Re: Display scaling?

[Eli Zaretskii <eliz@gnu.org>]

> From: Po Lu <luangruo@yahoo.com>
> Cc: emacs-devel@gnu.org
> Date: Thu, 27 Jan 2022 08:57:27 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > From past discussions, the initial solution you propose will be
> > considered as bug by users.
> 
> Could you point me to some of those discussions?

Sorry, I don't have the references handy.  You'll need to search the
archives for HiDpi+fringe+bitmap, perhaps.

> AFAIU, the scaling on the NS and PGTK ports is generally considered
> superior to the other ports, and they simply scale the bitmaps up.

You mean, if you scale up enough, you actually see the pixels as small
squares?

> > In the past we discussed only 2 resolutions, in which case providing
> > another set of fringe bitmaps sounds plausible.  But you seem to be
> > talking about supporting any arbitrary scale, not just the double one
> > of HiDpi displays, and that calls for a different implementation that
> > we should IMO think over up front.
> 
> Some of those monitors already default to a 400% scale, so GNOME and NS
> already aren't constrained to double scales.

My point wasn't about the scale value itself, it was about the number
of scale values we want to support.  If it is a small number of
discrete values, we could prepare bitmaps for each of the supported
values, but if the number is practically infinite, we cannot use such
a solution.

> How about using a vector graphics format for the "new" fringe bitmaps?
> We already have SVG support, but IMHO SVG is too heavy and isn't present
> on every system, so maybe a custom vector graphics format for fringe
> bitmaps would be in order.

That's exactly the issue that may need to be resolved, yes.  If indeed
we want to support a large number of scales.