[SOLVED] Qt 5.7 SVG takes seconds to be drawn (QWebEngine/QWebKit)

Discussion in 'Yocto' started by cyrilf, Dec 9, 2016.

  1. cyrilf

    cyrilf Active Member

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    Hi,

    I have a lot of troubles to make Qt 5 working properly on both the UDOO Quad and Neo (same behavior). Qt 4.8 built with Buildroot used to work like a charm on Quad. Now I found that SVG takes a very long time to be redrawn (~5 sec for a simple text) by JavaScript when it was immediate using Qt 4.8. The issue is probably more related to the framebuffer EGLFS that I suspect to be way heavier than the QWS plugin used before Qt 5.5. But maybe I'm wrong.

    This is very strange because other JavaScript animations run faster with QWebEngine 5.7. I tried Bootstrap modal animations (jQuery animations by the way) for example and it's really reactive.

    Another idea could be the GPU that is not well supported as EGLFS is recommanded for GPU featured boards. I do compile the imx-gpu-viv and imx-vpu recipes and everything looks fine on the screen (like the fonts or images).

    I have an other bug related to SVG with QWebEngine 5.7 I don't have with QWebKit 5.7. All the <text> tags display superposed characters instead of characters following each other (!!). This is also very strange and hard to understand. It may open a track to an engine bug.

    Any idea is welcome :)
     
    Last edited: Dec 9, 2016
  2. modjo

    modjo Active Member

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    Sorry Cyrilf but i don't use this module of Qt ... Perhaps it would be great to post your question on qt5 irc or forum ... see here
     
  3. oxoocoffee

    oxoocoffee Member

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    cyrilf

    Do you have clean downloadable image I could try. I am interested in QML or Neo board with EGL. Before I spend time on figuring out how to cook actual image I would like to experiment first with my touch screen and QML. If you could post image ready to develop and run QML somewhere that would be great. I am also interested in SVG :)
     
  4. cyrilf

    cyrilf Active Member

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    To update, I found a weird solution by hiding the SVG, updating the text tag and showing back the SVG. Curiously, if the text tag is directly edited, it bugs but when I do it in 3 steps, everything works "fine".
     

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