[Interest] redirecting Qt pixel data to designated buffer

Thiago Macieira thiago.macieira at intel.com
Tue Jan 6 16:56:25 CET 2015

On Tuesday 06 January 2015 16:31:11 Selmeci, Tamás wrote:
> On Tue, 2015-01-06 at 15:05 +0000, Rutledge Shawn wrote:
> > QtQuick 2 items have no built-in support for rendering via QPainter, so it
> > normally doesn’t work without OpenGL.  One way to get back an image after
> > the rendering is done is QQuickItem::​grabToImage().  There is a
> > commercial add-on to use the raster engine for rendering though, in case
> > you really don’t have an OpenGL-capable GPU:
> > http://doc.qt.io/QtQuick2DRenderer/index.html
> I not only want to get back an image after rendering, I want to prevent
> Qt from drawing anything onto the screen, except for my buffer. This is
> offscreen rendering, but I don't know how to use the 'offscreen' plugin
> for this...
> Maybe the best would be to refactor 'linuxfb' so it doesn't write
> to /dev/fb*, but to my buffer. I'm just hesitating to begin this work
> until someone says there's no simpler solution...

You'll probably need that and patching Mesa too.
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center

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