[GRASS-SVN] r55912 - grass/branches/develbranch_6/vector/v.in.ogr

[svn_grass at osgeo.org]

Author: mmetz
Date: 2013-04-19 01:51:24 -0700 (Fri, 19 Apr 2013)
New Revision: 55912

Modified:
   grass/branches/develbranch_6/vector/v.in.ogr/main.c
Log:
v.in.ogr: suggest a minimum snapping threshold if topological errors are encountered

Modified: grass/branches/develbranch_6/vector/v.in.ogr/main.c
===================================================================
--- grass/branches/develbranch_6/vector/v.in.ogr/main.c	2013-04-19 08:49:37 UTC (rev 55911)
+++ grass/branches/develbranch_6/vector/v.in.ogr/main.c	2013-04-19 08:51:24 UTC (rev 55912)
@@ -94,6 +94,8 @@
     int layer_id;
     int overwrite;
     double area_size = 0.;
+    int ncentr, n_overlaps;
+    BOUND_BOX box;
 
     G_gisinit(argv[0]);
 
@@ -622,6 +624,8 @@
 
     Vect_hist_command(&Map);
 
+    ncentr = n_overlaps = n_polygons = 0;
+
     /* Points and lines are written immediately with categories. Boundaries of polygons are
      * written to the vector then cleaned and centroids are calculated for all areas in cleaan vector.
      * Then second pass through finds all centroids in each polygon feature and adds its category
@@ -652,7 +656,6 @@
 	    if (ncnames > 0) {
 		cat_col_name = cnames_opt->answers[0];
 	    }
-
 	    /* replace all spaces with underscore, otherwise dbln can't be read */
 	    lname = G_store(layer_names[layer]);
 	    G_strip(lname);
@@ -952,11 +955,10 @@
 
     if (!no_clean_flag->answer &&
 	Vect_get_num_primitives(&Tmp, GV_BOUNDARY) > 0) {
-	int ret, centr, ncentr, otype, n_overlaps, n_nocat;
+	int ret, centr, otype, n_nocat;
 	CENTR *Centr;
 	SPATIAL_INDEX si;
 	double x, y, total_area, overlap_area, nocat_area;
-	BOUND_BOX box;
 	struct line_pnts *Points;
 	int nmodif;
 
@@ -1176,6 +1178,46 @@
     Vect_delete(tempvect);
 
     Vect_build(&Map);
+
+    if (n_polygons) {
+	ncentr = Vect_get_num_primitives(&Map, GV_CENTROID);
+	/* this test is not perfect:
+	 * small gaps (areas without centroid) are not detected
+	 * because they may be true gaps */
+	if (ncentr != n_polygons || n_overlaps) {
+	    double new_snap;
+
+	    Vect_get_map_box(&Map, &box);
+	    
+	    if (abs(box.E) > abs(box.W))
+		xmax = abs(box.E);
+	    else
+		xmax = abs(box.W);
+	    if (abs(box.N) > abs(box.S))
+		xmax = abs(box.N);
+	    else
+		xmax = abs(box.S);
+
+	    if (xmax < ymax)
+		xmax = ymax;
+
+	    new_snap = log2(xmax) - 52;
+	    new_snap = pow(2, new_snap);
+	    new_snap = log10(new_snap);
+	    if (new_snap < 0)
+		new_snap = (int)new_snap;
+	    else
+		new_snap = (int)new_snap + 1;
+	    new_snap = pow(10, new_snap);
+
+	    if (snap < new_snap) {
+		G_important_message("%s", separator);
+		G_warning(_("Errors were encountered during the import"));
+		G_important_message(_("Try to import again, snapping with at least %g: 'snap=%g'"), new_snap, new_snap);
+	    }
+	}
+    }
+
     Vect_close(&Map);