#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include "writemesh.h"

#define NU 50
#define NV 30
#define A 2.0
#define B 0.7
#define C 0.3

static FILE *outfile;
double a, b, c, d, e, f;
int ifun;

char *outfilename;

int
main (int argc, char *argv[])
{
  double pi;
  double u0, u1, v0, v1;
  double du, dv;
  int i, j;
  char defaultfilename[] = "mesh.povinc";

  pi = 4*atan(1.0);

  du = 2*pi/NU;
  dv = 2*pi/NV;

  a = A;
  b = B;
  c = C;
  ifun = F_TORUS;
  outfilename = defaultfilename;

  parseargs (argc, argv);

  outfile = fopen (outfilename, "w");
  u0 = -pi;
  for (i = 0; i < NU; i++)
  {
    u1 = u0 + du;
    v0 = -pi;
    for (j = 0; j < NV; j++)
    {
      v1 = v0 + dv;
      quadrilateral (u0, u1, v0, v1);
      v0 = v1;
    }
    u0 = u1;
  }

  fclose (outfile);
  exit (0);
}

void
quadrilateral (double u0, double u1, double v0, double v1)
{
  struct point p00, p10, p01, p11;

  surface (u0, v0, &p00);
  surface (u1, v0, &p10);
  surface (u0, v1, &p01);
  surface (u1, v1, &p11);

  triangle (p00, p10, p11);
  triangle (p00, p11, p01);
}

void
triangle (struct point pa, struct point pb, struct point pc)
{
  fprintf (outfile, "smooth_triangle {\n");
  fprintf (outfile, "<%lf, %lf, %lf>, <%lf, %lf, %lf>,\n",
           pa.p[0], pa.p[2], pa.p[1], pa.n[0], pa.n[2], pa.n[1]);
  fprintf (outfile, "<%lf, %lf, %lf>, <%lf, %lf, %lf>,\n",
           pb.p[0], pb.p[2], pb.p[1], pb.n[0], pb.n[2], pb.n[1]);
  fprintf (outfile, "<%lf, %lf, %lf>, <%lf, %lf, %lf>}\n",
           pc.p[0], pc.p[2], pc.p[1], pc.n[0], pc.n[2], pc.n[1]);
}

void
parseargs (int argc, char *argv[])
{
  int i;

  for (i = 1; i < argc; i++)
  {
    if (strcmp (argv[i], "-o") == 0)
    {
      outfilename = argv[++i];
    } else if (strcmp (argv[i], "-s") == 0)
    {
      ifun = atoi (argv[++i]);
    } else
    {
      printf ("Invalid option %s\n", argv[i]);
    }
  }
}