read_sites.c

#include <stdio.h>
#include <stdlib.h>
#include <grass/glocale.h>
#include <grass/gis.h>
#include <grass/dbmi.h>
#include <grass/vector.h>
#include "proto.h"

/* 1/2001 added field parameter MN
 * update 12/99 to read multi-dim sites properly MN
 * updated 28 June 1995 to use new sites API.
 * Only uses floating point attributes. 
 * mccauley
 */

void read_sites(const char *name, const char *field_name, const char *col,
                int noindex)
{
    extern long npoints;
    int nrec, ctype = 0, type, field, with_z;
    struct Map_info Map;
    struct field_info *Fi;
    dbDriver *Driver;
    dbCatValArray cvarr;
    struct line_pnts *Points;
    struct line_cats *Cats;

    Vect_set_open_level(1);     /* without topology */
    if (Vect_open_old2(&Map, name, "", field_name) < 0)
        G_fatal_error(_("Unable to open vector map <%s>"), name);

    field = Vect_get_field_number(&Map, field_name);
    with_z = col == NULL && Vect_is_3d(&Map);   /* read z-coordinates
                                                   only when column is
                                                   not defined */
    if (!col) {
        if (!with_z)
            G_important_message(_("Input vector map <%s> is 2D - using categories to interpolate"),
                                Vect_get_full_name(&Map));
        else
            G_important_message(_("Input vector map <%s> is 3D - using z-coordinates to interpolate"),
                                Vect_get_full_name(&Map));

    }

    if (col) {
        db_CatValArray_init(&cvarr);

        Fi = Vect_get_field(&Map, field);
        if (Fi == NULL)
            G_fatal_error(_("Database connection not defined for layer %s"),
                          field_name);

        Driver = db_start_driver_open_database(Fi->driver, Fi->database);
        if (Driver == NULL)
            G_fatal_error(_("Unable to open database <%s> by driver <%s>"),
                          Fi->database, Fi->driver);

        nrec =
            db_select_CatValArray(Driver, Fi->table, Fi->key, col, NULL,
                                  &cvarr);
        G_debug(3, "nrec = %d", nrec);

        ctype = cvarr.ctype;
        if (ctype != DB_C_TYPE_INT && ctype != DB_C_TYPE_DOUBLE)
            G_fatal_error(_("Column type not supported"));

        if (nrec < 0)
            G_fatal_error(_("Unable to select data from table"));

        G_verbose_message(n_
                          ("One record selected from table",
                           "%d records selected from table", nrec), nrec);

        db_close_database_shutdown_driver(Driver);
    }


    Points = Vect_new_line_struct();
    Cats = Vect_new_cats_struct();

    while ((type = Vect_read_next_line(&Map, Points, Cats)) >= 0) {
        double dval;

        if (!(type & GV_POINTS))
            continue;

        if (!with_z) {
            int cat;

            /* TODO: what to do with multiple cats */
            Vect_cat_get(Cats, field, &cat);
            if (cat < 0)        /* skip features without category */
                continue;

            if (col) {
                int ival, ret;

                if (ctype == DB_C_TYPE_INT) {
                    ret = db_CatValArray_get_value_int(&cvarr, cat, &ival);
                    dval = ival;
                }
                else {          /* DB_C_TYPE_DOUBLE */
                    ret = db_CatValArray_get_value_double(&cvarr, cat, &dval);
                }
                if (ret != DB_OK) {
                    G_warning(_("No record for point (cat = %d)"), cat);
                    continue;
                }
            }
            else {
                dval = cat;
            }
        }
        else
            dval = Points->z[0];

        newpoint(dval, Points->x[0], Points->y[0], noindex);
    }

    if (col)
        db_CatValArray_free(&cvarr);

    Vect_set_release_support(&Map);
    Vect_close(&Map);

    G_message(n_("%ld point loaded", "%ld points loaded", npoints), npoints);
}