v.fill.holes: Remove isles, keep outer boundary

vector/Makefile

@@ -22,6 +22,7 @@ SUBDIRS = \
 	v.edit \
 	v.extract \
 	v.extrude \
+	v.fill.holes \
 	v.generalize \
 	v.hull \
 	v.info \

vector/v.fill.holes/Makefile

@@ -0,0 +1,12 @@
+MODULE_TOPDIR = ../..
+
+PGM = v.fill.holes
+
+LIBES = $(VECTORLIB) $(DBMILIB) $(GISLIB)
+DEPENDENCIES = $(VECTORDEP) $(DBMIDEP) $(GISDEP)
+EXTRA_INC = $(VECT_INC)
+EXTRA_CFLAGS = $(VECT_CFLAGS)
+
+include $(MODULE_TOPDIR)/include/Make/Module.make
+
+default: cmd

vector/v.fill.holes/main.c

@@ -0,0 +1,224 @@
+
+/****************************************************************
+ *
+ * MODULE:     v.fill.holes
+ *
+ * AUTHOR:     Vaclav Petras
+ *
+ * PURPOSE:    Fill holes in an area, i.e., preserve only its outer boundary
+ *
+ * COPYRIGHT:  (C) 2022 by Vaclav Petras and 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.
+ *
+ ****************************************************************/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <grass/gis.h>
+#include <grass/vector.h>
+#include <grass/dbmi.h>
+#include <grass/glocale.h>
+
+struct VFillHolesParameters
+{
+    struct GModule *module;
+    struct Option *input;
+    struct Option *output;
+    struct Option *field;
+    struct Option *cats;
+    struct Option *where;
+};
+
+int main(int argc, char *argv[])
+{
+    struct Map_info input;
+    struct Map_info output;
+    int open3d;
+
+    G_gisinit(argv[0]);
+
+    struct VFillHolesParameters options;
+
+    options.module = G_define_module();
+    G_add_keyword(_("vector"));
+    G_add_keyword(_("geometry"));
+    G_add_keyword(_("fill"));
+    G_add_keyword(_("exterior"));
+    G_add_keyword(_("ring"));
+    G_add_keyword(_("perimeter"));
+    options.module->description =
+        _("Fill holes in areas by keeping only outer boundaries");
+
+    options.input = G_define_standard_option(G_OPT_V_INPUT);
+
+    options.field = G_define_standard_option(G_OPT_V_FIELD);
+
+    options.cats = G_define_standard_option(G_OPT_V_CATS);
+
+    options.where = G_define_standard_option(G_OPT_DB_WHERE);
+
+    options.output = G_define_standard_option(G_OPT_V_OUTPUT);
+
+    if (G_parser(argc, argv))
+        exit(EXIT_FAILURE);
+
+    Vect_check_input_output_name(options.input->answer,
+                                 options.output->answer, G_FATAL_EXIT);
+    Vect_set_open_level(2);
+
+    if (1 >
+        Vect_open_old2(&input, options.input->answer, "",
+                       options.field->answer))
+        G_fatal_error(_("Unable to open vector map <%s>"),
+                      options.input->answer);
+
+    /* Check if old vector is 3D. We should preserve 3D data. */
+    if (Vect_is_3d(&input))
+        open3d = WITH_Z;
+    else
+        open3d = WITHOUT_Z;
+
+    /* Set error handler for input vector map */
+    Vect_set_error_handler_io(&input, NULL);
+
+    /* Open new vector for reading/writing */
+    if (0 > Vect_open_new(&output, options.output->answer, open3d)) {
+        G_fatal_error(_("Unable to create vector map <%s>"),
+                      options.output->answer);
+    }
+
+    /* Set error handler for output vector map */
+    Vect_set_error_handler_io(NULL, &output);
+
+    int field = Vect_get_field_number(&input, options.field->answer);
+
+    if (field <= 0 && options.cats->answer)
+        G_fatal_error(_("Option %s cannot be combined with %s=%s"),
+                      options.cats->key, options.field->key,
+                      options.field->answer);
+    if (field <= 0 && options.where->answer)
+        G_fatal_error(_("Option %s cannot be combined with %s=%s"),
+                      options.where->key, options.field->key,
+                      options.field->answer);
+
+    /* Copy header and history data from old to new map */
+    Vect_copy_head_data(&input, &output);
+    Vect_hist_copy(&input, &output);
+    Vect_hist_command(&output);
+
+    // Set category constraint.
+    struct cat_list *constraint_cat_list = NULL;
+
+    if (field > 0)
+        constraint_cat_list =
+            Vect_cats_set_constraint(&input, field, options.where->answer,
+                                     options.cats->answer);
+
+    /* Create and initialize struct's where to store points/lines and categories */
+    struct line_pnts *points = Vect_new_line_struct();
+    struct line_cats *area_cats = Vect_new_cats_struct();
+    struct line_cats *empty_cats = Vect_new_cats_struct();
+
+    struct ilist *all_cats = Vect_new_list();
+    struct ilist *field_cats = Vect_new_list();
+
+    plus_t num_areas = Vect_get_num_areas(&input);
+
+    G_percent(0, num_areas, 1);
+    for (plus_t area = 1; area <= num_areas; area++) {
+        G_percent(area, num_areas, 1);
+
+        int centroid = Vect_get_area_centroid(&input, area);
+
+        if (!centroid)
+            continue;
+
+        Vect_read_line(&input, points, area_cats, centroid);
+
+        if (constraint_cat_list &&
+            !Vect_cats_in_constraint(area_cats, field, constraint_cat_list)) {
+            continue;
+        }
+        Vect_write_line(&output, GV_CENTROID, points, area_cats);
+
+        Vect_get_area_points(&input, area, points);
+        Vect_write_line(&output, GV_BOUNDARY, points, empty_cats);
+
+        if (field > 0) {
+            Vect_field_cat_get(area_cats, field, field_cats);
+            Vect_list_append_list(all_cats, field_cats);
+        }
+    }
+
+    Vect_destroy_cats_struct(empty_cats);
+    Vect_destroy_cats_struct(area_cats);
+    Vect_destroy_line_struct(points);
+
+    /* Let's get vector layers db connections information */
+    struct field_info *input_info = NULL;
+
+    if (field > 0 && all_cats->n_values)
+        input_info = Vect_get_field2(&input, options.field->answer);
+
+    if (input_info) {
+        G_verbose_message(_("Copying attributes for layer <%s>"),
+                          options.field->answer);
+
+
+        /* outputput information useful for debuging 
+           include/vect/dig_structs.h
+         */
+        G_debug(1,
+                "Field number:%d; Name:<%s>; Driver:<%s>; Database:<%s>; Table:<%s>; Key:<%s>;\n",
+                input_info->number, input_info->name, input_info->driver,
+                input_info->database, input_info->table, input_info->key);
+
+        struct field_info *output_info =
+            Vect_default_field_info(&output, field, NULL, GV_1TABLE);
+        /* Create database for new vector map */
+        dbDriver *driver = db_start_driver_open_database(output_info->driver,
+                                                         output_info->
+                                                         database);
+
+        G_debug(1,
+                "Field number:%d; Name:<%s>; Driver:<%s>; Database:<%s>; Table:<%s>; Key:<%s>;\n",
+                output_info->number, output_info->name, output_info->driver,
+                output_info->database, output_info->table, output_info->key);
+
+        /*
+           Vect_map_add_dblink(&output, output_info->number, output_info->name,
+           output_info->table, input_info->key,
+           output_info->database, output_info->driver);
+         */
+
+        /* Copy attribute table data */
+        if (db_copy_table_by_ints
+            (input_info->driver, input_info->database, input_info->table,
+             output_info->driver, Vect_subst_var(output_info->database,
+                                                 &output), output_info->table,
+             input_info->key, all_cats->value,
+             all_cats->n_values) == DB_FAILED)
+            G_fatal_error(_("Unable to copy attribute table to vector map <%s>"),
+                          options.output->answer);
+        db_close_database_shutdown_driver(driver);
+    }
+
+    Vect_destroy_list(field_cats);
+    Vect_destroy_list(all_cats);
+
+    Vect_build(&output);
+
+    Vect_set_release_support(&input);
+    Vect_set_release_support(&output);
+
+    Vect_close(&input);
+
+    /* Build topology for vector map and close them */
+
+    Vect_close(&output);
+
+    exit(EXIT_SUCCESS);
+}

vector/v.fill.holes/v.fill.holes.html

@@ -0,0 +1,21 @@
+<h2>DESCRIPTION</h2>
+
+<em>v.fill.holes</em>
+
+<h2>EXAMPLE</h2>
+
+ (North Carolina sample dataset):
+
+<div class="code"><pre>
+v.fill.holes input= output=
+</pre></div>
+
+<h2>SEE ALSO</h2>
+
+<em>
+<a href="v.clean.html">v.clean</a>,
+</em>
+
+<h2>AUTHOR</h2>
+
+Vaclav Petras