git.gag.com Git - fw/tmflights/blob - gps_parse

   1 typedef struct {
   2         int     type;
   3         int     time;
   4         int     a;
   5         int     b;
   6 } flight_record;
   7
   8 flight_record
   9 read_record(file in) {
  10         flight_record   r;
  11         File::fscanf(in, "%c %x %x %x\n",
  12                &r.type, &r.time, &r.a, &r.b);
  13         return r;
  14 }
  15
  16 typedef struct {
  17         int     degrees;
  18         int     minutes;
  19         int     minutes_fraction;
  20 } gps_pos;
  21
  22 typedef struct {
  23         int     hour;
  24         int     minute;
  25         int     second;
  26 } gps_time;
  27
  28 real combine_gps_pos(gps_pos p, bool flag)
  29 {
  30         real sign = flag ? -1 : 1;
  31         return sign * (p.degrees + (p.minutes +
  32                                     p.minutes_fraction / 10000)
  33                        / 60);
  34 }
  35
  36 void read_gps(file in)
  37 {
  38         gps_time        time;
  39         gps_pos         lat, lon;
  40         int             flags;
  41         int             alt;
  42
  43         while (!File::end(in)) {
  44                 flight_record r = read_record(in);
  45                 switch (r.type) {
  46                 case 'G':
  47                         time.hour = r.a & 0xff;
  48                         time.minute = r.a >> 8;
  49                         time.second = r.b & 0xff;
  50                         flags = r.b >> 8;
  51                         break;
  52                 case 'N':
  53                         lat.degrees = r.a & 0xff;
  54                         lat.minutes = r.a >> 8;
  55                         lat.minutes_fraction = r.b;
  56                         break;
  57                 case 'W':
  58                         lon.degrees = r.a & 0xff;
  59                         lon.minutes = r.a >> 8;
  60                         lon.minutes_fraction = r.b;
  61                         break;
  62                 case 'H':
  63                         alt = r.a;
  64                         printf ("%5d %d sat ", r.time, flags & 0xf);
  65                         if ((flags & (1 << 4)) != 0) {
  66                                 printf ("%02d:%02d:%02d ",
  67                                         time.hour, time.minute, time.second);
  68                                 printf ("%4d°%02d.%04d'%c %2d°%02d.%04d'%c %5dm ",
  69                                         lat.degrees, lat.minutes,
  70                                         lat.minutes_fraction,
  71                                         (flags & (1 << 6)) != 0 ? 'S' : 'N',
  72                                         lon.degrees, lon.minutes,
  73                                         lon.minutes_fraction,
  74                                         (flags & (1 << 5)) != 0 ? 'W' : 'E',
  75                                         alt);
  76                                 printf ("%11.6f %11.6f %5d\n",
  77                                         combine_gps_pos(lat,
  78                                                         (flags & (1 << 6)) !=
  79                                                         0),
  80                                         combine_gps_pos(lon,
  81                                                         (flags & (1 << 5)) !=
  82                                                         0),
  83                                         alt);
  84                         } else {
  85                                 printf ("unlocked\n");
  86                         }
  87                         break;
  88                 }
  89         }
  90 }
  91
  92 read_gps(stdin);