kicad-developers team mailing list archive

[Lorenzo Marcantonio <l.marcantonio@xxxxxxxxxxxx>]

On Sun, Apr 21, 2013 at 03:48:06PM +0000, Solonen Vesa wrote:
> While investigating the Pcbnew drawing performance problems it became evident that quite a lot of time is spent calculating distances. The attached logs were captured by Pauli Sundberg while zooming in and out the video demo board. He also suggested using squared distances (d^2 = a^2 + b^2) for DRC calculations as that would save expensive square roots [1].

When comparing distances, yes, that would be a good idea, it's a common
trick (IIRC it's already done that way during track editing). That
aside, for what reason should be pcbnew computing distances during
redraw? Shouldn't a bounding box check suffice for drawing purposes?

With *a lot* of track and a big board some kind of spatial index would
be useful maybe (something like an r-tree) but it's not exactly trivial
to build (and maintain). The video demo board is only moderately busy
(8500 track segments and 2000 pads): in fact I can't see performance
issues even with an atom core:P

It's interesting work anyway, I'll give a look to these logs.

-- 
Lorenzo Marcantonio
Logos Srl