[GRASS5] Re: max res. PPM image dump from NVIZ

[Hamish]

> > > > > X Error of failed request:  GLXBadContextTag
> > > > >   Major opcode of failed request:  144 (GLX)
> > > > >   Minor opcode of failed request:  1 (X_GLXRender)
> > > > >   Serial number of failed request:  3736
> > > > >   Current serial number in output stream:  3737
> > > > 
> > > > I can't reproduce this with 5.3, and I don't have an up-to-date
> > > > 5.7 built right now. Can you see if it happens for you with 5.3?
> > > 
> > > Happens both with the latest 5.3 and 5.7.
> > > 
> > > Just after it finishes writting the PPM, the low-res 'grid' is
> > > drawn, but the southern 10-15% is missing. When you change the
> > > view angle you are looking at a blank screen, when you finish it
> > > redraws the hi-res'polygon' version ok.
> > > 
> > > -> Resizing the viewing window causes the above error (& crash).
> > 
> > I can't reproduce this.
> 
> However, I have re-discovered something which could cause problems:
> 
> 	# Set the cancel function for drawing
> 	Nset_cancel_func update
> 
> Essentially, this means that Tk's event-processing code will be called
> repeatedly throughout the drawing process. If this results in the Togl
> widget receiving configure/expose/etc events, Togl will reinstate the
> original (on-screen) GLX context, with unpredictable results.
> 
> Try commenting out the above line (in nviz2.2_script), and see if the
> problems still occur.


Still occurs after commenting..

(also that change has latency issues, cutting into usability badly for me)



Hamish