[Kstars-devel] KStars for astrophotography

[Aleksey Khudyakov]

On 22.10.2012 21:58, Akarsh Simha wrote:
> Yes, I agree that we really need both rotation and mirrored view.
>
> I thought it might be easy to implement if we rewrote the projector
> base class to also perform some sort of a coordinate rotation. Not
> sure if it would be the most efficient way.
>
> I agree that coordinate rotations in polar coordinates are a pain,
> unless we use quaternions. I agree it would be best to move into
> quaternions, but like Alexey points out, that's a rewrite of large
> chunks of code.
>
But there are a lot of benefits as well

  1. Simplicity and clarity. Since conversion between coordinate systems 
is cheap there is no need to cache horizontal/equatorial coordinates. No
need to maintain them in sync. All objects without proper motion become 
immutable.

  2. Performance. AFAIR you profiled kstars and projection code took 
significant portion of running time.