Re: gEDA-user: centroid data generated by pcb-20050315

["Joel N. Weber II" <jwgeda@xxxxxxxxxxxxx>]

> 2. Median, average, and bounds algorithms all seem useful.

What's the difference between median and bounds?

If PCB is going to generate multiple formats, I'm inclined to think
that it may be best to either write each format to a differently named
file, or generate a single file that has multiple sets of coordinates;
depending on remembering to pick the right option from the print menu
each time seems like it would invite accidentally sending off the
wrong data file.

> 3. We also have the element's mark, which we could define as
>    "pick-n-place location", but that would mean that users would have
>    to be able to move those on placed elements.

Screaming Circuits told me something to the effect that most CAD
software generates center of the part, center of pin 1, and center of
the pad for pin 1.  Of course, since they only are going to use the
center of the part, I don't have any need for the pin 1 related
formats.

> 4. Rotation is another can of worms too.

Yeah.  When I asked Screaming Circuits about this one, they said that
they line up the rotation on the first board of the run by hand; they
didn't have any preferred format.  (And I bet if you're using a short
enough piece of tape, it's easy to feed the wrong end of the tape into
the machine and rotate the parts 180 degrees.)

It might be worth having some mechanism where you could enter into pcb
the name of the current rotation of the part next to the name and
value and reference designator of the part, but it seems like that
functionality wouldn't actually be useful to me, so I don't know if it
would be useful to anyone.  (And I don't even know if there's any
clear convention about whether rotations are expressed clockwise or
counterclockwise.)