Whats the difference in sharing a QGLContext and sharing a QGLWidget

[high_flyer]

What do you mean when you say "sharing a QGLWidget"?

[Wali]

When creating a QGLWidget you can pass its constructor a pointer to another QGLWidget to mutually share a context.

QGLWidget::QGLWidget ( QWidget * parent = 0, const QGLWidget * shareWidget = 0, Qt::WindowFlags f = 0 )

QGLWidget::QGLWidget ( QWidget * parent = 0, const QGLWidget * shareWidget = 0, Qt::WindowFlags f = 0 )

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What does it mean to pass in a QGLContext and another QGLWidget, as in the following constructor.

QGLWidget::QGLWidget ( QGLContext * context, QWidget * parent = 0, const QGLWidget * shareWidget = 0, Qt::WindowFlags f = 0 )

QGLWidget::QGLWidget ( QGLContext * context, QWidget * parent = 0, const QGLWidget * shareWidget = 0, Qt::WindowFlags f = 0 )

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[high_flyer]

Here is what the docs say, maybe you can ask specifically what it is you don't understand in the following (for a shared QGLWidget):

If shareWidget is a valid QGLWidget, this widget will share OpenGL display lists and texture objects with shareWidget. But if shareWidget and this widget have different formats, sharing might not be possible. You can check whether sharing is in effect by calling isSharing().

And a context is:

An OpenGL rendering context is a complete set of OpenGL state variables.

As you can see, sharing openGL "resources" (as shared QGLWidget) and sharing "rendering state variables" is not the same.

Did I help you?

[Wali]

Ok I think I understand thanks.