X-Authentication-Warning:	delorie.com: mail set sender to geda-user-bounces using -f
X-Recipient:	geda-user AT delorie DOT com
X-Yahoo-Newman-Property:	ymail-3
X-Yahoo-Newman-Id:	972432 DOT 549 DOT bm AT omp1085 DOT mail DOT ne1 DOT yahoo DOT com
DKIM-Signature:	v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1403821657; bh=ecRg2QwL791VyxJ46dI1ZKWaOBfNV6wOr39MMz6aO5w=; h=References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=KHZTBJ0u25KSWsxzqSPI3isdEMrMeD7BPYlqJxSEVAOmAvtqv1hbjtF/ju5avoWzGGNmLGzcHW80hPsP8T6idWb4qmCrlIwlIsLU1kPo4jZXghyOlE3vHihMMF3m37ASGfH4bXzY6urXZQIjaAU8wkIhvnVTibaInFvMhmKyH5Y=
X-YMail-OSG:	Th9W7HgVM1licZCEI1zvmD2gm6ROl9yRjsbhkEVOUVOdZEn
	KTACT.3rc9NiLe08JER2n5bXhmiqBLMydQTrQk0PAvM1Z7ksbgaReG8C_y4a
	vM9VD0xaeh40W43mbyIpYAxN2pGkcOqO2y2gYIdLTcAtK4KnfV.HPHkWfAzb
	4rrt4lR_y08DfJquq63Oc0TNVlQ30FHNYvIHKd1Ny_xSnC19v.8_uEtCEv57
	FbSbWUOM3EeyI_M_ySSe29t3XGTs6lQNJAGDi.W9RZi1aboGN_5Gs_Qk_NwU
	WVpA5CgS0qEfLsuJ4s14FgfN7g.lpmKX.2ZnVk8Iy_PkhpC.eMd3YYmldshG
	mMZhsUkqN2FT6jGTmH.aEldlpuRknGf4XTvuAV.gWHYtEBzpgWpX0b3g5Iy9
	Jt_gQ9jB2zEH9_Z5w1i2VR3mJgIoM_91Hz7LLTGPCuiCKwtqRHlLdRc8xALl
	sB72JqvLmsb8nFYU_wZLCGvNH8y0029sP2fAYE5eN0EMfXZSc5PZup_YY3K7
	ihgO2IWJetfy8Jr2loluEDgaj1HzgBC_WJYy6giYwrysbPSoOOAQ_m9P.qqb
	bcQ--
X-Rocket-MIMEInfo:	002.001,LS0tLS0gT3JpZ2luYWwgTWVzc2FnZSAtLS0tLQoKPiBGcm9tOiBESiBEZWxvcmllIDxkakBkZWxvcmllLmNvbT4KPiBUbzogZ2VkYS11c2VyQGRlbG9yaWUuY29tCj4gQ2M6IAo.IFNlbnQ6IEZyaWRheSwgSnVuZSAyNywgMjAxNCAyOjI1IEFNCj4gU3ViamVjdDogUmU6IFtnZWRhLXVzZXJdIHBjYjogUGF0Y2ggZm9yIGFyY3Mgd2l0aCBkaWZmZXJlbnQgcmFkaWkgZm9yIHggYW5kIHkgb24gc2NyZWVuCj4gCj4gCj4.ICBTcGVha2luZyBvZiBHZXJiZXIgLSBhdCBzb21lIHBvaW50LCB3ZSBzaG91bGQgcmUtdmEBMAEBAQE-
X-Mailer:	YahooMailWebService/0.8.191.1
References:	<ojbt218fi23of8gryausfclb DOT 1403353431756 AT email DOT android DOT com> <201406211627 DOT s5LGR0aR004148 AT envy DOT delorie DOT com> <1403799508 DOT 25929 DOT 8 DOT camel AT pcjc2lap> <201406261625 DOT s5QGPPEA007064 AT envy DOT delorie DOT com>
Message-ID:	<1403821657.38392.YahooMailNeo@web120505.mail.ne1.yahoo.com>
Date:	Thu, 26 Jun 2014 15:27:37 -0700
From:	Cirilo Bernardo <cirilo_bernardo AT yahoo DOT com>
Subject:	Re: [geda-user] pcb: Patch for arcs with different radii for x and y on screen
To:	"geda-user AT delorie DOT com" <geda-user AT delorie DOT com>
In-Reply-To:	<201406261625.s5QGPPEA007064@envy.delorie.com>
MIME-Version:	1.0
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

----- Original Message -----

> From: DJ Delorie <dj AT delorie DOT com>
> To: geda-user AT delorie DOT com
> Cc: 
> Sent: Friday, June 27, 2014 2:25 AM
> Subject: Re: [geda-user] pcb: Patch for arcs with different radii for x and y on screen
> 
> 
>>  Speaking of Gerber - at some point, we should re-validate our output
>>  choices against current UCAMCO recommended practice.
> 
> Note that UCAMCO says "standard gerber is obsolete" so we're going 
> to
> have a hard time following them...
> 


It's not a problem, when they say "standard Gerber" they mean the
original commands for driving the historic photo typsetting machine.
Some of that of course is now a subset of the 274-X specification
which is now on Revision J. Since Revision J has just been released
it will be some time before we see the new features exploited by
CAM software, but even when that happens you don't have to make use
of the newer features.

>>  I would suggest that we re-enable arc features in gerbers at some
>>  point,
> 
> We only interpolate non-circular arcs, which gerber simply doesn't
> 
> support.


Nor is Gerber ever likely to support non-circular arcs. The question
should be what types of arcs do you want to support and why?
I think circular arcs only makes the most sense since it is so simple.
If someone wants more interesting board edges or cutouts then it's
better to draw those in 2D CAD and use some tool to import the shapes,
possibly converting to straight segments. Even the elliptical arcs
aren't currently adequately supported - how do you control the rotation,
the arc angle, or the endpoints? What is the value of having elliptical
arcs?

- Cirilo

- Raw text -