Okay, with your test app it's not bad at all, certainly enough to plot an accurate mouse path. It's generating many more events than I am getting with my reimplementation of Qt's x11EventFilter, (the method you use in Qt to access the app's X event loop). So it looks like it's Qt's sources that I have to check.
Thanks for all the quick replies! I know Xlib but usually I was using it in conjunction with Motif ;-) On Monday 06 May 2002 8:36 pm, Mark Vojkovich wrote: > On Mon, 6 May 2002, Mosfet wrote: > > Thanks for the replies Mark and Keith! > > > > Interpolation isn't a problem but it just didn't seem to be like the > > frequency of events was enough to accurately emulate the mouse motion > > when the mouse is moved quickly. It certainly wasn't 60 or 120hz, at > > least I didn't get nearly that many events or items in the mouse > > history... when the mouse is moved quickly the gap is quite large. I'm > > almost positive apps like Gimp must be getting more coordinates than this > > because doing things like spinning the mouse in circles really fast gives > > more accurate results than interpolating between MotionNotify coordinates > > would allow. > > The server will give you all the events the mouse produced while > the pointer was over the window. > > > For XGetMotionEvents I simply called it from the my MotionNotify handler > > with the timestamp of the last MotionNotify event as the start time and > > CurrentTime as the stop time. I assume this is a valid way to get all > > positions and the result was the same as just using XMotionEvents > > themselves. This gives a very wide spacing between points during fast > > movements. > > The temporal spacing for a constantly moving mouse should be the same. > The spatial spacing will be larger when you move it faster, of course. > More so because of pointer acceleration. > > You can increase the sampling rate in the Section "InputDevice" > in the XF86Config like follows: > > Option "SampleRate" "80" > > The rates available depend on the type of mouse, but many go > as high as 200 Hz. I don't know where the defaults are. > > I've got a test app that plots the mouse path and also the > latencies as well as the computed sample rate at: > > http://www.xfree86.org/~mvojkovi/mousetest.c > > You have to swipe the pointer across the window. It starts > collecting data when the pointer enters and stops when it leaves. > > > Mark. > > _______________________________________________ > Xpert mailing list > [EMAIL PROTECTED] > http://XFree86.Org/mailman/listinfo/xpert _______________________________________________ Xpert mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/xpert
