SolTrack
SolTrack is a simple, free, fast and accurate C routine to compute the position of the Sun
All Data Structures Files Functions Variables Macros
Data Structures
Here are the data structures with brief descriptions:
 CLocationLocation to compute the Sun's position for
 CPositionPosition of the Sun
 CRiseSetRise and set data for the Sun
 CTimeDate and time to compute the Sun's position for, in UT