kicad-developers team mailing list archive

[jp charras <jp.charras@xxxxxxxxxx>]

Le 10/07/2015 19:17, Matthew Beckler a écrit :
> I have some python code to convert an SVG image to a Kicad pcb module
> silkscreen, however it doesn't work great for polygons that contain cutouts
> (such as the holes in the characters A, B, Q, etc). It seems like pcbnew
> does not support having cutouts inside a filled region. I've noticed that
> bitmap2component works around this by creating infinitely-thin connections
> from a polygon's outside edge to each of the cutouts, effectively
> connecting each cutout with the exterior.
> 
> The code isn't great, but here's what I've got so far. It's based on the
> Egg-Bot code (used for driving a two-axis plotter based on SVG files), and
> I need to figure out what sort of licensing is needed for it based on all
> the library files used.
> https://github.com/wayneandlayne/svg2kicadmod
> 
> Right now you need to pick the desired width and/or height in mm when you
> run the script, so if you need different sizes of your logo then you need
> to create several .kicad_mod files. Eventually it would be really great to
> have support for changing the scaling of the rasterized logo right within
> pcbnew, so I perhaps having a python plugin for fancy SVG-based board
> graphics would be neat.
> 
> -Matthew Beckler
> Co-founder and Engineer
> W&L
> 

Generally speaking, about polygons with holes, there are 2 dual
representations, and they are both used in Kicad:

- The first is (obviously) "polygon with holes", which handles a set of
polygons: the main outline and its holes.
It is very useful to edit a complex polygon shape, but not usable to
draw/plot it.

- The second is to use only one polygon which is the main outline with
all its holes "connected" to the main outline by overlapping segments
(what you are calling "infinitely-thin connections").
It is very useful to draw/plot a complex polygon shape, but not very
usable to edit it.

When you want to handle complex polygons, many times you have to change
the polygon description from the first to the second, and from the
second to the first representation.

-- 
Jean-Pierre CHARRAS