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QOpenGLShaderProgram in different Threads and QOpenGLContexts [SOLVED]



  • Hi together,

    I am using QOpenGLShaderProgram objects to compile, link and bind my OpenGL shaders which works pritty awesome!
    The thing is that i have more than one rendering thread with different QOpenGLContexts each.

    Now the problem:
    Each thread needs to have the shaders (which are mostly the same!) and i encapsulated the compile and link step into a separate method which is part of my derived QOpenGLShaderProgram class. This method will be called if the renderer accesses the shader the first time. But the renderer is in a different thread. So i get this message:
    QObject: Cannot create children for a parent that is in a different thread.
    (Parent is QOpenGLShaderProgram(0x5e0884), parent's thread is QThread(0x6e9d98), current thread is QThread(0x5d1860) )

    So i guess that QOpenGLShader program is instantiating new QOpenGLShader instances and sets itself as the parent!?

    Now my question:
    Is there a possibility to either deactivate adding new child objects in QOpenGLShader program or can i somehow share the shaders between different QOpenGLContexts? Thus, that the graphics card has to compile the shader only once and each thread just has to call QOpenGLShaderProgram::bind()!?

    The second solution would be the finest! But i don't know if it is possible or how to make it!

    Thanks in advance.



  • I solved the problem. I just create a new QOpenGLShader program instance for each thread once it renders the object the first time.


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