This change is similar to D7232 and moves the scene_qpainter into a
dedicated plugin. Compared to the XRender case it's more complicated as
the platform plugins need to implement a platform specific backend.
The base implementation for this part used to be in scene_qpainter. As
the idea is to completly move it away from KWin core it would be point
less to still have the backend definition in KWin core, but it cannot
be in the scene plugin as otherwise all platforms need to link the
plugin.
To solve this a new platformsupport subdirectory is added which contains
the scene platform backend as a static library. For the OpenGL scene such
a static library will also be required.
Test Plan: SceneQPainter test still passes, nested compositor still works
Reviewers: #kwin, #plasma
Subscribers: plasma-devel
Tags: #plasma
Differential Revision: https://phabricator.kde.org/D7259
Summary:
First step for loading the compositor Scenes through plugins. The general
idea is that we currently needlessly pull in all the Scenes although only
one will be used.
E.g. on X11 we pull in QPainter, although they are not compatible. On
Wayland we pull in XRender although they are not compatible.
Furthermore our current Scene creation strategy is not really fault
tolerant and can create situations where we don't get a compositor. E.g
on fbdev backend the default settings won't work as it does not support
OpenGL.
Long term I want to tackle those conceptional problems together:
we try to load all plugins supported by the current platform till we have
a scene which works. Thus on Wayland we don't end up in a situation where
we don't have a working compositor because the configuration is bad.
To make this possible the switch statement in the Scene needs to go and
needs to be replaced by a for loop iterating over all the available
scenes on the platform. If we go there it makes sense to replace it
directly with a plugin based approach.
So this is a change which tackles the problem by first introducing the
plugin loading. The xrender based scene (as it's the most simple one)
is moved into a plugin. It is first tried to find a scene plugin and only
if there is none the existing code is used.
Test Plan: Tested all scenes
Reviewers: #kwin, #plasma
Subscribers: plasma-devel, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D7232
Summary:
The OverlayWindowX11 also inherits from X11EventFilter and performs
the filtering itself.
Test Plan: Compiles, not yet tested as I'm on Wayland
Reviewers: #kwin, #plasma
Subscribers: plasma-devel
Tags: #plasma
Differential Revision: https://phabricator.kde.org/D7197
Introduce a method Workspace::markXStackingOrderAsDirty
Summary:
This method replaces the calls x_stacking_dirty = true in the code base
allowing for further refactoring of that functionality.
Remove roundtrip to XServer from Workspace::xStackingOrder
The method xStackingOrder is only used during a Compositor paint pass.
If the stacking order had changed, the method updated the stacking order
from X by performing a sync XQueryTree. With other words we had a round
trip to the X server directly in the paint pass.
This change rearchitectures this area by making better use of xcb. When
we notice that the stacking order changed and an XQueryTree is needed,
we directly send out the request. When xStackingOrder is finally called,
which normally happens a few milliseconds later, the reply is retreived.
In the worst case it still blocks, but in most cases the roundtrip is
gone.
If the stacking order changed again before accessing xStackingOrder the
running request is cancelled and a new request is issued. So whenever we
get into xStackingOrder it will have the current state.
The updating of the xStackingOrder is moved into a dedicated method and
xStackingOrder invokes it through a const_cast instead of operating on
mutable variables.
Test Plan: Normal system usage, no issues
Reviewers: #kwin, #plasma
Subscribers: plasma-devel, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D6323
Summary:
While investigating a repaint issue I had a hard time to work with the
code and decided to change it to a more modern variant.
Instead of duplicating the same logic for each of the lists it's now
moved into a dedicated templated method which used std::any_of. Which is
exactly the algorithm we need: if there is any window with a non empty
repaints region it should return true.
Reviewers: #kwin, #plasma
Subscribers: plasma-devel, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D3397
Summary:
With nouveau driver it can happen that KWin gets frozen when first trying
to render with OpenGL. This results in a freeze of the complete desktop
as the compositor is non functional.
Our OpenGL breakage detection is only able to detect crashes, but not
freezes. This change improves it by also added a freeze protection.
In the PreInit stage a thread is started with a QTimer of 15 sec. If the
timer fires, qFatal is triggered to terminate KWin. This can only happen
if the creation of the OpenGL compositor takes longer than said 15 sec.
In the PostInit stage the timer gets deleted and the thread stopeed
again.
Thus if a freeze is detected the OpenGL unsafe protection is written into
the config. KWin aborts and gets restarted by DrKonqui. The new KWin
instance will no longer try to activate the freezing OpenGL as the
protection is set.
If KWin doesn't freeze the protection is removed from the config as
we are used to.
Check for freezes for the first n frames, not just the first
This patch changes the freeze detection code to detect freezes in the
first 30 frames (by default, users can change that with the
KWIN_MAX_FRAMES_TESTED environment variable). This detects
successfully the freezes associated to nouveau drivers
in https://bugzilla.suse.com/show_bug.cgi?id=1005323
Reviewers: davidedmundson, #plasma, #kwin, graesslin
Reviewed By: #plasma, #kwin, graesslin
Subscribers: luebking, graesslin, kwin, plasma-devel, davidedmundson
Tags: #plasma
Differential Revision: https://phabricator.kde.org/D3132
This fixes a regression found in TestSceneQPainter for restarting the
Compositor. The internal clients were never added to the Scene.
We cannot just call setupCompositing because there is a phase during
startup where setupCompositing already passes but the Compositor is not
yet fully initialized. Thus it could happen that it's called twice which
makes the Scene assert.
To solve that setupCompositing and finishCompositing are now overriden
in ShellClient and track whether they successfully called
setupCompositing.
We should be able to restart the Compositor also on Wayland.
As the Compositor might be terminated after Workspace we need to
ensure to not call into Workspace while doing finishCompositing.
Reviewed-By: bshah
Summary:
Rational: unredirect fullscreen windows is a weird beast. It's intended
to make fullscreen windows "faster" by not compositing that screen. But
that doesn't really work as KWin jumps out of that condition pretty
quickly. E.g. whenever a tooltip window is shown. KWin itself has a
better functionality by supporting to block compositing completely.
The complete code was full of hacks around it to try to ensure that
things don't break.
Overall unredirect fullscreen has always been the odd one. We had it
because a compositor needs to have it, but it never got truly integrated.
E.g. effects don't interact with it properly so that some things randomly
work, others don't. Will it trigger the screenedge, probably yes, but
will it show the highlight: properly no.
By removing the functionality we finally acknowledge that this mode is
not maintained and has not been maintained for years and that we do not
intend to support it better in future. Over the years we tried to make
it more and more hidden: it's disabled for Intel GPUs, because it used
to crash KWin. It's marked as an "expert" option, etc.
It's clearly something we tried to hide from the user that it exists.
For Wayland the whole unredirect infrastructure doesn't make sense
either. There is no such thing as "unredirecting". We might make use
of passing buffers directly to the underlying stack, but that will be
done automatically when we know it can be done, not by some magic is
this a window of specific size.
Test Plan:
Compiles, cannot really test as I am an Intel user who never
had that working.
Reviewers: #kwin, #plasma, #vdg
Subscribers: kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D2180
Summary:
This change ensures that KWin doesn't crash in the QPainter scene if
the compositor gets restarted and if there are Wayland clients.
BUG: 365471
Test Plan:
Test case added to scene qpainter which triggers a restart
of the Compositor with a window being shown. Verifies that rendering
is correct afterwards.
Reviewers: #kwin, #plasma_on_wayland
Subscribers: plasma-devel, kwin
Tags: #plasma_on_wayland, #kwin
Differential Revision: https://phabricator.kde.org/D2185
Summary:
KWin needs to support restarting the OpenGL compositor in case of a
graphics reset event.
On Wayland the tricky part is that the applications should not notice
this. Most importantly KWin cannot just destroy the EGLDisplay and create
a new one. But this is how a restart works: the complete compositor gets
torn down and recreated - including the EGLDisplay.
This change moves ownership of the EGLDisplay to the Platform.
The AbstractEglBackend subclasses query the Platform whether there is
already an EGLDisplay. Only if there is no EGLDisplay the EGLDisplay is
created and only if no EGLDisplay is registered with Wayland the bind
is performed.
Another change is regarding the destruction: the AbstractEglDisplay does
no longer unbind the Wayland display and does no longer destroy the
EGLDisplay. The EGLDisplay is destroyed by the Platform - so very late
on application exit. The Wayland display is unbound when the Compositor
terminates.
Test Plan:
Limited testing with the added auto-test. This one needs to
be extended to fully verify that OpenGL applications continue to work.
But this requires build.kde.org to support OpenGL on Wayland.
Reviewers: #kwin, #plasma_on_wayland
Subscribers: plasma-devel, kwin
Tags: #plasma_on_wayland, #kwin
Differential Revision: https://phabricator.kde.org/D2202
This is responsible for plasmashell freezing when screen is locked.
The change itself was not wrong, but we first need to enable the
infrastructure to "fake" rendering when screen is locked/disabled, etc.
Summary:
So far when a ShellClient got unmapped ready_for_painting was set to
false. That is the ShellClient was treated in the same way as a not
yet shown window. It was completely excluded from painting, a close
animation impossible.
This change makes use of the functionality available in
Client::hiddenInternal(). The window is considered as hidden, thus
still excluded from e.g. getting input events, but could be rendered
any time as we still have a previous window pixmap (if referenced).
This allows to have it considered in the rendering pass, but effects
still cannot make use of it as that state is not yet exposed to the
effects.
Reviewers: #kwin, #plasma_on_wayland
Subscribers: plasma-devel, kwin
Tags: #plasma_on_wayland, #kwin
Differential Revision: https://phabricator.kde.org/D2083
On Wayland tear down the Workspace gets destroyed before the Compositor
gets destroyed. If the timer fires in that area, the Compositor would
crash. It's not possible to start the timer if the Workspace is
destroyed, thus it should also be stoped on Workspace destroy.
Reviewed-By: Bhushan Shah
Summary:
A new virtual method createOpenGLSafePoint is added to Platform.
This is invoked through the Compositor with a PreInit and a PostInit
argument pre and post creating the SceneOpenGL.
The Platform plugin can implement this and use it for detecting whether
creating the OpenGL compositor on this platform crashed in the past.
Thus it's the base for the openGLIsBroken platform check.
The x11 standalone plugin is the first to implement this functionality
using the previous code which was designed for X11.
This also means that a crash of the OpenGL compositor during init on
Wayland won't result in OpenGL being disabled.
Reviewers: #plasma
Subscribers: plasma-devel
Projects: #plasma
Differential Revision: https://phabricator.kde.org/D1582
Summary:
So far the OpenGL is unsafe check functionality in Compositor disabled
OpenGL compositing if glx is not available and we are in standalone X11
mode.
This is technically no longer correct for quite some time. Just because
GLX is not available doesn't mean that OpenGL doesn't work. We have an
EGL backend. So let's try to use that if glx is not available.
This change removes the check completely from Compositor. Instead the
standalone x11 plugin checks whether glx is available prior to createing
the glx backend. If not available it falls through to the egl backend.
Reviewers: #plasma
Subscribers: plasma-devel
Projects: #plasma
Differential Revision: https://phabricator.kde.org/D1581
Summary:
CompositingPrefs is only relevant for X11 standalone. It had some
"hacks" to make it not block Compositing on Wayland. Thus it was in
its current form not really useful.
Now all the functionality is provided through Platform with a default
implementation which is sensible for Wayland platforms.
The X11 standalone platform implements the new methods with the
Wayland checks removed.
In addition all calls to CompositingPrefs now go through the platform
directly and CompositingPrefs is completely dropped.
Reviewers: #plasma
Subscribers: plasma-devel
Projects: #plasma
Differential Revision: https://phabricator.kde.org/D1576
Summary:
This change reduces the windowing system specific code pathes. Instead
of checking whether we are on X11 or Wayland to decide whether
compositing is required, we just ask the Platform.
The default is true, only x11 standalone allows to not require
compositing.
Reviewers: #plasma
Subscribers: plasma-devel
Projects: #plasma
Differential Revision: https://phabricator.kde.org/D1575
Summary:
This ensures that frameRendered is also sent if we start a Wayland Server
on X11.
Reviewers: #plasma
Subscribers: plasma-devel
Projects: #plasma
Differential Revision: https://phabricator.kde.org/D1597
Summary:
Instead of checking the operation mode for X11, we check whether the
damage_handle is created. This fixes a bad damage warning for Wayland
windows in kwin_x11.
Reviewers: #plasma
Subscribers: plasma-devel
Projects: #plasma
Differential Revision: https://phabricator.kde.org/D1490
Summary:
If the Toplevel has a Wayland Surface we don't want an X11 damage
handle. Ideally we would just check for the Surface and get rid of
the operation mode check. But setupCompositing is called for Xwayland
clients before the surface is set.
Reviewers: #plasma
Subscribers: plasma-devel
Projects: #plasma
Differential Revision: https://phabricator.kde.org/D1486
Summary:
Instead of binding to the OperationMode whether the damage_handle
should be destroyed, we bind it to whether damage_handle got created.
Reviewers: #plasma
Subscribers: plasma-devel
Projects: #plasma
Differential Revision: https://phabricator.kde.org/D1483
So far if the Scene creation failed kwin_wayland went into a shutdown,
but didn't succeed because the thread to start Xwayland was already
running: it froze.
This change introduces a new signal in Compositor: sceneCreated. The
startup of Xwayland is bound to this signal. If it gets fired KWin can
startup Xwayland. If it does not get fired, KWin terminates correctly.
When screen is locked,
- No window other then screenlocker or inputmethods gets rendered
- Only screenlocker gets keyboard events
- Only screenlocker and inputmethods get mouse events
Things that are not secured/tested are :
- Touch events
- Global shortcuts for screenlocker
- Fallback/emergency screen not yet working
REVIEW: 126015
During Compositor tear down Xwayland is already destroyed. Thus it
doesn't make sense to try to delete the support properties: either
it freezes in xcb or it crashes because the connection is null.
At the same time we also ensure that the connection internally is
reset to null. Note: the one in kwinglobals.h caches and could cause
use-after-free errors. Any tear-down code must be migrated to
kwinApp()->x11Connection().
-use qstringliteral only when necessary (i.e. not in concat or comparison)
-use qbytearray instead of qstring when dealing with latin1 input and output (glplatform)
-use qstringref to extract numbers from strings (glplatform)
-define qt_use_qstringbuilder to optimize all string concatenations
-anidata: use ctor init lists, add windowType member initialization
REVIEW: 125933
The check whether Workspace is created is not sufficient. There's a
time when Workspace is already created but Compositor not ready yet
and where we can hit this code path.
This ensures that the Compositor doesn't perform compositing and doesn't
run the compositing timer if e.g. all outputs are dpms disabled. Thus
we don't render any more, don't trigger wakeups and block applications
from rendering if they properly implement the frame rendered callback.
The creation of PlasmaWindowInterface is moved from WaylandServer into
AbstractClient. This allows the sub classes to better control when to
create/destroy the Client.
For creation it's bound to becoming visible - that is Windows which are
only created but never shown are not announced at all.
For Client it's destroyed with the normal tear-down of a Client, for
ShellClient it's destroyed on unmapped (which also means a new one
will be created again in case of another mapping of the surface).
As a side effect, this works around the problem that ShellClients do not
yet get destroyed for QtWayland's menus (needs further investigation).
It's possible that the Workspace doesn't get created at all (e.g.
Xwayland failed to start). In that case we must ensure to not call into
Workspace calls during tear down.
only return early if we cannot create a
selectionwatcher, otherwise the claiming
code turns unreachable after the creation
of cm_selection
BUG: 347813
REVIEW: 123826
The ShellClient is a Toplevel subclass for a
KWayland::Server::ShellSurfaceInterface. It gets created when a new
ShellSurfaceInterface is created and destoryed when it gets unmapped.
So far the usage is still rather limited. The ShellClient is opened
at position (0/0). While it's possible to pass pointer events to it,
it's not yet possible to activate it, so no keyboard focus.
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
This new backend allows to start a kwin_wayland server nested on an
X-Server by using a normal X11 window as output. This allows testing
kwin_wayland without needing to start another Wayland server first.
The behavior is triggered by using new command line arguments:
--windowed
--x11-display=<:0>
With optional --width and --height arguments.
In this mode the WaylandBackend is not created at all.
So far the backend is not fully integrated yet and only the QPainter
backend supports this mode.
On Wayland we get the damage from the SurfaceInterface instead of
using a damage handle. This change ensures that the damage handle
interaction is only used on platform X11, while on Wayland we get
the damage from the SurfaceInterface directly.
For Xwayland we need to have the Scene (and EglDisplay) created prior
to starting Xwayland and having X11. This requires creating the
Compositor before creating Workspace and starting Xwayland.
To support this the startup of Compositor is split into two parts:
prior and after Workspace creation.
The change might also be interesting for the kwin_x11 case as it could
result in the compositor being up in a quicker way.
Don't start the composite timer at the end of performPaint() when a
buffer swap is pending and vsync is enabled. Instead set
m_composeAtSwapCompletion to true so performPaint() gets called again
as soon as the swap completes.
This makes the repaint cycle look like this:
scene->paint()
SwapBuffers()
Process events
·
·
Swap completes
Fetch and reset damage (if applicable)
scene->paint()
SwapBuffers()
Process events
·
·
Swap completes
...
This results in a noticeable improvement in animation smoothness with
drivers that support GLX_INTEL_swap_event, since we're now able to
consistently render at the monitor refresh rate.
The Compositor is destroyed before the Client and Decorations are
destroyed on shutdown. This meant the Decorations reacted needlessly
on the alpha channel supported. E.g. Aurorae recreated the Decoration
and most likely crashed in Qt.
With this change the signal gets disconnected and the Decorations
just don't do anything.
Instead of getting size from displayWidth() and displayHeight() use
the information we have from Screens. This means there is only one
place to have the information and by that we can ensure that all
components use the same data to rely on. displayWidth/displayHeight
seem to provide the wrong information when unplugging an output
without disabling the output. This results in rendering artefacts.
But KWin::Screens has the correct information available.
Move the buffer-swap-pending state from the compositing backends to
the Compositor class. The Compositor is the only class that needs to
access the state, and this way it to do it without calling through
a chain of virtual functions. This commit adds two new functions to
Compositor; aboutToSwapBuffers() and bufferSwapComplete(). The
backends call these functions to set and reset the buffer-swap-pending
state.
This commit also renames a number of functions and variables to make
their meaning clear.
The act of promoting the contents of the back buffer to become the
contents of the front buffer is referred to as posting the buffer,
presenting the buffer, or swapping the buffers; rendering the buffer
is what paintScreen() does.
Create and import X sync fences into GL and use them to synchronize
the kwin command stream with the X command stream.
This prevents damaged windows from being composited by kwin before
the rendering that triggered the damage events have finished on
the GPU.
Requires GL_EXT_x11_sync_object.
Tested-by: Marco Martin <notmart@gmail.com>
The Wayland event queue is moved into a dedicated thread and a
new class is created for just creating the connection and listening
for events. The WaylandBackend creates the thread and uses an event
queue for the main thread.
REVIEW: 119761
So far the DecorationRenderer got destroyed and recreated after
the signal compositing toggled was emitted. But that's too late for
e.g. the OpenGL Textures to be destroyed. So lets trigger the destroy
directly in setup/finish compositing. The new renderer will still be
created after the compositing toggled is emitted - we don't want to
have it recreated for the still active compositer type.
NOTE: this is not working completely yet, lots of code is still ifdefed
other parts are still broken.
The main difference for the new decoration API is that it is neither
QWidget nor QWindow based. It's just a QObject which processes input
events and has a paint method to render the decoration. This means all
the workarounds for the QWidget interception are removed. Also the paint
redirector is removed. Instead each compositor has now its own renderer
which can be optimized for the specific case. E.g. the OpenGL compositor
renders to a scratch image which gets copied into the combined texture,
the XRender compositor copies into the XPixmaps.
Input events are also changed. The events are composed into QMouseEvents
and passed through the decoration, which might accept them. If they are
not accpted we assume that it's a press on the decoration area allowing
us to resize/move the window. Input events are not completely working
yet, e.g. wheel events are not yet processed and double click on deco
is not yet working.
Overall KDecoration2 is way more stateful and KWin core needs more
adjustments for it. E.g. borders are allowed to be disabled at any time.
Similar to the already existing DBusInterface wrapper for the
org.kde.KWin interface a new CompositorDBusInterface is introduced for
org.kde.kwin.Compositing.
That way the DBus interface is split from the implementation and DBus
specific methods are no longer required in the Compositor class.
The deprecated DBus methods
* toggleCompositing(bool)
* setCompositing(bool)
are removed.
REVIEW: 118463
The Scene connects to the deletedRemoved signal and tries to remove the
Deleted from it's list of Windows, which will fail because a SceneWindow
doesn't get created for an existing Deleted in the Scene setup.
It doesn't make sense to create a SceneWindow for a Deleted as there is
no pixmap around anyway. Thus the best approach is to ensure that there
are no Deleted by just discarding all prior to creating the Scene.
BUG: 333275
REVIEW: 117557
So far the Unmanaged got released after an XCB_UNMAP_NOTIFY. This event
gets created after xcb_unmap_window or after xcb_destroy_window. In the
latter case the window is already distroyed and any of KWin's cleanup
calls will cause a BadWindow (or similar) error.
The idea to circumvent these errors is to try to wait for the
DESTROY_NOTIFY event. To do so the processing of the release is slightly
delayed. If KWin gets the destroy notify before the delay times out the
Unamanged gets released immediately but with a Destroy flag. For this a
new enum ReleaseToplevel is introduced and Unmanage::release takes this
as an argument instead of the bool which indicated OnShutdown. Also this
enum is added to Toplevel::finishCompositing so that it can ignore the
destroyed case and not generate an error.
REVIEW: 117422
The Wayland Backend watches the socket it uses for communicating with the
Wayland compositor. If the socket is removed we have to perform a kind of
emergency stop. The backend tears down all data structures created from
the Wayland display and emits a signal that the system compositor died.
In addition the Wayland Backend starts to monitor the XDG_RUNTIME_DIR for
the socket to be added again. If the socket is created again the backend
reinitializes the Wayland connection.
This also requires the Compositor to restart. Therefore it connects to
the new signals emitted by the Wayland Backend to stop and start
compositing.
KWin already has a de facto OpenGL 2 dependency through QML. Combined
with the fact that the OpenGL 1 backend is basically unmaintained and
also unused, it's better to remove it for the new major release.
This change includes:
* Removal of cmake option KWIN_BUILD_OPENGL_1_COMPOSITING
* Removal of KWIN_HAVE_OPENGL_1 compile option and all code
ifdef'ed with it (partially removal of if-else constructs)
* Removal of CompositingType::OpenGL1Compositing (flags are kept
as a core flag should get introduced)
* Driver recommendation for OpenGL1Compositing changed to XRender
(should be evaluated whether the drivers can provide GL2)
* Removal of configuration option "GLLegacy"
* Removal of fooMatrix function in kwinglutils
* Removal of ARBBlurShader
* Removal of legacy code path in GLVertexBuffer
* Removal of GLShaderManager::disable
* if-blocks with ShaderManager::instance()->isValid() removed
REVIEW: 116042
In the Wayland world we need to have a compositor. This means we have to
enforce that the compositor is running. If the setup fails we have to
quit, because it doesn't make any sense any more to be running.
A new method requiresCompositing() is added to the Application. If it
returns true the useCompositing option will always return true and the
unredirect fullscreen option will always return false. That way
compositing is enforced at startup and cannot end by unredirecting.
In addition this method is checked if actions are performed which would
suspend compositing. E.g. the shortcut to toggle compositing. Restarting
the compositor is still possible in order to change the selected
compositing backend without a restart. But if it fails KWin will quit.
This compositor uses only the QPainter API to perform rendering. The
window's X Pixmap is mapped to a QImage using XShm. As rendering backend
a QImage is used.
The new compositing type "QPainterCompositing" is introduced. Effects
need to be adjusted to explicitly check the compositing type and no
longer assume the compositing type is XRender if it's not OpenGL.
This compositor can be selected with using "Q" as the value for
KWIN_COMPOSE env variable or setting the config value to "QPainter".
The GUI is not yet adjusted to select this compositor.
The QPainter scene provides currently the following features:
* 2D transformations (translation and scalation)
* opacity modifications
* rendering of decorations (new PaintRedirector sub class)
* rendering of shadows
* rendering of effect frames
* rendering to a Wayland surface
The following features are currently not provided:
* saturation changes
* brightness changes
* 3D transformations
* rendering to X Overlay window
* offscreen rendering (e.g. needed for screen shot effect)
* custom rendering in the effects to the current back buffer
Only the X based Scenes need an overlay window, so the Compositor doesn't
need to check for it in the Wayland case.
OverlayWindow is moved from OpenGLBackend to the sub classes which need
to provide it.
The egl wayland backend registers for the callback for a rendered frame.
This allows to throttle KWin's compositor so that we don't render frames
which wouldn't end up on the screen.
For this the Scene provides a method to query whether the last frame got
rendered. By default this returns true in all backends. The Egl Wayland
backend returns true or false depending on whether the callback for the
last frame was recieved.
In case the last frame has not been renderd when performCompositing is
tried to be called, the method returns just like in the case when the
overlay window is not visible. Once the frame callback has been recieved
performCompositing is invoked again.
An abstract backend is split out of SceneXRender which takes care of
managing the render pictures and swapping them after a frame is rendered.
Having this abstract allows to implement further backends for XRender
which do not use the Overlay Window for compositing.
To have it consistant the SceneXRender is now also created by a factory
method.
The ActionCollection was only used for two features:
* setting the object name
* finding the action for retrieving it's shortcut
This can also be achieved by just setting the object name and searching
for the children of the Workspace singleton.
The main purpose of the opengl testapp was to set the environment
variable LIBGL_ALWAYS_INDIRECT if direct rendering is not supported
before glx gets initialized.
With Qt5 we may no longer set this environment variable. QtQuick
requires direct rendering. On IvyBridge QtQuick is crashing if the
variable is set. Thus we are no longer allowed to set it and thus the
complete test becomes pointless.
The test app basically whitelisted most drivers anyway, the only
drivers which were problematic are the proprietary Catalyst drivers.
It that's still a problem we can also disable OpenGL compositing on
those drivers through the recommendation in the GLPlatform.
This also means that the KWIN_DIRECT_GL variable is no longer useful.
