help-gnu-emacs
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Emacs flickers periodically


From: Dmitry Gutov
Subject: Re: Emacs flickers periodically
Date: Sat, 17 Jun 2017 22:27:56 +0300
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:54.0) Gecko/20100101 Thunderbird/54.0

On 6/17/17 9:35 PM, Eli Zaretskii wrote:

Flickering is not caused by display synchronization.  It is caused by
constant redrawing of large portions of display with the same content.

Not necessarily large ones. And vice versa, large portions of display can be redrawn often and the user might be fine with it if only consistent states are shown. The result might be called "animation".

AFAIK, Emacs never redraws display in inconsistent state (barring
bugs, of course).

But that's the effect that the double-buffering patch brings: limiting
redrawing to consistent states only.

So maybe those were bugs (like 12363 and 16621), but they went unfixed
until Daniel's patch.

That's not what double-buffering does.  What it does, AFAIU, is let
Emacs redraw however many times it wants, and then bitblt the result
only once to the glass.

Those are implementation details. In effect, the redraw happens once.

But *when* does it happen? If the choice of this moment was not good enough, bugs 12363 and 16621 would continue occurring.



reply via email to

[Prev in Thread] Current Thread [Next in Thread]