[Kstars-devel] Drawing comet tail patch

[Akarsh Simha]

> James Bowlin told me to use atan2 instead of correcting quadrant
> myself to increase both speed and maintainability. So I'm submitting
> the patch again, still wondering how to handle the situation when the
> Sun is not on screen.

You don't need the sun on the screen, as Vipul corrected me sometime
on chat.

See http://www.windows.ucar.edu/tour/link=/comets/tail.html&edu=high

The more commonly found tail is the dust tail, so I guess we need to
depict it as pointing along the trajectory.

Regards
Akarsh