width option in d.vect

[Ronald Wiemer]

Hi,

In fact I have a version of d.vect that lets you specify color and linewidth.
But, in order to achieve this you will have to change a number of things 
in your source code. The modifications you make will only give results when
you use the XDRIVER for display.

I have modified the raster library, the Xdriver, and recompiled every program 
that displays things on the graphics window.

This is what you have to do:

Create a file in $GISBASE/src/raster called

Linemod.c
*************************************
#include "graph.h"

R_linemode(index)
	int index;
{
	int i;
	i = index;
	_send_ident(LINEMOD) ;
	_send_int(&i);
}


*************************************

This function is called by every program that wants to change the linewidth.

Then you have to add the line

R_linemode(0);

in the file $GISBASE/libes/raster/io/c.

after the lines:

default:
sync_driver(name); /* syncronize driver */

and recompile the the raster library. Don't forget to add the Linemod.c in the
Gmakefile.

Next you have to do is modifying your Xdriver.
Edit the file:

$GISBASE/src/display/devices/XDRIVER/XDRIVER/SWITCHER.c

Uncomment the line

/* Linemod(index);   */

Create a file 

$GISBASE/src/display/devices/XDRIVER/XDRIVER/Linemod.c

*************************************************

#include <stdio.h>
#include "includes.h"

extern Display *dpy;
extern GC gc;

Linemod(number)
int number;
{
	XSetLineAttributes (dpy, gc, number, NULL, NULL, NULL );
}
***************************************************

and recompile your XDRIVER. (Don't forget to add Linemod.c in the Gmakefile)

Now the basics is done. In fact you can now use  the R_linemode() call in your 
programs.

For d.vect it's simple, just edit the file:

$GISBASE/src/display/d.vect/cmd/main.c:

edit the line

int i, stat ;

to be

int i, stat, width ;

edit the line

struct Option *opt1, *opt2;

to be

struct Option *opt1, *opt2, *opt3;

Insert the following lines ;

Opt3 = G_define_option() ;
opt3->key="width";
opt3->type=TYPE_INTEGER;
opt3->anser = "0" ;
opt3->description="Linewidth";

between

opt2->description="Color desired for drawing map";
and
G_gisinit(argv[0]);

The last thing you have to do is add the line:

R_linemode(width);

after the line

R_standard_color(color);

Now recompile d.vect.

If you would not recompile all other display programs, and you would interrupt 
the d.vect program, any other program would draw lines in the last selected 
linemode.

I have another program which uses a lookup table for setting colors and line-
widths, based on attributenumber. This program is called d.vect.lu, An older
version in the incoming directory on moon. As soon as I have time, I will
put a new version there, which also takes linewidth into account.

Ronald Wiemer