[GRASS5] XDRIVER pad list and d.rast

[Markus Neteler]

On Sun, Jan 13, 2002 at 04:37:10PM +0000, Glynn Clements wrote:
> 
> Andreas Lange wrote:
> 
> > > > after working in a GRASS session for some more time without
> > > > d.erase I realized by resizing the monitor, that some
> > > > 20 display commands had been accumulated (generally fine!).
> > > >
> > > > My question/suggestion is: If
> > > > d.rast map
> > > > is used, can't this be used to erase the command list in GRASS
> > > > monitor? As d.rast will overwrite everything (am I wrong?) it's
> > > > effectively the same as
> > > > d.erase
> > > > d.rast map
> > > 
> > > Have you never used d.rast to display more than one adjacent or
> > > overlapping raster?  I think the answer to that question will
> > > answer your question ;-)
> > 
> > The behaviour of d.rast was as Markus outlined above (calls
> > D_clear_window if no -o option). 
> > But i believe that this is not consistent, as no other display module
> > wipes out the display. And i had problems with the window re-creation
> > and d.save, because the pad structure was erased with this original
> > setup. 
> > And the manual page says:
> > If the active graphics frame already contains text or graphics, and the
> > user does not wish to use the -o option, it is wise to first invoke
> > d.erase to clear the active graphics frame before running d.rast.
> > 
> > So i think the existing users of GRASS have to learn the new setup, and
> > the new users will enjoy enhanced consistency. Just remember to run
> > d.frame -e and/or d.erase to initialize the display.
> > 
> > But if you all disagree, i will revert my changes in
> > src/display/d.rast/cmd/display.c .
> 
> Now that we're on the subject, I'm wondering why -o isn't the default
> behaviour. It was understandable before the introduction of null
> values, but now -o should probably be the default, possibly with a
> separate option to fill null-valued cells.

In my opinion a good suggestion. 
 
> Also, even without "-o", d.rast doesn't overwrite the entire display.


Markus