Steve Harris ([EMAIL PROTECTED]): > On Wed, Sep 25, 2002 at 06:12:31 +0200, Tim Goetze wrote: > > >> I seem to remeber that on the Amiga and in GL I could issue a call to wait > > >> for the next vertical blank, forcing the redraw to be in sync with the > > >> video hardware. Is there an equivalent in FLTK or X? > > >> > > >> How do other people get round this? > > > > i'd look at the GL kernel support sites, they might have a patch that > > creates some sort of a '/dev/retrace', or add it to GLX. with vanilla > > linux/X there's no way to do this except busy-wait reading inb > > (0x3da) afaik. > > There is a copy-on-next-vert-refresh call in X, I think. Part of the > dbe extension.
I don't think so. X tears all the time. I think that DBE does something else, the main X server doesn't page flip. > I dont think I can use it with FLTK though, as I can't find a way of > drawing onto an non-screen surface and then using the dbe. > > Its probably just a bad choice of toolkit. GDK and SDL seem to be able > to do it. Nope, SDL applications tear all the time also. The reason is that to handle the vertical interrupt, you need to have a kernel driver that provides it/does the right thing. nVidia's binary driver does it for GL games in fullscreen. No DRI drivers can do it, which is why and DRI-based GL driver tears like mad even fullscreen. Michel Danzer has just donne a patch to export an ioctl for the retrace interrupt on the Radeons though, but that's a new development. For video overlay surfaces it's a bit easier: most cards can page flip their overlay surfaces easily. So, you won't see tearing with XVideo-based apps in general. HTH, -- Billy Biggs [EMAIL PROTECTED] _______________________________________________ linux-audio-dev mailing list [EMAIL PROTECTED] http://music.columbia.edu/mailman/listinfo/linux-audio-dev
