[Qt-qml] on device performance

[Thorbjørn Lindeijer]

Well, Thunderbird ate my reply when I cancelled sending when I noticed 
that I was once again replying the author and not the list...

On 12/13/2010 04:59 PM, ext Alexey Zaryanov wrote:
> Hi. I was really surprised when I saw the performance of QML
> applications on the device (n900) ( deckarative demos : twitter, rss
> etc. ). Its only about 12-15 fps. Its not smooth ! Look at any iphone apps!
> But video on youtube shows me very fast UI. What wrong ?

Short answers:

* Make sure you're using OpenGL when you do any blending, scaling or 
rotating. (-opengl to qmlviewer or QGLWidget as viewport of 
QDeclarativeView)

* Run fullscreen rather than maximized to avoid compositing overhead. 
(-fullscreen to qmlviewer or use showFullscreen() rather than show())

Regards,
Bjørn

-- 
Thorbjørn Lindeijer
Software Engineer
Nokia, Qt Development Frameworks