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Date: Wed, 2 Jul 2014 19:33:25 +0200
From: Gabriel Paubert <paubert AT iram DOT es>
To: geda-user AT delorie DOT com
Subject: Re: [geda-user] line end styles?
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On Wed, Jul 02, 2014 at 11:01:48AM -0400, DJ Delorie wrote:
> 
> > Why is this? Obviously it hasn't been implemented, but is that
> > because internal representation of lines/traces makes it extra
> > difficult, or rather that noone has had an itch yet?
> 
> Because nobody's implemented it yet (which implies nobody itched
> enough to do so ;)
> 
> Round end caps are ideal for traces because there's no need to worry
> about miter angles.

And some exporters would become more complex, for example for non round
ends, the only way to perform Gerber export is basically to transform it 
into a contour. Gerber only allows round apertures for circular interpolation.
Rectangular apertures are also allowed for linear interpolation, but only
when the rectangle sides are along the major axes, therefore they only
work satisfactorily for horizontal and vertical traces.

It's not that difficult to add polygons at the end of the traces and it 
gives you much more freedom (I've had microstrip lines ending with strange
shapes for wire-bonding).

Speaking of Gerber, we should add a G01* block at the beginning of every
Gerber files produced by the exporter. The specification says that the
interpolation mode (G0[123]) is undefined at the beginning of a file.
I suspect that most Gerber readers assume linear interpolation but this
is not guaranteed.

	Gabriel