[PyOpenGL-Users] wxglcanvas and double buffer

[Ian K. <Ian...@rm...>]

I'm having a problem with vertical synchronization/refresh with a map browser application.  

When the application is running and I am scrolling around the map space I see a subtle vertical shift that starts at the bottom of the screen and flows to the top.

I am using a wxGlCanvas, the scrolling display is updated on a 12 ms recursive animation timer.  My first thought was that there were perhaps other timers in the application firing off, this was not the case.  I then checked the vertical sync setting on the video card, it was on.  So far so good

The code snippet is below:

class MapWindow(glcanvas.GLCanvas):
    def __init__(self,parent):
        glcanvas.GLCanvas.__init__(self,parent)

    def OnPaint(self, event=None):
        dc = wx.PaintDC(self) 
        self.SetCurrent()           #set this canvas to recieve Opengl calls
        self.DrawGL()               #call to draw opengl model
        self.SwapBuffers()          

From my understanding SwapBuffers() will sync the buffer swap with the vertical refresh of the hardware.  I believe the problem my be in the glCanvas.  After searching through various posts it seems the glcanvas does double buffer, but when I check the class reference documents there is a Constant WX_GL_DOUBLEBUFFER.  Is it necessary to include this constant?  In addtion I'm not sure about the syntax since these constants are in a attribList.  
I think this may be the crux of the problem, any suggestions would be appreciated.

Ian