Move gps2decimal years

Author: JADC362

include/swiftnav/gnss_time.h

@@ -336,6 +336,13 @@ void gps2date_params(const gps_time_t *gps_time,
                      s32 *min,
                      double *sec,
                      const utc_params_t *p);
+/**
+ * @brief Converts a GPS time to a decimal year.
+ *
+ * @param gps_time The GPS epoch to convert.
+ * @return The epoch in decimal years representation.
+ */
+double gps2decimal_years(const gps_time_t &gps_time);
 
 /* GPS-UTC time offset at given GPS time */
 double get_gps_utc_offset(const gps_time_t *t, const utc_params_t *p);

src/gnss_time.c

@@ -316,6 +316,19 @@ time_t gps2time(const gps_time_t *t_gps) {
   return t;
 }
 
+double gps2decimal_years(const gps_time_t &gps_time) {
+  utc_tm utc;
+  make_utc_tm(&gps_time, &utc);
+  double days_in_year = YEAR_DAYS;
+
+  if (is_leap_year(utc.year)) {
+    days_in_year = LEAP_YEAR_DAYS;
+  }
+
+  return static_cast<double>(utc.year) +
+         static_cast<double>(utc.year_day) / days_in_year;
+}
+
 /** Convert a Unix `time_t` to a `gps_time_t` GPS time structure.
  *  Both input and output are assumed to be in GPS Time scale so no leap second
  * is applied
@@ -977,6 +990,20 @@ void gps2date_params(const gps_time_t *gps_time,
   utc2date(&utc_time, year, month, day, hour, min, sec);
 }
 
+double gps_time_to_decimal_years(const gps_time_t &gps_time) {
+  utc_tm utc;
+  make_utc_tm(&gps_time, &utc);
+  double days_in_year = YEAR_DAYS;
+
+  if (is_leap_year(utc.year)) {
+    days_in_year = LEAP_YEAR_DAYS;
+  }
+
+  return static_cast<double>(utc.year) +
+         static_cast<double>(utc.year_day) / days_in_year;
+}
+
+
 /** Return the number of days in given month */
 u8 days_in_month(u16 year, u8 month) {
   static u8 days_in_month_lookup[13] = {