public virtual List <MyPoint> getP(double u1, double v1)
{
double step = 0.05;
MyPoint p1 = new MyPoint();
MyPoint p2 = new MyPoint();
MyPoint p3 = new MyPoint();
p1.SetCoordinates(this.ComputePointForParameter(u1, v1));
p2.SetCoordinates(this.ComputePointForParameter(u1, v1 + step));
p3.SetCoordinates(MyMath.Substract(p2, p1));
p3.Normalized();
//points.Clear();
//_knots.Clear();
double delta = 0.001f;
//_knots2.Clear();
int l = this.isCylinder ? 3 : 0;
double step1, step2;
int m = DeBoorControlPoints.GetLength(0) + Degree + 1 + l;
//for (int i = 0; i < m; i++)
// _knots.Add((double)i / (double)(m - 1));
//m = DeBoorControlPoints.GetLength(1) + Degree + 1;
//for (int i = 0; i < m; i++)
// _knots2.Add((double)i / (double)(m - 1));
step1 = (_knots2[DeBoorControlPoints.GetLength(1)] - _knots2[Degree]) / (double)(samplesNumber - 1);
step2 = (_knots[DeBoorControlPoints.GetLength(0) + l] - _knots[Degree]) / (double)(samplesNumber - 1);
double u, v;
List <MyPoint> qPoints = new List <MyPoint>();
v = _knots2[Degree]; //N
double x = 0, y = 0, z = 0, a = 0, b = 0, c = 0;
while (v - delta <= _knots2[DeBoorControlPoints.GetLength(1)])
{
for (int i = 0; i < mSize + l; i++)
{
x = y = z = 0;
for (int j = 0; j < nSize; j++)
{
x += (DeBoorControlPoints[i % mSize, j].x * Nik2(v, j, Degree));
y += (DeBoorControlPoints[i % mSize, j].y * Nik2(v, j, Degree));
z += (DeBoorControlPoints[i % mSize, j].z * Nik2(v, j, Degree));
}
qPoints.Add(new MyPoint(x, y, z));
v += step1;
}
}
List <MyPoint> qPointsDer = new List <MyPoint>();
qPointsDer.Add(new MyPoint());
for (int i = 0; i < qPoints.Count - 1; i++)
{
qPointsDer.Add(new MyPoint());
qPointsDer[i].SetCoordinates(MyMath.Difference(qPoints[i + 1], qPoints[i]));
}
//qPointsDer[0].SetCoordinates(MyMath.AddDifference(qPointsDer[0], qPointsDer[1]));
//policzyc krzywa stalego parametru
//Qi = (delta P)
_knotsDeriv.Clear();
m = qPointsDer.Count + Degree - 1 + 1; //stopień = 2
for (int i = 0; i < m; i++)
{
_knotsDeriv.Add((double)i / (double)(m - 1));
}
double t;
t = u1;
// while (t < _knotsDeriv[qPointsDer.Count])
// {
x = y = z = 0;
for (int i = 0; i < qPointsDer.Count; i++)
{
x += (qPointsDer[i].x * Nik3(t, i, Degree - 1));
y += (qPointsDer[i].y * Nik3(t, i, Degree - 1));
z += (qPointsDer[i].z * Nik3(t, i, Degree - 1));
}
// }
//Ci = suma i = 0 .. n-1 Ni,p-1(u),Qi
return(qPointsDer);
// return p3;
}
