Re: MS Windows double buffering

[Eli Zaretskii <eliz@gnu.org>]

> From: Po Lu <luangruo@yahoo.com>
> Cc: kbrown@cornell.edu,  emacs-devel@gnu.org
> Date: Sat, 30 Apr 2022 17:55:32 +0800
> 
> > This still flickers considerably here, albeit with a significantly
> > lower frequency.
> 
> What if you comment out these lines in w32term.c?
> 
>       if (f && !w32_disable_double_buffering
> 	  && FRAME_OUTPUT_DATA (f)->paint_buffer_dirty
> 	  && !f->garbaged && ignore_dirty_back_buffer)
> 	w32_show_back_buffer (f);

Then the flicker of the window parts of the frame (the tool bar, the
text area, the scroll bar, and the mode line) don't flicker at all,
but the menu bar and the title bar still do, albeit very
insignificantly.  Overall, the result is much better.

> > What other test cases in the discussions would you recommend to try?
> 
>   (run-hooks 'xref-after-jump-hook)
> 
> for example, which causes considerable flickering without double
> buffering, but none at all when double buffering is enabled.

Just evaluating it in "emacs -Q"?  I see no flickering at all, with or
without double-buffering.