[Development] OpenGL Support in Qt5

[Sean Harmer]

On Monday 16 July 2012 07:21:23 Thiago Macieira wrote:
> On segunda-feira, 16 de julho de 2012 15.12.15, Sean Harmer wrote:
> > On Monday 16 July 2012 07:08:38 Thiago Macieira wrote:
> > > I'm asking for Qt 5.0: what should we tell Linux distributors to
> > > configure
> > > qtbase with? Considering what requirements qtwayland has, I think it
> > > needs
> > > to be -opengl es2.
> > > 
> > > Correct?
> > 
> > If using wayland then yes I believe so.
> > 
> > If using xcb backend then -opengl desktop works fine.
> 
> There's only one build of Qt. The choice is made at compile-time of qtbase,
> not at run-time like the platform plugin.
> 
> So everyone should use OpenGL ES 2.

Unless they want to support applications that use legacy OpenGL calls or 
develop new applications that use modern desktop GL.

There seems to be a dependency issue here that needs resolving. Qtbase itself 
has a configure time switch for OpenGL ES vs Desktop whereas the QPA plugins 
can be decided upon at runtime. Is there some way we can move the GL decision 
to be runtime too I wonder?

I don't like how even building the wayland QPA plugin means that we limit Qt 
and the apps built with it to OpenGL ES. I really don't want to get into a 
situation where we can build modern OpenGL apps for the desktop that work fine 
on Windows and Mac but not on Linux just because Qt for Linux has the wayland 
qpa plugin built.

Ideas welcome.

Sean

--
Dr Sean Harmer | sean.harmer at kdab.com | Senior Software Engineer
Klarälvdalens Datakonsult AB, a KDAB Group company
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