ref: d4f4b292ca9c8665ef938036340ff32bf5128755
dir: /man/8/touchcal/
.TH TOUCHCAL 8 .SH NAME touchcal \- touch screen calibration .SH SYNOPSIS .B touchcal .SH DESCRIPTION .I Touchcal draws a cross-hair in each corner of the screen in turn (clockwise from the lower left hand corner), and waits each time for the user to touch the centre of the cross-hair with the stylus. It then prompts with a final cross-hair in the centre of the screen, and waits once more for the user to touch its centre with the stylus. The process is repeated until .I touchcal can calculate a transformation matrix that consistently maps the touch panel to screen coordinates. It then writes corresponding calibration commands for .IR touch (3) on its standard output, which can be saved in a file on the device, perhaps provided in NVRAM by .IR tinyfs (3) or a file system in .IR ftl (3). .PP .I Touchcal can be used both inside and outside the .IR wm (1) environment, allowing calibration when the system is initialised, and whilst the window system is running. .SH FILES .TF "/dev/touchctl " .TP .B /dev/touchctl reset or read existing settings .SH SOURCE .B /appl/cmd/touchcal.b .SH SEE ALSO .IR touch (3)