On Apr 11, 2013, at 6:31 PM, Michael Andersen <mich...@steelcode.com> wrote:
> Hi list,
>
> I have a loading throbber in my application that is completely killing the
> performance. If it is rotating then the application does not repaint while it
> is being dragged and if more than two or three copies of the application are
> running then it starts lagging Unity. I'm on Ubuntu 12.04 with Qt 5.0.1
> 64-bit. I was going to wait until 5.2 was out and check again, but it's
> taking a little longer than I expected for a stable version to be released.
Is vsync enabled in your driver? Sounds like it might not be. If not, then Qt
Quick 2.0 will render at 100% cpu rendering maybe many thousands of frames per
second, even though you only see 60 of them.
cheers,
Gunnar
>
> Here is a simple reproducer of the problem, I create a QtQuick2 application
> in Qt Creator 2.7. I adjust the QML to look like this:
>
> import QtQuick 2.0
>
> Rectangle {
> width: 400
> height: 400
> Rectangle {
> id: redsquare
> color: "red"
> width: 50
> height: 50
> x: 50
> y: 50
> }
> RotationAnimation {
> loops: Animation.Infinite
> target: redsquare
> properties: "rotation"
> from: 0
> to: 360
> duration: 300*5
> direction: RotationAnimation.Clockwise
> running: true
> }
> }
>
> My main.cpp is the default, but that looks like this:
>
> #include <QtGui/QGuiApplication>
> #include "qtquick2applicationviewer.h"
>
> int main(int argc, char *argv[])
> {
> QGuiApplication app(argc, argv);
>
> QtQuick2ApplicationViewer viewer;
> viewer.setMainQmlFile(QStringLiteral("qml/SimpleRotator/main.qml"));
> viewer.showExpanded();
>
> return app.exec();
> }
>
> I am new to Qt, so perhaps I am doing something wrong with my animation, but
> I have tried a couple other methods of animating and they all lag equally
> badly. The PC I develop on is quite a monster, so if it is lagging on this, I
> hate to think what it's going to do on my clients' laptops.
>
> Anyone have any ideas?
>
> Regards
> Michael
> _______________________________________________
> Interest mailing list
> Interest@qt-project.org
> http://lists.qt-project.org/mailman/listinfo/interest
_______________________________________________
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest
