more visiting and less buffering in drawinglayer/

[Luboš Luňák]

On Friday 03 of December 2021, Thorsten Behrens wrote:
> Luboš Luňák wrote:
> > I've implemented a cache in the Skia backend to handle cases of
> > drawinglayer being dumb and repeatedly asking to do expensive
> > redraws of the same stuff over and over again, which requires that
> > the underlying bitmap is the same object and not something created
> > from scratch every time.
>
> You meant to say application code being dumb & dropping their
> ViewObjectContact instead of keeping it for the next paint? ;)

 I don't understand in enough detail how all that stuff works, but I'd say 
that the answer is that not always. I think application code is not involved 
in tdf#104878, and even if, it's Impress, the app that AFAIK should be the 
most adapted to drawinglayer&friends, so there is probably something wrong if 
even that one can't get it right. And I definitely remember dumb things in 
graphics stack code, a random example that comes to mind is Impress/canvas 
having 0% hit rate for cached scaled bitmaps (with at leats two different 
reasons for the caching being broken).

-- 
 Luboš Luňák
 l.lunak at collabora.com