[Gpm] repeat and accel

Andrew Pimlott gpm@lists.prosa.it
Thu, 15 Feb 2001 00:36:52 -0500

I am using X with mouse input from gpm in repeater mode, and I
noticed that the pointer started acting funny when I tried to move
it quickly.  I discovered that when dx or dy exceeds the eight bits
that can be repeated faithfully (FWIW, this is with the ms3
repeater, which Debian adds as a patch), the repeater just sends the
low bits, causing weird aliasing.  The dx and dy can be too big
because of an accel option to gpm (which defaults to 2), or perhaps
because some mice have more than eight bits of motion input (?).

I'm sure nobody cares much about this trifle, but supposing I wanted
to fix it, I think I can either properly cap the dx and dy in the
repeater, or just not apply accel in repeater mode.  The later seems
to be done for the sensitivity setting (in processMouse, opt_scale
is only applied if not repeating); was that done for this reason?
That's actually sort of annoying, since XFree86 doesn't offer a
plain sensitivity setting.  Also, I don't know if there is any other
reason the dx and dy might be more than eight bits.

Any suggestions?