Comment 0 for bug 774938

Stefan Löffler (st.loeffler) wrote :

Binary package hint: xserver-xorg-input-evdev

When using something like `xinput set-float-prop $INPUTDEV "Coordinate Transformation Matrix" 0.0 -1.0 1.0 1.0 0.0 0.0 0.0 0.0 1.0` to match the coordinates of a touchscreen/tablet to a rotated (transformed) screen, the cursor moves around erratically.

From the original report of david-dklevine (
when a horizontal or vertical drag is performed the cursor jumps wildly - it appears to jump between what it should be according to the coordinate transformation and what it would be if x=0 and y=1 (that is if the second line of the matrix was the identity). With a diagonal drag or a touch the cursor appears where it should be.

In addition to the Cando Multi Touch Panel reported at, it also affects me with a AsusTek, Inc. MultiTouch(TTI) (on Asus EeePC T101MT)

lsb_release -rd
Description: Ubuntu 11.04
Release: 11.04

$ apt-cache policy xserver-xorg-input-evdev
  Installed: 1:2.6.0-1ubuntu12
  Candidate: 1:2.6.0-1ubuntu12
  Version table:
 *** 1:2.6.0-1ubuntu12 0
        500 natty/main amd64 Packages
        100 /var/lib/dpkg/status