I don't know if this is going to do what I want, but I'm
hoping I can customize the Markdown output generated by moxygen
to be useful for a simple C library like this. It appears to be
customized for a class-oriented C++ program.
Certain macros and typedefs were ending up in Doxygen output
that have no reason to be documented for outside users.
Mostly I used Doxygen conditionals to hide them.
In a couple of cases I had some internal functions that needed
to be declared static so Doxygen hides them.
Added DoxygenLayout.xml, but not using it yet.
Still trying to figure out how to make Markdown output
that doesn't look terrible. Not sure I can get Moxygen
to do what I want. I may have to create my own simple(?) tool.
These functions allow generating a Gregorian calendar date and time
in UTC from an astro_time_t, and vice versa.
This filled in a gap where we needed a way to transform an astronomy
time value into something a user would recognize.
I may have to revisit this later for compatibility with the <time.h>
standard library, etc.
I made sure it is not possible to get stuck in an infinite
loop inside SearchLunarApsis, both the C and JavaScript versions.
If we loop over more time than 2 synodic months (more than enough time),
bail out with an exception (JS) or an internal error (C).
Astronomy_Ecliptic was using midnight on 2000-01-01 as the epoch,
but it should have been using noon. Fixed it. Discovered because
there was a tiny but larger than expected error in calculating
the tilt of Saturn's rings.
This is a refactoring to follow suit with what I did in the C
version of the code. It improves accuracy by using different
geocentric vector calculations for j2000 and ofdate equatorial
coordinates. Allow optional aberration corrections.
SkyPos was doing 2 different calculations and mashing them together.
Created a more general Equator function that does both jobs one at a time.
Equator can enable/disable rotation to of-date coordinates (precession+nutation)
and enable/disable aberration correction.
Equatorial coordinate type astro_equatorial_t now has a status field
just like astro_vector_t, so we can report errors.
I have figured out how to make a simple correction for aberration
when calculating geocentric vectors.
To include aberration, not only do I back-date the heliocentric
position of the observed body, but I also backdate the
heliocentric position of the Earth by the same amount of time.
This works because for time periods of a few hours or less,
it is a very good approximation for the aberration angle asin(v/c).
To match NOVAS, astrometric coordinates used for J2000 return value
must exclude the aberration correction, while of-date coordinates
must include aberration.
This requires changing the parameters passed in to SkyPos.
I will have to circle back and make the same changes in the
JavaScript code.
This significantly reduces horizontal angular errors for the planets.
