[GRASS-dev] 7.x Status Update

[Glynn Clements]

Moritz Lennert wrote:

> >> Another potentially disruptive update: the raster library now uses
> >> floating point values for coordinates.
> > 
> > Next update: the cairo driver is now the default, assuming that GRASS
> > was built --with-cairo. If you haven't been enabling this, now is the
> > time to try, as the PNG driver may not be around for much longer.
> > 
> > It's still possible to force the PNG driver to be used by setting
> > GRASS_RENDER_IMMEDIATE=PNG.
> > 
> > At present, it uses the "toy" font backend, which means that it only
> > understands a limited set of fonts (AFAICT, it understands mono, serif
> > and sans, and -bold and -italic variants), although support for
> > FreeType and stroke fonts will be added soon.
> 
> Seems to work great on the command line (aside a few questions below), 
> however, there seems to be problems in the guis:
> 
> - tcltk gui (gis.m): I cannot display any vector maps; raster map 
> display becomes very slow when zooming out, with memory usage rising 
> steadily
> 
> - wxpython gui: I can display vector maps, but as soon as I ask not to 
> display centroids, nothing is displayed at all

Can you get the GUI to display the exact commands being used, and
check whether the problem exists when the command is run from the
shell?

> And here a few questions:
> 
> - How do I configure which format the cairo driver writes to (i.e. other 
> than PNG) ? GRASS_CAIROFILE doesn't seem to work:
> 
> GRASS 7.0.svn (nc_spm_06):~ > export GRASS_CAIROFILE=map.ps
> GRASS 7.0.svn (nc_spm_06):~ > d.rgb r=blend.r b=blend.b g=blend.g
> cairo: collecting to file: map.png
> 
> 
> - How to tell it to read from an existing file ? Again, GRASS_CAIRO_READ 
> doesn't seem to work.

I changed it to use the same variables as the PNG driver, i.e.
GRASS_PNGFILE, GRASS_PNG_READ, etc. Specifically:

	GRASS_CAIRO_DRAWABLE
	GRASS_CAIRO_VISUAL
	GRASS_PNGFILE
	GRASS_PNG_MAPPED
	GRASS_PNG_READ
	GRASS_BACKGROUNDCOLOR
	GRASS_TRANSPARENT
	GRASS_PNG_AUTO_WRITE

[You can ignore the first two; I don't even know if that feature works.]

It is supposed to be a drop-in replacement for the PNG driver, but
there may well be factors which I have overlooked.

Also, the changes to the display library may have broken stuff. If you
find a command which doesn't work as expected, it's worth trying it
withe GRASS_RENDER_IMMEDIATE=PNG to determine whether the problem is
caused by the cairo driver or by the changes to the display library.

-- 
Glynn Clements <glynn at gclements.plus.com>