[GRASS5] zoom and pan in v.digit (was raster map file format)

[Michael Barton]

Sounds interesting, though I have no idea what would be involved
programming-wise.

Michael
__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution and Social Change
Arizona State University
Tempe, AZ 85287-2402

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



> From: Daniel Calvelo Aros <dcalvelo at minag.gob.pe>
> Reply-To: <daniel.calvelo at minag.gob.pe>
> Date: Mon, 07 Nov 2005 22:32:22 -0500
> To: Glynn Clements <glynn at gclements.plus.com>, Michael Barton
> <michael.barton at asu.edu>
> Cc: <grass5 at grass.itc.it>
> Subject: Re: [GRASS5] zoom and pan in v.digit (was raster map file format)
> 
> How about introducing a "stack of WIND settings" from which you can pop
> previous settings and push new settings, and maybe select them from a list?
> Then, assuming d.view.pop and d.view.push commands, not only v.digit could
> push on entering and popping on leaving, but I guess other users/scripts would
> benefit.
> 
> It would be just a kind of versioning system for the WIND file, wouldn't it?
> 
> -- Daniel Calvelo Aros
> 
> ---------- Original Message -----------
> From: Glynn Clements <glynn at gclements.plus.com>
> To: Michael Barton <michael.barton at asu.edu>
> Cc: grass5 at grass.itc.it
> Sent: Mon, 7 Nov 2005 21:11:23 +0000
> Subject: Re: [GRASS5] zoom and pan in v.digit (was raster map file format)
> 
>> Michael Barton wrote:
>> 
>>> I'd like to add, a bit different from what Maciek suggests, that any zooming
>>> OR panning in v.digit should stay in v.digit and have no effect on the
>>> region for display or analysis outside of v.digit.
>> 
>> v.digit does this so that any external commands which it invokes use
>> the same region settings as v.digit.
>> 
>> AFAICT, there are two cases, both in display.c:
>> 
>> 1. display_bg() executes a sequence of user-specified commands to
>> draw the background.
>> 
>> 2. display_erase() executes d.erase to erase the background.
>> 
>> The second is gratuitous; it should just erase the background itself.
>> 
>> However, there's no getting around the former; the only way to make
>> an external command use a specific region is to modify the WIND file.
>> 
>> One option is to save the WIND file prior to executing the commands
>> then restore them afterwards.
>> 
>> Another option would be to modify G_get_window() so that you can
>> force it to read a different file by using an environment variable.
>> Then,
>> v.digit could write the modified region to a temporary file and
>> force the background commands to use that via the environment variable.
>> 
>> In either case, the auto-redraw feature won't work, as the commands
>> will get the normal region rather than v.digit's internal version.
>> 
>> -- 
>> Glynn Clements <glynn at gclements.plus.com>
>> 
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> ------- End of Original Message -------
>