//static public void GetFittingMesh(ISurface s, double vMid, out List<Vect2> uv, out List<Vect3> xyz)
//{
// FixedPoint[] fits = new FixedPoint[2];
// fits[0] = new FixedPoint(0, vMid);
// fits[1] = new FixedPoint(1, vMid);
// SurfaceCurve midcur = new SurfaceCurve("MidCur", s, fits);
//}
public static void xRad(ISurface s, Vect2 uv, ref Vect3 xyz, ref double k)
{
Vect3 dxu = new Vect3(), dxv = new Vect3(), ddxu = new Vect3(), ddxv = new Vect3(), dduv = new Vect3(), xnor = new Vect3();
s.xCvt(uv, ref xyz, ref dxu, ref dxv, ref ddxu, ref ddxv, ref dduv);
s.xNor(uv, ref xyz, ref xnor);
//calculate first fundamental form
double E = dxu.Norm;
double F = dxu.Dot(dxv);
double G = dxv.Norm;
//double E = BLAS.dot(dxu, dxu);
//double F = BLAS.dot(dxu, dxv);
//double G = BLAS.dot(dxv, dxv);
double detI = E * G - F * F;
//calculate second fundamental form
double e = xnor.Dot(ddxu);
double f = xnor.Dot(dduv);
double g = xnor.Dot(ddxv);
//double e = BLAS.dot(ddxu, xnor);
//double f = BLAS.dot(dduv, xnor);
//double g = BLAS.dot(ddxv, xnor);
double detII = e * g - f * f;
k = detII / detI;
}
public static bool xClosest(ISurface s, ref Vect2 uv, ref Vect3 xyzTarget, ref double dist, double tol)
{
Vect3 x = new Vect3(xyzTarget);
Vect3 dxu = new Vect3(), dxv = new Vect3();
Vect3 ddxu = new Vect3(), ddxv = new Vect3(), dduv = new Vect3();
Vect3 h = new Vect3();
Vect2 c = new Vect2();
Vect2 res = new Vect2();
Vect2 a = new Vect2(), b = new Vect2();
double det, r;
Vect2 d = new Vect2();
int loop = 0, max_loops = 150;
while (loop++ < max_loops)
{
s.xCvt(uv, ref x, ref dxu, ref dxv, ref ddxu, ref ddxv, ref dduv);
h = x - xyzTarget;
//h = BLAS.subtract(x, xyzTarget);
dist = h.Magnitude;
//e[0] = s;
c[0] = h.Dot(dxu);// BLAS.dot(h, dxu); // error, dot product is 0 at pi/2
c[1] = h.Dot(dxv);// BLAS.dot(h, dxv); // error, dot product is 0 at pi/2
if (Math.Abs(c[0]) < tol && Math.Abs(c[1]) < tol) // error is less than the tolerance
{
xyzTarget.Set(x);// return point to caller
return true;
}
a[0] = dxu.Norm + h.Dot(ddxu);
a[1] = b[0] = dxu.Dot(dxv) + h.Dot(dduv);
b[1] = dxv.Norm + h.Dot(ddxv);
//a[0] = BLAS.dot(dxu, dxu) + BLAS.dot(h, ddxu);
//a[1] = BLAS.dot(dxu, dxv) + BLAS.dot(h, dduv);
//b[0] = a[1];
//b[1] = BLAS.dot(dxv, dxv) + BLAS.dot(h, ddxv);
det = a.Cross(b);
//det = BLAS.cross2d(a, b);
d[0] = c.Cross(b) / det;
d[1] = a.Cross(c) / det;
//d[0] = BLAS.cross2d(c, b) / det;
//d[1] = BLAS.cross2d(a, c) / det;
c[0] = 0.01 > Math.Abs(d[0]) ? 1 : 0.01 / Math.Abs(d[0]);
c[1] = 0.01 > Math.Abs(d[1]) ? 1 : 0.01 / Math.Abs(d[1]);
//enforce maximum increment
r = Math.Min(c[0], c[1]);
//increment uv by scaled residuals
//uv = BLAS.subtract(uv, BLAS.scale(d, r));
uv = uv - d * r;
//logger.write_format_line("%.5g\t%.5g\t%.5g\t%.5g\t%.5g\t", x[ox], x[oy], e[ox], e[oy], dist);
}
//s = s0;
return false;
}
