[Development] About inheriting QBlitterPaintEngine from QGL2PaintEngineEx class

[Allan Sandfeld Jensen]

On Thursday 10 July 2014, haithem rahmani wrote:
> Hi,
> 
> When running Qt-5 on top of the directfb qpa plugin,  some benchmarks are
> quite slow.
> (http://smashcat.org/av/canvas_test)
> 
>  I've found that the 2D painting ops are going through the
> QBlitterPaintEngine class
> that is inheriting the QRasterPaintEngine class, which is doing all the
> painting via CPU.
> 
> Qt provides another paintEgine class, QGL2PaintEngineEx, that is doing the
> same paintings via the GPU.
> 
> So I want to know whether is possible to make the QBlitterPaintEngine
> inherit this QGL2PaintEngineEx
> instead of QRasterPaintEngine and got things working correctly or not?
> 
It will probably be easier for you to use Qt 5.4 or cherry-pick 
https://codereview.qt-project.org/88787 . It uses the QOpenGLPaintDevices for 
2D canvases. Note that it only makes some operations faster and other 
especially pixel access slower.

Best regards
`Allan