This is pentablet calibrator You can save six calibration pattern. Disconnect tablet for multi tablet. This script works display runnining in mirror mode only.
./INSTALL.sh
git clone https://github.com/megamuteki/pencal.git or
wget https://github.com/megamuteki/pencal/archive/master.zip -O ./pencal.zip ; unzip pencal.zip ; rm ./pencal.zip
./INSTALL.sh
./UNINSTALL
memo:Select from PEN List and Monitor List.
