Problems with Open-Source Downloads read https://www.qt.io/blog/problem-with-open-source-downloads and https://forum.qt.io/post/638946

Qt Quick and FrameBuffer issues



  • I'm using QQuickFramebufferObject to render a custom OpenGL 3d scene inside a QtQuick Item.
    Following the Qt Quick + FBO example, I'm having two issues. I'm using the Windows ANGLE version, Qt 5.3.1

    • Multisampling : I ask for 4 samples using the format.setSamples(4) function. In the latest version multisampling is enabled even with ANGLE, so I actually see it working.
      I would like to render some primitives in an anti-aliased way, some others not. Using glDisable(GL_MULTISAMPLE) doesn't works, so every primitive gets antialiased. How can I disable it for some primitives?

    • It seems that the projection matrix requires a "Y *=-1" scaling inversion. I'm not able to understand why , I'm currently adapting an opengl "Matrix" class which work flawlessly in a standalone context, but when I use it in a framebuffer Item renderer in QtQuick , everything seems to be reversed. Not a problem ,I just want to understand why....

    Thank for any hint,
    Qb


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