vlib: Vect_remove_colors() and Vect_write_colors() implemeneted

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@47561 15284696-431f-4ddb-bdfa-cd5b030d7da7

include/vector.h

@@ -542,5 +542,7 @@ GEOSCoordSequence *Vect_get_isle_points_geos(struct Map_info *, int);
 
     /* Raster color tables */
 int Vect_read_colors(const char *, const char *, struct Colors *);
+int Vect_remove_colors(const char *, const char *);
+void Vect_write_colors(const char *, const char *, struct Colors *);
 
 #endif /* GRASS_VECT_H */

lib/vector/Vlib/color_remove.c

@@ -0,0 +1,50 @@
+/*!
+  \file lib/vector/Vlib/color_remove.c
+ 
+  \brief Vector Library - remove color table of vector map
+  
+  (C) 2011 by the GRASS Development Team
+  
+  This program is free software under the GNU General Public License
+  (>=v2). Read the file COPYING that comes with GRASS for details.
+  
+  \author Martin Landa <landa.martin gmail.com>
+*/
+
+#include <string.h>
+
+#include <grass/gis.h>
+
+/*!
+  \brief Remove color table of raster map
+
+  \param name name of raster map
+  \param mapset name of mapset 
+
+  \return -1 on error
+  \return 0 color table not found
+  \return 1 on success
+*/
+int Vect_remove_colors(const char *name, const char *mapset)
+{
+    char element[GPATH_MAX];
+    char xname[GNAME_MAX], xmapset[GMAPSET_MAX];
+    int stat;
+
+    if (G_name_is_fully_qualified(name, xname, xmapset)) {
+	if (strcmp(xmapset, mapset) != 0)
+	    return -1;
+	name = xname;
+    }
+
+    /* get rid of existing colr2, if any */
+    sprintf(element, "vector/%s", name);
+    stat = G_remove(element, "colr2");
+
+    if (strcmp(mapset, G_mapset()) == 0) {
+	sprintf(element, "vector/%s", name);
+	stat = G_remove(element, "colr");
+    }
+    
+    return stat;
+}

lib/vector/Vlib/color_write.c

@@ -0,0 +1,94 @@
+/*!
+  \file lib/vector/Vlib/color_write.c
+ 
+  \brief Vector Library - write color table for vector map
+  
+  (C) 2011 by the GRASS Development Team
+  
+  This program is free software under the GNU General Public License
+  (>=v2). Read the file COPYING that comes with GRASS for details.
+  
+  \author Martin Landa <landa.martin gmail.com>
+*/
+
+#include <grass/gis.h>
+#include <grass/vector.h>
+#include <grass/raster.h>
+#include <grass/glocale.h>
+
+/*!
+  \brief Write color table for vector map
+  
+  The color table is written for the vector map <i>name</i> in the
+  specified <i>mapset</i> from the <i>colors</i> structure.
+  
+  The <i>colors</i> structure must be created properly, i.e.,
+  Rast_init_colors() to initialize the structure and
+  Rast_add_c_color_rule() to set the category colors. These routines
+  are called by higher level routines which read or create entire
+  color tables, such as Rast_read_colors() or Rast_make_ramp_colors().
+  
+  <b>Note:</b> The calling sequence for this function deserves
+  special attention. The <i>mapset</i> parameter seems to imply that
+  it is possible to overwrite the color table for a vector map which
+  is in another mapset. However, this is not what actually
+  happens. It is very useful for users to create their own color
+  tables for vector maps in other mapsets, but without overwriting
+  other users' color tables for the same raster map. If <i>mapset</i>
+  is the current mapset, then the color file for <i>name</i> will be
+  overwritten by the new color table. But if <i>mapset</i> is not the
+  current mapset, then the color table is actually written in the
+  current mapset under the <tt>colr2</tt> element as:
+  <tt>vector/name/colr2/tt>.
+  
+  The rules are written out using floating-point format, removing
+  trailing zeros (possibly producing integers). The flag marking the
+  colors as floating-point is <b>not</b> written.
+  
+  If the environment variable FORCE_GRASS3_COLORS is set (to anything
+  at all) then the output format is 3.0, even if the structure
+  contains 4.0 rules.  This allows users to create 3.0 color files for
+  export to sites which don't yet have 4.0
+  
+  \param name vector map name
+  \param mapset mapset name
+  \param colors pointer to structure Colors which holds color info
+  
+  \return void
+*/
+void Vect_write_colors(const char *name, const char *mapset,
+		       struct Colors *colors)
+{
+    char element[GPATH_MAX], *cname;
+    char xname[GNAME_MAX], xmapset[GMAPSET_MAX];
+    FILE *fd;
+	
+    if (G_name_is_fully_qualified(name, xname, xmapset)) {
+	if (strcmp(xmapset, mapset) != 0)
+	    G_fatal_error(_("Qualified name <%s> doesn't match mapset <%s>"),
+			  name, mapset);
+	name = xname;
+    }
+
+    /*
+      if mapset is current mapset, remove colr2 file (created by pre 3.0 grass)
+      and then write original color table
+      else write secondary color table
+    */
+    if (strcmp(mapset, G_mapset()) == 0) {
+	/* get rid of existing colr2, if any */
+	sprintf(element, "vector/%s/colr2", name);
+	G_remove(element, name); 
+	cname = "colr";
+    }
+    else {
+	cname = "colr2";
+    }
+    sprintf(element, "vector/%s", name);
+    if (!(fd = G_fopen_new(element, cname)))
+	G_fatal_error(_("Unable to create <%s> file for map <%s>"),
+		      element, name);
+
+    Rast__write_colors(fd, colors);
+    fclose(fd);
+}