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I am working on Qt application in the linux Desktop enviromet. Most desktop Linux uses xwindows to display onto the screen. But now I want to try my hands on DirectFB on my desktop. Related to which i have some questions :---

1> Can i make my desktop QT application to make use of DirectFB to run my QT application .

2> If yes then do i have to disable xwindow server on my desktop first Or directfb can run simultaneously.

3> Also is it the right way to configure QT for using directFB .
http://qt-project.org/doc/qt-4.8/qt-embeddedlinux-directfb.html
http://qt-project.org/wiki/DirectFBAndQt

4> How does Qt and directFB & openGL works together. Is this how communication flow occurs :---
Qt ----> OpenGL ----> DirectFB --> screen

5> Also if i install Directfb library then will it automatically come to know how to communicate with video h/w driver ?
http://en.wikipedia.org/wiki/DirectFB Please suggest on these points.

Claudio
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Katoch
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2 Answers2

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  1. try to inform the display plugin your Qt application should use

    ./qt-app -display directfb

  2. DirectFB can create windows over X, but you need to configure it to do so (XNest or something like it)

  3. Probably yes

  4. Don't know

  5. Nope, you need a plugin backend for your platform. When dealing with custom boards, usually the vendor ships the code needed to build such component

milton
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The Qt library is able to draw either on X11 or on the framebuffer without the need of the (additional) DirectFB layer. Recent versions of the library also have OpenGL support. Adding such a layer would just be a waste of time/memory/cpu.

Claudio
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  • This is great to hear, but how exactly does one configure a Qt application to run in this way? – Username Obfuscation Mar 05 '16 at 11:26
  • There are plenty of web pages explaining how to do that. Just google for *"Qt framebuffer"*. On old version of Qt, you had to specify the `-qws' argument (see http://doc.qt.io/qt-4.8/qt-embedded-running.html) and to set a few environment variables. With Qt 5 the arguments have been changed, but I can't remember the new arguments. – Claudio Mar 07 '16 at 07:49