/* > diffpos.c */

/* Quick and dirty program to compare two SURVEX .pos files */
/* Copyright (C) 1994,1996 Olly Betts */

/*
1994.04.16 Written
1994.11.22 Now displays names of stations added/deleted at end of .pos file
           Now displays and skips lines which it can't parse (eg headers)
           Negative thresholds allowed (to force a "full" compare)
           Syntax expanded
1996.04.04 fixed Borland C warning
1996.05.06 fixed STRING() macro to corret Syntax: message
*/

/* size of line buffer */
#define BUFLEN 256

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

#define sqrd(X) ((X)*(X))

/* macro to just convert argument to a string */
#define STRING(X) _STRING(X)
#define _STRING(X) #X

/* very small value for comparing floating point numbers with */
#define EPSILON 0.00001

/* default threshold is 1cm */
#define DFLT_MAX_THRESHOLD 0.01

static void diff_pos(FILE *fh1, FILE *fh2, double threshold );
static int read_line(FILE *fh, double *px, double *py, double *pz, char*id);

int main( int argc, char *argv[] ) {
 double threshold=DFLT_MAX_THRESHOLD;
 char *fnm1,*fnm2;
 FILE *fh1,*fh2;
 if (argc!=3) {
  char *p;
  if (argc==4)
   threshold=strtod(argv[3],&p);
  if (argc!=4 || *p) {
   /* complain if not 4 args, or threshold didn't parse cleanly */
   printf("Syntax: %s <pos file> <pos file> [<threshold>]\n",argv[0]);
   printf(" where <threshold> is the max. permitted change along any axis"
          " in metres\n"
          " (default <threshold> is "STRING(DFLT_MAX_THRESHOLD)"m)\n");
   exit(1);
  }
 }
 fnm1=argv[1];
 fnm2=argv[2];
 fh1=fopen(fnm1,"rb");
 if (!fh1) {
  printf("Can't open file '%s'\n",fnm1);
  exit(1);
 }
 fh2=fopen(fnm2,"rb");
 if (!fh2) {
  printf("Can't open file '%s'\n",fnm2);
  exit(1);
 }
 diff_pos(fh1,fh2,threshold);
 return 0;
}

static void diff_pos( FILE *fh1, FILE *fh2, double threshold ) {
 double x1,y1,z1,x2,y2,z2;
 int cmp;
 char id1[BUFLEN], id2[BUFLEN];
 int fRead1=1, fRead2=1;
 while (!feof(fh1) && !feof(fh2)) {
  if (fRead1) {
   if (!read_line(fh1,&x1,&y1,&z1,id1))
    continue;
   fRead1=0;
  }
  if (fRead2) {
   if (!read_line(fh2,&x2,&y2,&z2,id2))
    continue;
   fRead2=0;
  }
  cmp=strcmp(id1,id2);
  if (cmp==0) {
   if (fabs(x1-x2)-threshold>EPSILON
    || fabs(y1-y2)-threshold>EPSILON
    || fabs(z1-z2)-threshold>EPSILON)
    printf("Moved by (%3.2f,%3.2f,%3.2f): %s\n", x1-x2, y1-y2, z1-z2, id1 );
   fRead1=fRead2=1;
  } else {
   if (cmp<0) {
    printf("Deleted: %s\n",id1);
    fRead1=1;
   } else {
    printf("Added: %s\n",id2);
    fRead2=1;
   }
  }
 }
 while (!feof(fh1) && read_line(fh1,&x1,&y1,&z1,id1))
  printf("Deleted: %s (at end of file)\n",id1);
 while (!feof(fh2) && read_line(fh2,&x2,&y2,&z2,id2))
  printf("Added: %s (at end of file)\n",id2);
}

static int read_line(FILE *fh, double *px, double *py, double *pz, char *id) {
 char buf[BUFLEN];
 if (!fgets(buf,BUFLEN,fh))
  return 0;
 if (sscanf(buf,"(%lf,%lf,%lf )%s",px,py,pz,id)<4) {
  printf("Ignoring line: %s\n",buf);
  return 0;
 }
 return 1;
}