Originally Posted by ericshliao
Honestly, I am totally ignorant about DirectFB. But I wonder if it can be ported to iLiad. If it does, maybe we can get better performance.
DirectFB is just another display target for GTK (as are X11 and win32).
The main problem with Gtk on the iliad is that it has not been modified to make itself the necessary refreshes of the screen, so the app must do them explicitly when it detects that some Gtk widget has changed its appearance or updated its contents.
Using directfb one would not need the X server running, so one layer less (but having X has a lot of advantages, so much that there is a port of X that is capable of running in DirectFb).
Last time I checked (and it was indeed a long time ago), directfb fared well, but had problems when you wanted to display multiple apps simultaneously.
One more thing: the reason that ipdf uses the fb directly is to be a little more responsive when flipping pages, but normally that's not so critical.
That said, is possible that DirectFb can have advantages in the refreshes front (it's a small codebase, thus more friendly to hack in some refresh algorith in there), but I would expect that the advantages in performance be very small.
Hope this makes things a bit more clear :-).