v.overlay: implement `atype=auto`

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@59154 15284696-431f-4ddb-bdfa-cd5b030d7da7

vector/v.overlay/main.c

@@ -11,7 +11,7 @@
  *               OGR support by Martin Landa <landa.martin gmail.com>
  *               Markus Metz
  * PURPOSE:      
- * COPYRIGHT:    (C) 2003-2009, 2012-2013 by the GRASS Development Team
+ * COPYRIGHT:    (C) 2003-2014 by the GRASS Development Team
  *
  *               This program is free software under the GNU General
  *               Public License (>=v2). Read the file COPYING that
@@ -75,8 +75,8 @@ int main(int argc, char *argv[])
     type_opt[0] = G_define_standard_option(G_OPT_V_TYPE);
     type_opt[0]->label = _("Feature type (vector map A)");
     type_opt[0]->key = "atype";
-    type_opt[0]->options = "line,area";
-    type_opt[0]->answer = "area";
+    type_opt[0]->options = "line,area,auto";
+    type_opt[0]->answer = "auto";
 
     in_opt[1] = G_define_standard_option(G_OPT_V_INPUT);
     in_opt[1]->label = _("Name of input vector map (B)");
@@ -144,8 +144,10 @@ int main(int argc, char *argv[])
     for (input = 0; input < 2; input++) {
 	type[input] = Vect_option_to_types(type_opt[input]);
     }
+    /* not needed
     if (type[0] & GV_AREA)
 	type[0] = GV_AREA;
+    */
 
     ofield[0] = ofield[1] = ofield[2] = 0;
     i = 0;
@@ -165,17 +167,33 @@ int main(int argc, char *argv[])
     else
 	G_fatal_error(_("Unknown operator '%s'"), operator_opt->answer);
 
+    Vect_check_input_output_name(in_opt[0]->answer, out_opt->answer,
+				 G_FATAL_EXIT);
+    Vect_check_input_output_name(in_opt[1]->answer, out_opt->answer,
+				 G_FATAL_EXIT);
+
+    for (input = 0; input < 2; input++) {
+        Vect_set_open_level(2);
+        Vect_open_old2(&(In[input]), in_opt[input]->answer, "", field_opt[input]->answer);
+	field[input] = Vect_get_field_number(&(In[input]), field_opt[input]->answer);
+    }
+    if (type[0] == 0) { /* atype=auto */
+        type[0] = Vect_read_next_line(&(In[0]), NULL, NULL);
+        if (type[0] == -1)
+            G_fatal_error(_("Unable to determine feature type for <%s>"),
+                          in_opt[0]->key);
+        if (!(type[0] & (GV_LINE | GV_AREA)))
+            G_fatal_error(_("Invalid fearure type for <%s>. Only '%s' or '%s' supported."),
+                          in_opt[0]->key, "line", "area");
+        G_debug(1, "auto -> atype=%d", type[0]);
+    }
+
     /* OP_OR, OP_XOR is not supported for lines,
        mostly because I'am not sure if they make enouhg sense */
     if (type[0] == GV_LINE && (operator == OP_OR || operator == OP_XOR))
 	G_fatal_error(_("Operator '%s' is not supported for type line"),
 		      operator_opt->answer);
 
-    Vect_check_input_output_name(in_opt[0]->answer, out_opt->answer,
-				 G_FATAL_EXIT);
-    Vect_check_input_output_name(in_opt[1]->answer, out_opt->answer,
-				 G_FATAL_EXIT);
-
     snap_thresh = atof(snap_opt->answer);
 
     Points = Vect_new_line_struct();
@@ -225,10 +243,6 @@ int main(int argc, char *argv[])
     for (input = 0; input < 2; input++) {
 	int ncats, index, nlines_out, newline;
 
-	Vect_set_open_level(2);
-	Vect_open_old2(&(In[input]), in_opt[input]->answer, "", field_opt[input]->answer);
-	field[input] = Vect_get_field_number(&(In[input]), field_opt[input]->answer);
-
 	G_message(_("Copying vector features from <%s>..."),
 		  Vect_get_full_name(&(In[input])));
 

vector/v.overlay/v.overlay.html

@@ -1,21 +1,21 @@
 <h2>DESCRIPTION</h2>
 
 <em>v.overlay</em> allows the user to overlay two vector maps. Features 
-in <em>ainput</em> can be lines or areas and are cut with areas in 
-<em>binput</em>. Simple clipping can be performed with the <em>and</em> 
+in <b>ainput</b> can be lines or areas and are cut with areas in 
+<b>binput</b>. Simple <i>clipping</i> can be performed with the <b>and</b> 
 oerator.
 <p>
-If areas in <em>ainput</em> are overlaid with areas in <em>binput</em>, 
-it is sometimes necessary to snap areas of <em>binput</em> to those of 
-<em>ainput</em>, otherwise areas can go missing or many sliver areas 
+If areas in <b>ainput</b> are overlaid with areas in <b>binput</b>, 
+it is sometimes necessary to snap areas of <b>binput</b> to those of 
+<b>ainput</b>, otherwise areas can go missing or many sliver areas 
 can be created. Snapping is enabled by default and can be disabled by 
-setting the <em>snap</em> option to a negative value. Recommended values 
+setting the <b>snap</b> option to a negative value. Recommended values 
 are between 0.00000001 and 0.0001. Using larger values for snapping can 
 have undesired side-effects, but may sometimes be necessary to get a 
 clean output (see example below). In general, it is recommended to start 
 with a small snapping threshold, gradually increasing the threshold until 
 the result is reasonably clean. Snapping modifies only boundaries in 
-binput, which are snapped to boundaries in ainput. Boundaries in ainput 
+binput, which are snapped to boundaries in ainput. Boundaries in <b>ainput</b> 
 are not modified.
 <!-- This is outdated 
 There are 3 links attached to features in output map, 
@@ -31,36 +31,40 @@ There are 3 links attached to features in output map,
 </ul>
 -->
 <p>
-If the first number of the <em>olayer</em> option is > 0, then the 
+If the <i>first</i> number of the <b>olayer</b> option is greater than 0, then the 
 resulting output map has a merged attribute table in the given layer 
 number. The original column names have a prefix (<em>a_</em> and 
-<em>b_</em>) corresponding to <em>ainput</em> and <em>binput</em> map.
+<em>b_</em>) corresponding to <b>ainput</b> and <b>binput</b> map.
 <p>
-If the second number of the <em>olayer</em> option is > 0, then the 
-categories of <em>ainput</em> in layer <em>alayer</em> are transferred to
+If the <i>second</i> number of the <b>olayer</b> option is greater than 0, then the 
+categories of <b>ainput</b> in layer <b>alayer</b> are transferred to
 the output layer with the second number.
 <p>
-If the third number of the <em>olayer</em> option is > 0, then the 
-categories of <em>binput</em> in layer <em>blayer</em> are transferred to
+If the <i>third</i> number of the <b>olayer</b> option is greater than 0, then the 
+categories of <b>binput</b> in layer <em>blayer</em> are transferred to
 the output layer with the third number.
 
 <h2>NOTES</h2>
-Currently only areas in <em>ainput</em> are supported for the operators 
-<em>or</em> and <em>xor</em>! See also <a href="v.select.html">v.select</a>.
+Currently only areas in <b>ainput</b> are supported for the operators 
+<em>or</em> and <em>xor</em>! See also <em><a href="v.select.html">v.select</a></em>.
 
 The operator defines what kind of operation will be done. Features are 
-written to output, if the result of an operation 'ainput operator binput' 
+written to output, if the result of an operation <b>ainput</b> operator <b>binput</b> 
 is true.
 <p>
-If the first number of the <em>olayer</em> option is > 0, then attributes 
-of the tables from ainput and binput are joined into a new table linked 
+If the <i>first</i> number of the <b>olayer</b> option is greater than 0, then attributes 
+of the tables from <b>ainput</b> and <b>binput</b> are joined into a new table linked 
 to the output map with a new cat column. 
 <p>
-If the second number of the <em>olayer</em> option is > 0, then the 
-attribute table of ainput is copied to the output map. 
+If the <i>second</i> number of the <b>olayer</b> option is greater than 0, then the 
+attribute table of <b>ainput</b> is copied to the output map. 
 <p>
-If the third number of the <em>olayer</em> option is > 0, then the 
-attribute table of binput is copied to the output map. 
+If the <i>third</i> number of the <b>olayer</b> option is greater than 0, then the 
+attribute table of <b>binput</b> is copied to the output map. 
+
+<p>
+If <b>atype</b>=auto is given than <em>v.overlay</em> determines
+feature type for <b>ainput</b> from the first found feature.
 
 <!-- This is outdated
 <p><div class="code"><pre>
@@ -75,7 +79,7 @@ connect the copied tables to the output map.-->
 
 <h2>EXAMPLES</h2>
 
-<h4>Polygons overlaid with ploygons</h4>
+<h3>Polygons overlaid with ploygons</h3>
 <div class="code"><pre>
 v.overlay ainput=lake binput=province output=lakeXprovince operator=or
 </pre></div>
@@ -131,7 +135,7 @@ As can be seen by the resulting large number of centroids on boundaries,
 the urban areas do not match exactly the Census 2000 areas. In this case 
 a clean result can be obtained by snapping with a threshold of 0.1 m.
 
-<h4>Lines overlaid with polygons</h4>
+<h3>Lines overlaid with polygons</h3>
 
 Using the North Carolina sample dataset, we clip the roads map to the area
 of city of Raleigh, preserving road attributes in layer 1:
@@ -171,4 +175,5 @@ v.overlay ainput=roadsmajor atype=line binput=raleigh \
 Radim Blazek, ITC-Irst, Trento, Italy<br>
 Markus Metz
 
-<p><i>Last changed: $Date$</i>
+<p>
+<i>Last changed: $Date$</i>