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Diffstat (limited to 'navit/sunriset.h')
| -rw-r--r-- | navit/sunriset.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/navit/sunriset.h b/navit/sunriset.h new file mode 100644 index 000000000..1ccad5797 --- /dev/null +++ b/navit/sunriset.h @@ -0,0 +1,115 @@ +extern const char* timezone_name; +extern long int timezone_offset; + +#define TMOD(x) ((x)<0?(x)+24:((x)>=24?(x)-24:(x))) +#define DAYSOFF(x) ((x)<0?"(-1) ":((x)>=24?"(+1) ":"")) + +#define HOURS(h) ((int)(floor(h))) +#define MINUTES(h) ((int)(60*(h-floor(h)))) + +#define ABS(x) ((x)<0?-(x):(x)) + +/* A macro to compute the number of days elapsed since 2000 Jan 0.0 */ +/* (which is equal to 1999 Dec 31, 0h UT) */ +/* Dan R sez: This is some pretty fucking high magic. */ +#define days_since_2000_Jan_0(y,m,d) \ + (367L*(y)-((7*((y)+(((m)+9)/12)))/4)+((275*(m))/9)+(d)-730530L) + +/* Some conversion factors between radians and degrees */ + +#ifndef PI + #define PI 3.1415926535897932384 +#endif + +#define RADEG ( 180.0 / PI ) +#define DEGRAD ( PI / 180.0 ) + +/* The trigonometric functions in degrees */ + +#define sind(x) sin((x)*DEGRAD) +#define cosd(x) cos((x)*DEGRAD) +#define tand(x) tan((x)*DEGRAD) + +#define atand(x) (RADEG*atan(x)) +#define asind(x) (RADEG*asin(x)) +#define acosd(x) (RADEG*acos(x)) +#define atan2d(y,x) (RADEG*atan2(y,x)) + +/* Following are some macros around the "workhorse" function __daylen__ */ +/* They mainly fill in the desired values for the reference altitude */ +/* below the horizon, and also selects whether this altitude should */ +/* refer to the Sun's center or its upper limb. */ + + +/* This macro computes the length of the day, from sunrise to sunset. */ +/* Sunrise/set is considered to occur when the Sun's upper limb is */ +/* 50 arc minutes below the horizon (this accounts for the refraction */ +/* of the Earth's atmosphere). */ +/* The original version of the program used the value of 35 arc mins, */ +/* which is the accepted value in Sweden. */ +#define day_length(year,month,day,lon,lat) \ + __daylen__( year, month, day, lon, lat, -50.0/60.0, 1 ) + +/* This macro computes the length of the day, including civil twilight. */ +/* Civil twilight starts/ends when the Sun's center is 6 degrees below */ +/* the horizon. */ +#define day_civil_twilight_length(year,month,day,lon,lat) \ + __daylen__( year, month, day, lon, lat, -6.0, 0 ) + +/* This macro computes the length of the day, incl. nautical twilight. */ +/* Nautical twilight starts/ends when the Sun's center is 12 degrees */ +/* below the horizon. */ +#define day_nautical_twilight_length(year,month,day,lon,lat) \ + __daylen__( year, month, day, lon, lat, -12.0, 0 ) + +/* This macro computes the length of the day, incl. astronomical twilight. */ +/* Astronomical twilight starts/ends when the Sun's center is 18 degrees */ +/* below the horizon. */ +#define day_astronomical_twilight_length(year,month,day,lon,lat) \ + __daylen__( year, month, day, lon, lat, -18.0, 0 ) + + +/* This macro computes times for sunrise/sunset. */ +/* Sunrise/set is considered to occur when the Sun's upper limb is */ +/* 35 arc minutes below the horizon (this accounts for the refraction */ +/* of the Earth's atmosphere). */ +#define sun_rise_set(year,month,day,lon,lat,rise,set) \ + __sunriset__( year, month, day, lon, lat, -35.0/60.0, 1, rise, set ) + +/* This macro computes the start and end times of civil twilight. */ +/* Civil twilight starts/ends when the Sun's center is 6 degrees below */ +/* the horizon. */ +#define civil_twilight(year,month,day,lon,lat,start,end) \ + __sunriset__( year, month, day, lon, lat, -6.0, 0, start, end ) + +/* This macro computes the start and end times of nautical twilight. */ +/* Nautical twilight starts/ends when the Sun's center is 12 degrees */ +/* below the horizon. */ +#define nautical_twilight(year,month,day,lon,lat,start,end) \ + __sunriset__( year, month, day, lon, lat, -12.0, 0, start, end ) + +/* This macro computes the start and end times of astronomical twilight. */ +/* Astronomical twilight starts/ends when the Sun's center is 18 degrees */ +/* below the horizon. */ +#define astronomical_twilight(year,month,day,lon,lat,start,end) \ + __sunriset__( year, month, day, lon, lat, -18.0, 0, start, end ) + + +/* Function prototypes */ + +double __daylen__( int year, int month, int day, double lon, double lat, + double altit, int upper_limb ); + +int __sunriset__( time_t ts, double lon, double lat, + double altit, int upper_limb, double *rise, double *set ); + +void sunpos( double d, double *lon, double *r ); + +void sun_RA_dec( double d, double *RA, double *dec, double *r ); + +double revolution( double x ); + +double rev180( double x ); + +double GMST0( double d ); + |