initial commit for v.rmarea

Makefile

@@ -1,7 +1,14 @@
+
 MODULE_TOPDIR = ../..
 
-PGM = v.example
+PGM = v.rmarea
+
+LIBES = $(VECTORLIB) $(DIG2LIB) $(DBMILIB) $(GISLIB)
+DEPENDENCIES = $(VECTORDEP) $(DIG2DEP) $(DBMIDEP) $(GISDEP)
+EXTRA_INC = $(VECT_INC)
+EXTRA_CFLAGS = $(VECT_CFLAGS)
+CLEAN_SUBDIRS = test
 
-include $(MODULE_TOPDIR)/include/Make/Script.make
+include $(MODULE_TOPDIR)/include/Make/Module.make
 
-default: script
+default: cmd

main.c

@@ -0,0 +1,210 @@
+/***************************************************************
+ *
+ * MODULE:       v.rmarea
+ *
+ * AUTHOR(S):    Markus Metz
+ *               based on v.clean
+ *
+ * PURPOSE:      Remove small areas with identical attributes
+ *
+ * COPYRIGHT:    (C) 2024 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.
+ *
+ **************************************************************/
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <grass/gis.h>
+#include <grass/vector.h>
+#include <grass/glocale.h>
+
+#include "proto.h"
+
+static void error_handler_err(void *p);
+
+int main(int argc, char *argv[])
+{
+    struct Map_info In, Out, Err, *pErr;
+    int with_z, native;
+    struct GModule *module;
+    struct {
+        struct Option *in, *field, *out, *thresh, *err, *cols;
+    } opt;
+    struct {
+        struct Flag *no_build;
+    } flag;
+    double thresh;
+    int count;
+    double size;
+    int layer;
+
+    G_gisinit(argv[0]);
+
+    module = G_define_module();
+    G_add_keyword(_("vector"));
+    G_add_keyword(_("topology"));
+    G_add_keyword(_("geometry"));
+    G_add_keyword(_("snapping"));
+    module->description = _("Toolset for cleaning topology of vector map.");
+
+    opt.in = G_define_standard_option(G_OPT_V_INPUT);
+
+    opt.field = G_define_standard_option(G_OPT_V_FIELD);
+    opt.field->answer = "1";
+    opt.field->guisection = _("Selection");
+
+    opt.cols = G_define_standard_option(G_OPT_DB_COLUMNS);
+    opt.cols->required = YES;
+    opt.cols->guisection = _("Selection");
+
+    opt.out = G_define_standard_option(G_OPT_V_OUTPUT);
+
+    opt.err = G_define_standard_option(G_OPT_V_OUTPUT);
+    opt.err->key = "error";
+    opt.err->description = _("Name of output map where errors are written");
+    opt.err->required = NO;
+
+    opt.thresh = G_define_option();
+    opt.thresh->key = "threshold";
+    opt.thresh->type = TYPE_DOUBLE;
+    opt.thresh->required = YES;
+    opt.thresh->multiple = NO;
+    opt.thresh->label = _("Minimum area size in square meters");
+
+    flag.no_build = G_define_flag();
+    flag.no_build->key = 'b';
+    flag.no_build->description =
+        _("Do not build topology for the output vector");
+
+    if (G_parser(argc, argv))
+        exit(EXIT_FAILURE);
+
+    Vect_check_input_output_name(opt.in->answer, opt.out->answer, G_FATAL_EXIT);
+    if (opt.err->answer) {
+        Vect_check_input_output_name(opt.in->answer, opt.err->answer,
+                                     G_FATAL_EXIT);
+    }
+
+    /* Read threshold */
+    thresh = atof(opt.thresh->answer);
+    G_message(_("Tool: Threshold"));
+
+    G_message("%s: %.15g", _("Remove small areas"), thresh);
+
+    G_message(SEP);
+
+    /* Input vector may be both on level 1 and 2. Level 2 is necessary for
+     * virtual centroids (shapefile/OGR) and level 1 is better if input is too
+     * big and build in previous module (like v.in.ogr or other call to v.clean)
+     * would take a long time */
+    if (Vect_open_old2(&In, opt.in->answer, "", opt.field->answer) < 0)
+        G_fatal_error(_("Unable to open vector map <%s>"), opt.in->answer);
+
+    with_z = Vect_is_3d(&In);
+
+    if (Vect_open_new(&Out, opt.out->answer, with_z) < 0)
+        G_fatal_error(_("Unable to create vector map <%s>"), opt.out->answer);
+
+    Vect_set_error_handler_io(&In, &Out);
+
+    if (opt.err->answer) {
+        Vect_set_open_level(2);
+        if (Vect_open_new(&Err, opt.err->answer, with_z) < 0)
+            G_fatal_error(_("Unable to create vector map <%s>"),
+                          opt.err->answer);
+        G_add_error_handler(error_handler_err, &Err);
+        pErr = &Err;
+    }
+    else {
+        pErr = NULL;
+    }
+
+    /* Copy input to output */
+    Vect_copy_head_data(&In, &Out);
+    Vect_hist_copy(&In, &Out);
+    Vect_hist_command(&Out);
+
+    native = Vect_maptype(&Out) == GV_FORMAT_NATIVE;
+
+    if (!native) {
+        /* area cleaning tools might produce unexpected results for
+         * non-native vectors */
+        G_warning(_(
+            "Topological cleaning works best with native GRASS vector format"));
+        /* Copy attributes (OGR format) */
+        Vect_copy_map_dblinks(&In, &Out, TRUE);
+    }
+
+    /* This works for both level 1 and 2 */
+    Vect_copy_map_lines_field(
+        &In, Vect_get_field_number(&In, opt.field->answer), &Out);
+
+    if (native) {
+        /* Copy attribute tables (native format only) */
+        if (Vect_copy_tables(&In, &Out, 0))
+            G_warning(_("Failed to copy attribute table to output vector map"));
+    }
+    Vect_set_release_support(&In);
+    Vect_close(&In);
+
+    if (Vect_get_built(&Out) >= GV_BUILD_CENTROIDS) {
+        Vect_build_partial(&Out, GV_BUILD_CENTROIDS);
+        G_message(SEP);
+    }
+    else {
+        G_important_message(_("Rebuilding parts of topology..."));
+        Vect_build_partial(&Out, GV_BUILD_CENTROIDS);
+        G_message(SEP);
+    }
+
+    G_message(_("Tool: Remove small areas"));
+    layer = Vect_get_field_number(&Out, opt.field->answer);
+    /* new function to also consider attributes */
+    count = remove_small_areas(&Out, thresh, pErr, &size, layer, opt.cols->answers);
+    if (count > 0) {
+        Vect_build_partial(&Out, GV_BUILD_BASE);
+        G_message(SEP);
+        G_message(_("Tool: Merge boundaries"));
+        Vect_merge_lines(&Out, GV_BOUNDARY, NULL, pErr);
+    }
+
+    G_message(SEP);
+
+    if (!flag.no_build->answer) {
+        G_important_message(_("Rebuilding topology for output vector map..."));
+        Vect_build_partial(&Out, GV_BUILD_NONE);
+        Vect_build(&Out);
+    }
+    else {
+        Vect_build_partial(&Out, GV_BUILD_NONE); /* -> topo not saved */
+    }
+    Vect_close(&Out);
+
+    if (pErr) {
+        G_message(SEP);
+        G_important_message(_("Building topology for error vector map..."));
+        Vect_build(pErr);
+        Vect_close(pErr);
+    }
+
+    exit(EXIT_SUCCESS);
+}
+
+void error_handler_err(void *p)
+{
+    char *name;
+    struct Map_info *Err;
+
+    Err = (struct Map_info *)p;
+
+    if (Err && Err->open == VECT_OPEN_CODE) {
+        name = G_store(Err->name);
+        Vect_delete(name);
+        G_free(name);
+    }
+}