Re: Missing items to make Cairo ready

[Jean Abou Samra]

Le 04/01/2023 à 12:52, Han-Wen Nienhuys a écrit :
> On Thu, Dec 29, 2022 at 1:53 AM Jean Abou Samra <jean@abou-samra.fr> wrote:
> > Hi,
> >
> > I have just opened issues for the missing features of
> > the Cairo backend that I am aware of.
> >
> > https://gitlab.com/lilypond/lilypond/-/issues/6500
> > https://gitlab.com/lilypond/lilypond/-/issues/6501
> > https://gitlab.com/lilypond/lilypond/-/issues/6502
> > https://gitlab.com/lilypond/lilypond/-/issues/6503
> > https://gitlab.com/lilypond/lilypond/-/issues/6504
> >
> > Are there any others?
> I've read through the discussion you started here, but IMO we're too
> fixated on backward compatibility, which is unfortunate because the PS
> -> GS -> PDF route was never thought through carefully. We started
> dumping PostScript because we were going through TeX before, and
> creating PDF at the time involved .tex => .dvi => .ps  => .pdf (with
> .eps included into .dvi for graphics).  However, at the time, PDF
> rather than PS was already the common format for print documents. We
> were also lazy, and didn't want to bother learning how to dump PDF
> directly.
>
> PNG images will always be clunky for embedding line art, so it can't
> be the recommended solution. What makes most sense for users? Other
> illustration programs also can't process EPS (for the same reasons we
> don't), so how do those programs embed line art? What is the preferred
> format for logos today? SVG? AI? PDF?



PNG?

Look here:

https://www.gnu.org/graphics/package-logos.fr.html

More than half of the logos are in PNG, some are in SVG, a
some in JPG.

I still don't understand the criticism against logos in PNG. For
something like a page watermark, I understand that vector graphics
may be important, but for something the size of a logo?

I looked a little bit at librsvg. On the plus side, their
COMPILING.md describes how to cross-compile it with MinGW,
so we know that it works. On the minus side, it pulls in
Gdk-pixbuf and Libxml2.



> Given the sorry state of the SVG backend, and the niche quality of the
> output-attributes feature, we could be justified to drop the SVG
> backend rather than implementing attributes in Cairo-SVG (although it
> sounds like a straightforward extension to Cairo).


I don't think so; look at the kind of stuff it would break:

https://github.com/paopre/Spontini

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