C++ Vect_read_line函数代码示例

/**
 * \brief Create network arcs (edge) based on given point vector map (nodes)
 *
 * \param file input file defining arcs
 * \param Points input vector point map
 * \param Out output vector map
 * \param afield arcs layer 
 * \param nfield nodes layer 
 *
 * \return number of new arcs
 */
int create_arcs(FILE * file, struct Map_info *Pnts,
		struct Map_info *Out, int afield, int nfield)
{
    char buff[1024];
    int lcat, fcat, tcat;
    int node1, node2;
    int narcs;

    struct line_pnts *points, *points2;
    struct line_cats *cats;

    points = Vect_new_line_struct();
    points2 = Vect_new_line_struct();
    points = Vect_new_line_struct();
    cats = Vect_new_cats_struct();

    narcs = 0;

    while (G_getl2(buff, sizeof(buff) - 1, file)) {
	if (sscanf(buff, "%d%d%d", &lcat, &fcat, &tcat) != 3)
	    G_fatal_error(_("Error reading file: '%s'"), buff);

	node1 = find_node(Pnts, afield, fcat);
	node2 = find_node(Pnts, afield, tcat);

	if (node1 < 1 || node2 < 1) {
	    G_warning(_("Skipping arc %d"), lcat);
	    continue;
	}

	/* geometry */
	Vect_read_line(Pnts, points, cats, node1);
	field2n(cats, nfield);
	Vect_write_line(Out, GV_POINT, points, cats);
	Vect_read_line(Pnts, points2, cats, node2);
	field2n(cats, nfield);
	Vect_write_line(Out, GV_POINT, points2, cats);
	Vect_append_points(points, points2, GV_FORWARD);

	/* category */
	Vect_reset_cats(cats);
	Vect_cat_set(cats, afield, lcat);
	Vect_write_line(Out, GV_LINE, points, cats);

	narcs++;
    }

    Vect_destroy_line_struct(points);
    Vect_destroy_cats_struct(cats);

    return narcs;
}

int point_in_buffer(struct buf_contours *arr_bc, struct spatial_index *si,
		    struct Map_info *Buf, double x, double y)
{
    int i, j, ret, flag;
    struct bound_box bbox;
    static struct ilist *List = NULL;
    static struct line_pnts *Points = NULL;

    if (List == NULL)
	List = Vect_new_list();
    if (Points == NULL)
	Points = Vect_new_line_struct();

    /* select outer contours overlapping with centroid (x, y) */
    bbox.W = bbox.E = x;
    bbox.N = bbox.S = y;
    bbox.T = PORT_DOUBLE_MAX;
    bbox.B = -PORT_DOUBLE_MAX;

    Vect_spatial_index_select(si, &bbox, List);

    for (i = 0; i < List->n_values; i++) {
	Vect_read_line(Buf, Points, NULL, arr_bc[List->value[i]].outer);
	ret = Vect_point_in_poly(x, y, Points);
	if (ret == 0)
	    continue;

	flag = 1;
	for (j = 0; j < arr_bc[List->value[i]].inner_count; j++) {
	    if (arr_bc[List->value[i]].inner[j] < 1)
		continue;

	    Vect_read_line(Buf, Points, NULL, arr_bc[List->value[i]].inner[j]);
	    ret = Vect_point_in_poly(x, y, Points);
	    if (ret != 0) {	/* inside inner contour */
		flag = 0;
		break;
	    }
	}

	if (flag) {
	    /* (x,y) is inside outer contour and outside inner contours of arr_bc[i] */
	    return 1;
	}
    }

    return 0;
}

/*!
   \brief Get list of nodes from varray

   Returns the list of all nodes on features selected by varray.
   nodes_to_features conains the index of a feature adjecent to each
   node or -1 if no such feature specified by varray
   exists. Nodes_to_features might be NULL, in which case it is left
   unitialised.

   \param map pointer to Map_info structure
   \param varray pointer to varray structure
   \param[out] nodes list of node ids
   \param node_to_features ?
 */
void NetA_varray_to_nodes(struct Map_info *map, struct varray *varray,
			  struct ilist *nodes, int *nodes_to_features)
{
    int nlines, nnodes, i;

    nlines = Vect_get_num_lines(map);
    nnodes = Vect_get_num_nodes(map);
    if (nodes_to_features)
	for (i = 1; i <= nnodes; i++)
	    nodes_to_features[i] = -1;

    for (i = 1; i <= nlines; i++)
	if (varray->c[i]) {
	    int type = Vect_read_line(map, NULL, NULL, i);

	    if (type == GV_POINT) {
		int node;

		Vect_get_line_nodes(map, i, &node, NULL);
		Vect_list_append(nodes, node);
		if (nodes_to_features)
		    nodes_to_features[node] = i;
	    }
	    else {
		int node1, node2;

		Vect_get_line_nodes(map, i, &node1, &node2);
		Vect_list_append(nodes, node1);
		Vect_list_append(nodes, node2);
		if (nodes_to_features)
		    nodes_to_features[node1] = nodes_to_features[node2] = i;
	    }
	}
}

/**
   \brief Reverse list selection
   
   \param[in] Map vector map
   \param[in] type feature type
   \param[in,out] reversed list

   \return 1
*/
int reverse_selection(struct Map_info *Map, int type, struct ilist **List)
{

    struct ilist *list_reverse;
    int line, nlines, ltype;

    list_reverse = Vect_new_list();

    nlines = Vect_get_num_lines(Map);

    for (line = 1; line <= nlines; line++) {
	ltype = Vect_read_line(Map, NULL, NULL, line);

	if (!(ltype & type))
	    continue;

	if (!Vect_val_in_list(*List, line))
	    Vect_list_append(list_reverse, line);
    }

    Vect_destroy_list(*List);
    *List = list_reverse;

    return 1;
}

/*!
  \brief Get area boundary points (native format)
  
  Used by Vect_build_line_area() and Vect_get_area_points().
  
  \param Map pointer to Map_info struct
  \param lines array of boundary lines
  \param n_lines number of lines in array
  \param[out] APoints pointer to output line_pnts struct

  \return number of points
  \return -1 on error
*/
int Vect__get_area_points_nat(const struct Map_info *Map, const plus_t *lines, int n_lines,
                              struct line_pnts *BPoints)
{
    int i, line, aline, dir;
    static struct line_pnts *Points;
    
    if (!Points)
        Points = Vect_new_line_struct();
    
    Vect_reset_line(BPoints);
    for (i = 0; i < n_lines; i++) {
        line = lines[i];
        aline = abs(line);
        G_debug(5, "  append line(%d) = %d", i, line);
        
        if (0 > Vect_read_line(Map, Points, NULL, aline))
            return -1;
        
        dir = line > 0 ? GV_FORWARD : GV_BACKWARD;
        Vect_append_points(BPoints, Points, dir);
        BPoints->n_points--;    /* skip last point, avoids duplicates */
    }
    BPoints->n_points++;        /* close polygon */

    return BPoints->n_points;
}

int sort_areas(struct Map_info *Map, struct line_pnts *Points,
               int field, struct cat_list *cat_list)
{
    int i, centroid, nareas_selected;
    struct line_cats *Cats;
    CELL cat;

    G_begin_polygon_area_calculations();
    Cats = Vect_new_cats_struct();

    /* first count valid areas */
    nareas = Vect_get_num_areas(Map);
    if (nareas == 0)
	return 0;

    /* allocate list to hold valid area info */
    list =
	(struct list *)G_calloc(nareas * sizeof(char), sizeof(struct list));

    /* store area size,cat,index in list */
    nareas_selected = 0;
    for (i = 0; i < nareas; i++) {

	centroid = Vect_get_area_centroid(Map, i + 1);
	SETNULL(&cat);
	if (centroid <= 0) {
	    G_debug(2,_("Area without centroid (OK for island)"));
	}
	else {
	    Vect_read_line(Map, NULL, Cats, centroid);
	    if (field > 0) {
		if (Vect_cats_in_constraint(Cats, field, cat_list)) {
		    Vect_cat_get(Cats, field, &cat);
		    nareas_selected++;
		}
		else {
		    G_debug(2, _("Area centroid without category"));
		}
	    }
	    else {
		/* field < 1, process all areas with centroid */
		cat = 0;
		nareas_selected++;
	    }
	}

	list[i].index = i + 1;
	Vect_get_area_points(Map, i + 1, Points);
	list[i].size =
	    G_area_of_polygon(Points->x, Points->y, Points->n_points);

	list[i].cat = cat;
    }
    if (nareas_selected > 0) {
	/* sort the list by size */
	qsort(list, nareas * sizeof(char), sizeof(struct list), compare);
    }

    return nareas_selected;
}

/* Check if point is inside area with category of given field. All cats are set in 
 * Cats with original field.
 * returns number of cats.
 */
int point_area(struct Map_info *Map, int field, double x, double y,
	       struct line_cats *Cats)
{
    int i, area, centr;
    static struct line_cats *CCats = NULL;

    Vect_reset_cats(Cats);
    area = Vect_find_area(Map, x, y);
    G_debug(4, "  area = %d", area);

    if (!area)
	return 0;

    centr = Vect_get_area_centroid(Map, area);

    if (centr <= 0)
	return 0;

    if (!CCats)
	CCats = Vect_new_cats_struct();
    Vect_read_line(Map, NULL, CCats, centr);

    for (i = 0; i < CCats->n_cats; i++) {
	if (CCats->field[i] == field) {
	    Vect_cat_set(Cats, field, CCats->cat[i]);
	}
    }

    return Cats->n_cats;
}

/*!
   \brief Returns polygon array of points (outer ring) of given area

   \param Map pointer to Map_info structure
   \param area area id
   \param[out] BPoints points array

   \return number of points
   \return -1 on error
 */
int Vect_get_area_points(const struct Map_info *Map,
			 int area, struct line_pnts *BPoints)
{
    int i, line, aline, dir;
    const struct Plus_head *Plus;
    struct P_area *Area;
    static int first_time = 1;
    static struct line_pnts *Points;

    G_debug(3, "Vect_get_area_points(): area = %d", area);
    BPoints->n_points = 0;

    Plus = &(Map->plus);
    Area = Plus->Area[area];

    if (Area == NULL) {		/* dead area */
	G_warning(_("Attempt to read points of nonexistent area"));
	return -1;		/* error , because we should not read dead areas */
    }

    if (first_time == 1) {
	Points = Vect_new_line_struct();
	first_time = 0;
    }

    G_debug(3, "  n_lines = %d", Area->n_lines);
    for (i = 0; i < Area->n_lines; i++) {
	line = Area->lines[i];
	aline = abs(line);
	G_debug(3, "  append line(%d) = %d", i, line);

	if (0 > Vect_read_line(Map, Points, NULL, aline)) {
	    G_fatal_error(_("Unable to read read line %d"), aline);
	}

	G_debug(3, "  line n_points = %d", Points->n_points);

	if (line > 0)
	    dir = GV_FORWARD;
	else
	    dir = GV_BACKWARD;

	Vect_append_points(BPoints, Points, dir);
	if (i != (Area->n_lines - 1))	/* all but not last */
	    BPoints->n_points--;
	G_debug(3, "  area n_points = %d", BPoints->n_points);
    }

    return BPoints->n_points;
}

/*!
   \brief Get node cost

   For each node in the map, finds the category of the point on it (if
   there is any) and stores the value associated with this category in
   the array node_costs. If there is no point with a category,
   node_costs=0.

   node_costs are multiplied by 1000000 and truncated to integers (as
   is done in Vect_net_build_graph)

   \param In pointer to Map_info structure
   \param layer layer number
   \param column name of column
   \param[out] node_costs list of node costs

   \returns 1 on success
   \return 0 on failure
 */
int NetA_get_node_costs(struct Map_info *In, int layer, char *column,
			int *node_costs)
{
    int i, nlines, nnodes;
    dbCatValArray vals;
    struct line_cats *Cats;
    struct line_pnts *Points;

    dbDriver *driver;
    struct field_info *Fi;

    Fi = Vect_get_field(In, layer);
    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);

    nlines = Vect_get_num_lines(In);
    nnodes = Vect_get_num_nodes(In);
    Cats = Vect_new_cats_struct();
    Points = Vect_new_line_struct();
    for (i = 1; i <= nnodes; i++)
	node_costs[i] = 0;

    db_CatValArray_init(&vals);

    if (db_select_CatValArray(driver, Fi->table, Fi->key, column, NULL, &vals)
	== -1)
	return 0;
    for (i = 1; i <= nlines; i++) {
	int type = Vect_read_line(In, Points, Cats, i);

	if (type == GV_POINT) {
	    int node, cat;
	    double value;

	    if (!Vect_cat_get(Cats, layer, &cat))
		continue;
	    Vect_get_line_nodes(In, i, &node, NULL);
	    if (db_CatValArray_get_value_double(&vals, cat, &value) == DB_OK)
		node_costs[node] = value * 1000000.0;
	}
    }

    Vect_destroy_cats_struct(Cats);
    db_CatValArray_free(&vals);
    db_close_database_shutdown_driver(driver);
    return 1;
}

/*!
  \brief Fetches FIRST category number for given vector line and field
  
  \param Map pointer to Map_info structure
  \param line line id
  \param field layer number

  \return -1 no category
  \return category number (>=0)
 */
int Vect_get_line_cat(const struct Map_info *Map, int line, int field)
{

    static struct line_cats *cats = NULL;
    int cat, ltype;

    if (cats == NULL)
	cats = Vect_new_cats_struct();

    ltype = Vect_read_line(Map, NULL, cats, line);
    Vect_cat_get(cats, field, &cat);
    G_debug(3, "Vect_get_line_cat: display line %d, ltype %d, cat %d", line,
	    ltype, cat);

    return cat;
}

/*!
   \brief Get area categories

   \param Map pointer to Map_info structure
   \param area area id
   \param[out] Cats list of categories

   \return 0 centroid found (but may be without categories)
   \return 1 no centroid found
 */
int Vect_get_area_cats(const struct Map_info *Map, int area, struct line_cats *Cats)
{
    int centroid;

    Vect_reset_cats(Cats);

    centroid = Vect_get_area_centroid(Map, area);
    if (centroid > 0) {
	Vect_read_line(Map, NULL, Cats, centroid);
    }
    else {
	return 1;		/* no centroid */
    }


    return 0;
}

/*!
   \brief Returns polygon array of points for given isle

   \param Map vector map
   \param isle island id
   \param[out] BPoints points array

   \return number of points
   \return -1 on error
 */
int
Vect_get_isle_points(const struct Map_info *Map,
		     int isle, struct line_pnts *BPoints)
{
    int i, line, aline, dir;
    const struct Plus_head *Plus;
    struct P_isle *Isle;
    static int first_time = 1;
    static struct line_pnts *Points;

    G_debug(3, "Vect_get_isle_points(): isle = %d", isle);
    BPoints->n_points = 0;

    Plus = &(Map->plus);
    Isle = Plus->Isle[isle];

    if (first_time == 1) {
	Points = Vect_new_line_struct();
	first_time = 0;
    }

    G_debug(3, "  n_lines = %d", Isle->n_lines);
    for (i = 0; i < Isle->n_lines; i++) {
	line = Isle->lines[i];
	aline = abs(line);
	G_debug(3, "  append line(%d) = %d", i, line);

	if (0 > Vect_read_line(Map, Points, NULL, aline)) {
	    G_fatal_error(_("Unable to read line %d"), aline);
	}

	G_debug(3, "  line n_points = %d", Points->n_points);

	if (line > 0)
	    dir = GV_FORWARD;
	else
	    dir = GV_BACKWARD;

	Vect_append_points(BPoints, Points, dir);
	if (i != (Isle->n_lines - 1))	/* all but not last */
	    BPoints->n_points--;
	G_debug(3, "  isle n_points = %d", BPoints->n_points);
    }

    return (BPoints->n_points);
}

int rmdac(struct Map_info *Out, struct Map_info *Err)
{
    int i, type, area, ndupl, nlines;

    struct line_pnts *Points;
    struct line_cats *Cats;

    nlines = Vect_get_num_lines(Out);

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

    G_debug(1, "nlines =  %d", nlines);

    ndupl = 0;

    for (i = 1; i <= nlines; i++) {
	G_percent(i, nlines, 2);
	if (!Vect_line_alive(Out, i))
	    continue;

	type = Vect_read_line(Out, Points, Cats, i);
	if (!(type & GV_CENTROID))
	    continue;

	area = Vect_get_centroid_area(Out, i);
	G_debug(3, "  area = %d", area);

	if (area < 0) {
	    Vect_delete_line(Out, i);
	    ndupl++;

	    if (Err) {
		Vect_write_line(Err, type, Points, Cats);
	    }
	}
    }

    G_verbose_message(_("Duplicate area centroids: %d"), ndupl);

    Vect_destroy_line_struct(Points);
    Vect_destroy_cats_struct(Cats);

    return ndupl;
}

/**
   \brief Select features by id

   \param[in] Map vector map
   \param[in] type feature type
   \param[in] ids ids list
   \param[in,out] List list of selected features
 
   \return number of selected lines
*/
int sel_by_id(struct Map_info *Map, int type, char *ids, struct ilist *List)
{
    int i;
    int num, id;
    struct cat_list *il;	/* NOTE: this is not cat list, but list of id's */
    struct ilist *List_tmp;

    if (first_selection) {
	List_tmp = List;
	first_selection = 0;
    }
    else {
	List_tmp = Vect_new_list();
    }

    il = Vect_new_cat_list();
    Vect_str_to_cat_list(ids, il);

    num = Vect_get_num_lines(Map);

    for (i = 0; i < il->n_ranges; i++) {
	for (id = 1; id <= num; id++) {
	    if (!(Vect_read_line(Map, NULL, NULL, id) & type)) {
		continue;
	    }
	    if (id >= il->min[i] && id <= il->max[i]) {
		Vect_list_append(List_tmp, id);
	    }
	}
    }

    G_debug(1, "  %d lines selected (by id)", List_tmp->n_values);

    /* merge lists (only duplicate items) */
    if (List_tmp != List) {
	merge_lists(List, List_tmp);
	Vect_destroy_list(List_tmp);
    }

    Vect_destroy_cat_list(il);

    return List->n_values;
}

/** counts the number of individual segments ( boundaries and lines ) and vertices
*/
void count(struct Map_info *map, int *num_points, int *num_lines)
{
    int index_line = 0;
    int index_point = 0;
    struct line_pnts *sites;
    struct line_cats *cats;
    int type, i;

    sites = Vect_new_line_struct();
    cats = Vect_new_cats_struct();

    for (i = 1; i <= map->plus.n_lines; i++) {

	type = Vect_read_line(map, sites, cats, i);

	if (type != GV_LINE && type != GV_BOUNDARY && type != GV_POINT)
	    continue;

	if (type == GV_LINE) {
	    index_point += sites->n_points;
	    index_line += sites->n_points - 1;
	}
	else if (type == GV_BOUNDARY) {
	    index_point += sites->n_points - 1;
	    index_line += sites->n_points - 1;
	}
	else if (type == GV_POINT) {
	    index_point++;
	}


    }

    *num_points = index_point;
    *num_lines = index_line;

    Vect_destroy_line_struct(sites);
    Vect_destroy_cats_struct(cats);
}