GRASS GIS 7 Programmer's Manual  7.5.svn(2018)-r72274
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Pages
ll_format.c
Go to the documentation of this file.
1 
2 /***************************************************************
3 G_lat_format (lat, buf)
4  double lat;
5  char *buf;
6 
7 G_lon_format (lon, buf)
8  double lon;
9  char *buf;
10 
11 G_llres_format (res, buf)
12  double res;
13  char *buf;
14 
15  formats lat (latitude in degrees), or lon (longitude in degrees)
16  into buf as dd:mm:ssH, where H (hemishpere) is
17  N for northern hemishpere, S for southern,
18  W for western hemishpere, E for eastern
19  none for resolution
20  (lat > 0 is northern, lat < 0 is southern)
21  (lon > 0 is eastern, lon < 0 is western)
22 
23 Note: lat should be in the range -90 to 90s, but
24  the range is NOT checked by G_lat_format().
25  lon can be anything, but
26  values outside [-180,180] are moved into this range
27  by adding (or subtracting) 360.
28 
29 NOTE: These routines are used by G_format_northing(), G_format_easting(), and
30  G_format_resolution(). Those routines are intended to provide
31  a general interface to window values and should be used instead of
32  these projection specific routines. In other words, these routines
33  are for the library only, programmers shouldn't use them.
34 ***************************************************************/
35 #include <grass/gis.h>
36 #include <string.h>
37 
38 static void format(char *, int, int, double, char);
39 static void ll_parts(double, int *, int *, double *);
40 
41 void G_lat_format(double lat, char *buf)
42 {
43  int d, m;
44  char h;
45  double s;
46 
47  G_lat_parts(lat, &d, &m, &s, &h);
48  format(buf, d, m, s, h);
49 }
50 
51 const char *G_lat_format_string(void)
52 {
53  return "dd:mm:ss{N|S}";
54 }
55 
56 void G_lon_format(double lon, char *buf)
57 {
58  int d, m;
59  char h;
60  double s;
61 
62  G_lon_parts(lon, &d, &m, &s, &h);
63  format(buf, d, m, s, h);
64 }
65 
66 const char *G_lon_format_string(void)
67 {
68  return "ddd:mm:ss{E|W}";
69 }
70 
71 void G_llres_format(double res, char *buf)
72 {
73  int d, m;
74  char h;
75  double s;
76 
77  G_lat_parts(res, &d, &m, &s, &h);
78  h = 0;
79  format(buf, d, m, s, h);
80 }
81 
82 const char *G_llres_format_string(void)
83 {
84  return "dd:mm:ss";
85 }
86 
87 static void format(char *buf, int d, int m, double s, char h)
88 {
89  char temp[50];
90  double ss;
91 
92  sprintf(temp, "%f", s);
93  sscanf(temp, "%lf", &ss);
94  if (ss >= 60) {
95  ss = 0; /* force it to zero */
96  if (++m >= 60) {
97  m = 0;
98  d++;
99  }
100  }
101 
102  if (ss < 10.0)
103  sprintf(temp, "0%f", ss);
104  else
105  sprintf(temp, "%f", ss);
106  G_trim_decimal(temp);
107  if (strcmp(temp, "00") != 0 && strcmp(temp, "0") != 0)
108  sprintf(buf, "%d:%02d:%s%c", d, m, temp, h);
109  else if (m > 0)
110  sprintf(buf, "%d:%02d%c", d, m, h);
111  else if (d > 0)
112  sprintf(buf, "%d%c", d, h);
113  else
114  sprintf(buf, "0");
115 }
116 
117 void G_lat_parts(double lat, /* lat in degrees to be split into parts */
118  int *d, int *m, /* degrees, minutes */
119  double *s, /* seconds */
120  char *h /* hemisphere */
121  )
122 {
123  if (lat < 0) {
124  *h = 'S';
125  lat = -lat;
126  }
127  else
128  *h = 'N';
129 
130  ll_parts(lat, d, m, s);
131 }
132 
133 void G_lon_parts(double lon, /* lon in degrees to be split into parts */
134  int *d, int *m, /* degrees, minutes */
135  double *s, /* seconds */
136  char *h /* hemisphere */
137  )
138 {
139 #if 0
140  while (lon > 180.0)
141  lon -= 360.0;
142  while (lon < -180.0)
143  lon += 360.0;
144 #endif
145 
146  if (lon < 0) {
147  *h = 'W';
148  lon = -lon;
149  }
150  else
151  *h = 'E';
152 
153  ll_parts(lon, d, m, s);
154 }
155 
156 static void ll_parts(double ll, /* ll in degrees to be split into parts */
157  int *d, int *m, /* degrees, minutes */
158  double *s /* seconds */
159 )
160 {
161  if (ll == 0.0) {
162  *d = 0;
163  *m = 0;
164  *s = 0.0;
165  }
166  else {
167  *d = ll;
168  *m = (ll - *d) * 60;
169  if (*m < 0)
170  *m = 0;
171  *s = ((ll - *d) * 60 - *m) * 60;
172  if (*s < 0)
173  *s = 0;
174  }
175 }
const char * G_llres_format_string(void)
Definition: ll_format.c:82
const char * G_lat_format_string(void)
Definition: ll_format.c:51
void G_trim_decimal(char *buf)
Removes trailing zeros from decimal number.
Definition: trim_dec.c:24
void G_lon_parts(double lon, int *d, int *m, double *s, char *h)
Definition: ll_format.c:133
void G_lon_format(double lon, char *buf)
Definition: ll_format.c:56
void G_lat_parts(double lat, int *d, int *m, double *s, char *h)
Definition: ll_format.c:117
const char * G_lon_format_string(void)
Definition: ll_format.c:66
void G_llres_format(double res, char *buf)
Definition: ll_format.c:71
void G_lat_format(double lat, char *buf)
Definition: ll_format.c:41