hi, Mark Vojkovich [EMAIL PROTECTED] wrote on Wed, 16 May 2001 11:32:20 -0700 (PDT) > On Wed, 16 May 2001, Peter Ronnquist wrote: > > > Hello, > > > > I am trying to figure out how to update the screen > > during vertical retrace. Is this possible with Xfree? > > No. Not in any portable way. Only if the client knows > hardware specifics and runs as root and pokes registers. > > If you are using OpenGL, your OpenGL implementation may > be able to do buffer swaps synced to the retrace. Probably > not though. > > Mark.
Sorry to quote a quite old posting. Just a short question related to the topic above: Isn't the following fairly portable without OpenGL (at least to architectures where DGA2 is available)? [ From README.DGA ]: void XDGASetViewport( Display *dpy, int screen, int x, int y, int flags ); [...] viewportFlags Any of the following may be OR'd together: XDGAFlipRetrace Indicates that the hardware can switch viewports during the vertical retrace. XDGAFlipImmediate Indicates that the hardware can switch viewports immediately without waiting for the vertical retrace. [...] I'm using this to get smooth animations with DGA2, and to some extent it works. As it's not perfect (probably my fault) I'm still interested in this topic. thanx, martin PS: please CC to my address above, as I'm not subscribed to the Xpert list. Thanx. _______________________________________________ Xpert mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/xpert