vertex.c

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/*!
   \file lib/vector/vedit/vertex.c
 
   \brief Vedit library - vertex manipulation
 
   (C) 2006-2008 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 Jachym Cepicky <jachym.cepicky gmail.com>
   \author Martin Landa <landa.martin gmail.com>
 */
 
#include <grass/vedit.h>
 
/*!
   \brief Move all vertices in bounding box(es)
 
   \param Map pointer to Map_info
   \param BgMap, nbgmaps list of background vector maps for snapping
   \param List list of selected lines
   \param coord points location
   \param thresh_coords threshold value for selecting lines
   \param thresh_snap threshold value used for snapping
   \param move_x,move_y,move_z direction (move_z is used when map is 3D)
   \param move_first move only first vertex found in the bounding box
   \param snap snapping mode (see vedit.h)
 
   \return number of moved vertices
   \return -1 on error
 */
int Vedit_move_vertex(struct Map_info *Map, struct Map_info **BgMap,
                      int nbgmaps, struct ilist *List, struct line_pnts *coord,
                      double thresh_coords, double thresh_snap, double move_x,
                      double move_y, double move_z, int move_first, int snap)
{
    int nvertices_moved, nvertices_snapped;
 
    int i, j, k;
    int line, type, rewrite;
    int npoints;
    double east, north, dist;
    double *x, *y, *z;
    char *moved;
 
    struct line_pnts *Points;
    struct line_cats *Cats;
 
    nvertices_moved = nvertices_snapped = 0;
    moved = NULL;
 
    Points = Vect_new_line_struct();
    Cats = Vect_new_cats_struct();
 
    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, Cats, line);
 
        if (!(type & GV_LINES))
            continue;
 
        npoints = Points->n_points;
        x = Points->x;
        y = Points->y;
        z = Points->z;
 
        /* vertex moved
           0 not moved
           1 moved
           2 moved and snapped
         */
        moved =
            (char *)G_realloc((void *)moved, Points->n_points * sizeof(char));
        G_zero((void *)moved, Points->n_points * sizeof(char));
 
        rewrite = 0;
        for (j = 0; j < coord->n_points; j++) {
            east = coord->x[j];
            north = coord->y[j];
 
            /* move all vertices in the bounding box */
            for (k = 0; k < Points->n_points; k++) {
                if (moved[k] == 0) {
                    dist = Vect_points_distance(east, north, 0.0, x[k], y[k],
                                                z[k], WITHOUT_Z);
                    if (dist <= thresh_coords) {
                        G_debug(3,
                                "Vedit_move_vertex(): line=%d; x=%f, y=%f -> "
                                "x=%f, y=%f",
                                line, x[k], y[k], x[k] + move_x, y[k] + move_y);
                        x[k] += move_x;
                        y[k] += move_y;
                        if (Vect_is_3d(Map))
                            z[k] += move_z;
 
                        moved[k] = 1;
 
                        G_debug(3, "Vedit_move_vertex(): line=%d, point=%d",
                                line, k);
 
                        if (snap != NO_SNAP) {
                            if (Vedit_snap_point(
                                    Map, line, &x[k], &y[k], &z[k], thresh_snap,
                                    (snap == SNAPVERTEX) ? 1 : 0) == 0) {
                                /* check also background maps */
                                int bgi;
 
                                for (bgi = 0; bgi < nbgmaps; bgi++) {
                                    if (Vedit_snap_point(
                                            BgMap[bgi], -1, &x[k], &y[k], &z[k],
                                            thresh_snap,
                                            (snap == SNAPVERTEX) ? 1 : 0))
                                        moved[k] = 2;
                                    break; /* snapped, don't continue */
                                }
                            }
                            else {
                                moved[k] = 2;
                            }
                        }
 
                        rewrite = 1;
                        nvertices_moved++;
 
                        if (move_first)
                            break;
                    }
                }
            } /* for each line vertex */
 
            /* close line or boundary */
            if ((type & GV_LINES) &&
                Vect_points_distance(x[0], y[0], z[0], x[npoints - 1],
                                     y[npoints - 1], z[npoints - 1],
                                     WITHOUT_Z) <= thresh_snap) {
 
                if (moved[0] == 1) { /* first node moved */
                    x[0] = x[npoints - 1];
                    y[0] = y[npoints - 1];
                    if (Vect_is_3d(Map))
                        z[0] = z[npoints - 1];
                }
                else if (moved[npoints - 1] == 1) { /* last node moved */
                    x[npoints - 1] = x[0];
                    y[npoints - 1] = y[0];
                    if (Vect_is_3d(Map))
                        z[npoints - 1] = z[0];
                }
            }
        } /* for each coord */
 
        if (rewrite) {
            if (Vect_rewrite_line(Map, line, type, Points, Cats) < 0) {
                nvertices_moved = -1;
                goto free_exit;
            }
        }
    } /* for each selected line */
 
free_exit:
    /* destroy structures */
    Vect_destroy_line_struct(Points);
    Vect_destroy_cats_struct(Cats);
    G_free(moved);
 
    return nvertices_moved;
}
 
/*!
   \brief Add new vertex to line
 
   Shape of line is not changed.
 
   \todo 3D
 
   \param Map pointer to Map_info
   \param List list of lines
   \param coord points location
   \param thresh find line in given threshold
 
   \return number of add vertices
   \return -1 on error
 */
int Vedit_add_vertex(struct Map_info *Map, struct ilist *List,
                     struct line_pnts *coord, double thresh)
{
    int i, j;
    int type, line, seg;
    int nvertices_added, rewrite;
    double east, north, dist;
    double *x, *y, *z;
    double px, py;
 
    struct line_pnts *Points;
    struct line_cats *Cats;
 
    nvertices_added = 0;
    Points = Vect_new_line_struct();
    Cats = Vect_new_cats_struct();
 
    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, Cats, line);
 
        if (!(type & GV_LINES))
            continue;
 
        G_debug(3, "Vedit_add_vertex(): line = %d, thresh = %f", line, thresh);
 
        x = Points->x;
        y = Points->y;
        z = Points->z;
        rewrite = FALSE;
        for (j = 0; j < coord->n_points; j++) {
            east = coord->x[j];
            north = coord->y[j];
 
            seg = Vect_line_distance(Points, east, north, 0.0, /* standpoint */
                                     WITHOUT_Z, &px, &py,
                                     NULL,  /* point on line */
                                     &dist, /* distance to line */
                                     NULL, NULL);
 
            if (dist <= thresh &&
                Vect_points_distance(px, py, 0.0, x[seg], y[seg], z[seg],
                                     WITHOUT_Z) > 0 &&
                Vect_points_distance(px, py, 0.0, x[seg - 1], y[seg - 1],
                                     z[seg - 1], WITHOUT_Z) > 0) {
                /* add new vertex */
                Vect_line_insert_point(Points, seg, px, py, 0.0);
                G_debug(3, "Vedit_add_vertex(): line=%d; x=%f, y=%f, index=%d",
                        line, px, py, seg);
                rewrite = TRUE;
                nvertices_added++;
            }
        } /* for each point */
 
        /* rewrite the line */
        if (rewrite) {
            Vect_line_prune(Points);
            if (Vect_rewrite_line(Map, line, type, Points, Cats) < 0) {
                return -1;
            }
        }
    } /* for each line */
 
    /* destroy structures */
    Vect_destroy_line_struct(Points);
    Vect_destroy_cats_struct(Cats);
 
    return nvertices_added;
}
 
/*!
   \brief Remove vertex from line
 
   \todo 3D
 
   \param Map pointer to Map_info
   \param List list of selected lines
   \param coord points location
   \param thresh threshold value to find a line
 
   \return number of removed vertices
   \return -1 on error
 */
int Vedit_remove_vertex(struct Map_info *Map, struct ilist *List,
                        struct line_pnts *coord, double thresh)
{
    int i, j, k;
    int type, line;
    int nvertices_removed, rewrite, nlines_modified;
    double east, north;
    double dist;
    double *x, *y, *z;
 
    struct line_pnts *Points;
    struct line_cats *Cats;
 
    nvertices_removed = nlines_modified = 0;
 
    Points = Vect_new_line_struct();
    Cats = Vect_new_cats_struct();
 
    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, Cats, line);
 
        if (!(type & GV_LINES))
            continue;
 
        x = Points->x;
        y = Points->y;
        z = Points->z;
        rewrite = 0;
        for (j = 0; j < coord->n_points; j++) {
            east = coord->x[j];
            north = coord->y[j];
 
            for (k = 0; k < Points->n_points; k++) {
                dist = Vect_points_distance(east, north, 0.0, x[k], y[k], z[k],
                                            WITHOUT_Z);
                if (dist <= thresh) {
                    /* remove vertex */
                    Vect_line_delete_point(Points, k);
                    G_debug(
                        3,
                        "Vedit_remove_vertex(): line=%d; x=%f, y=%f, index=%d",
                        line, x[k], y[k], k);
                    k--;
                    nvertices_removed++;
                    rewrite = 1;
                }
            } /* for each point */
        } /* for each bounding box */
 
        if (rewrite) {
            /* rewrite the line */
            if (Vect_rewrite_line(Map, line, type, Points, Cats) < 0) {
                return -1;
            }
 
            nlines_modified++;
        }
    } /* for each line */
 
    /* destroy structures */
    Vect_destroy_line_struct(Points);
    Vect_destroy_cats_struct(Cats);
 
    return nvertices_removed;
}