Hi all! I'm new to KDE and hope to be able to contibute in the future. Been in limbo since the launch of Gnome 3 and Unity and think that I've finally found a new home in KDE.

I'm running Plasma 5.5.2 on Manjaro and it's been a really solid and inpressive experience. However I'm having trouble with the Zoom Desktop Effect. My eyesight is really bad so I zoom in quite a lot. The mouse pointer movement is choppy when i move the cursor and so is the movement of the rest of the screen. I've got brand new Core i7 Broadwell-U-based NUC with Iris Graphics 6100, so it's probably not due to insufficient hardware or poor drivers.

I solved the very same issue in Gnome Classic (on older hardware) by increasing the mousepoll speed in compiz. Can't find any similar desktop effect setting in KDE so I've been increasing the usbhid mousepoll speed instead without any luck. Have been testing quite a lot in accordance with https://utcc.utoronto.ca/~cks/space/blo ... ollingRate and https://wiki.archlinux.org/index.php/Mouse_polling_rate.

Any suggestions on what to try next?

diff --git a/cursor.cpp b/cursor.cpp
index db68ce7..c1a29d4 100644
--- a/cursor.cpp
+++ b/cursor.cpp
@@ -258,7 +258,7 @@ X11Cursor::X11Cursor(QObject *parent)
m_resetTimeStampTimer->setSingleShot(true);
connect(m_resetTimeStampTimer, SIGNAL(timeout()), SLOT(resetTimeStamp()));
// TODO: How often do we really need to poll?
- m_mousePollingTimer->setInterval(50);
+ m_mousePollingTimer->setInterval(30);
connect(m_mousePollingTimer, SIGNAL(timeout()), SLOT(mousePolled()));

connect(this, &Cursor::themeChanged, this, [this] { m_cursors.clear(); });


It's not configurable. Given the comment it maybe should. There were also vague plans to utilize xinput2 events (instead of polling)

luebking wrote:It's not configurable. Given the comment it maybe should. There were also vague plans to utilize xinput2 events (instead of polling)

Thanks for the reply! So this is not as out of date as i hoped then: https://git.reviewboard.kde.org/r/111875/.

It might not need to be manualltý configurable but the poll rate should really be increased when using some effects such as the zoom. If xinput2 is not implemented yet my only option seems to be to "wait for wayland". :/

Short term: Is it possible to change the rate in cursor.cpp and recompile parts of the source without to much hassle?
Long term: Shuld i file a bug/wish report to get some attention to this? Or perhaps send a email to one of the mailing lists? I'd like to help out, if i can, in order to fix this.

git clone git://anongit.kde.org/kwin.git
cd kwin
git checkout Plasma/5.5
mkdir build
cd build
ccmake ..
[press c, adjust pathes and most likely check to use qt plugin paths!, press c again, then g, last q]
[if there were no errors]
make
[if there were no errors, apply the patch]
make && sudo make install

Thanks! I've got some trouble with configuring the paths, but that's mostly due to lack of time. Can't find or figure out how to install the Extra CMake Modules for KDE in order to set $ECM_DIR.

I have, for the record, filed this bug in regards to this issue: https://bugs.kde.org/show_bug.cgi?id=357692