bug#40845: SVG rendering issues

[Eli Zaretskii]

> From: Pip Cet <pipcet@gmail.com>
> Date: Sat, 25 Apr 2020 15:48:39 +0000
> Cc: cpitclaudel@gmail.com, 40845@debbugs.gnu.org
> 
> On Sat, Apr 25, 2020 at 3:30 PM Eli Zaretskii <eliz@gnu.org> wrote:
> >
> > I don't think I understand why we need to call a function for this.
> > This is about displaying an image with a specific background color,
> > isn't it?
> 
> Even if the problem were just the choice of background color, that
> would require significant and non-trivial changes for some cases: for
> example, an emoji might have to choose foreground colors that provide
> sufficient contrast to the background color, and antialiasing and
> sub-pixel rendering would also need to be taken into account.

We are talking about displaying images, not characters, right?  So why
are emoji relevant to this?

> I want to be able to define something that behaves like a character,
> including displaying differently in different frames and depending
> on different face parameters such as weight, slant, and RTL-ness.

All of that is possible with images, so I don't think I understand why
we need to handle this as a character.  This very bug report was filed
because I said we shouldn't use characters and fonts for these
purposes, so let's not discuss that alternative, please, at least not
here.