X-Authentication-Warning:	delorie.com: mail set sender to geda-user-bounces using -f
X-Recipient:	geda-user AT delorie DOT com
X-Virus-Status:	Clean
X-Virus-Scanned:	clamav-milter 0.98.4 at av01.lsn.net
Subject:	Re: [geda-user] The nature of gEDA layers
To:	geda-user AT delorie DOT com
References:	<alpine DOT DEB DOT 2 DOT 00 DOT 1601180756390 DOT 9035 AT igor2priv>
	<CAC4O8c-ZyNnCzCDHXkYYabSD4fG8vf+CKmhMycNJujGMPKzQDQ AT mail DOT gmail DOT com>
	<s6nr3h49hrq DOT fsf AT blaulicht DOT dmz DOT brux>
	<DDB07351-7C94-4B5C-99FA-83750CD4592A AT noqsi DOT com>
	<20160126233332 DOT dec2f06f5c74354a3841989c AT gmail DOT com>
	<s6n1t93h4ub DOT fsf AT blaulicht DOT dmz DOT brux>
	<20160127091746 DOT 1c7a976c2752f913921688ac AT gmail DOT com>
	<s6npowne74w DOT fsf AT blaulicht DOT dmz DOT brux>
	<20160127141334 DOT c738feb9dbeb54a7dec3dff8 AT gmail DOT com>
	<s6n37tjt1tv DOT fsf AT falbala DOT ieap DOT uni-kiel DOT de> <56A8F74B DOT 8080304 AT ecosensory DOT com>
	<CAC4O8c9UKLsh5FAAwUMEtHThKH-w3gUmCU2i9dRW9igkyRt-TQ AT mail DOT gmail DOT com>
	<CAJZxidDmjMtd_fKvR5qZVRa+hwDUbvfaz79oZjkBgDuE1m8RBg AT mail DOT gmail DOT com>
	<56A961BC DOT 3040405 AT ecosensory DOT com>
	<CAJZxidC=nbxAinOtpfGHHqwPXbEMrhfat7jKgA9KBp3EVVg4_Q AT mail DOT gmail DOT com>
	<s6nbn863xlu DOT fsf AT blaulicht DOT dmz DOT brux> <56A9E416 DOT 8080500 AT ecosensory DOT com>
	<20160128124020 DOT 8f2f33210481f637a696f5d0 AT gmail DOT com>
	<CAJZxidD7=NE+Q3FGOU+ER3Xh7TRskEPRTKa=yrwUm51_VaYw0A AT mail DOT gmail DOT com>
From:	John Griessen <john AT ecosensory DOT com>
Message-ID:	<56AA3753.6020109@ecosensory.com>
Date:	Thu, 28 Jan 2016 09:44:19 -0600
User-Agent:	Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101
	Icedove/38.4.0
MIME-Version:	1.0
In-Reply-To:	<CAJZxidD7=NE+Q3FGOU+ER3Xh7TRskEPRTKa=yrwUm51_VaYw0A@mail.gmail.com>
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

On 01/28/2016 07:59 AM, Chad Parker (parker DOT charles AT gmail DOT com) [via geda-user AT delorie DOT com] wrote:
>     The drill-layers are marked as such with a property that is hardwired to
>     the code that handled connectivity.
>
>
> I would try to keep connectivity and geometry separate if possible.
>
>     Geometry and connectivity needs to be hardwired in the core data
>     structures. That is the core of what is needed to be efficient while
>     drawing.
>
>
> Ultimately a layout tool is a connectivity aware drawing package, although some would argue that the connectivity awareness is
> optional. You certainly -can- layout a board without net lines, but I think many if not most board designers find them quite useful.

The connectivity and geometry are interdependent.  If you move a layer up the stack, what is adjacent changes and some of the 
netlist/ratlines data is now stale.  That data can be updated and reconciled by running DRCs usually. Since we almost always use
netlist/ratlines data and DRCs, the connectivity doesn't really NEED to be in core data structures -- it can be an attribute 
associated with a trace or pad's unique ID.

One thing needed in core data structures is room for and a mechanism for a unique ID for each atomic board element such as
trace, pad, polygon, text...

Which brings us to text.  Should text be a separate type of atomic board element still?  With fonts to swapping out?
Could it reduce to a small bitmap and the idea of text and fonts be handled at a higher abstraction level in the code?

What about bitmaps?  Allow them to be made from square pixels of arbitrary size, or only from other bits of trace atomic board 
elements?

- Raw text -