add vlegend column separation control (see trac https://trac.osgeo.org/grass/ticket/355; merge from devbr6)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@34744 15284696-431f-4ddb-bdfa-cd5b030d7da7

ps/ps.map/ps.map.html

@@ -1466,6 +1466,7 @@ USAGE:	<B>vlegend</B>
 	<B>fontsize</B> font size
 	<B>width</B> width of color symbol
 	<B>cols</B> number of columns to print
+	<B>span</B> column separation
 	<B>border</B> color|none
 	<B>end</B>
 </PRE>
@@ -1474,14 +1475,18 @@ scale, grid and region information, starting at the left edge of the map.
 If the <EM>where</EM> instruction is present and <EM>y</EM> is less than or
 equal to zero, the vector legend will be positioned immediately below
 the map, starting <EM>x</EM> inches from the left edge of the page.
-
 <P>
 <EM>width</EM> is the width in inches of the color symbol (for lines)
 in front of the  legend text. The default is 1/24 * fontsize inches.
 <P>
-<EM>cols</EM> is the number of columns to split the legend into. The default is one 
-column. The maximum number of colums is 10, or equal to the number of legend entries 
-if there are less than 10 entries.
+<EM>cols</EM> is the number of columns to split the legend into. The
+default is one column. The maximum number of colums is 10, or equal
+to the number of legend entries if there are less than 10 entries.
+<P>
+<EM>span</EM> is the column separation distance between the left edges of 
+two columns in a multicolumn legend. It is given in inches. 
+The default is automatic scaling based on the left margin and the right 
+hand side of the map box. 
 <P>
 <EM>border</EM> will draw a border around the legend using the specified color.
  (see <a href="#NAMED_COLORS">NAMED COLORS</a>)

ps/ps.map/ps_vlegend.c

@@ -70,6 +70,7 @@ int PS_vlegend(void)
 
     /* get text location */
     dy = 1.5 * fontsize;
+
     if (vector.x > 0.0)
 	x = 72.0 * vector.x;
     else
@@ -90,12 +91,11 @@ int PS_vlegend(void)
     if (lcount < vector.cols)
 	vector.cols = lcount;
 
-/* FIXME (somehow): allow multi column to draw to the right margin would 
-    be nice, but for normal use locking to the right side of the map box
-    looks better. What's the correct compromise if the right side is always
-    automatically chosen? */
-    dx = (PS.map_right - x) / vector.cols;
-/*    dx = ((PS.page_width-PS.right_marg)*72 - x) / vector.cols; */
+    if(vector.span < 0)
+	dx = (PS.map_right - x) / vector.cols;
+	/* dx = ((PS.page_width-PS.right_marg)*72 - x) / vector.cols; */
+    else
+	dx = vector.span*72;
 
     xs = x;			/*save x and y */
     ys = y;

ps/ps.map/r_vlegend.c

@@ -18,6 +18,7 @@ static char *help[] = {
     "width	sample box width",
     "cols	number of columns",
     "border	color|none",
+    "span	column separation",
     ""
 };
 
@@ -26,13 +27,14 @@ int read_vlegend(void)
     char buf[1024];
     char *key, *data;
     int fontsize, cols, border;
-    double x, y, width;
+    double x, y, width, cseparation;
 
     fontsize = 0;
     x = y = 0.0;
     width = -1;
     cols = 1;
     border = -1;
+    cseparation = -1;
 
     while (input(2, buf, help)) {
 	if (!key_data(buf, &key, &data))
@@ -81,6 +83,12 @@ int read_vlegend(void)
 	    continue;
 	}
 
+	if (KEY("span")) {
+	    G_strip(data);
+	    cseparation = atof(data);
+	    continue;
+	}
+
 	error(key, data, "illegal vlegend sub-request");
     }
     vector.x = x;
@@ -95,6 +103,7 @@ int read_vlegend(void)
 
     vector.cols = cols;
     vector.border = border;
+    vector.span = cseparation;
 
     return 0;
 }

ps/ps.map/vector.h

@@ -8,6 +8,7 @@
 #include "clr.h"
 
 #define PI M_PI
+
 /* #define MAXVECTORS 20 */
 
 /* layer type */
@@ -103,6 +104,7 @@ struct vector
     double width;		/* width of legend symbols */
     int cols;			/* number of colums  */
     int border;			/* border color number or -1 for none */
+    double span;		/* column separation in inches */
     LAYER *layer;
 };