[GRASS5] color in GRASS - solved for PNG but I don't know why

[Michael Barton]

OK,

I've solved the problem but don't know why it is a problem. I've been 
messing with this all day with various suggestions. I'm copying this to 
the list in case it indicates an obscure bug that needs fixing.

Here is the situation:

I have a

     GRASS_TRUECOLOR: TRUE

statement in my .grassrc5 file (exactly this format, following the 
format for other statements in the file)

When I ran a g.gisenv, it said that

    GRASS_TRUECOLOR=TRUE

(exactly this format). When I typed d.mon start=PNG it responded

    PNG: GRASS_TRUECOLOR status: FALSE

(exactly this format). So, I have the right version of PNG and the 
correct statement in .grassrc5, but PNG didn't know to use truecolor.

So, I tried to set this variable at the shell level using

setenv GRASS_TRUECOLOR TRUE

(quitting GRASS first, then restarting)

Now GRASS creates a 332 Kb PNG file that DOES look like the screen. 
Clearly it IS now producing a 24 bit graphic image. Apparently, the 
truecolor statement in the .grassrc5 file is not parsing correctly on 
my system.

Do I need to change the format to

GRASS_TRUECOLOR=TRUE

--using an equals sign instead of a colon? Is this some other kind of 
error. It SEEMS that my other settings in .grassrc5 are being read 
correctly (but now I'm unsure).

I tried tiff output using my script to send the display to the 
cell_driver and then to r.out.tiff. However, it still looks 8bit. 
Apparently, it is not convinced by the truecolor environment variable 
yet.

Michael



On Tuesday, March 23, 2004, at 02:28  PM, Glynn Clements wrote:

>
> Michael Barton wrote:
>
>> Well, I THOUGHT this might be the magic solution.
>>
>> I had GRASS_TRUECOLOR=true in lowercase. With great excitement, I just
>> tried it with GRASS_TRUECOLOR=TRUE (restarting GRASS, of course) and
>> sadly had the same result.
>
> 1. Which versions of GRASS/PNGdriver/GD are you using? The PNG driver
> in 5.0.x and 5.3 snapshots prior to 2003-10-31 only support 24-bit
> images if built using GD 2.x. 5.3 from 2003-10-31 onwards doesn't use
> GD, and always supports 24-bit images.
>
> 2. If you're using a suitable PNG driver, did you export the variable
> setting?
>
> For bash, you need to use either:
>
> 	GRASS_TRUECOLOR=TRUE
> 	export GRASS_TRUECOLOR
> or:
> 	export GRASS_TRUECOLOR=TRUE
>
> [The latter is a bash extension; the former should work with all
> Bourne-style shells.]
>
> For C shells (csh, tcsh), the syntax is:
>
> 	setenv GRASS_TRUECOLOR TRUE
>
> -- 
> Glynn Clements <glynn.clements at virgin.net>
>
______________________________
Michael Barton, Professor & Curator
Department of Anthropology
Arizona State University
Tempe, AZ  85287-2402
USA

voice: 480-965-6262; fax: 480-965-7671