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Thread: QOpenGLVertexArrayObject crash if QGLWidget not visible on close action

  1. #1
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    Default QOpenGLVertexArrayObject crash if QGLWidget not visible on close action

    I have a Qt 5.2.1 program that uses QOpenGLVertexArrayObjects and creates more than one QGLWidget, each placed inside of a QStackedWidget. Thus, only one QGLWidget is visible at any one time.

    The issue is -- if I close the program and the QGLWidget that uses a QOpenGLVertexArrayObject ISN'T currently visible, it crashes with the message:

    Warning: QOpenGLVertexArrayObject::~QOpenGLVertexArrayObjec t() failed to make VAO's context current (opengl/qopenglvertexarrayobject.cpp:370, virtual QOpenGLVertexArrayObject::~QOpenGLVertexArrayObjec t())
    Looking through the source code, the destructor of QOpenGLVertexArrayObject contains the following code:

    Qt Code:
    1. /*!
    2.   Destroys the QOpenGLVertexArrayObject and the underlying OpenGL resource.
    3. */
    4. QOpenGLVertexArrayObject::~QOpenGLVertexArrayObject()
    5. {
    6. QOpenGLContext* ctx = QOpenGLContext::currentContext();
    7.  
    8. Q_D(QOpenGLVertexArrayObject);
    9. QOpenGLContext *oldContext = 0;
    10. if (d->context && ctx && d->context != ctx) {
    11. oldContext = ctx;
    12. if (d->context->makeCurrent(oldContext->surface())) {
    13. ctx = d->context;
    14. } else {
    15. qWarning("QOpenGLVertexArrayObject::~QOpenGLVertexArrayObject() failed to make VAO's context current");
    16. ctx = 0;
    17. }
    18. }
    19.  
    20. if (ctx)
    21. destroy();
    22.  
    23. if (oldContext) {
    24. if (!oldContext->makeCurrent(oldContext->surface()))
    25. qWarning("QOpenGLVertexArrayObject::~QOpenGLVertexArrayObject() failed to restore current context");
    26. }
    27. }
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    - Is it possible to use QOpenGLVertexArrayObjects in a QGLWidget that's not currently visible and close the program successfully?

    - Is this a bug?

  2. #2
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    Default Re: QOpenGLVertexArrayObject crash if QGLWidget not visible on close action

    The warning issued is not a crash. Where does it crash? Have you looked at the backtrace?

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