/// <summary>
/// Constructs a nurbs curve representation of this polyline.
/// </summary>
/// <returns>A Nurbs curve shaped like this polyline.</returns>
private void ToNurbs()
{
double lengthSum = 0;
List <double> weights = new List <double>();
KnotVector knots = new KnotVector {
0, 0
};
List <Point4> ctrlPts = new List <Point4>();
for (int i = 0; i < ControlPointLocations.Count - 1; i++)
{
lengthSum += Segments[i].Length;
knots.Add(lengthSum);
weights.Add(1.0);
ctrlPts.Add(new Point4(ControlPointLocations[i], 1.0));
}
knots.Add(lengthSum);
weights.Add(1.0);
ctrlPts.Add(new Point4(ControlPointLocations.Last(), 1.0));
Weights = weights;
Knots = knots.Normalize();
Degree = 1;
ControlPoints = ctrlPts;
}
public void It_Throws_An_Exception_If_Input_Knot_Vector_Is_Empty()
{
// Assert
KnotVector knots = new KnotVector();
// Act
Func <KnotVector> func = () => knots.Normalize();
// Arrange
func.Should().Throw <Exception>().WithMessage("Input knot vector cannot be empty");
}
public void It_Returns_A_Normalized_Knot_Vector()
{
// Arrange
KnotVector knots = new KnotVector {
-5, -5, -3, -2, 2, 3, 5, 5
};
KnotVector knotsExpected = new KnotVector {
0.0, 0.0, 0.2, 0.3, 0.7, 0.8, 1.0, 1.0
};
// Act
KnotVector normalizedKnots = knots.Normalize();
// Assert
normalizedKnots.Should().BeEquivalentTo(knotsExpected);
}
/// <summary>
/// Internal constructor used to validate the NURBS surface.
/// </summary>
/// <param name="degreeU">The degree in the U direction.</param>
/// <param name="degreeV">The degree in the V direction.</param>
/// <param name="knotsU">The knotVector in the U direction.</param>
/// <param name="knotsV">The knotVector in the V direction.</param>
/// <param name="controlPts">Two dimensional array of points.</param>
internal NurbsSurface(int degreeU, int degreeV, KnotVector knotsU, KnotVector knotsV, List <List <Point4> > controlPts)
{
if (controlPts == null)
{
throw new ArgumentNullException("Control points array connot be null!");
}
if (degreeU < 1)
{
throw new ArgumentException("DegreeU must be greater than 1!");
}
if (degreeV < 1)
{
throw new ArgumentException("DegreeV must be greater than 1!");
}
if (knotsU == null)
{
throw new ArgumentNullException("KnotU cannot be null!");
}
if (knotsV == null)
{
throw new ArgumentNullException("KnotV cannot be null!");
}
if (knotsU.Count != controlPts.Count() + degreeU + 1)
{
throw new ArgumentException("Points count + degreeU + 1 must equal knotsU count!");
}
if (knotsV.Count != controlPts.First().Count() + degreeV + 1)
{
throw new ArgumentException("Points count + degreeV + 1 must equal knotsV count!");
}
if (!knotsU.IsValid(degreeU, controlPts.Count()))
{
throw new ArgumentException("Invalid knotsU!");
}
if (!knotsV.IsValid(degreeV, controlPts.First().Count()))
{
throw new ArgumentException("Invalid knotsV!");
}
DegreeU = degreeU;
DegreeV = degreeV;
KnotsU = (Math.Abs(knotsU.GetDomain(degreeU).Length - 1.0) > GSharkMath.Epsilon) ? knotsU.Normalize() : knotsU;
KnotsV = (Math.Abs(knotsV.GetDomain(degreeV).Length - 1.0) > GSharkMath.Epsilon) ? knotsV.Normalize() : knotsV;
Weights = Point4.GetWeights2d(controlPts);
ControlPointLocations = Point4.PointDehomogenizer2d(controlPts);
ControlPoints = controlPts;
DomainU = new Interval(KnotsU.First(), KnotsU.Last());
DomainV = new Interval(KnotsV.First(), KnotsV.Last());
}