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

#include "3d.h"
#include "model.h"

static MODEL *m;

static void errf(const char *s)
{
 fprintf(stderr,"error in model, offset %lu:\n%s\n",ftell(stdin),s);
}

static void read_model(void)
{
 m = load_model(stdin,&errf);
 if (! m) exit(1);
}

static PT3 xyz_to_pt3(XYZ p)
{
 return((PT3){.x=p.x,.y=p.y,.z=p.z});
}

static void dump_stl(void)
{
 int i;
 TRIANGLE *t;
 PT3 n;
 PT3 l[3];

 printf("solid foo\n");
 for (i=n_triangles(m)-1;i>=0;i--)
  { t = get_triangle(m,i);
    l[0] = xyz_to_pt3(get_location(m,get_point(m,t->corner[0])->loc)->l);
    l[1] = xyz_to_pt3(get_location(m,get_point(m,t->corner[1])->loc)->l);
    l[2] = xyz_to_pt3(get_location(m,get_point(m,t->corner[2])->loc)->l);
    n = unit3(cross(sub3(l[2],l[0]),sub3(l[1],l[0])));
    printf("facet normal %g %g %g\n",n.x,n.y,n.z);
    printf(" outer loop\n");
    printf("  vertex %g %g %g\n",l[2].x,l[2].y,l[2].z);
    printf("  vertex %g %g %g\n",l[1].x,l[1].y,l[1].z);
    printf("  vertex %g %g %g\n",l[0].x,l[0].y,l[0].z);
    printf(" endloop\n");
    printf("endfacet\n");
  }
 printf("endsolid foo\n");
}

int main(void);
int main(void)
{
 read_model();
 dump_stl();
 return(0);
}