/*!
\brief Returns area of area without areas of isles
\param Map vector map
\param area area id
\return area of area without areas of isles
*/
double Vect_get_area_area(const struct Map_info *Map, int area)
{
const struct Plus_head *Plus;
struct P_area *Area;
struct line_pnts *Points;
double size;
int i;
static int first_time = 1;
G_debug(3, "Vect_get_area_area(): area = %d", area);
if (first_time == 1) {
G_begin_polygon_area_calculations();
first_time = 0;
}
Points = Vect_new_line_struct();
Plus = &(Map->plus);
Area = Plus->Area[area];
Vect_get_area_points(Map, area, Points);
size = G_area_of_polygon(Points->x, Points->y, Points->n_points);
/* substructing island areas */
for (i = 0; i < Area->n_isles; i++) {
Vect_get_isle_points(Map, Area->isles[i], Points);
size -= G_area_of_polygon(Points->x, Points->y, Points->n_points);
}
Vect_destroy_line_struct(Points);
G_debug(3, " area = %f", size);
return (size);
}
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;
}