#include <stdio.h>
#include <math.h>

#define A 2.0
#define B 0.7
#define NU 30
#define NV 30

int
main (int argc, char *argv[])
{
  FILE *outfile;
  double u, v, a, b, du, dv;
  double x, y, z, ro, ron, nux, nuy;
  double pi;

  outfile = fopen ("torus.mesh", "w");

  fprintf (outfile, "NuvMESH\n");
  pi = 4.0*atan(1.0);
  du = 2*pi/NU;
  dv = 2*pi/NV;
  a = A;
  b = B;
  fprintf (outfile, "%d %d\n", NU, NV);

  for (u = -pi; u <= pi - du/2; u += du)
  {
    for (v = -pi; v <= pi - dv/2; v += dv)
    {
      z = b*sin(v);
      ron = b*cos(v);
      ro = ron + a;
      x = ro*cos(u);
      y = ro*sin(u);
      nux = ron*cos(u);
      nuy = ron*sin(u);
      fprintf (outfile, "%lf %lf %lf ", x, y, z);
      fprintf (outfile, "%lf %lf %lf\n", nux, nuy, z);
    }
  }
  fclose (outfile);

  return (0);
}