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.
QGraphicsRotation and Scale are QObject wrappers. It's not useful in
data structures where we're creating mulitple of these every frame. It's
large enough to appear in hotspot as taking over 1% of a regular frame.
We don't even use the QGraphicsRotation mapping inside scene for a
reason, so it's not giving us much.
It's technically an API break in libkwineffects. Pragamatically no-one
would use these. We also lose QGraphicsScale's origin, but we never
exposed this in PaintData's public header.
On Wayland, a surface must be displayed the same way no matter how the
attached buffer is transformed. In order to guarantee that, we build the
surface-to-buffer matrix, which is used to compute the texture coords.
The surface-to-buffer matrix represents an affine transformation. Thus,
performing linear interpolation between texture coordinates won't end up
in corrupted rendered results. This is the main assumption that we make
during generation of contents window quads. After creating a sub-quad,
the new quad's texture coordinates are computed by interpolating between
the source quad's texture coords.
However, WindowQuad::makeSubQuad() makes a concrete assumption about the
order of texture coords, which might be false if the attached wayland
buffer is rotated 90 or 270 degrees.
This issue went unnoticed after merging the viewporter patches because
the developer who was working on it had been using primarily nested
kwin_wayland for testing purposes. And it appears like kwin schedules
full screen repaints even though it supports buffer age. It still needs
some investigation why that happens.
BUG: 428003
Instead of looping through the rects in the region, emit the region at
bulk. It reduces the amount of emissions we do and allows us to pack the
response accordingly.
Prefer for() to foreach(), as the latter is deprecated.
Prefer iterating QList using the iteration_expression for() loops,
rather than doing it by index.
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.
If the Xwayland process crashes, it will bring down the entire session
together with itself. Obviously, we don't want that. At least, Wayland
clients should survive the crash.
This change refactors relevant X11 parts to handle Xwayland crashes in a
less fatal way.
In order to handle Xwayland crashes better, a pair of start() and stop()
methods had been introduced in the Xwayland class to allow starting and
stopping the Xwayland process at any moment.
If we detect that the Xwayland process has crashed, we will immediately
stop the Xwayland server, which in its turn will deactivate the socket
notifier and destroy all connected X11 clients. Unfortunately, a couple
of subtle changes in X11Client::releaseWindow() and Unmanaged::release()
had to be made to ensure that we are left with a valid state after the
Xwayland server has been stopped.
Currently in order to load an Xcursor theme, kwin uses libwayland api,
which looks really awkward because of the way how the compositor talks
to itself via the internal connection.
The main motivation behind this change is to limit the usage of kwayland
client api in kwin.
Summary:
The screenshot made on screens with scale factor were downscaled by their scale factor making them blurry.
It prevents taking screenshots of missing Hidpi related bugs showing the issues under Wayland.
This fix the case of a single screenshot, but not the rest:
Multiscreen screenshot downscales the screen using scale factor.
Spectacle rectangular selection screenshot is broken as soon as some scale factor different than 1 is used on any screen.
Test Plan:
Under Wayland with a scale factor on a screen, take a screenshot using spectacle.
The output image is not downscaled and has the same size as the screen resolution.
No other change to any other screenshot mode, or under X.
Reviewers: davidedmundson, #kwin
Reviewed By: davidedmundson, #kwin
Subscribers: kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D29010
Summary:
It has been broken for many years and no one has filed bug
reports about it (besides me).
BUG: 419285
Test Plan: Ran kwin with KWIN_GL_DEBUG and it still works.
Reviewers: #kwin, davidedmundson
Reviewed By: #kwin, davidedmundson
Subscribers: kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D28332
Summary: No need to keep them around for no reason.
Test Plan: Tested the plugins I thought could be affected. Have been using it for a couple of days without problems
Reviewers: #kwin, zzag
Reviewed By: #kwin, zzag
Subscribers: zzag, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D28062
Summary:
KWin only renders into the default framebuffer, which is for example an EGL
surface.
To prepare a post-processing step with a different framebuffer allow the
framebuffer to be changable. For that KWin's current framebuffer must be
communicated to the GLRenderTarget class, which otherwise does not set it back
to KWin's current one when a render target is disabled again.
Test Plan: Compiles, with other patches for Gl based screen rotation
Reviewers: #kwin
Subscribers: fredrik, zzag, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D25904
Summary:
Lots of red, does the same thing in a simplified way avoiding creating a
real window and having to hack round it.
Test Plan: Click add and remove, remove button disables appropriately
Reviewers: #kwin, zzag
Reviewed By: #kwin, zzag
Subscribers: meven, zzag, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D26381
