On 2015-08-28 13:24, Mark H Weaver wrote:
> Hi Luis, thanks for the quick response.
> 
> Luis Felipe López Acevedo <felipe.lopez@openmailbox.org> writes:
> 
>> On 2015-08-27 16:19, ludo@gnu.org wrote:
>>> Mark H Weaver <mhw@netris.org> skribis:
>>> 
>>>> The main difficulty here was that our SVG artwork is partially
>>>> transparent, and includes a "Background" layer with a checker-board
>>>> pattern.  I guess this layer is for convenience when editing in
>>>> Inkscape, and apparently Inkscape excludes the "Background" layer 
>>>> when
>>>> exporting to png.  Other tools render all layers.  Therefore, 
>>>> avoiding
>>>> Inkscape required code to remove that layer before conversion to 
>>>> png.
>>> 
>>> Fun.  :-)
>>> 
>>> If possible, I would rather remove said layer directly in the
>>> guix-artwork repo, or somehow make that layer invisible to
>>> rsvg-convert.  Luis Felipe: What’s your take on this?
>> 
>> If I understand correctly, the problem is transparency, right? I don't
>> understand why transparency would be an issue when exporting PNG
>> images, but I don't know how rsvg works.
>> 
>> In any case, the SVG has transparency in several parts:
>> 
>> - The logo.
>> - The checkerboard pattern (which is part of the design as in the slim
>> login screen).
> 
> Ah, okay, so my guesses were incorrect.  I guess the problem is 
> actually
> that rsvg-convert (from librsvg) fails to render these SVG files
> correctly.  Here's how it renders grub/GuixSD-fully-black-4-3.svg on a
> black background:
> 
> rsvg-convert --width 640 --height 480 --background-color black \
>              --format png --output ~/grub-background.png \
>              grub/GuixSD-fully-black-4-3.svg
> 
> 
> 
>> Modifying the first to be fully opaque is time consuming, but can be
>> done.
> 
> No need, we should keep the source file in the preferred form for
> editing.  I'll see if I can figure out what librsvg is doing wrong,
> and in the meantime we can keep using inkscape to do the conversion.
> 
> Thanks again,
> 
>     Mark

OK, so the culprit is the checkerboard pattern. I generated it with 
Inkscape, and it seems that it uses raster images instead of SVG. I 
tried doing one by hand and it works alright with rsvg-convert (see 
attached SVG).

I would commit changes directly to the repo, but I don't have a computer 
right now where I can install my tools. If you want, I can modify the 
files that use the checkerboard pattern this Saturday or Sunday and send 
them to you to put them in the repo.

Is that OK?

-- 
Luis Felipe López Acevedo
http://sirgazil.bitbucket.org/