X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f
Date: Sat, 28 Jun 2014 12:14:48 -0400
Message-Id: <201406281614.s5SGEm2m030282@envy.delorie.com>
From: DJ Delorie <dj AT delorie DOT com>
To: geda-user AT delorie DOT com
In-reply-to: <1403964458.21012.13.camel@pcjc2lap> (message from Peter Clifton
	on Sat, 28 Jun 2014 15:07:38 +0100)
Subject: Re: [geda-user] pcb: Patch for arcs with different radii for x and
 y on screen
References: <ojbt218fi23of8gryausfclb DOT 1403353431756 AT email DOT android DOT com>
	 <53A7E8F0 DOT 8020905 AT philippklostermann DOT de>
	 <1403800440 DOT 25929 DOT 14 DOT camel AT pcjc2lap>
	 <20140627112707 DOT GB21723 AT visitor2 DOT iram DOT es>
	 <1403900109 DOT 6474 DOT 8 DOT camel AT pcjc2lap> <877g422gyf DOT fsf AT rover DOT gag DOT com>
	 <1403918513 DOT 6474 DOT 37 DOT camel AT pcjc2lap> <874mz53cxn DOT fsf AT rover DOT gag DOT com> <1403964458 DOT 21012 DOT 13 DOT camel AT pcjc2lap>
Reply-To: geda-user AT delorie DOT com
Errors-To: nobody AT delorie DOT com
X-Mailing-List: geda-user AT delorie DOT com
X-Unsubscribes-To: listserv AT delorie DOT com
Precedence: bulk


> A question still unclear in my head.. should we define a pad stack
> which has the relevant properties / pad geometry, and call that out
> repeatedly, OR.. should we continue in PCB's current approach, and
> have every single via entity describe these aspects individually.

I've used both types of tools, and IMHO it's better to have a "canned"
geometry that you can reference, as well as making exceptions.
Sketchup has a good implementation of this, but lacks a way of finding
all features that are exceptions.

> I really wish PCB didn't have the concept of layer groups to
> complicate this. They are REALLY unhelpful. Plain _layers_, defined
> to be in a particular numerical order through the board stack-up
> would be a MUCH easier model to use.

We'd still need a way to have one layer be composed of different
things-that-become-gerbers.  An obvious example of this is the
top/bottom layers, which have copper, mask, paste, and silk.

> then the board stack-up of is considered to be the numerical
> sequence (either ascending or descending) of these two layer-groups
> and any in between.

Photo mode does this too, and OSH Park interprets PCB layouts this
way.