Does QT on Symbian^3 use OpenVG as rendering backend by default?
.. Or do I have to do some trick to make basic QT rending code such as QGraphicsView and QPixmaps to use OpenVG for rendering on Symbian^3?
I'd like to know how to optimize the rendering performance of my application on Symbian^3.
Yes, unless you configure and compile Qt to use some other graphics system.
Also, if you need to have application level exceptions, you can give a launch parameter
'-graphicssystem <raster|openvg|...>' to force certain graphics system for that application.