public void RotateVector(double alpha)
{
NIRotMatrix rotation = new NIRotMatrix(alpha);
double X = this.x1;
double Y = this.x2;
this.x1 = rotation.r11 * X + rotation.r12 * Y;
this.x2 = rotation.r21 * X + rotation.r22 * Y;
}
public static NI2dPoint line2DIntersection(NI2dPoint P, NI2dVector v, NI2dPoint Q, NI2dVector u)
{
NIRotMatrix rotation = new NIRotMatrix(Math.PI / 2);
u.RotateVector(Math.PI / 2);
NI2dVector up = u;
NI2dVector qp = new NI2dVector(Q - P);
NI2dPoint isl = P + (((qp.DotProduct(up)) / v.DotProduct(up)) * v).ConverttoPoint();
return(isl);
}