> -----Original Message----- > From: [email protected] [mailto:qt- > [email protected]] On Behalf Of > VStevenP > Sent: Thursday, October 31, 2013 5:57 PM > To: [email protected] > Subject: [Qt-creator] QML Profiler questions > > I have 2 QML Profiler questions. I am profiling a simple Knob widget which is > made out of an Image and a MouseArea, with some Javscript to control the > rotation property of the Image. > > When I profile the Knob in QML Profiler, I see that the Knob is efficient, in > that there are no Paint events. This must mean that when the Knob is > created, the Knob png is sent to the GPU, and after that, the rotation is > simply controlled by a rotation command sent to the GPU for that > Image. Hopefully, I understand that correctly.
I guess you're using the open source version of Qt Creator, together with Qt 5. Here the 'Paint' column in Qt Creator only shows the timing/number of animations running, and doesn't give you any information about the scene graph itself. That is only available in the commercial version so far: Here you see also the status of the Pixmap Cache + the timing of the Renderer thread (consisting of Polish, Sync, Update, Binding, Render, Swap states). If you're happy with console output you can try setting the 'QSG_RENDER_TIMING' environment variable. > Question 1: Is the rotation command that is sent to the GPU considered to > be a 'compositing event', and if so, will QML Profiler show compositing > activity separately, as in Chrome Dev Tools in Chrome? I'm not sure what a 'compositing event' exactly is (but then again, I'm not an expert on the scene graph ...). I'd personally expect that any changes to the rotation property result in a changed transformation matrix only. > I also discovered that in Qt 5.1, if you manipulate opacity on an Item during > onPressed and onReleased mouse events, Paint events occur for that Item > even when the Item has visible: false. I would think that visible property > would supersede opacity to ensure most efficient draw. If you saw activity in the 'Painting' column of the QML Profiler, see above: This does only show the number of animations that have been running in Qt 5. (We should probably rename it for Qt 5 traces ... 'Painting' is Qt 4 heritage). > Question 2: Should I report this as a bug? Might be the easiest to file a bug indeed, including a minimal example + what you observe + what you expect to observe. > I was going to try and test these on Qt 5.2 Beta, because I know the scene > graph renderer has been reworked, but I'm not able to run the QML Profiler > in Qt 5.2 Beta like I can in Qt Creator 2.7.2/Qt 5.1 due to an already-logged > bug. I think that bug is fixed by now :) As a workaround, go to the Project Mode, Build Settings, expand qmake step, and check 'Enable QML debugging:'. > - VStevenP > > > _______________________________________________ > Qt-creator mailing list > [email protected] > http://lists.qt-project.org/mailman/listinfo/qt-creator _______________________________________________ Qt-creator mailing list [email protected] http://lists.qt-project.org/mailman/listinfo/qt-creator
