Subject: bug#74214: 30.0.92; Feature request - Support fringe bitmaps of width > 16 pixel

From: Eli Zaretskii <[email-masked]>
Date: Tue, 05 Nov 2024 21:10:44 +0200

> Date: Tue, 05 Nov 2024 18:11:24 +0100
> From:  Daniel Mendler via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <[email-masked]>
> 
> Dear Emacs devs,
> 
> on high resolution displays, fringe bitmaps of 8 or even 16 pixel are
> quite small. The function `define-fringe-bitmap' requires the bitmap
> width to be an integer from 1 to 16. I would like to request to lift
> this restriction, maybe allowing widths up to 64 or even larger. The
> fringe itself is already allowed to be larger, e.g., the following is
> supported, but the bitmaps cannot take advantage of the larger fringe:
> 
> (setq-local left-fringe-width 64
>             right-fringe-width 64)

This is not easy.  For some history, see bug#37755 and bug#37689.

Po Lu, ISTR that we established at some point that there were some
technical difficulties to implementing scaling of fringe bitmaps, but
I cannot find the relevant discussion.  Do you happen to remember the
details?  Or am I dreaming and we never talked about this?