Re: macOS metal rendering engine in mac port

[Alan Third]

On Thu, May 20, 2021 at 06:17:18PM -0700, Aaron Jensen wrote:
> Hi,
> 
> I recently went from working entirely on my laptop screen to working on a
> large 5k2k monitor on macOS with Emacs 28. When I made that move, when
> Emacs was sized to take up 2/3rds of the monitor there was severe typing
> lag. Enough that typing in it felt really frustrating. I realized that
> shrinking the frame size helped alleviate the typing lag significantly.
> 
> Inspired by a recent reddit post, I decided to give the emacs macport a try
> again with its metal rendering engine (--with-mac-metal). I'm pleasantly
> surprised by its performance. It's very usable regardless of my window size.

Out of interest, is it the metal renderer making the difference, or is
the Mac port just better anyway?

I only ask because on my Mac enabling metal rendering results in a
*much* lower frame rate (although whether that equates to higher input
lag I don't know).

> I'm curious if now might be a good time to consider bringing over at least
> this rendering engine from the mac port and making it a part of Emacs
> proper. I'm not familiar with all of the reasons for keeping the mac port
> separate so maybe this whole thing is a non-starter, but I wanted to raise
> it because it's a real quality of life improvement on larger/higher dpi
> screens.

At that level the two ports don't really look alike, so it's not like
it's just a case of copying the relevant code over.

What might be helpful is to profile to find out what's slowing the NS
port down.
-- 
Alan Third