Hımm. So what can I do for fluently and perfect painting? Also I know a program which can make some good paintings and of course it uses SDL. But it is written by C. Here: http://www.newbreedsoftware.com/tuxpaint/ and it's ok on my machine.

And can you look at http://www.icculus.org/~lucasw/prog/paintwin.exe
This is a native SDL example. How does it do this kind of drawing fluently and catching all mouse movements?