# File gtkglext/sample/share-lists.rb, line 72
def expose_event(w)
    glcontext = w.gl_context
    gldrawable = w.gl_drawable

    gldrawable.gl_begin(glcontext) do
        GL.Clear(GL::COLOR_BUFFER_BIT | GL::DEPTH_BUFFER_BIT)
        GL.CallList(1)

        if gldrawable.double_buffered?
            gldrawable.swap_buffers
        else
            GL.Flush
        end
        true
    end
end