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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.

Brian
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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?
cheers.
-Luke