Restrict graphic tablet to primary display

 https://unix.stackexchange.com/questions/428747/restrict-graphic-tablet-to-primary-display

 

xinput  # get the IDs for all relevant pieces of my tablet. 

xrandr  # get the names of my displays 

xinput map-to-output 13 HDMI-A-0
xinput map-to-output 14 HDMI-A-0   

xinput map-to-output 21 VGA-1