gEDA-dev: footprint cleanup

[Dan McMahill]

Peter TB Brett wrote:
> Case in point: I've just discovered a quick and easy way to use M4 to 
make the
> footprint for a giant axial capacitor (thanks Dan).  Under your proposed 
> system, I'd have to go and make the footprint myself, probably by digging 
> around in the PCB source tree for M4 files.  It looks to me like what you 
> guys want to do *removes* useful flexibility.
> 
> On the other hand, yes, many of the footprints currently in the M4 library are 
> eminently suitable to being moved into newlib, because the generators that 
> create them aren't particularly flexible (I think specifically of the PCI 
> connector footprints).
> 
> I agree that the way the PCB footprint libraries work at the moment are really 
> pretty impenetrable and user-unfriendly.  But *please* don't throw the baby 
> out with the bathwater!

One problem is that there are a lot of macros in use in those libraries 
and there is no documentation right now as to which could be considered 
public and which should be considered private.  The consequence is that 
we may realize that a certain internal macro is insufficient for a 
particular footprint family and its api may be changed along with the 
footprints which call it.  Now things are broken for those who directly 
called that macro.

Moving the calling of m4 to compile time btw, wouldn't change the 
ability for gsch2pcb to call m4 anyway.  Also with the way it is 
currently set up, the list of what you are able to feed m4 from within 
pcb is limited to the "toplevel" footprints.  In other words, you can't 
get any more footprints out of it than you would if they had been 
compiled to individual files in the first place.

It seems like there should be a good work flow for using all sorts of 
generators though.  I guess the trick is how one tells gsch2pcb which 
generator.

-Dan