Hi to everybody,first of all,thanks for the development of this great program.
My name is Giuseppe and I'm from Italy.
I'm following the development of Krita since 2.2(waiting for a windows release ),but at the end I decided to try krita on ubuntu.
I tried first the 2.3 version some months ago,I found it really good,I like a lot how brushes work,I see a lot of potential for this application,I really hoped to try krita 2.4 as soon as possible but I don't have much time to dedicate to linux.
As I'm not a linux guru only today I was able to install the beta 3 for 2.4 version(on ubuntu 11.04 with ppa neon package).
I like the general feeling of the new version,but I have a problem not found on the previous 2.3 version.
The pixel brush is really slow(on 2.3 it worked like a charm),
I'm testing it on a q6600 with an nvidia card(old 8600 gt),with this system the 2.3 version was really a joy to work with.
The pixel brush it's really slow with small radius(from size 1 to 5),what from my point of view it's really not understandable is that with bigger brush size the performance are much better(not as 2.3 version but acceptable),for example a 50 brush size is 5/10 times better than a 5 brush size.
It's a known issue or it can be related to a not good installation from my part?
Sorry to start writing on the forum bothering with performance issues but I don't understand if it's a problem with my system or with a poor installation from me.
Some help is really appreciated.
Thanks.
Bye

Are you sure that it's beta 3? The problem should be fixed in that version.

Hi slangkamp,yes,it should be version 2.4 beta 3(at least this is what the about Krita screen prints).
From what I can understand,the more the stroke is long,the more it lags(to avoid lagging I need to do really slow strokes,if I do stroke faster,the stroke ends some seconds after I have allready finished the stroke).
But for example with the hairy brush,I can do really fast strokes without lagging.

That's a know issue and also very tricky. It's a two-folded problem.

First the are the small brushes. Small brush are really slower than medium sized brush in Krita. Every brush stroke is a series of brush "potato stamps". Every single stamp has some performance cost that can be divided into a fixed amount that is needed for every stamp and a dynamic amount that depends on the size of the brush. With a small brush we have to do lots of stamps which means that we have a high amount of fixed costs, when the brush get bigger we do less stamps and the fixed part get smaller.

The other issue is that we changed the interaction between the painting tool and the actual painting. There were some issues in 2.3 that we needed to solve by that. The lag from the stroke is a side effect from that. We haven't analyzed it yet, but I suspect that the problem is that we don't skip input data anymore. In 2.3 when the application was busy some inputs were ignored.

thanks slangkamp for the answer,at least it's not a problem with my installation,I was thinking to some conflict as 2.3 worked really smooth.
Bye

Well, I can definitely confirm this. Using Krita 2.4, my 3.7 GHz dual core machine with 6 GB RAM, admittedly not the newest on the market, is too weak to draw a circle with a 5 px brush on a 1600x1200 8bit RGB canvas.

Had to get this _very_ surprising fact off my chest, but to give at least some minimum meaning to this post: The behaviour is significantly improving when setting the density slider in the brush settings to 0.25 (instead of 0.10 which was the default I found there). Result looks still acceptable.

Some brushes have a very small spacing setting and those can be quite slow. But your machine should up to painting 500px brushes on a 300dpi A4 image without lag; but are you using Windows or Linux?

Hello Boudewijn,
I'm running Krita on Slackware Linux 13.37 (32 bit with PAE). I don't completely rule out that I did something wrong when building it, although I don't see how.

Ah, you built yourself. A couple of gotchas:

* always build with at least some optimizations: build_type=RelWithDebInfo or build_type=KritaDevs
* make sure you disable the memory checker using cmake:
-DHAVE_MEMORY_LEAK_TRACKER=off -DHAVE_BACKTRACE_SUPPORT=off

you probably need to remove CMakeCache.txt before building again, or you can edit that file directly.

Thanks for the hints! Memory Leak Tracker and Backtrace Support had been off all along, but I supplied the RelWithDebInfo build type and compiled from a fresh build directory (Krita 2.4.1).

I didn't notice any difference in the mentioned behaviour, though. With a 5 px brush and 0.10 density, a circle can only be drawn slowly and carefully, otherwise there's just a lot of straight lines following the general direction of my stroke and ending a good deal before the point at which I stop drawing.

On a sidenote, I don't know if it is considered good style to discuss these things here, or if it would be more appropriate to open a bug report. If the latter, I must admit that I didn't do a research in the bug tracker yet.

Discussing here is fine. If a brush is slow, it's not really a bug... We're trying to optimize all the time, I committed a big optimization patch yesterday, but there's always more work to do.