Rewrite time module in pure Rust (#125)

The next chunk of changes from
#122.

This re-implements the time related functionality in native Rust. This
one is a bit larger, mostly from the fact that the conversions in the C
implementation are very inter-dependent and so several new bits of
functionality were pulled in to make the Rust implementation mirror the
C implementation. There's a few bits of functionality thrown out because
they caused some significant unsoundness, but I'm sure there is still
several bits of unsoundness in this translation (e.g. several
panics/asserts are still present). I'd prefer to keep this PR as close
to a straight translation as possible, and re-consider the soundness
concerns in a future PR.

## What's been changed

- I don't think any implementations are still present but meaningfully
modified

## What's been removed

- `GloTime` - GLONASS time is particularly complicated and rarely used
- `GpsTime::to_glo()` and `GpsTime::to_glo_hardcoded()` - See above
- `impl Sub<GpsTime> for GpsTime` - It turns out a `std::time::Duration`
can't hold a negative value. This implementation would occasionally
panic because of this. [The `chrono`
crate](https://docs.rs/chrono/latest/chrono/#time-delta--duration)
handles this better, maybe we can move towards their approach in a later
PR?
- `UtcParams::decode()` - Decoding low-level messages seem unlikely to
be needed
- `impl Default for UtcParams` - Defaulting this data can cause
unexpected errors
- `impl Default for UtcTime` - Defaulting this type can cause unexpected
errors

## What's been added

- The `time::consts` module
- `GpsTime::from_date()` and `GpsTime::from_date_hardcoded()`
- `GpsTime::to_mjd()` and `GpsTime::to_mjd_hardcoded()`
- `GpsTime::to_date()` and `GpsTime::to_date_hardcoded()`
- `UtcTime::to_date()`
- `MJD::to_gps()` and `MJD::to_gps_hardcoded()`
- `MJD::to_date()`

---------

Co-authored-by: Alejandro Duarte <[email protected]>

Author: jbangelo

swiftnav/src/coords.rs

@@ -764,8 +764,8 @@ mod tests {
 
     #[test]
     fn coordinate_epoch() {
-        let initial_epoch = UtcTime::from_date(2020, 1, 1, 0, 0, 0.).to_gps_hardcoded();
-        let new_epoch = UtcTime::from_date(2021, 1, 1, 0, 0, 0.).to_gps_hardcoded();
+        let initial_epoch = UtcTime::from_parts(2020, 1, 1, 0, 0, 0.).to_gps_hardcoded();
+        let new_epoch = UtcTime::from_parts(2021, 1, 1, 0, 0, 0.).to_gps_hardcoded();
         let initial_coord = Coordinate::with_velocity(
             ReferenceFrame::ITRF2020,
             ECEF::new(0.0, 0.0, 0.0),

swiftnav/src/ephemeris.rs

@@ -320,7 +320,7 @@ impl Ephemeris {
         let result = unsafe {
             swiftnav_sys::calc_sat_state(
                 &self.0,
-                t.c_ptr(),
+                &t.to_gps_time_t(),
                 sat.pos.as_mut_array_ref(),
                 sat.vel.as_mut_array_ref(),
                 sat.acc.as_mut_array_ref(),
@@ -348,7 +348,7 @@ impl Ephemeris {
         let result = unsafe {
             swiftnav_sys::calc_sat_az_el(
                 &self.0,
-                t.c_ptr(),
+                &t.to_gps_time_t(),
                 pos.as_array_ref(),
                 swiftnav_sys::satellite_orbit_type_t_MEO,
                 &mut sat.az,
@@ -377,7 +377,7 @@ impl Ephemeris {
         let result = unsafe {
             swiftnav_sys::calc_sat_doppler(
                 &self.0,
-                t.c_ptr(),
+                &t.to_gps_time_t(),
                 pos.as_array_ref(),
                 vel.as_array_ref(),
                 swiftnav_sys::satellite_orbit_type_t_MEO,
@@ -401,13 +401,13 @@ impl Ephemeris {
 
     pub fn detailed_status(&self, t: GpsTime) -> Status {
         Status::from_ephemeris_status_t(unsafe {
-            swiftnav_sys::ephemeris_valid_detailed(&self.0, t.c_ptr())
+            swiftnav_sys::ephemeris_valid_detailed(&self.0, &t.to_gps_time_t())
         })
     }
 
     /// Is this ephemeris usable?
     pub fn is_valid_at_time(&self, t: GpsTime) -> bool {
-        let result = unsafe { swiftnav_sys::ephemeris_valid(&self.0, t.c_ptr()) };
+        let result = unsafe { swiftnav_sys::ephemeris_valid(&self.0, &t.to_gps_time_t()) };
         result == 1
     }
 

swiftnav/src/ionosphere.rs

@@ -73,7 +73,7 @@ impl Ionosphere {
     ///   * IS-GPS-200H, Section 20.3.3.5.1.7
     pub fn decode_parameters(words: &[u32; 8]) -> Result<Ionosphere, IonoDecodeFailure> {
         let mut iono = Ionosphere(swiftnav_sys::ionosphere_t {
-            toa: GpsTime::unknown(),
+            toa: GpsTime::default().to_gps_time_t(),
             a0: 0.0,
             a1: 0.0,
             a2: 0.0,
@@ -104,7 +104,7 @@ impl Ionosphere {
     ///
     /// \return Ionospheric delay distance for GPS L1 frequency \[m\]
     pub fn calc_delay(&self, t: &GpsTime, lat_u: f64, lon_u: f64, a: f64, e: f64) -> f64 {
-        unsafe { swiftnav_sys::calc_ionosphere(t.c_ptr(), lat_u, lon_u, a, e, &self.0) }
+        unsafe { swiftnav_sys::calc_ionosphere(&t.to_gps_time_t(), lat_u, lon_u, a, e, &self.0) }
     }
 }
 
@@ -193,7 +193,7 @@ mod tests {
         ];
         let result = Ionosphere::new(
             /* reference data provided by u-blox receiver */
-            GpsTime::new_unchecked(0, 0.),
+            GpsTime::default(),
             0.0000000111758,
             0.0000000223517,
             -0.0000000596046,

swiftnav/src/reference_frame/mod.rs

@@ -57,14 +57,14 @@
 //! let transformation = get_transformation(ReferenceFrame::ITRF2014, ReferenceFrame::NAD83_2011)
 //!     .unwrap();
 //!
-//! let epoch_2020 = UtcTime::from_date(2020, 3, 15, 0, 0, 0.).to_gps_hardcoded();
+//! let epoch_2020 = UtcTime::from_parts(2020, 3, 15, 0, 0, 0.).to_gps_hardcoded();
 //! let itrf_coord = Coordinate::with_velocity(
 //!     ReferenceFrame::ITRF2014, // The reference frame of the coordinate
 //!     ECEF::new(-2703764.0, -4261273.0, 3887158.0), // The position of the coordinate
 //!     ECEF::new(-0.221, 0.254, 0.122), // The velocity of the coordinate
 //!     epoch_2020); // The epoch of the coordinate
 //!
-//! let epoch_2010 = UtcTime::from_date(2010, 1, 1, 0, 0, 0.).to_gps_hardcoded();
+//! let epoch_2010 = UtcTime::from_parts(2010, 1, 1, 0, 0, 0.).to_gps_hardcoded();
 //! let itrf_coord = itrf_coord.adjust_epoch(&epoch_2010); // Change the epoch of the coordinate
 //!
 //! let nad83_coord = transformation.transform(&itrf_coord);

swiftnav/src/solver.rs

@@ -416,7 +416,7 @@ pub fn calc_pvt(
         swiftnav_sys::calc_PVT(
             measurements.len() as u8,
             meas_ptr,
-            tor.c_ptr(),
+            &tor.to_gps_time_t(),
             settings.disable_raim,
             settings.disable_velocity,
             &obs_config,