Re: [PyOpenGL-Users] Attempt to retrieve context when no valid context - repost

[Mike C. F. <mcf...@vr...>]

Mads Ipsen wrote:
...
> I am running an app in a PyQt based QGLWidget. If the window is minimized,
> and the method for rendering the object that should be displayed is
> called, I get the error 'OpenGL.error.Error: Attempt to retrieve context
> when no
> valid context' (included below), when glColorPointerd() is called.
>   
This is actually *not* really a necessary operation for any situation 
where you have retained a pointer to your data and avoided any data-copy 
operations, but if GetCurrentContext() is returning null you're likely 
going to blow up at some point anyway.
> Is there:
>
> * a way to check whether a valid context is set?
>   
OpenGL.platform.CurrentContextIsValid() -> bool
> * force the context to be set?
>   
This is windowing-system dependent, you will likely find something like 
self.setCurrent() in your QGLWidget, it may not work when the window is 
minimized, however.  I'm a bit surprised that the widget is calling the 
draw callback without doing a setCurrent(), would be more likely that it 
just can't get the context to be current when it's not on-screen.

HTH,
Mike

-- 
________________________________________________
  Mike C. Fletcher
  Designer, VR Plumber, Coder
  http://www.vrplumber.com
  http://blog.vrplumber.com