Libhybris input events are generated in a different thread, but we want
them in the main thread (InputRedirection and KWayland are not (yet)
thread safe). Thus all events need to be send to the main thread using
QMetaObject::invokeMethod.
Unfortunately on libhybris enabled systems libinput doesn't work, thus
the backend needs to handle input events which can be read from hybris.
So far the backend only handles touch events properly, though some
aspects look wrong. E.g. motion gives only for one touch contact point.
Unfortunately the documentation is quite weak, so there might be
something important missing.
Allows to read the DPI information and export the physical display
size from it. DPI is scaled by 1000 in hwcomposer, split by X and Y,
which allows to calculate size in mm from pixel size.
This backend interacts with libhybris to create a hwcomposer which is
used for creating the egl context and surface. The initial version of
this backend is based on test_hwcomposer.cpp provided by libhybris.
Please note that using the hwcomposer backend requires a newer libepoxy,
the latest stable release is not able to bring up OpenGLES, so one needs
a master build of libepoxy.
Notes on licensing:
libhybris is Apache 2.0 licensed, which is not compatile with GPLv2.
But it is compatible with GPLv3. Thus the source files in the hwcomposer
backend are licensed GPLv3+ and not GPLv2+ as the rest of KWin. If one
uses KWin without the hwcomposer backend (which is obviously the default)
the licence doesn't change. But if the hwcomposer backend is used the
overall license of KWin changes to GPLv3+.
