ubuntu-x-swat team mailing list archive

[rawphi <raphael@xxxxxxxxxxxxxxxx>]

it seems that something scales the touchpad x/y speeds to the virtual
screen size, without respecting aspect ratio. as this does not happen
with other mice, the synaptics driver probably is to be blamed.

there's a crude hack for this bug: mimick the aspect ratio via setting
the virtual screen size with xrandr

1) figure out the virtual screen size (the screen size is automatically shrink-wrapped to the smallest possible size to contain all monitors)
e.g. on my laptop, with an external monitor connected:

~$ xrandr
Screen 0: minimum 320 x 200, current 3360 x 1080, maximum 8192 x 8192
LVDS1 connected 1440x900+0+180 (normal left inverted right x axis y axis) 261mm x 163mm
   1440x900       50.0*+
   1360x768       59.8     60.0  
   1152x864       60.0  
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9  
VGA1 connected 1920x1080+1440+0 (normal left inverted right x axis y axis) 509mm x 286mm
   1920x1080      60.0*+
   1280x1024      75.0     60.0  
   1152x864       75.0  
   1024x768       75.1     60.0  
   800x600        75.0     60.3  
   640x480        75.0     60.0  
   720x400        70.1  
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)


2) increase the screen size to have the same aspect ratio as your synaptics touchpad (here, it's ~3360/1.938):
~$ xrandr --fb 3660x1734

-- 
You received this bug notification because you are a member of Ubuntu-X,
which is subscribed to xserver-xorg-input-synaptics in Ubuntu.
https://bugs.launchpad.net/bugs/825548

Title:
  Touchpad cursor moves twice as fast horizontally after connecting an
  external monitor

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