X-Authentication-Warning:	delorie.com: mail set sender to geda-user-bounces using -f
X-Recipient:	geda-user AT delorie DOT com
Message-ID:	<1436477539.1747.21.camel@ssalewski.de>
Subject:	[geda-user] What is the hardest part in a PCB layout program?
From:	Stefan Salewski <mail AT ssalewski DOT de>
To:	geda-user AT delorie DOT com
Date:	Thu, 09 Jul 2015 23:32:19 +0200
X-Mailer:	Evolution 3.12.11
Mime-Version:	1.0
Reply-To:	geda-user AT delorie DOT com

I have to admit that I do not know much about internals of a PCB layout
program. About 7 years ago I had a short look into the PCB code -- I
think I was very positive surprised that code size was not too big, but
of course I did not understand much.

For a long time it was my impression that gerber export is very hard.
But about one year ago I had a short discussion with someone working on
some gerber stuff, and he said that for polygons, circular arcs and
straight  lines gerber export is not that difficult. (I think he was
talking about constructing arbitrary curves in KiCad by line segments.
Can not really remember.) I think long time ago I read something about
polygon slicer on this list -- can not find it currently with google. I
had a look into wikipedia about gerber274X recently. My impression was
that we had positive and negative shapes for polygons, arcs and line
segments, which we can draw in arbitrary order. So my current impression
is that gerber export maybe is not that hard. Maybe it was with old
gerber274D ?

Next difficult point is of course real time DRC, but that is basically
geometric intersection check. For elliptical arcs segments it may be
difficult I guess?

And no, I do not plan one more layout tool currently...
But while so many smart people are still on this list, it may be a good
time to ask.

- Raw text -