Quote Originally Posted by Bojan
I just have a question regarding that example. What's the difference between the three renderers? Even from the source code, I am not sure I understand. The SvgRasterView (used for Image), renders on top of an image; SvgNativeView (for Native) renders on top of the widget (this), and SvgGLView paints on top of the QGLWidget (this). I dont really know what this means?
Yes, yes, yes! Finally, someone agrees with me! I have posted messages to qt-interest about this with no reply. What is going on?

Quote Originally Posted by Bojan
Clearly there is a difference between the 3 modes. The native one usually has transparent background when viewed. Same for OpenGL renderer. Also, for me OpenGL renderer doesn't look as good.
Again, I totally agree. On my machine, the OpenGL is even worse - if you zoom in to far the image becomes totally scrambled and messed up. Could you try that on your machine please and see if the same happens?

As I've had no response from qt-interest I have just read and read the documentation and studied the example. It seems, the Arthur paint engine does indeed support multiple paint engines (such as PostScript and opengl) but this isn't an abstraction - you must derive from QGLWdiget to use OpenGL, and you must derive from QPSPrinter to use PostScript.

Although it's not as impressive as I initially thought, I can live with it as long as the OpenGL examples works. But in SVGViewer, as you state the OpenGL provides no visible performance improvement - in fact, it looks and performs worse than the other renderers.

What is going on?