Effects are given the interval between two consecutive frames. The main
flaw of this approach is that if the Compositor transitions from the idle
state to "active" state, i.e. when there is something to repaint,
effects may see a very large interval between the last painted frame and
the current. In order to address this issue, the Scene invalidates the
timer that is used to measure time between consecutive frames before the
Compositor is about to become idle.
While this works perfectly fine with Xinerama-style rendering, with per
screen rendering, determining whether the compositor is about to idle is
rather a tedious task mostly because a single output can't be used for
the test.
Furthermore, since the Compositor schedules pointless repaints just to
ensure that it's idle, it might take several attempts to figure out
whether the scene timer must be invalidated if you use (true) per screen
rendering.
Ideally, all effects should use a timeline helper that is aware of the
underlying render loop and its timings. However, this option is off the
table because it will involve a lot of work to implement it.
Alternative and much simpler option is to pass the expected presentation
time to effects rather than time between consecutive frames. This means
that effects are responsible for determining how much animation timelines
have to be advanced. Typically, an effect would have to store the
presentation timestamp provided in either prePaint{Screen,Window} and
use it in the subsequent prePaint{Screen,Window} call to estimate the
amount of time passed between the next and the last frames.
Unfortunately, this is an API incompatible change. However, it shouldn't
take a lot of work to port third-party binary effects, which don't use the
AnimationEffect class, to the new API. On the bright side, we no longer
need to be concerned about the Compositor getting idle.
We do still try to determine whether the Compositor is about to idle,
primarily, because the OpenGL render backend swaps buffers on present,
but that will change with the ongoing compositing timing rework.
This change moves the XRender backend to platformsupport directory,
similar to the OpenGL and the QPainter backend. This allows to put
platform-specific logic in XRenderBackend.
In order to allow per screen rendering, we need the Compositor to be
able to drive rendering on each screen. Currently, it's not possible
because Scene::paint() paints all screen.
With this change, the Compositor will be able to ask the Scene to paint
only a screen with the specific id.
If you play some video and the software cursor doesn't hover it, then
the shadow cast by the cursor will be getting darker and darker with
every frame.
The main reason for that is that kwin paints the software cursor even
if the rect behind it hasn't been damaged or repainted.
The main advantage of SPDX license identifiers over the traditional
license headers is that it's more difficult to overlook inappropriate
licenses for kwin, for example GPL 3. We also don't have to copy a
lot of boilerplate text.
In order to create this change, I ran licensedigger -r -c from the
toplevel source directory.
Summary:
This will save the copy of some objects, especially PaintData classes that are
not copy-on-write.
It also follows the practice on other parts of the system.
Test Plan: Running it right now
Reviewers: #kwin, davidedmundson
Reviewed By: #kwin, davidedmundson
Subscribers: kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D28031
Summary:
The buffer shape is in buffer-local coordinates and must be mapped to
window coordinates. After that, we are free to map it to the global screen
coordinates.
Reviewers: #kwin, davidedmundson
Reviewed By: #kwin, davidedmundson
Subscribers: kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D25733
Summary:
Qt has its own thing where a type might also have corresponding list
alias, e.g. QObject and QObjectList, QWidget and QWidgetList. I don't
know why Qt does that, maybe for some historical reasons, but what
matters is that we copy this pattern here in KWin. While this pattern
might be useful with some long list types, for example
QList<QWeakPointer<TabBoxClient>> TabBoxClientList
in general, it causes more harm than good. For example, we've got two
new client types, do we need corresponding list typedefs for them? If
no, why do we have ClientList and so on?
Another problem with these typedefs is that you need to include utils.h
header in order to use them. A better way to handle such things is to
just forward declare a client class (if that's possible) and use it
directly with QList or QVector. This way translation units don't get
"bloated" with utils.h stuff for no apparent reason.
So, in order to make code more consistent and easier to follow, this
change drops some of our custom typedefs. Namely ConstClientList,
ClientList, DeletedList, UnmanagedList, ToplevelList, and GroupList.
Test Plan: Compiles.
Reviewers: #kwin
Subscribers: kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D24950
Summary:
EffectQuickView/Scene is a convenient class to render a QtQuick
scenegraph into an effect.
Current methods (such as present windows) involve creating an underlying
platform window which is expensive, causes a headache to filter out
again in the rest of the code, and only works as an overlay.
The new class exposes things more natively to an effect where we don't
mess with real windows, we can perform the painting anywhere in the view
and we don't have issues with hiding/closing.
QtQuick has both software and hardware accelerated modes, and kwin also
has 3 render backends. Every combination is supported.
* When used in OpenGL mode for both, we render into an FBO export the
texture ID then it's up to the effect to render that into a scene.
* When using software QtQuick rendering we blit into an image, upload
that into a KWinGLTexture which serves as an abstraction layer and
render that into the scene.
* When using GL for QtQuick and XRender/QPainter in kwin everything is
rendered into the internal FBO, blit and exported as an image.
* When using software rendering for both an image gets passed directly.
Mouse and keyboard events can be forwarded, only if the effect
intercepts them.
The class is meant to be generic enough that we can remove all the
QtQuick code from Aurorae.
The intention is also to replace EffectFrameImpl using this backend and
we can kill all of the EffectFrame code throughout the scenes.
The close button in present windows will also be ported to this,
simplifiying that code base.
Classes that handle the rendering and handling QML are intentionally
split so that in the future we can have a declarative effects API create
overlays from within the same context. Similar to how one can
instantiate windows from a typical QML scene.
Notes:
I don't like how I pass the kwin GL context from the backends into the
effect, but I need something that works with the library separation. It
also currently has wayland problem if I create a QOpenGLContext before
the QPA is set up with a scene - but I don't have anything better?
I know for the EffectFrame we need an API to push things through the
effects stack to handle blur/invert etc. Will deal with that when we
port the EffectFrame.
Test Plan: Used in an effect
Reviewers: #kwin, zzag
Reviewed By: #kwin, zzag
Subscribers: zzag, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D24215
Summary:
This patch is a first take at splitting up of the Compositor class into
Wayland and X11 child classes.
In this first patch we mostly deal with setup and teardown procedures.
A future goal is to further differentiate the compositing part itself too.
Test Plan: Manually X from VT and Wayland nested. Autotests pass.
Reviewers: #kwin
Subscribers: sbergeron, anthonyfieroni, zzag, kwin
Tags: #kwin
Maniphest Tasks: T11071
Differential Revision: https://phabricator.kde.org/D22195
Summary:
So far we were following a bit unique and rare doxygen comment style:
/**
* Contents of the comment.
**/
Doxygen comments with this style look balanced and neat, but many people
that contribute to KWin don't follow this style. Instead, they prefer
more traditional doxygen comment style, i.e.
/**
* Contents of the comment.
*/
Reviewing such changes has been a bit frustrating for me (so selfish!)
and for other contributors.
This change switches doxygen comment style in KWin to a more traditional
style. The main reason for doing this is to make code review process easier
for new contributors as well us.
Reviewers: #kwin, davidedmundson
Reviewed By: #kwin, davidedmundson
Subscribers: kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D22812
Summary:
Currently code base of kwin can be viewed as two pieces. One is very
ancient, and the other one is more modern, which uses new C++ features.
The main problem with the ancient code is that it was written before
C++11 era. So, no override or final keywords, lambdas, etc.
Quite recently, KDE compiler settings were changed to show a warning if
a virtual method has missing override keyword. As you might have already
guessed, this fired back at us because of that ancient code. We had
about 500 new compiler warnings.
A "solution" was proposed to that problem - disable -Wno-suggest-override
and the other similar warning for clang. It's hard to call a solution
because those warnings are disabled not only for the old code, but also
for new. This is not what we want!
The main argument for not actually fixing the problem was that git
history will be screwed as well because of human factor. While good git
history is a very important thing, we should not go crazy about it and
block every change that somehow alters git history. git blame allows to
specify starting revision for a reason.
The other argument (human factor) can be easily solved by using tools
such as clang-tidy. clang-tidy is a clang-based linter for C++. It can
be used for various things, e.g. fixing coding style(e.g. add missing
braces to if statements, readability-braces-around-statements check),
or in our case add missing override keywords.
Test Plan: Compiles.
Reviewers: #kwin, davidedmundson
Reviewed By: #kwin, davidedmundson
Subscribers: davidedmundson, apol, romangg, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D22371
Summary:
We have a mix of different doxygen comment styles, e.g.
/*!
Foo bar.
*/
/**
* Foo bar.
*/
/** Foo bar.
*/
/**
* Foo bar.
*/
/**
* Foo bar.
**/
To make the code more consistent, this change updates the style of all
doxygen comments to the last one.
Test Plan: Compiles.
Reviewers: #kwin, davidedmundson
Reviewed By: #kwin, davidedmundson
Subscribers: kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D18683
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
