Re: What is the proper way to scale fringe-bitmaps for high-DPI displays?

[Clément Pit-Claudel]

On 2019-03-20 15:44, Eli Zaretskii wrote:
>> Cc: address@hidden
>> From: Clément Pit-Claudel <address@hidden>
>> Date: Wed, 20 Mar 2019 15:34:26 -0400
>>
>>> Instead, I think when a frame is created, we should record its
>>> high-DPI state in the frame structure, or maybe in the frame's
>>> parameters, and then use that when we prepare the fringe bitmaps for
>>> display.
>>
>> That would be nice.  In fact, we already have code to detect high-DPI 
>> displays in C, in x_get_scale_factor in xterm.c (used to scale wavy 
>> underlines).  Would the way to go be to record the value returned by this 
>> function in the frame's parameters?
>
> The frame's parameters is a better way if we think such a parameter
> will be useful to Lisp programs, and calling a function for that is
> too much overhead.  Otherwise, a simple field of 'struct frame' will
> be somewhat less hassle, because you don't need to mess with the likes
> of frame-parameter to teach them about this new parameter.  But either
> way, the job is not hard.

Oh, so Emacs' C code would scale the bitmaps? I expected the Lisp code would do 
that.