[PATCH weston 00/25] A new touchscreen calibrator

Fri Mar 23 13:46:46 UTC 2018

I am very much in favor of the overall approach on this patch series.
I've experienced every single one of the problems described in this
summary, and my company currently resorts to maintaining a hacky
out-of-tree calibration tool to paper over these problems.

On Fri, Mar 23, 2018 at 7:00 AM, Pekka Paalanen <ppaalanen at gmail.com> wrote:
> From: Pekka Paalanen <pekka.paalanen at collabora.co.uk>
>
> Hi all,
>
> the existing touchscreen calibrator in Weston has several problems. This
> proposal intends to solve them all by introducing a new protocol
> extension for touchscreen calibration and a new calibrator tool.
>
> The benefits of the new tool, which the old tool lacks, are:
>
> - You can unambiguously pick a physical touch device to calibrate.
>
> - You can be sure your touch events come only from that particular
>   device, and that you cannot miss touch events even if the current
>   calibration is horribly wrong.
>
> - You can be sure the calibration window (pattern) is shown on the right
>   output with the right coordinates.
>
> - You can unambiguously calibrate even multiple touchscreens that are
>   all cloned (showing the same image).
>
> - You get a libinput style calibation matrix instead of the
>   WL_CALIBRATION format which depends on output resolution.
>
> - You can load a new calibration into the compositor without playing
>   tricks with udev or restarting the compositor.
>
> There is more discussion about the topic at:
> https://phabricator.freedesktop.org/T7868
>
> This patch series depends on the clone mode series:
> https://patchwork.freedesktop.org/series/32898/
>
> There is a full branch available at:
> https://gitlab.collabora.com/pq/weston/commits/touchcalib-1
>
> This series contains many patches that could be landed separately, but I
> have not pulled them out at this point.
>
> A notable single patch is patch 3 which deprecates the udev property
> WL_CALIBRATION. It is completely already superseded by
> LIBINPUT_CALIBRATION_MATRIX property. I would hope to remove
> WL_CALIBRATION support after few releases and the old calibrator tool
> with it.
>
> Patch 21 adds the touchscreen calibration protocol, patch 24 adds the
> new calibrator tool, and patch 25 gives suggestions on how to let the
> server permanently store a new calibration into udev rules.
>
> As LIBINPUT_CALIBRATION_MATRIX is automatically handled by libinput,
> being a description of the physical input device (like e.g. mouse dpi),
> it perfectly possible to run Weston and the calibrator once to calibrate
> your touchscreens, and then run whatever compositor you want.
>
> One major thing this patch series does not address is how a Wayland
> client gets authorized to use the touchscreen calibration interface. The
> interface offers two privileged actions: the ability to grab all touch
> input (but with provision for the server to cancel at will - not
> implemented in weston so far), and the ability to upload a new
> calibration for a touch device. Obviously these should not be free for
> all. The method implemented here is a simple global configuration
> setting to advertise or not the touchscreen calibration interface. If
> advertised, it is free for all. Therefore it is not advertised by
> default.
>
>
> Thanks,
> pq
>
>
> Louis-Francis Ratté-Boulianne (7):
>   input: introduce weston_touch_device
>   libweston: fix weston_touch_start_grab() arg name
>   input: move touchpoint counting up
>   input: introduce touch event mode for calibrator
>   libweston: implement touch calibration protocol
>   weston: add touchscreen_calibrator option
>   clients: add a new touchscreen calibrator
>
> Pekka Paalanen (18):
>   libinput: remove evdev_device::devnode
>   libinput: note if calibrating without an output
>   libinput: deprecate WL_CALIBRATION
>   libinput: log input device to output associations
>   libinput: make setting the same output a no-op
>   libinput: allow evdev_device_set_output(dev, NULL)
>   libinput: use head names for output matching
>   libweston: require connected heads for input devices
>   libinput: do not switch output associations on disable
>   man: document WESTON_LIBINPUT_LOG_PRIORITY env
>   tests: add test_seat_release() for symmetry
>   libinput: move calibration printing into do_set_calibration()
>   libweston: notify_touch API to use weston_touch_device
>   libweston: unexport weston_{pointer,keyboard,touch}_{create,destroy}()
>   libweston: introduce notify_touch_cal() and doc
>   input: do not forward unmatched touch-ups
>   protocol: add weston_touch_calibration
>   doc: add example calibration-helper script
>
>  .gitignore                            |   1 +
>  Makefile.am                           |  21 +-
>  clients/touch-calibrator.c            | 774 ++++++++++++++++++++++++++++++++++
>  clients/window.c                      |   4 +-
>  clients/window.h                      |   4 +
>  compositor/main.c                     |  68 +++
>  doc/calibration-helper.bash           |  44 ++
>  libweston/compositor-wayland.c        |  31 +-
>  libweston/compositor.c                |  32 ++
>  libweston/compositor.h                | 174 +++++++-
>  libweston/input.c                     | 330 +++++++++++++--
>  libweston/libinput-device.c           | 238 ++++++++---
>  libweston/libinput-device.h           |   4 +-
>  libweston/libinput-seat.c             |  88 +++-
>  libweston/libinput-seat.h             |   1 +
>  libweston/touch-calibration.c         | 667 +++++++++++++++++++++++++++++
>  man/weston-drm.man                    |   4 +
>  man/weston.ini.man                    |  36 ++
>  protocol/weston-touch-calibration.xml | 320 ++++++++++++++
>  tests/weston-test.c                   |  64 ++-
>  20 files changed, 2771 insertions(+), 134 deletions(-)
>  create mode 100644 clients/touch-calibrator.c
>  create mode 100755 doc/calibration-helper.bash
>  create mode 100644 libweston/touch-calibration.c
>  create mode 100644 protocol/weston-touch-calibration.xml
>
> --
> 2.16.1
>
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