RE: [pygame] Speed of mouse position capture

["Brian Bull" <Brian.Bull@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx>]

> -----Original Message-----
> From: owner-pygame-users@xxxxxxxx 
> [mailto:owner-pygame-users@xxxxxxxx] On Behalf Of Luke Paireepinart
> Sent: Monday, 15 May 2006 2:41 p.m.
> To: pygame-users@xxxxxxxx
> Subject: Re: [pygame] Speed of mouse position capture
> 
> Brian Bull wrote:
> >>> I am encountering one difficulty, which is that the speed 
> of mouse 
> >>> position capture seems quite slow. I had expected that the
> >>>       
> >> app would
> >>     
> >>> receive a MOUSEMOTION event every time the mouse shifted to a new 
> >>> pixel, and that connecting up the locations of these MOUSEMOTION 
> >>> events would give an almost exact representation of the 
> path of the 
> >>> mouth across the screen. However, what happens in practice
> >>>       
> >> is that, if
> >>     
> >>> the mouse is moving fast, consecutive MOUSEMOTION events can be 
> >>> separated by more than 20 pixels. This makes it very hard
> >>>       
> >> to interpret
> >>     
> >>> the path of the mouse with enough precision - it ends up
> >>>       
> >> divided into
> >>     
> >>> a small number of long line segments.
> >>>       
> >> What OS? Win9X sampled the mouse less frequently that 
> Win2K and later.
> >> Also serial mouse is slower than ps2, which is slower that usb.
> >>
> >> Alan
> >>     
> >
> > Os is XP so presumably not the problem. I think it might be 
> a serial 
> > mouse though. Will check. I'm sure I've got a usb mouse 
> sitting about 
> > somewhere.
> 
> I wrote a simple "loop through and print out all the 
> mousemotion events" 
> script.
> I even made it to where it only updated a few pixels of the 
> screen rather than the entire thing per iteration.
> I have an optical USB mouse on WinXP and a 1.3ghz AMD 1500+ 
> w/ 512 mb ram and a Geforce FX 5600.
> Granted, my processor's a little on the slow side, but it's 
> decently fast for our purposes, I believe.
> Either way, the result of my test is, as yours was, some 
> coordinates being as far as 40 px apart when I moved the 
> mouse very quickly.
> So I'd say none of the following are the issue
> 1) Your mouse format (ps2/serial/usb),   2) your OS,   3) your 
> CPU/ram/video card.
> I'm guessing, like the guy mentioned earlier, that SDL just 
> doesn't by default update the mousemotion event fast enough.
> Have you considered just doing a pygame.mouse.get_pos() in a 
> separate thread or something of that sort?

[embarrassed] I don't know how to multi thread. Will try using DirectX,
failing that will investigate multi threading (can you point me to a
good reference?)

Brian
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