[GRASS5] New gui.tcl generic user interface

[Michael Barton]

> From: Glynn Clements <glynn at gclements.plus.com>
> Date: Fri, 17 Mar 2006 20:53:54 +0000
> To: Michael Barton <michael.barton at asu.edu>
> Cc: <grass5 at grass.itc.it>
> Subject: Re: [GRASS5] New gui.tcl generic user interface
> 
> 
> Michael Barton wrote:
> 
>>>> 1) using r.profile and TclTk charts to create a new terrain profile utility
>>>> that would replace d.profile, produce postscript text and graphics, and not
>>>> need x11.
>>> 
>>> That would be nice, but v.digit is probably the most urgent candidate
>>> for replacement, followed by i.points.
>> 
>> I agree that these are more important. But they take rewriting the relevant
>> C code, so someone other than me will need to work on this.
> 
> I would have thought that you could get a usable v.digit replacement
> using only Tcl/Tk, v.in.ascii and a few other GRASS commands.

You need to be able to display a vector in such a way that it can be
manipulated in a canvas (see your issue below), then add, delete, or change
the coordinates of vector nodes, selecting them interactively with a mouse.
You also need to be able to add/delete centroids of areas, and join them to
tables. I've thought about this a little and don't think that there any
GRASS tools available to do this...yet.

Michael

> 
>>> More generally, in order to be able to show existing vector maps in a
>>> Tk canvas, we need a way to export vectors to a usable text format.
>>> 
>>> v.out.ascii has the (major) drawback that areas are output as disjoint
>>> segments which the application then has to piece together to form
>>> closed polygons. AFAICT, currently the only tool which provides
>>> polygons is v.out.pov, but that loses all of the structural
>>> information.
>> 
>> If solved, this would produce the kind of high quality vector output that
>> many people wish for.
> 
> Unfortunately, I don't really know enough about the vector API to do
> this myself.
> 
> AFAICT, the main issue is that v.out.ascii uses
> Vect_set_open_level(1), whereas an application which displays filled
> areas needs level 2.
> 
> -- 
> Glynn Clements <glynn at gclements.plus.com>


__________________________________________
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