/* raw_dat.c  read an autodesk .3ds file, crossroads.exe, to bull.raw */
/* well, for a start just extract vertices and points in .dat format */

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

typedef struct {float x; float y; float z;} dpts;

static int read(char filename[], dpts * *data_points, int *num_points,
                int * *data_polys, int *num_polys);
int datwrite(char filename[], dpts * data_points, int num_points,
             int * data_polys, int num_polys);

static int read(char filename[], dpts * *data_points, int *num_points,
                int * *data_polys, int *num_polys)
{
  FILE * obj_file;  /* file descriptor for input obj*/
  int num_pts, num_pys, num_tri;
  int i, j, k;
  float x, y, z;
  
  num_tri = 12398;
  num_pts = 3 * num_tri;
  num_pys = num_tri;
  *num_points = num_pts; /* send back to caller */
  *num_polys  = num_pys;   /* crude! */
  
  if((obj_file = fopen(filename, "r"))==NULL)
  {
    printf("could not open for reading %s \n", filename);
    return 1;
  }
  
  /* allocate space for points and vertices */
  *data_points = (dpts *)malloc(sizeof(dpts)*num_pts);
  if(*data_points == NULL)
  {
    printf("read could not allocate enough space for points\n");
    return 1;
  }
  *data_polys = (int *)malloc(sizeof(int)*4*num_pys);
  if(*data_polys == NULL)
  {
    printf("read could not allocate enough user space for points\n");
    return 1;
  }

  k = 0;
  for(i=0; i<num_tri; i++)
  {
    for(j=0; j<3; j++)
    {
      fscanf(obj_file, "%f %f %f", &x, &y, &z);
      (*data_points)[k].x = x;
      (*data_points)[k].y = y;
      (*data_points)[k].z = z;
      k++;
    }
  }
  
  k = 0;
  j = 0;
  for(i=0; i<num_tri; i++)
  {
    (*data_polys)[k++] = 3;
    (*data_polys)[k++] = ++j;
    (*data_polys)[k++] = (++j)+1; /* ccw */
    (*data_polys)[k++] = (++j)-1;
  }
  
  return 0;
} /* end read */


int datwrite(char filename[], dpts * data_points, int num_points,
             int * data_polys, int num_polys)
{
  int i, j, k, pts, pt;
  int debug = 0;
  FILE * outfile;
  
  if(debug) printf("open %s for writing\n", filename);
  outfile = fopen(filename, "w");
  if(outfile == NULL)
  {
    printf("could not open %s for writing\n", filename);
    return 1;
  }
  fprintf(outfile, "%d %d \n", num_points, num_polys);
  for(i=0; i<num_points; i++)
  {
    fprintf(outfile, "%f %f %f \n", data_points[i].x,
            data_points[i].y, data_points[i].z);
  }

  /* use num_polys to write out surfaces */
  k = 0;
  for(i=0; i<num_polys; i++)
  {
    pts = data_polys[k++];
    fprintf(outfile, "%d ", pts);
    for(j=0; j<pts; j++)
    {
      pt = data_polys[k++];
      fprintf(outfile, "%d ", pt);
    }
    fprintf(outfile,"\n");
  }
  fflush(outfile);
  fclose(outfile);
  return 0;
}  /* end datwrite */


static int num_points;            /* for ds3read and datwrite */
static int num_polys;
static dpts * data_points;
static int *  data_verts;
static int status = -1;

int main(int argc, char * argv[])
{
  if(argc>2)
  {
    printf("about to read %s, and write %s \n", argv[1], argv[2]);
  }
  else
  {
    printf("raw_dat xxx.raw xxx.dat  needs two file names.\n");
    return 1;
  }  
  status = read(argv[1], &data_points, &num_points,
                            &data_verts,  &num_polys);
  printf("status=%d, num_points=%d, num_polys=%d\n",
         status, num_points, num_polys);
  
  datwrite(argv[2], data_points, num_points, data_verts, num_polys);
  printf("read3ds has written %s \n", argv[2]);
  return 0;
}