tiles & memory

[Cyrille Berger]

On Wednesday 11 October 2006 23:39, Bart Coppens wrote:
> > Relatedly: let's set the minimum number of tiles
> > (64x64xchannelsxchanneldepth bytes) to at least 1000, and let's not allow
> > the user to specify a value lower than that. Krita is an image editor,
> > not a postage stamp editor!
>
> Sure, but setting it to extremely low values is useful to debug stuff ;-)
> It exposes many subtle bugs a lot more rapidly. Bugs that would otherwise
> continue being there, lurking, until it can randomly attack a wary user of
> a stable Krita release. Which we obviously won't be able to reproduce,
> because it's a lot more random with regular values. Just to say that it has
> its advantages, even though not for the user :-)
No one prevents you to set during developement the number of tiles to one :)

But we really have to do something about the convolution painter, it's 
performance is _catastrophic_. And around half of the time is spend in memcpy 
of the pixels, which is mostly the difference between 1.5 and 1.6. That's 
mostly to solve this problem that boud and me have consider the lock region.

As for locking too big area, we can limit size, like preventing the user to 
lock in memory more tiles than the maximum numbers of allowed tiles.

-- 
--- Cyrille Berger ---