OpenGL plot canvas

[Uwe R. <Uwe...@ti...>]

Hi all,

This weekend I have decoupled QwtPlot and QwtPlotCanvas, so that QwtPlot 
accepts any type of QWidget as canvas.
This step opens QwtPlot for using OpenGL and so to hardware accelerated 
rendering on platforms, where Qt uses a software renderer ( f.e Windows 
or Qt/Embedded ).

I played a bit myself with a QGLWidget as canvas what was not faster 
than X11 ( no surprise as it is also hardware accelerated on my box ) 
but significantly faster than the raster paint engine - especially for 
stuff like long polygons with a pen width > 0.

Now it's time to make something useful - and I would like to have the 
following:

1) A mode for QwtPlotCanvas, where the items are rendered to a 
QGLFramebufferObject/QGLPixelBuffer first and the result is then 
translated to a QImage/QPixmap.
2) A QwtPlotGLCanvas ( derived from QGLWidget ) with an optional 
internal backing store ( QGLFramebufferObject/QGLPixelBuffer ).

Unfortunately my OpenGL experiences are limited and I'm looking for 
support from someone with a more solid background ?

Uwe