// l=r*(w)*r^(-1)
public void LtoW_V(ref RPoint LP, out RPoint WP)
{
QPoint Q = new QPoint(LP, 0.0);
Q.LMul(ref m_R);
Q.RDiv(ref m_R);
WP = Q.PT;
}
//
// new(L) = par(this(L))
protected void ApplyRt(ref RPoint tr, ref QPoint rt)
{
QPoint QT = new QPoint(m_T, 0);
QT.LMul(ref rt);
QT.RDiv(ref rt);
m_T = QT.PT;
m_T.Add(ref tr);
m_R.LMul(ref rt);
}
//
public static CTrans FromAxis(RPoint pt, RPoint vec, double an)
{
an *= Math.PI / 360.0; // half in radians
RPoint T = RPoint.Zero;
RPoint C = pt;
double lR = vec.Dist();
double xc = Math.Cos(an), xs = Math.Sin(an);
vec.Mul(xs / lR);
QPoint R = new QPoint(vec, xc);
R.Norm();
// w=R^(-1)*(l-C)*R+C
T.Add(ref C);
QPoint QC = new QPoint(C, 0);
QC.LMul(ref R);
QC.RDiv(ref R);
T.Sub(ref QC.PT);
return(new CTrans(T, R));
}