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DropShadow doesn't display on Embedded



  • So I'm running 5.12 on BBB with an HDMI display, using the linuxfb platform. When I build and run the app on my desktop the QML DropShadow looks perfect. When I cross-compile and run it on the BBB, it runs, no errors or warning about missing libraries or plugins, however the drop shadow doesn't display at all?

    Any insight here? I would expect if it was a library/plugin issue I would at least get a warning in console about it. So the only starting point I have is maybe the linuxfb can't support it for some odd reason? Any workarounds?



  • Suspicions have been confirmed, if I used XCB dropshadow works as expected. So for some using the linuxfb platform is causing the issue.


  • Moderators

    @While_e
    the linuxfb platform plugin doesn't support OpenGL (ES), which is mandatory for the QtGraphicsEffects plugin
    Are you bound to linuxfb? EGLFS would work if you can use it.



  • Excellent, thank you for the confirmation. I may try to use eglfs, just don't currently have supporting libraries built just yet. If it becomes an issue that I absolutely have to have graphical effects, I'll head down that road.

    Do you know performance wise how eglfs stands up to linuxfb in the embedded world? I imagine fairly similar. I just know something like xcb is horrifically slow when I tried it the first time.


  • Moderators

    @While_e said in DropShadow doesn't display on Embedded:

    Do you know performance wise how eglfs stands up to linuxfb in the embedded world?

    thats exactly it's purpose. Bring graphics acceleration to embedded devices without much overhead ;)

    Just one note: due to the nature of EGLFS there can only be exactly one window in your application. Just to keep this considered. QtQuickControls2 works just fine, where QtQuickControls1 does not.


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