Date: Wed, 03 Nov 1999 14:23:15 -0800 From: Amancio Hasty <hasty@rah.star-gate.com> To: current@FreeBSD.ORG Subject: vga driver and signal Message-ID: <199911032223.OAA39942@rah.star-gate.com>
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Say is there anyone that can add signal delivery to the /sys/dev/fb/vga.c? (For now any quick hack to the driver for delivering the signal will do ) The context is from a posting to the xfree86 mailing list: keithp@suse.com said: > You need to fit one event in per retrace. If you knew > the phase of the sampling clock with respect to the retrace > you could do that by skipping one sample then two then one, etc... > But we don't know the phase and if you do that with > arbitrary phase you end up sending two events in one retrace > and then skipping the next and it looks worse. > If we had a signal delivered at vertical retrace time, we could easily > sync the mouse rate with the video rate -- run the mouse events > through a simple filter and estimate mouse position at the vertical > retrace interval using some forward estimation. > Additionally, the vertical retrace signal could be used for the double > buffering extension to avoid tearing, and for the sync extension which > kinda wants this. And for many video cards which can't update > colormaps or cursor positions at other times without visible artifacts > on the screen. > It would take some kernel work though; the results might well be worth > the effort. > -keith I am too busy nowdays working :( Have Fun Guys! -- Amancio Hasty hasty@rah.star-gate.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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