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+.
The glVersion was not set at all for gles causing any code doing a
hasGLVersion check to fail which means that the compositor doesn't
start at all, because it has a hasGLVersion(2, 0) check.
The complete ifdef is no longer needed. The used additional glGetStringi
is also available in gles 3.0, thus epoxy can handle it quite well
without a need for ifdef.
Unfortunately the version string can be "strange" on GLES. On desktop
it looks like: "3.0 some driver foo", on GLES it could also be:
"OpenGL ES 3.0 some driver bar". Thus to make the logic work we are
first removing any leading "OpenGL ES " and hope that then the version
is encoded just like on GL.
Each of the backends becomes a plugin. This allows kwin_wayland to load
the requested plugin and kwin itself doesn't need to link all the
libraries needed. E.g. libdrm is no longer linked if running kwin_x11.
Also this allows to create backends for the non-standard EGL platforms
(examples could be raspberrypi or Android devices).
With this change all backends need to emit the screensQueried signal
at some point. So far only x11 backend did not provide the signal,
wayland had a comparable delayed init mechanism. Now all backends use
the same mechanism.
Replaces the functionality of the WaylandBackend and makes it available
to all backends by providing the functionality directly in
AbstractBackend. By default a backend is not ready and the implementation
must call setReady(true) to indicate that setup has finished
successfully. The compositor won't start till the backend indicates that
it is ready.
The aim is to be able to create a plugin for each of the backends.
The following directories are created:
* backends/drm
* backends/fbdev
* backends/wayland
* backends/x11
Each available mode on the connector is added to the
KWayland::Server::OutputInterface for the DrmOutput.
The logic to calculate the refreshRate is highly inspired from Weston's
implementation in compositor-drm.c.
Documentation for the wonderful EDID format can be found at:
http://read.pudn.com/downloads110/ebook/456020/E-EDID%20Standard.pdf
In case the link breaks: wikipedia also has a good section on it.
We read out the following information:
* EISA code (3 characters)
* serial number
* monitor name (up to 12 characters)
* physical size (stored in cm)
Unfortunately the EDID information cannot be trusted at all.
My 24" screen reports a sice of 16x9 cm. So we need to provide users
a way to overwrite the broken data in an easy way through kwinrc
[EdidOverwrite][EISA code/maker name][monitor name][serial number]
PhysicalSize=trueWidthInMM,trueHeightInMM
Unfortunately monitor name is not a sufficient enough identifier, that's
why serial number is also used. This makes automatic distribution of
overwrites difficult. But in the example above the monitor name is
"SyncMaster" which is a rather broad field in Samsung :-(
The extracted information from EDID is also used to set the corresponding
fields in KWayland::Server::OutputInterface.
Requires to move the screensQueried signal and disconnect during
Application startup.
As Screens only hold the geometry of each screen and the overall
geometry, there is no need (yet) to update in more detail when a
DrmOutput is added or removed. The overall queried is sufficient.
The DrmBackend installs a UdevMonitor to listen for output hotplug
events. Whenever a hotplug event occurrs the resources are queried
again and a signal is emitted for each removed and added output.
The complete rendering is now splitted per output including present which
means that we only need to make the context per output current once per
rendering.
Unfortunately our architecture does not properly support gathering the
damage for multiple outputs. In fact the damage information is lost after
the first output got rendered. Thus we currently only support buffer age
for the first output, on other outputs full repaints are caused.
For each DrmOutput a gbm_surface and EglSurface is created. When
rendering per screen the context is made current on each of the
surfaces.
Note: viewport handling needs to be improved by e.g. passing through
the scene to restore to correct viewport after dropping an FBO.
Furthermore it seems like buffer age is not working correctly in this
setup (not overly surprising).
Dynamic changes are not yet supported.
For each DrmOutput a set of buffers is created and presented. The
renderig is still in one go and not synced to the individual screens.
Dynamic changes are not yet supported.
The backend can indicate that the rendering needs to be split per screen.
In that case it has to provide a different rendering buffer per screen.
The painting in the scene is adjusted to either take a splitted path
or the existing path for all screens in one go.
Includes better error handling for when page flip failed. If it fails,
we shouldn't set the current buffer as otherwise each new attempt to
present a buffer will fail, too.
* blocks compositor while session is inactive
* prevents page flips while session is inactive
* restores modes when going to inactive
* hides cursor when going to inactive
* blanks screens when going active
* shows cursor again when going active
* triggers a repaint when going active
Martin Gräßlin