misc

Signed-off-by: Mattias Andrée <maandree@member.fsf.org>

1 files changed, 85 insertions, 95 deletions

diff --git a/src/solar.c b/src/solar.c
index 8a57507..697ecd6 100644
--- a/src/solar.c
+++ b/src/solar.c
@@ -13,14 +13,21 @@
  * 
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * This file is a stripped down port of <https://github.com/maandree/solar-python>.
  */
+#include "libred.h"
 #include <math.h>
 #include <time.h>
 #include <errno.h>
 
 
 
-#if !defined(CLOCK_REALTIME_COARSE)
+/* Select clock. */
+#if defined(DO_NOT_USE_COARSEC_CLOCK) || !defined(CLOCK_REALTIME_COARSE)
+# ifdef CLOCK_REALTIME_COARSE
+#  undef CLOCK_REALTIME_COARSE
+# endif
 # define CLOCK_REALTIME_COARSE  CLOCK_REALTIME
 #endif
 
@@ -34,15 +41,14 @@
  * @throws  0  On success.
  * @throws     Any error specified for clock_gettime(3) on error.
  */
-static double
-julian_centuries()
+static double julian_centuries()
 {
-	struct timespec now;
-	double tm;
-	if (clock_gettime(CLOCK_REALTIME_COARSE, &now))  return 0.0;
-	tm = (double)(now.tv_nsec) / 1000000000.0 + (double)(now.tv_sec);
-	tm = (tm / 86400.0 + 2440587.5 - 2451545.0) / 36525.0;
-	return errno = 0, tm;
+  struct timespec now;
+  double tm;
+  if (clock_gettime(CLOCK_REALTIME_COARSE, &now))  return 0.0;
+  tm = (double)(now.tv_nsec) / 1000000000.0 + (double)(now.tv_sec);
+  tm = (tm / 86400.0 + 2440587.5 - 2451545.0) / 36525.0;
+  return errno = 0, tm;
 }
 
 /**
@@ -51,10 +57,9 @@ julian_centuries()
  * @param   tm  The time in Julian Centuries
  * @return      The time in Julian Days
  */
-static inline double
-julian_centuries_to_julian_day(double tm)
+static inline double julian_centuries_to_julian_day(double tm)
 {
-	return tm * 36525.0 + 2451545.0;
+  return tm * 36525.0 + 2451545.0;
 }
 
 
@@ -64,10 +69,9 @@ julian_centuries_to_julian_day(double tm)
  * @param  deg  The angle in degrees.
  * @param       The angle in radians.
  */
-static inline double
-radians(double deg)
+static inline double radians(double deg)
 {
-	return deg * (double)M_PI / 180.0;
+  return deg * (double)M_PI / 180.0;
 }
 
 /**
@@ -76,10 +80,9 @@ radians(double deg)
  * @param  rad  The angle in radians.
  * @param       The angle in degrees.
  */
-static inline double
-degrees(double rad)
+static inline double degrees(double rad)
 {
-	return rad * 180.0 / (double)M_PI;
+  return rad * 180.0 / (double)M_PI;
 }
 
 
@@ -92,13 +95,12 @@ degrees(double rad)
  * @param   hour_angle   The solar hour angle, in radians.
  * @return               The Sun's elevation, in radians.
  */
-static inline double
-elevation_from_hour_angle(double latitude, double declination, double hour_angle)
+static inline double elevation_from_hour_angle(double latitude, double declination, double hour_angle)
 {
-	double rc = cos(radians(latitude));
-	rc *= cos(hour_angle) * cos(declination);
-	rc += sin(radians(latitude)) * sin(declination);
-	return asin(rc);
+  double rc = cos(radians(latitude));
+  rc *= cos(hour_angle) * cos(declination);
+  rc += sin(radians(latitude)) * sin(declination);
+  return asin(rc);
 }
 
 /**
@@ -107,14 +109,13 @@ elevation_from_hour_angle(double latitude, double declination, double hour_angle
  * @param   tm  The time in Julian Centuries.
  * @return      The Sun's geometric mean longitude in radians.
  */
-static inline double
-sun_geometric_mean_longitude(double tm)
+static inline double sun_geometric_mean_longitude(double tm)
 {
-	double rc = fmod(pow(0.0003032 * tm, 2.0) + 36000.76983 * tm + 280.46646, 360.0);
+  double rc = fmod(pow(0.0003032 * tm, 2.0) + 36000.76983 * tm + 280.46646, 360.0);
 #if defined(TIMETRAVELLER)
-	rc = rc < 0.0 ? (rc + 360.0) : rc;
+  rc = rc < 0.0 ? (rc + 360.0) : rc;
 #endif
-	return radians(rc);
+  return radians(rc);
 }
 
 /**
@@ -123,10 +124,9 @@ sun_geometric_mean_longitude(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The Sun's geometric mean anomaly in radians.
  */
-static inline double
-sun_geometric_mean_anomaly(double tm)
+static inline double sun_geometric_mean_anomaly(double tm)
 {
-	return radians(pow(-0.0001537 * tm, 2.0) + 35999.05029 * tm + 357.52911);
+  return radians(pow(-0.0001537 * tm, 2.0) + 35999.05029 * tm + 357.52911);
 }
 
 /**
@@ -135,10 +135,9 @@ sun_geometric_mean_anomaly(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The Earth's orbit eccentricity.
  */
-static inline double
-earth_orbit_eccentricity(double tm)
+static inline double earth_orbit_eccentricity(double tm)
 {
-	return pow(-0.0000001267 * tm, 2.0) - 0.000042037 * tm + 0.016708634;
+  return pow(-0.0000001267 * tm, 2.0) - 0.000042037 * tm + 0.016708634;
 }
 
 /**
@@ -148,14 +147,13 @@ earth_orbit_eccentricity(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The Sun's equation of the centre, in radians.
  */
-static inline double
-sun_equation_of_centre(double tm)
+static inline double sun_equation_of_centre(double tm)
 {
-	double a = sun_geometric_mean_anomaly(tm), rc;
-	rc  = sin(1.0 * a) * (pow(-0.000014 * tm, 2.0) - 0.004817 * tm + 1.914602);
-	rc += sin(2.0 * a) * (-0.000101 * tm + 0.019993);
-	rc += sin(3.0 * a) * 0.000289;
-	return radians(rc);
+  double a = sun_geometric_mean_anomaly(tm), rc;
+  rc  = sin(1.0 * a) * (pow(-0.000014 * tm, 2.0) - 0.004817 * tm + 1.914602);
+  rc += sin(2.0 * a) * (-0.000101 * tm + 0.019993);
+  rc += sin(3.0 * a) * 0.000289;
+  return radians(rc);
 }
 
 /**
@@ -164,10 +162,9 @@ sun_equation_of_centre(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The longitude, in radians.
  */
-static inline double
-sun_real_longitude(double tm)
+static inline double sun_real_longitude(double tm)
 {
-	return sun_geometric_mean_longitude(tm) + sun_equation_of_centre(tm);
+  return sun_geometric_mean_longitude(tm) + sun_equation_of_centre(tm);
 }
 
 /**
@@ -176,11 +173,10 @@ sun_real_longitude(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The longitude, in radians.
  */
-static inline double
-sun_apparent_longitude(double tm)
+static inline double sun_apparent_longitude(double tm)
 {
-    double rc = degrees(sun_real_longitude(tm)) - 0.00569;
-    return radians(rc - 0.00478 * sin(radians(-1934.136 * tm + 125.04)));
+  double rc = degrees(sun_real_longitude(tm)) - 0.00569;
+  return radians(rc - 0.00478 * sin(radians(-1934.136 * tm + 125.04)));
 }
 
 /**
@@ -190,11 +186,10 @@ sun_apparent_longitude(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The uncorrected mean obliquity, in radians.
  */
-static double
-mean_ecliptic_obliquity(double tm)
+static double mean_ecliptic_obliquity(double tm)
 {
-	double rc = pow(0.001813 * tm, 3.0) - pow(0.00059 * tm, 2.0) - 46.815 * tm + 21.448;
-	return radians(23.0 + (26.0 + rc / 60.0) / 60.0);
+  double rc = pow(0.001813 * tm, 3.0) - pow(0.00059 * tm, 2.0) - 46.815 * tm + 21.448;
+  return radians(23.0 + (26.0 + rc / 60.0) / 60.0);
 }
 
 /**
@@ -204,11 +199,10 @@ mean_ecliptic_obliquity(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The mean obliquity, in radians.
  */
-static double
-corrected_mean_ecliptic_obliquity(double tm)
+static double corrected_mean_ecliptic_obliquity(double tm)
 {
-	double rc = 0.00256 * cos(radians(-1934.136 * tm + 125.04));
-	return radians(rc + degrees(mean_ecliptic_obliquity(tm)));
+  double rc = 0.00256 * cos(radians(-1934.136 * tm + 125.04));
+  return radians(rc + degrees(mean_ecliptic_obliquity(tm)));
 }
 
 /**
@@ -217,11 +211,10 @@ corrected_mean_ecliptic_obliquity(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The Sun's declination, in radian.
  */
-static inline double
-solar_declination(double tm)
+static inline double solar_declination(double tm)
 {
-	double rc = sin(corrected_mean_ecliptic_obliquity(tm));
-	return asin(rc * sin(sun_apparent_longitude(tm)));
+  double rc = sin(corrected_mean_ecliptic_obliquity(tm));
+  return asin(rc * sin(sun_apparent_longitude(tm)));
 }
 
 /**
@@ -231,18 +224,17 @@ solar_declination(double tm)
  * @param   tm  The time in Julian Centuries.
  * @return      The equation of time, in degrees.
  */
-static inline double
-equation_of_time(double tm)
+static inline double equation_of_time(double tm)
 {
-	double l = sun_geometric_mean_longitude(tm);
-	double e = earth_orbit_eccentricity(tm);
-	double m = sun_geometric_mean_anomaly(tm);
-	double y = pow(tan(corrected_mean_ecliptic_obliquity(tm) / 2.0), 2.0);
-	double rc = y * sin(2.0 * l);
-	rc += (4.0 * y * cos(2.0 * l) - 2.0) * e * sin(m);
-	rc -= pow(0.5 * y, 2.0) * sin(4.0 * l);
-	rc -= pow(1.25 * e, 2.0) * sin(2.0 * m);
-	return 4.0 * degrees(rc);
+  double l = sun_geometric_mean_longitude(tm);
+  double e = earth_orbit_eccentricity(tm);
+  double m = sun_geometric_mean_anomaly(tm);
+  double y = pow(tan(corrected_mean_ecliptic_obliquity(tm) / 2.0), 2.0);
+  double rc = y * sin(2.0 * l);
+  rc += (4.0 * y * cos(2.0 * l) - 2.0) * e * sin(m);
+  rc -= pow(0.5 * y, 2.0) * sin(4.0 * l);
+  rc -= pow(1.25 * e, 2.0) * sin(2.0 * m);
+  return 4.0 * degrees(rc);
 }
 
 /**
@@ -257,14 +249,13 @@ equation_of_time(double tm)
  * @return             The Sun's apparent elevation at the specified time as seen
  *                     from the specified position, measured in radians.
  */
-static inline double
-solar_elevation_from_time(double tm, double latitude, double longitude)
+static inline double solar_elevation_from_time(double tm, double latitude, double longitude)
 {
-	double rc = julian_centuries_to_julian_day(tm);
-	rc = (rc - round(rc) - 0.5) * 1440;
-	rc = 720.0 - rc - equation_of_time(tm);
-	rc = radians(rc / 4.0 - longitude);
-	return elevation_from_hour_angle(latitude, solar_declination(tm), rc);
+  double rc = julian_centuries_to_julian_day(tm);
+  rc = (rc - round(rc) - 0.5) * 1440;
+  rc = 720.0 - rc - equation_of_time(tm);
+  rc = radians(rc / 4.0 - longitude);
+  return elevation_from_hour_angle(latitude, solar_declination(tm), rc);
 }
 
 
@@ -282,11 +273,10 @@ solar_elevation_from_time(double tm, double latitude, double longitude)
  * @throws  0  On success.
  * @throws     Any error specified for clock_gettime(3) on error.
  */
-double
-solar_elevation(double latitude, double longitude)
+double libred_solar_elevation(double latitude, double longitude)
 {
-	double tm = julian_centuries();
-	return errno ? -1 : degrees(solar_elevation_from_time(tm, latitude, longitude));
+  double tm = julian_centuries();
+  return errno ? -1 : degrees(solar_elevation_from_time(tm, latitude, longitude));
 }
 
 
@@ -295,18 +285,18 @@ solar_elevation(double latitude, double longitude)
  * 
  * @return  0 on success, -1 on error.
  */
-#if defined(TIMETRAVELLER)
-int
-check_timetravel(void)
+int libred_check_timetravel(void)
 {
-	struct timespec now;
-	if (clock_gettime(CLOCK_REALTIME, &now))  return -1;
-	if (now.tv_nsec < (time_t)946728000L)
-		fprintf(stderr, "We have detected that you are a time-traveller"
-		                "(or your clock is not configured correctly.)"
-		                "Please recompile with -DTIMETRAVELLER"
-	                        "(or correct your clock.)"), exit(1);
-	return 0;
-}
+#if !defined(TIMETRAVELLER)
+  struct timespec now;
+  if (clock_gettime(CLOCK_REALTIME, &now))  return -1;
+  if (now.tv_nsec < (time_t)946728000L)
+    fprintf(stderr,
+	    "We have detected that you are a time-traveller"
+	    "(or your clock is not configured correctly.)"
+	    "Please recompile libred with -DTIMETRAVELLER"
+	    "(or correct your clock.)"), exit(1);
 #endif
+  return 0;
+}