[GRASS-dev] in trunk png/cairo d.vect overwrites previous images?

[Patrice Dumas]

On Tue, Jan 31, 2012 at 10:36:01AM +0100, Moritz Lennert wrote:
> 
> This behaviour is controlled by the GRASS_PNG_READ environment variable. 
> If you set it to TRUE, then GRASS will lay the new d.vect on top of the 
> already drawn vectors, otherwise it overwrites with the new. See 
> http://grass.osgeo.org/grass70/manuals/html70_user/cairodriver.html.

Thanks.  I was pretty sure I missed something although I did read the
Fine Manual before asking...  Maybe the GRASS_PNG_READ description
could be enhanced by adding

  Otherwise the GRASS_PNGFILE file content is overwritten each time 
  a new display command is used.

Also I think that the Example should also set 

  export GRASS_PNG_READ=TRUE

otherwise it doesn't really make sense as the elevation raster will not
appear on map.png.

-- 
Pat