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How to configure touch screen coordinate rotation with QPA Wayland

  • Re: TOUCHSCREEN rotation on QPA/Wayland

    We were able to achieve 180-degree rotation for the touch screen on TI's AM335x EVM foir QPA LinuxFB and EGLFS before per QT manual below.

    "Input on eglfs and linuxfb without libinput

    Parameters like the device node name can be set in the environment variables QT_QPA_EVDEV_MOUSE_PARAMETERS, QT_QPA_EVDEV_KEYBOARD_PARAMETERS and QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS. Additionally, the built-in input handlers can be disabled by setting QT_QPA_EGLFS_DISABLE_INPUT or QT_QPA_FB_DISABLE_INPUT to 1. On some touch screens the coordinates must be rotated, which is done by setting QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS to rotate=180."

    It is clear that this method is only applicable to EGLFS and LinuxFB without libinput.

    I am not able to find out an equivalent solution for QPA Wayland which invokes libinput.
    Can the touch screen rotation be implemented within QT, or such operation should be done within Weston/Wayland/Libinput?

    Any help and input will be highly appreciated!

    Best regards,


  • Lifetime Qt Champion


    I'd recommend asking that question on the interest mailing list. You'll find there Qt's developers/maintainers. This forum is more user oriented.

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