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One QGLWidget that manage QGLWidget childs



  • Hi devs.

    I would like to know if the following use case is supported by QT.

    I have one "TopLevel" QGLWidget :

    @class ParentGLWidget : public QGLWidget {
    ...
    ParentGLWidget(QGLContext * context, QWidget *parent = 0) : QGLWidget(context, parent) {... }
    ...
    void initializeGL()
    {
    qglClearColor(qtPurple.dark());
    glEnable(GL_CULL_FACE);
    ...
    }

    void paintGL()
    {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    }
    
    void resizeGL(int width, int height)
    {
    glViewport((width - side) / 2, (height - side) / 2, side, side);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrthof(-0.5, +0.5, -0.5, +0.5, 4.0, 15.0);
    glMatrixMode(GL_MODELVIEW);
    }
    

    }@

    There are other "GLWidget" that should be drawn inside the top level widget context :
    @class ChildGLWidget : public QGLWidget {
    ...
    ChildGLWidget(QGLContext * context, QWidget *parent = 0) : QGLWidget(context, parent) {... }
    ...
    void initializeGL()
    {
    // optional
    // at least, should not overwrite what have been done in the top level widget
    }

    void paintGL()
    {
    glLoadIdentity();
    glTranslatef(0.0, 0.0, -10.0);
    glRotatef(xRot, 1.0, 0.0, 0.0);
    // draw some object in the gl world
    }
    
    void resizeGL(int width, int height)
    {
     // optional
     // at least, should not overwrite what have been done in the top level widget
    }
    

    }@

    I would like to use them like this :
    @
    QGLContext * context = new QGLContext(QGLFormat(QGL::SampleBuffers));
    ParentGLWidget * parent = new ParentGLWidget(context);
    ChildGLWidget * child_1 = new ChildGLWidget(context, parent);
    ChildGLWidget * child_2 = new ChildGLWidget(context, parent);
    @

    The childs could be managed (drawing, deletion, ...) by the parent (like traditional widgets do).

    II haven't been able to run such a use case.

    Is there any design flaw in this use case ?

    Thank for your help.



  • If you comment out the childs creation, does the ParentGLWidget show up correctly (so without childs)?



  • Yes.

    My test code works if display independently each widget in different contexts.


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