libinput: the road to 1.0
spitzak at gmail.com
Mon Feb 23 11:14:35 PST 2015
On 02/23/2015 01:50 AM, Michal Suchanek wrote:
> What is the semantic of speed for trackballs? Technically the DPI of
> scanning the ball movement can be determined and is often part of the
> specification but the perceived speed will likely depend on ball size
> and mounting as well.
The trackball scanner is focused on the surface of the ball, so this
should mean the size of the ball does not matter, as that point is
moving the same speed as the point the fingers move (well to be exact
only the point exactly on the opposite surface of the ball is moving at
that speed. Looking at the trackball I have I can see the camera is not
actually at the bottom of the sphere, but somewhat up to the back,
opposite a point closer to the front than the top of the sphere. This
may indicate the manufacturer had to take this into consideration).
I have a Kensington trackball (Expert Mouse Model #K64325) and it was
just plugged into an existing Ubuntu machine that I don't think knows
much about it, so I assume it is treating it as a generic mouse. In this
case the speed of both the trackball and the scroll ring are fine, or at
least certainly not orders of magnitude wrong. Also appears to match how
it behaves in Windows. Not sure if that means anything however.
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