-
-
Notifications
You must be signed in to change notification settings - Fork 294
/
sign.c
83 lines (69 loc) · 1.11 KB
/
sign.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
/*
* Copyright (C) 1995. Bill Brown <brown@gis.uiuc.edu> & Michael Shapiro
*
* This program is free software under the GPL (>=v2)
* Read the file GPL.TXT coming with GRASS for details.
*/
#include <grass/datetime.h>
/*!
* \brief
*
* Returns:
* 1 if the Datetime is positive
* 0 otherwise
*
* \param dt
* \return int
*/
int datetime_is_positive(const DateTime * dt)
{
return dt->positive != 0;
}
/*!
* \brief
*
* Returns:
* 1 if the DateTime is negative
* 0 otherwise
*
* \param dt
* \return int
*/
int datetime_is_negative(const DateTime * dt)
{
return dt->positive == 0;
}
/*!
* \brief
*
* Makes the DateTime positive. (A.D. for ABSOLUTE DateTimes)
*
* \param dt
* \return void
*/
void datetime_set_positive(DateTime * dt)
{
dt->positive = 1;
}
/*!
* \brief
*
* Makes the DateTime negative. (B.C. for ABSOLUTE DateTimes)
*
* \param dt
* \return void
*/
void datetime_set_negative(DateTime * dt)
{
dt->positive = 0;
}
/*!
* \brief
*
* \param dt
* \return void
*/
void datetime_invert_sign(DateTime * dt)
{
dt->positive = !dt->positive;
}