[Proj] C API to calculate distances

[Oliver Eichler]

Hi,

I wonder if there is a C API to calculate the real great circle distance
of two points on a WGS84 ellipsoid. I know there is "geod" on the
command line. I had a look at it's source code however this looked quite
complicated. As this must be a standard problem isn't there something like;

distance(p1,p1, d, dir)

p1:  point 1
p2:  point 2
d:   distance
dir: direction in degrees





Oliver