zbulk.c

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/*!
   \file lib/vector/vedit/zbulk.c
 
   \brief Vedit library - Bulk labeling (automated labeling of vector
   features)
 
   (C) 2007-2008 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.
 
   \author Martin Landa <landa.martin gmail.com>
 */
 
#include <grass/dbmi.h>
#include <grass/vedit.h>
 
/*!
   \brief Lines z-bulk labeling
 
   Automated labeling (z coordinate assignment) of vector lines (iso-lines).
 
   \param Map pointer to Map_info
   \param List list of selected lines
   \param x1,y1,x2,y2 staring and ending point
   \param start starting value
   \param step step value
 
   \return number of modified features
   \return -1 on error
 */
int Vedit_bulk_labeling(struct Map_info *Map, struct ilist *List, double x1,
                        double y1, double x2, double y2, double start,
                        double step)
{
    int i, cv_i, p_i;
    int line, type, temp_line;
    int nlines_modified;
    double value, dist;
 
    struct line_cats *Cats;
    struct line_pnts *Points, *Points_se; /* start - end */
    struct bound_box box, box_se;
 
    /* for intersection */
    struct line_pnts **Points_a, **Points_b;
    int nlines_a, nlines_b;
 
    dbCatValArray cv; /* line_id / dist */
 
    nlines_modified = 0;
 
    value = start;
 
    Points = Vect_new_line_struct();
    Points_se = Vect_new_line_struct();
    Cats = Vect_new_cats_struct();
 
    db_CatValArray_alloc(&cv, List->n_values);
    cv.ctype = DB_C_TYPE_DOUBLE;
    cv.n_values = 0;
 
    Vect_append_point(Points_se, x1, y1, -PORT_DOUBLE_MAX);
    Vect_append_point(Points_se, x2, y2, PORT_DOUBLE_MAX);
 
    /* write temporary line */
    temp_line = Vect_write_line(Map, GV_LINE, Points_se, Cats);
    if (temp_line < 0) {
        nlines_modified = -1;
        goto free_exit;
    }
 
    Vect_line_box(Points_se, &box_se);
 
    /* determine order of lines */
    cv_i = 0;
    for (i = 0; i < List->n_values; i++) {
        line = List->value[i];
 
        if (!Vect_line_alive(Map, line))
            continue;
 
        type = Vect_read_line(Map, Points, NULL, line);
 
        if (!(type & GV_LINE))
            continue;
 
        Vect_line_box(Points, &box);
        if (Vect_line_check_intersection(Points_se, Points, WITH_Z)) {
            Vect_line_intersection(Points_se, Points, &box_se, &box, &Points_a,
                                   &Points_b, &nlines_a, &nlines_b, WITHOUT_Z);
 
            if (nlines_a < 2 || nlines_b < 1) /* should not happen */
                continue;
 
            /* calculate distance start point -> point of intersection */
            for (p_i = 0; p_i < Points_a[0]->n_points; p_i++) {
                Points_a[0]->z[p_i] = 0;
            }
            dist =
                Vect_line_length(Points_a[0]); /* always first line in array? */
 
            cv.value[cv_i].cat = line;
            cv.value[cv_i++].val.d = dist;
            cv.n_values++;
        }
    }
 
    /* sort array by distance */
    db_CatValArray_sort_by_value(&cv);
 
    /* z bulk-labeling */
    for (cv_i = 0; cv_i < cv.n_values; cv_i++) {
        line = cv.value[cv_i].cat;
        type = Vect_read_line(Map, Points, Cats, line);
 
        for (p_i = 0; p_i < Points->n_points; p_i++) {
            Points->z[p_i] = value;
        }
 
        if (Vect_rewrite_line(Map, line, type, Points, Cats) < 0) {
            nlines_modified = -1;
            goto free_exit;
        }
        nlines_modified++;
 
        value += step;
    }
 
    if (Vect_delete_line(Map, temp_line) < 0) {
        nlines_modified = -1;
    }
 
free_exit:
    db_CatValArray_free(&cv);
    Vect_destroy_line_struct(Points);
    Vect_destroy_line_struct(Points_se);
    Vect_destroy_cats_struct(Cats);
 
    return nlines_modified;
}