Commit graph

12 commits

Author SHA1 Message Date
Vlad Zahorodnii
4ce853e8e4 Prettify license headers 2020-08-07 19:57:56 +00:00
Vlad Zahorodnii
1fb9f6f13a Switch to SPDX license markers
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.
2020-08-07 19:57:56 +00:00
Vlad Zahorodnii
af71763be5 [scene] Fix decoration texture bleeding
Summary:
Quite long time ago, window decorations were painted on real X11 windows.
The nicest thing about that approach is that we get both contents of the
client and the frame window at the same time. However, somewhere around
KDE 4.2 - 4.3 times, decoration rendering architecture had been changed
to what we have now.

I've mentioned the previous decoration rendering design because it didn't
have a problem that the new design has, namely the texture bleeding issue.

In the name of better performance, opengl scene puts all decoration parts
to an atlas. This is totally reasonable, however we must be super cautious
about things such as the GL_LINEAR filter.

The GL_LINEAR filter may need to sample a couple of neighboring texels
in order to produce the final texel value. However, since all decoration
parts now live in a single texture, we have to make sure that we don't
sample texels that belong to another decoration part.

This patch fixes the texture bleeding problem by padding each individual
decoration part in the atlas. There is another solution for this problem
though. We could render a window into an offscreen texture and then map
that texture on the transformed window geometry. This would work well and
we definitely need an offscreen rendering path in the opengl scene,
however it's not feasible at the moment since we need to break the window
quads API. Also, it would be great to have as less as possible stuff going
on between invocation of Scene::Window::performPaint() and getting the
corresponding pixel data on the screen.

There is a good chance that the new padding stuff may make you vomit. If
it does so, I'm all ears for the suggestions how to make the code more
nicer.

BUG: 257566
BUG: 360549
CCBUG: 412573
FIXED-IN: 5.18.0

Reviewers: #kwin

Subscribers: fredrik, kwin, fvogt

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D25611
2020-01-09 15:13:07 +02:00
Vlad Zahorodnii
6e000314b3 Revert the fix for the texture bleeding issue
This reverts commit 9151bb7b9e.
This reverts commit ac4dce1c20.
This reverts commit 754b72d155.

In order to make the fix work, we need to redirect the client window
instead of the frame window. However, we cannot to do that because
Xwayland expects the toplevel window(in our case, the frame window)
to be redirected.

Another solution to the texture bleeding issue must be found.

CCBUG: 257566
CCBUG: 360549
2019-12-02 19:45:15 +02:00
Vlad Zahorodnii
ac4dce1c20 [scene] Fix decoration texture bleeding
Summary:
Quite long time ago, window decorations were painted on real X11 windows.
The nicest thing about that approach is that we get both contents of the
client and the frame window at the same time. However, somewhere around
KDE 4.2 - 4.3 times, decoration rendering architecture had been changed
to what we have now.

I've mentioned the previous decoration rendering design because it didn't
have a problem that the new design has, namely the texture bleeding issue.

In the name of better performance, opengl scene puts all decoration parts
to an atlas. This is totally reasonable, however we must be super cautious
about things such as the GL_LINEAR filter.

The GL_LINEAR filter may need to sample a couple of neighboring texels
in order to produce the final texel value. However, since all decoration
parts now live in a single texture, we have to make sure that we don't
sample texels that belong to another decoration part.

This patch fixes the texture bleeding problem by padding each individual
decoration part in the atlas. There is another solution for this problem
though. We could render a window into an offscreen texture and then map
that texture on the transformed window geometry. This would work well and
we definitely need an offscreen rendering path in the opengl scene,
however it's not feasible at the moment since we need to break the window
quads API. Also, it would be great to have as less as possible stuff going
on between invocation of Scene::Window::performPaint() and getting the
corresponding pixel data on the screen.

There is a good chance that the new padding stuff may make you vomit. If
it does so, I'm all ears for the suggestions how to make the code more
nicer.

BUG: 257566
BUG: 360549
CCBUG: 412573
FIXED-IN: 5.18.0

Reviewers: #kwin

Subscribers: fredrik, kwin, fvogt

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D25611
2019-12-02 15:08:44 +02:00
Vlad Zagorodniy
684b4b635e Use more traditional doxygen style
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
2019-07-29 22:06:19 +03:00
Vlad Zagorodniy
8af2fa73dc Run clang-tidy with modernize-use-override check
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
2019-07-22 20:03:22 +03:00
Martin Flöser
23ef40e638 Move the X11 Decoration Renderer into the X11 standalone platform
Summary:
Not needed except for X11/non-composited usage, so should be in the
plugin instead of core.

Platform API is extended to create a decoration renderer.

Reviewers: #kwin, #plasma

Subscribers: plasma-devel, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D7444
2017-09-01 17:49:32 +02:00
Martin Flöser
054d923411 Move SceneXRender into a plugin
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
2017-09-01 17:42:28 +02:00
Martin Gräßlin
b22317458c Override ::reparent in X11Renderer
Required to stop and disconnect the timer. Otherwise it's possible
that the render is invoked after the Client got destroyed. This
happened for example with e.g. opening Kickoff.
2014-08-11 11:41:08 +02:00
Martin Gräßlin
c12199a8e0 Pass Decoration::Renderer to Deleted and use it in the Scenes
The Renderer gets reparented to the Deleted. While passing it to
the Deleted the Scene's implementation can ensure that the buffers
are up to date. After passing to Deleted it's no longer allowed to
call the render method.
2014-07-25 14:02:27 +02:00
Martin Gräßlin
0030eb7f84 Initial import of support for new KDecoration2 based decorations
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.
2014-07-25 14:02:26 +02:00