Re: Drawing UI elements behind text

[Cecilio Pardo]

On 28/11/2024 7:53, Eli Zaretskii wrote:
> Those (and other similar ones) are the scenarios where the display
> engine activates its non-trivial optimization methods, and the
> questions of interest related to that are:
>
>    . do we need to disable some of the optimizations when these
>      segments are on display (because their assumptions are
>      incompatible with how these segments are drawn)?
>    . how do these segments affect redisplay times in each such case,
>      after we disable the optimizations, if any, that are incompatible
>      with them?
>
> These questions are prerequisites for deciding whether we need to make
> this particular case faster by some special measures.

The segments are drawn independently of redisplay, on top of its result, 
without affecting it (so that the next redisplay finds it exactly as it 
was). So no optimizations are disabled, and the time added by them is 
independent of what redisplay had to do.