x11-touchscreen-calibrator
X Window System’s Touchscreen Calibrator
X11 Touchscreen Calibrator runs as a daemon in the background. It will detect the touchscreen automatically and adjust the corresponding Coordinate Transformation Matrix of Touchscreen xinput when the resolution is changed. It should also support rotation, reflection and different scaling modes of display output.
Coordinate Transformation Matrix
Zoom
Restrict the cursor movement within the left half side of the touchscreen display.
⎡ 0.5 , 0 , 0 ⎤
⎜ 0 , 1 , 0 ⎥
⎣ 0 , 0 , 1 ⎦
$ xinput set-prop ‘<device name>’ ‘Coordinate Transformation Matrix’ 0.5 0 0 0 1 0 0 0 1
Restrict the cursor movement within the top half side of the touchscreen display.
⎡ 1 , 0 , 0 ⎤
⎜ 0 , 0.5 , 0 ⎥
⎣ 0 , 0 , 1 ⎦
$ xinput set-prop ‘<device name>’ ‘Coordinate Transformation Matrix’ 1 0 0 0 0.5 0 0 0 1
Map the cursor movement to the left half touchscreen area.
⎡ 2 , 0 , 0 ⎤
⎜ 0 , 1 , 0 ⎥
⎣ 0 , 0 , 1 ⎦
$ xinput set-prop ‘<device name>’ ‘Coordinate Transformation Matrix’ 2 0 0 0 1 0 0 0 1
Map the cursor movement to the top half touchscreen area.
⎡ 1 , 0 , 0 ⎤
⎜ 0 , 2 , 0 ⎥
⎣ 0 , 0 , 1 ⎦
$ xinput set-prop ‘<device name>’ ‘Coordinate Transformation Matrix’ 1 0 0 0 2 0 0 0 1
Translation
Make the cursor shift right by half the width of the touchscreen.
⎡ 1 , 0 , 0.5 ⎤
⎜ 0 , 1 , 0 ⎥
⎣ 0 , 0 , 1 ⎦
$ xinput set-prop ‘<device name>’ ‘Coordinate Transformation Matrix’ 1 0 0.5 0 1 0 0 0 1
Make the cursor shift left by half the width of the touchscreen.
⎡ 1 , 0 , -0.5 ⎤
⎜ 0 , 1 , 0 ⎥
⎣ 0 , 0 , 1 ⎦
$ xinput set-prop ‘<device name>’ ‘Coordinate Transformation Matrix’ 1 0 -0.5 0 1 0 0 0 1
Make the cursor shift down by half the height of the touchscreen.
⎡ 1 , 0 , 0 ⎤
⎜ 0 , 1 , 0.5 ⎥
⎣ 0 , 0 , 1 ⎦
$ xinput set-prop ‘<device name>’ ‘Coordinate Transformation Matrix’ 1 0 0 0 1 0.5 0 0 1
Make the cursor shift up by half the height of the touchscreen.
⎡ 1 , 0 , 0 ⎤
⎜ 0 , 1 , -0.5 ⎥
⎣ 0 , 0 , 1 ⎦
$ xinput set-prop ‘<device name>’ ‘Coordinate Transformation Matrix’ 1 0 0 0 1 -0.5 0 0 1
Zoom x Translation
For example, if we want the center 1/4 area of the touchscreen to operate the fullscreen cursor movement.
⎡ 2 , 0 , 0 ⎤ ⎡ 1 , 0 , 0 ⎤ ⎡ 1 , 0 , -0.25 ⎤ ⎡ 1 , 0 , 0 ⎤
⎜ 0 , 1 , 0 ⎥ X ⎜ 0 , 2 , 0 ⎥ X ⎜ 0 , 1 , 0 ⎥ X ⎜ 0 , 1 , -0.25 ⎥
⎣ 0 , 0 , 1 ⎦ ⎣ 0 , 0 , 1 ⎦ ⎣ 0 , 0 , 1 ⎦ ⎣ 0 , 0 , 1 ⎦
equals to
⎡ 2 , 0 , 0 ⎤ ⎡ 1 , 0 , -0.25 ⎤
⎜ 0 , 2 , 0 ⎥ X ⎜ 0 , 1 , -0.25 ⎥
⎣ 0 , 0 , 1 ⎦ ⎣ 0 , 0 , 1 ⎦
equals to
⎡ 2 , 0 , -0.5 ⎤
⎜ 0 , 2 , -0.5 ⎥
⎣ 0 , 0 , 1 ⎦
$ xinput set-prop ‘<device name>’ ‘Coordinate Transformation Matrix’ 2 0 -0.5 0 2 -0.5 0 0 1
Scaling mode
The touchscreen display may support four different modes, such as ‘None’, ‘Full’, ‘Center’ and ‘Full aspect’.
pw = preferred width
ph = preferred height
(The preferred resolution of touchscreen display.)
sw = screen width
sh = screen height
(The virtual screen of X Window System.)
dw = display width
dh = display height
dx = display X axis
dy = display Y axis
(The actual resolution and position of touchscreen display.)
‘None’ mode
The behavior is undefined. It may work like ‘Full’ mode or ‘Center’ mode.
‘Full’ mode
⎡ dw / sw , 0 , dx / sw ⎤
⎜ 0 , dh / sh , dy / sh ⎥
⎣ 0 , 0 , 1 ⎦
equals to
⎡ 1 , 0 , dx / sw ⎤ ⎡ dw / sw , 0 , 0 ⎤
⎜ 0 , 1 , dy / sh ⎥ X ⎜ 0 , dh / sh , 0 ⎥
⎣ 0 , 0 , 1 ⎦ ⎣ 0 , 0 , 1 ⎦
‘Center’ mode
⎡ pw / dw , 0 , (dw - pw) / sw / 2 + dx / sw ⎤
⎜ 0 , ph / sh , (dh - ph) / sh / 2 + dy / sh ⎥
⎣ 0 , 0 , 1 ⎦
equals to
⎡ dw / sw , 0 , dx / sw ⎤ ⎡ pw / dw , 0 , (dw - pw) / dw / 2 ⎤
⎜ 0 , dh / sh , dy / sh ⎥ X ⎜ 0 , ph / dh , (dh - ph) / dh / 2 ⎥
⎣ 0 , 0 , 1 ⎦ ⎣ 0 , 0 , 1 ⎦
equals to
⎡ dw / sw , 0 , dx / sw ⎤ ⎡ pw / dw , 0 , 0 ⎤ ⎡ 1 , 0 , - (1 - dw / pw) / 2 ⎤
⎜ 0 , dh / sh , dy / sh ⎥ X ⎜ 0 , ph / dh , 0 ⎥ X ⎜ 0 , 1 , - (1 - dh / ph) / 2 ⎥
⎣ 0 , 0 , 1 ⎦ ⎣ 0 , 0 , 1 ⎦ ⎣ 0 , 0 , 1 ⎦
‘Full aspect’ mode
(with left and right side blank)
⎡ pw * dh / ph / sw , 0 , (1 - pw * dh / ph / dw) * dw / sw / 2 + dx / sw ⎤
⎜ 0 , dh / sh , dy / sh ⎥
⎣ 0 , 0 , 1 ⎦
equals to
⎡ dw / sw , 0 , dx / sw ⎤ ⎡ pw * dh / ph / dw , 0 , (1 - pw * dh / ph / dw) / 2 ⎤
⎜ 0 , dh / sh , dy / sh ⎥ X ⎜ 0 , 1 , 0 ⎥
⎣ 0 , 0 , 1 ⎦ ⎣ 0 , 0 , 1 ⎦
equals to
⎡ dw / sw , 0 , dx / sw ⎤ ⎡ pw * dh / ph / dw , 0 , 0 ⎤ ⎡ 1 , 0 , (ph * dw / pw / dh - 1) / 2 ⎤
⎜ 0 , dh / sh , dy / sh ⎥ X ⎜ 0 , 1 , 0 ⎥ X ⎜ 0 , 1 , 0 ⎥
⎣ 0 , 0 , 1 ⎦ ⎣ 0 , 0 , 1 ⎦ ⎣ 0 , 0 , 1 ⎦
Rotation
$ xrandr -o left
⎡ 0 -1 1 ⎤
⎜ 1 0 0 ⎥
⎣ 0 0 1 ⎦
$ xrandr -o right
⎡ 0 1 0 ⎤
⎜ -1 0 1 ⎥
⎣ 0 0 1 ⎦
$ xrandr -o inverted
⎡ -1 0 1 ⎤
⎜ 0 -1 1 ⎥
⎣ 0 0 1 ⎦
Reflection
$ xrandr -x
⎡ -1 0 1 ⎤
⎜ 0 1 0 ⎥
⎣ 0 0 1 ⎦
$ xrandr -y
⎡ 1 0 0 ⎤
⎜ 0 -1 1 ⎥
⎣ 0 0 1 ⎦
