[GRASS-dev] Re: [GRASSGUI] something squirrelly with the PNG/PPM driver

Michael Barton michael.barton at asu.edu
Tue May 8 10:59:34 EDT 2007


Here are all the standard settings from the TclTk and wxPython GUI (from
TclTk syntax here)

    set env(GRASS_WIDTH) "$driver_w($mon)"
    set env(GRASS_HEIGHT) "$driver_h($mon)"
    set env(GRASS_PNGFILE) "$mapfile($mon)"
    set env(GRASS_BACKGROUNDCOLOR) "ffffff"


Add a barscale or legend (try a legend for elevation.10m from Spearfish) to
the GUI layer tree and render. Do you get correct colors?

I had updated, did a distclean, and compiled on Friday. Colors are not
rendering correctly, and I'm getting partial rendering in some cases. I can
look in the tmp directory where this stuff is getting rendered and check the
PPM (and PNG files in wxPython) and can see the colors problem in the
graphic file.

This is only happening when writing to the PNG (PPM) driver. Using the X
driver gives no problem. Oddly, maps seem OK, but scalebars and legends are
a problem. I suppose that the problem could be something that d.barscale and
d.legend are both using, but that maps are not.

It could be specific to my office workstation (Mac G5, OS X 4.9). If so,
I'll update and recompile. But I want to check to see if this is happening
to anyone else.


On 5/8/07 3:12 AM, "Glynn Clements" <glynn at gclements.plus.com> wrote:

> Michael Barton wrote:
>> I�ve been beating my head over what I thought was a bug introduced into the
>> rendering routines of wxgrass, only to just find out that it is something
>> introduced into the PNG display driver very recently�maybe on last Thursday
>> or Friday.
>> The easiest way to see what is happening is to display a legend or scale bar
>> in the GUI. In both, white goes to black in the display. Both display fine
>> in an xmon. 
>> If the scalebar background is set to transparent, it displays OK. But white
>> goes to black. The same is true for legends of cell maps. White turns to
>> black. For FP maps, the whole thing turns black and won�t even render
>> properly in wxPython (locks it up, maybe because it is generating a PNG for
>> this instead of a PPM).
> I can't reproduce this, probably because I don't entirely understand
> what you're saying.
> Please provide a specific sequence of commands, along with the values
> of any GRASS_* environment variables.

Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton

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