Mail Archives: geda-user/2015/05/13/18:14:23
DJ Delorie schreef op wo 13-05-2015 om 17:37 [-0400]:
> > So a part's rotation from its initial positioning is not a separately
> > stored parameter,
>
> Right, this is the root cause of the limitation. We've contemplated
> putting in a native center/angle but haven't yet. It would solve a
> few problems, but any change in the file format has its drawbacks, and
> it's difficult to know how to "migrate" old designs as you see and
> edit them.
Yes, changing formats is always the devil. Is assume that this is also
the cause why lots of old but default installed gEDA/geschem symbol
definitions (such as npn-1.sym) still feature pin numbers marked C/E/B
instead of actual numbers, even though PCB keeps choking on these
things.
> > The obvious question now is if there's a relatively easy way to get the
> > correct angle definitions for free-rotated parts in the XY file.
>
> If you go by the IPC spec, there's no way to know the *starting* angle
> of the footprint when you load it, aside from some "rules of thumb".
> Otherwise, you could re-load the original footprint and compare pin
> orientations to try to guess, I suppose.
>
> Or, you could hack in something to keep a rotation attribute around,
> and update it as needed. Attributes don't need file format changes at
> least.
I will think of something, and if I think it is useful enough to share,
I most certainly will :-)
> > Anyway, thank you again for your explanation. Things like this remind me
> > why open source can so very pleasant to work with.
>
> Heh. Try getting such an explanation out of Microsoft ;-)
Haha, yes, indeed ... and even then one must assume that they have
people around who actually know how their stuff has accreted (I think
that using the verb 'build' is giving them too much credit).
Anyway, thanks again. As usual, this has been both a pleasant and
educational experience.
Best regards,
Richard Rasker
- Raw text -