Donnerstag, 5. Februar 2009

QT rocks :)

I investigated the poor performance QT4 showed at QGears2 in the aliased case. (20fps vs. 80fps antialiased)
QT was using XRender in a quite inefficient way for the aliased case, as well as Xorg falling back to software although it could clearly do better. I hope I can fix that, shouldn't be too hard.

I sent them a mail, and after a short discussion a patch was written by trolltech targeted for 4.5, improving the performance of aliased shapes by a factor 2. Once Xorg is fixed performance should double again.

Sometimes its really a big plus to have a company behind an open source project maintaining it, like its the case for OpenJDK or QT. Some other projects I tried to contribute are in a far worse state.


absorbb hat gesagt…

I have compared performance of qgears2 with -graphicssystem raster
and jgears2 with rendering to BufferedImage.
Both methods are use software rasterization. But Qt does it much faster. Looks like there are lot of space for optimization in Java2D.

And thank you for work on Xrender backend. I waiting for it very. Because current linux performance of Java2D isn't good.

Linuxhippy hat gesagt…

absorbb: So why don't you grab the code and start hacking on it. your help is really welcome - especially for the oss rasterizer pisces