Re: [PATCH] system: grub: Convert grub background using rsvg-convert

[Luis Felipe López Acevedo]

On 2015-08-28 13:24, Mark H Weaver wrote:
> Hi Luis, thanks for the quick response.
>
> Luis Felipe López Acevedo <address@hidden> writes:
>
> > On 2015-08-27 16:19, address@hidden wrote:
> > > Mark H Weaver <address@hidden> 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/

GuixSD-fully-black-4-3.svg
Description: image/svg