplicities = knots.Multiplicities();
// Assert
multiplicities.Keys.Count.Should().Be(knotsValue.Length);
foreach ((double key, int value) in multiplicities)
{
key.Should().Be(knotsValue[count]);
value.Should().Be(multiplicityResult[count]);
count += 1;
}
}
