Interesting bug in mouse pointer handling

  • Thread starter Thread starter David Bala¾ic
  • Start date Start date
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David Bala¾ic

Guest
Hi!

With default settings*, when you move the mouse diagonaly up-right,
the pointer moves straight up instead of up-right.
I noticed this on Windows XP and 2003. It appears to be fixed in
Vista.

Details:
* - In Control Panel have some normal sensitivity and "Enhance
Pointer Precision" on (it is on by default).
Now place the mouse pointer to the right of some vertical line (like
an edge of some window, you can open Notepad for this) in middle
height (half of screen height for example).

Now put some object with a straight edge (like a book) left of the
mouse. Have to upper left edge of the mouse touch the book. Put you
thumb between the book and the lower left edge of the mouse. Now move
the mouse down and up, so that it is always touching the book with
both upper left edge and lower left edge (where also your thumb is).

This is so to get an always same diagonal movement of the mouse.

Now watch the mouse pointer. When you go down, the pointer goes down-
left, as it should. But when going up, it goes straight up instead of
up-right.
If the pointer was to the right of the windows edge and it crossed it
when moving down-left, it does not return to the right side when going
up-right.

If you don't see this, then try moving the mouse slower.

Note: custom mouse drivers (Logitech, Razer etc.) might change this
behavior.

I tried this with 4 different mouse (from 10 year old with ball to
modern optical) on 3 different PCs (laptop, work PC, home PC) and it
is the same on all (except Vista, as noted before).

Regards,
David Balažic
 
Re: Interesting bug in mouse pointer handling

David Balažic wrote:
> Hi!
>
> With default settings*, when you move the mouse diagonaly up-right,
> the pointer moves straight up instead of up-right.
> I noticed this on Windows XP and 2003. It appears to be fixed in
> Vista.
>
> Details:
> * - In Control Panel have some normal sensitivity and "Enhance
> Pointer Precision" on (it is on by default).
> Now place the mouse pointer to the right of some vertical line (like
> an edge of some window, you can open Notepad for this) in middle
> height (half of screen height for example).
>
> Now put some object with a straight edge (like a book) left of the
> mouse. Have to upper left edge of the mouse touch the book. Put you
> thumb between the book and the lower left edge of the mouse. Now move
> the mouse down and up, so that it is always touching the book with
> both upper left edge and lower left edge (where also your thumb is).
>
> This is so to get an always same diagonal movement of the mouse.
>
> Now watch the mouse pointer. When you go down, the pointer goes down-
> left, as it should. But when going up, it goes straight up instead of
> up-right.
> If the pointer was to the right of the windows edge and it crossed it
> when moving down-left, it does not return to the right side when going
> up-right.
>
> If you don't see this, then try moving the mouse slower.
>
> Note: custom mouse drivers (Logitech, Razer etc.) might change this
> behavior.
>
> I tried this with 4 different mouse (from 10 year old with ball to
> modern optical) on 3 different PCs (laptop, work PC, home PC) and it
> is the same on all (except Vista, as noted before).
>
> Regards,
> David Balažic

You have waaaaaaaaaaaaay too much time on your hands.

Alias
 
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