Preformance hit when lines on screen are long

[MarcellVokk]

Hello. I've recently started using this editor in a project and have been loving it so far, however,
I noticed that the performance of the editor (when scrolling) decreased dramatically when the lines on the screen were realy long (800+ chars). I don't know why this is exactly, but I think it is because the out-of-view parts of the line are still being drawn. It would be great if someone could look into this, even tough it is an edgecase scenario!

Thanks!

[jimfoye]

The horizontal scrolling? Or vertical? Or both?