Message-ID: <50D645FF.2030901@jump-ing.de>
Date: Sun, 23 Dec 2012 00:45:03 +0100
From: Markus Hitter <mah AT jump-ing DOT de>
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To: geda-help AT delorie DOT com
CC: joe M <joe9mail AT gmail DOT com>
Subject: Re: [geda-help] Adding voronoi regions to geda pcb
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Reply-To: geda-help AT delorie DOT com

Am 22.12.2012 22:58, schrieb joe M:

> I am wondering how hard it would to add voronoi regions to geda pcb
> gcode exporter.

Good question :-)

For my part, I'm interested in this, too, and I hacked this exporter 
quite a bit over the last two years. I also maintain Visolate 3, which 
produces G-code from Gerbers, using a 3D graphics card to generate the 
voronoi regions. Visolate is written in Java, in a flavour quite 
portable to C.

gEDA/pcb's G-code exporter traces track boundaries with potrace. potrace 
is B/W only. So, I think the biggest part would be to teach potrace to 
trace multicolour pictures. Or to find or write another tracer. potrace 
is quite good and fast at path optimisation; AFAIK it would even allow 
to export G-code using G5 (bezier curve).

The current tracing code starts in src/hid/gcode/gcode.c at line 600:

- Draw a PNG   (line 614..617)
- Convert this to a potrace bitmap (line 622..639)
- bm_to_pathlist()  (line 697)
- process_path()   (line 704)

That's it. Everything else there is non-essential code strayed in 
between for prettifying the G-code output.


Hope this answers the question,
Markus

-- 
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Dipl. Ing. (FH) Markus Hitter
http://www.jump-ing.de/