[Interest] opengl graphics system status in 4.8.x?

Simon St James kdedevel at etotheipiplusone.com
Tue Mar 19 08:01:52 CET 2013


Hi Thiago,

On Monday 18 Mar 2013 15:55:25 Thiago Macieira wrote:
> On segunda-feira, 18 de março de 2013 20.07.34, Simon St James wrote:
> > Currently, performance is surprisingly good considering we are still using
> > the "raster" graphics system where everything is plotted pixel by pixel by
> > Qt and then flushed to the canvas after pixel format conversion.  
> > However,
> > we suspect that we can get significant gains in rendering speed by writing
> > a Qt graphics system that uses HTML5 Canvas drawing primitives.
> 
> [snip]
> 
> > So I was wondering whether using Qt's opengl graphics system is feasible?
> > I
> > heard it was "experimental" and "not pixel-perfect", but I've not heard
> > any
> > reports that that matched mine, which makes me wonder if I just got very
> > unlucky
> 
> The OpenGL graphics system in Qt 4 is considered a done experiment, leading
> to the conclusion that an OpenGL graphics system is a very bad idea. The
> code itself never left experimental state and is considered flawed. Do not
> use it.
> 
> The experiment itself was a success, since it concluded that we should do
> something entirely different for performance using OpenGL. That's the Qt 5 /
> Qt Quick 2 scene graph.

Sounds pretty decisive, then :) Thanks for the information!

Si



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