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Calibration

New in version 1.9.0.

Recalibrate input device to a specific range / offset.

Let’s say you have 3 1080p displays, the 2 firsts are multitouch. By default, both will have mixed touch, the range will conflict with each others: the 0-1 range will goes to 0-5760 px (remember, 3 * 1920 = 5760.)

To fix it, you need to manually reference them. For example:

[input]
left = mtdev,/dev/input/event17
middle = mtdev,/dev/input/event15
# the right screen is just a display.

Then, you can use the calibration postproc module:

[postproc:calibration]
left = xratio=0.3333
middle = xratio=0.3333,xoffset=0.3333

Now, the touches from the left screen will be within 0-0.3333 range, and the touches from the middle screen will be within 0.3333-0.6666 range.

You can also match calibration rules to devices based on their provider type. This is useful when probesysfs is used to match devices. For example:

[input]
mtdev_%(name)s = probesysfs,provider=mtdev

Then to apply calibration to any mtdev device, you can assign rules to the provider name enclosed by parentheses:

[postproc:calibration]
(mtdev) = xratio=0.3333,xoffset=0.3333

Calibrating devices like this means the device’s path doesn’t need to be configured ahead of time. Note that with this method, all mtdev inputs will have the same calibration applied to them. For this reason, matching by provider will typically be useful when expecting only one input device.

class kivy.input.postproc.calibration.InputPostprocCalibration[source]

Bases: builtins.object

Recalibrate the inputs.

The configuration must go within a section named postproc:calibration. Within the section, you must have a line like:

devicename = param=value,param=value

If you wish to match by provider, you must have a line like:

(provider) = param=value,param=value
Parameters
xratio: float

Value to multiply X

yratio: float

Value to multiply Y

xoffset: float

Value to add to X

yoffset: float

Value to add to Y

auto: str

If set, then the touch is transformed from screen-relative to window-relative The value is used as an indication of screen size, e.g for fullHD:

auto=1920x1080

If present, this setting overrides all the others. This assumes the input device exactly covers the display area, if they are different, the computations will be wrong.

Changed in version 1.11.0: Added auto parameter

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