[Qt-qml] QML Slot

[michael.brasser at nokia.com]

On 15/07/2010, at 1:29 AM, ext Almo Nito wrote:
> I was wondering if this was the right way to enable HW Acceleration for QML:
> 
> http://pastebin.com/DLA1GuF2

If this is an embedded, X11-based system, you'll probably also want to call QApplication::setGraphicsSystem("raster") somewhere in your code. This combination (raster graphics system + QGLWidget viewport) is what you get from qmlviewer when running with -opengl on X11 (as qmlviewer uses raster by default for X11). Using the raster graphics system on its own will outperform this in some scenarios (for example when only a small portion of the screen needs to be updated), but it also has much, much worse 'worst-case' performance (e.g. with raster you might see a demo that runs 5fps at parts and 60fps at others; while with raster + QGLWidget the demo will stay between 40fps-55fps).

I've added this information to the performance docs, so it should show up in the snapshots (http://doc.qt.nokia.com/4.7-snapshot/qdeclarativeperformance.html) in the next few days.

Regards,
Michael