movement: add sunrise/sunset face

1 files changed, 95 insertions, 0 deletions

diff --git a/movement/lib/sunriset/sunriset.h b/movement/lib/sunriset/sunriset.h
new file mode 100644
index 00000000..f8b97e32
--- /dev/null
+++ b/movement/lib/sunriset/sunriset.h
@@ -0,0 +1,95 @@
+/*
+
+SUNRISET.H - computes Sun rise/set times, start/end of twilight, and
+             the length of the day at any date and latitude
+
+Written as DAYLEN.C, 1989-08-16
+
+Modified to SUNRISET.C, 1992-12-01
+
+(c) Paul Schlyter, 1989, 1992
+
+Released to the public domain by Paul Schlyter, December 1992
+
+*/
+
+#ifndef SUNRISET_H_
+#define SUNRISET_H_
+
+/* Function prototypes */
+
+double __daylen__( int year, int month, int day, double lon, double lat,
+                   double altit, int upper_limb );
+
+int __sunriset__( int year, int month, int day, 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 );
+
+
+/* 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    */
+/* 35 arc minutes below the horizon (this accounts for the refraction */
+/* of the Earth's atmosphere).                                        */
+#define day_length(year,month,day,lon,lat)  \
+        __daylen__( year, month, day, lon, lat, -35.0/60.0, 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 )
+
+#endif // SUNRISET_H_