/*!
\brief Find area outside island
\param Map vector map
\param isle isle id
\param box isle bbox
\return area id
\return 0 if not found
*/
int Vect_isle_find_area(struct Map_info *Map, int isle, const struct bound_box *box)
{
int i, j, line, sel_area, area, poly;
const struct Plus_head *plus;
struct P_line *Line;
struct P_node *Node;
struct P_isle *Isle;
struct P_area *Area;
struct P_topo_b *topo;
struct bound_box *abox, nbox;
static struct boxlist *List = NULL;
static BOX_SIZE *size_list;
static int alloc_size_list = 0;
/* see also Vect_find_area() */
/* Note: We should check all isle points (at least) because if topology is not clean
* and two areas overlap, isle which is not completely within area may be attached,
* but it would take long time */
G_debug(3, "Vect_isle_find_area () island = %d", isle);
plus = &(Map->plus);
if (plus->Isle[isle] == NULL) {
G_warning(_("Request to find area outside nonexistent isle"));
return 0;
}
if (!List) {
List = Vect_new_boxlist(1);
alloc_size_list = 10;
size_list = G_malloc(alloc_size_list * sizeof(BOX_SIZE));
}
Isle = plus->Isle[isle];
line = abs(Isle->lines[0]);
Line = plus->Line[line];
topo = (struct P_topo_b *)Line->topo;
Node = plus->Node[topo->N1];
/* select areas by box */
nbox.E = Node->x;
nbox.W = Node->x;
nbox.N = Node->y;
nbox.S = Node->y;
nbox.T = PORT_DOUBLE_MAX;
nbox.B = -PORT_DOUBLE_MAX;
Vect_select_areas_by_box(Map, &nbox, List);
G_debug(3, "%d areas overlap island boundary point", List->n_values);
/* sort areas by bbox size
* get the smallest area that contains the isle
* using the bbox size is working because if 2 areas both contain
* the isle, one of these areas must be inside the other area
* which means that the bbox of the outer area must be larger than
* the bbox of the inner area, and equal bbox sizes are not possible */
if (alloc_size_list < List->n_values) {
alloc_size_list = List->n_values;
size_list = G_realloc(size_list, alloc_size_list * sizeof(BOX_SIZE));
}
j = 0;
for (i = 0; i < List->n_values; i++) {
abox = &List->box[i];
if (box->E > abox->E || box->W < abox->W || box->N > abox->N ||
box->S < abox->S) {
G_debug(3, " isle not completely inside area box");
continue;
}
List->id[j] = List->id[i];
List->box[j] = List->box[i];
size_list[j].i = List->id[j];
size_list[j].box = List->box[j];
size_list[j].size = (abox->N - abox->S) * (abox->E - abox->W);
j++;
}
List->n_values = j;
if (List->n_values > 1) {
if (List->n_values == 2) {
/* simple swap */
if (size_list[1].size < size_list[0].size) {
size_list[0].i = List->id[1];
size_list[1].i = List->id[0];
size_list[0].box = List->box[1];
size_list[1].box = List->box[0];
}
}
else
qsort(size_list, List->n_values, sizeof(BOX_SIZE), sort_by_size);
}
sel_area = 0;
for (i = 0; i < List->n_values; i++) {
area = size_list[i].i;
G_debug(3, "area = %d", area);
Area = plus->Area[area];
/* Before other tests, simply exclude those areas inside isolated isles formed by one boundary */
if (abs(Isle->lines[0]) == abs(Area->lines[0])) {
G_debug(3, " area inside isolated isle");
continue;
}
/* Check box */
/* Note: If build is run on large files of areas imported from nontopo format (shapefile)
* attaching of isles takes very long time because each area is also isle and select by
* box all overlapping areas selects all areas with box overlapping first node.
* Then reading coordinates for all those areas would take a long time -> check first
* if isle's box is completely within area box */
abox = &size_list[i].box;
if (box->E > abox->E || box->W < abox->W || box->N > abox->N ||
box->S < abox->S) {
G_debug(3, " isle not completely inside area box");
continue;
}
poly = Vect_point_in_area_outer_ring(Node->x, Node->y, Map, area, abox);
G_debug(3, " poly = %d", poly);
if (poly == 1) { /* point in area, but node is not part of area inside isle (would be poly == 2) */
#if 1
/* new version */
/* the bounding box of the smaller area is
* 1) inside the bounding box of a larger area and thus
* 2) smaller than the bounding box of a larger area */
sel_area = area;
break;
#else
/* old version */
/* In rare case island is inside more areas in that case we have to calculate area
* of outer ring and take the smaller */
if (sel_area == 0) { /* first */
sel_area = area;
}
else { /* is not first */
G_debug(1, "slow version of Vect_isle_find_area()");
if (cur_size < 0) { /* second area */
/* This is slow, but should not be called often */
Vect_get_area_points(Map, sel_area, APoints);
/* G_begin_polygon_area_calculations();
cur_size =
G_area_of_polygon(APoints->x, APoints->y,
APoints->n_points); */
/* this is faster, but there may be latlon problems: the poles */
dig_find_area_poly(APoints, &cur_size);
G_debug(3, " first area size = %f (n points = %d)",
cur_size, APoints->n_points);
}
Vect_get_area_points(Map, area, APoints);
/* size =
G_area_of_polygon(APoints->x, APoints->y,
APoints->n_points); */
/* this is faster, but there may be latlon problems: the poles */
dig_find_area_poly(APoints, &size);
G_debug(3, " area size = %f (n points = %d)", size,
APoints->n_points);
if (size > 0 && size < cur_size) {
sel_area = area;
cur_size = size;
/* this can not happen because the first area must be
* inside the second area because the node
* is inside both areas */
G_warning(_("Larger bbox but smaller area!!!"));
}
}
G_debug(3, "sel_area = %d cur_size = %f", sel_area, cur_size);
#endif
}
}
if (sel_area > 0) {
G_debug(3, "Island %d in area %d", isle, sel_area);
}
else {
G_debug(3, "Island %d is not in area", isle);
}
return sel_area;
}
/*!
\brief Build area on given side of line (GV_LEFT or GV_RIGHT)
\param Map pointer to Map_info structure
\param iline line id
\param side side (GV_LEFT or GV_RIGHT)
\return > 0 area id
\return < 0 isle id
\return 0 not created (may also already exist)
*/
int Vect_build_line_area(struct Map_info *Map, int iline, int side)
{
int area, isle, n_lines;
struct Plus_head *plus;
struct bound_box box;
static struct line_pnts *APoints = NULL;
plus_t *lines;
double area_size;
plus = &(Map->plus);
G_debug(3, "Vect_build_line_area() line = %d, side = %d", iline, side);
if (!APoints)
APoints = Vect_new_line_struct();
/* get area */
area = dig_line_get_area(plus, iline, side);
if (area != 0) {
/* -> there is already an area on this side of the line, skip */
G_debug(3, " area/isle = %d -> skip", area);
return 0;
}
/* build an area with this line */
n_lines = dig_build_area_with_line(plus, iline, side, &lines);
G_debug(3, " n_lines = %d", n_lines);
if (n_lines < 1) {
return 0;
} /* area was not built */
/* get line points which forms a boundary of an area */
Vect__get_area_points(Map, lines, n_lines, APoints);
dig_line_box(APoints, &box);
Vect_line_prune(APoints);
if (APoints->n_points < 4) {
G_warning(_("Area of size = 0.0 (less than 4 vertices) ignored"));
return 0;
}
/* Area or island ? */
dig_find_area_poly(APoints, &area_size);
/* area_size = dig_find_poly_orientation(APoints); */
/* area_size is not real area size, we are only interested in the sign */
G_debug(3, " area/isle size = %f", area_size);
if (area_size > 0) { /* CW: area */
/* add area structure to plus */
area = dig_add_area(plus, n_lines, lines, &box);
if (area == -1) { /* error */
G_fatal_error(_("Unable to add area (map closed, topo saved)"));
}
G_debug(3, " -> area %d", area);
return area;
}
else if (area_size < 0) { /* CCW: island */
isle = dig_add_isle(plus, n_lines, lines, &box);
if (isle == -1) { /* error */
G_fatal_error(_("Unable to add isle (map closed, topo saved)"));
}
G_debug(3, " -> isle %d", isle);
return -isle;
}
else {
/* TODO: What to do with such areas? Should be areas/isles of size 0 stored,
* so that may be found and cleaned by some utility
* Note: it would be useful for vertical closed polygons, but such would be added twice
* as area */
G_warning(_("Area of size = 0.0 ignored"));
}
return 0;
}
/* area_outer and area_isles[i] must be closed non self-intersecting lines
side: 0 - auto, 1 - right, -1 left
*/
static void buffer_lines(struct line_pnts *area_outer, struct line_pnts **area_isles,
int isles_count, int side, double da, double db,
double dalpha, int round, int caps, double tol,
struct line_pnts **oPoints, struct line_pnts ***iPoints,
int *inner_count)
{
struct planar_graph *pg2;
struct line_pnts *sPoints, *cPoints;
struct line_pnts **arrPoints;
int i, count = 0;
int res, winding;
int auto_side;
int more = 8;
int allocated = 0;
double px, py;
G_debug(3, "buffer_lines()");
auto_side = (side == 0);
/* initializations */
sPoints = Vect_new_line_struct();
cPoints = Vect_new_line_struct();
arrPoints = NULL;
/* outer contour */
G_debug(3, " processing outer contour");
*oPoints = Vect_new_line_struct();
if (auto_side)
side =
get_polygon_orientation(area_outer->x, area_outer->y,
area_outer->n_points -
1) ? LEFT_SIDE : RIGHT_SIDE;
convolution_line(area_outer, da, db, dalpha, side, round, caps, tol,
sPoints);
pg2 = pg_create(sPoints);
extract_outer_contour(pg2, 0, *oPoints);
res = extract_inner_contour(pg2, &winding, cPoints);
while (res != 0) {
if (winding == 0) {
int check_poly = 1;
double area_size;
dig_find_area_poly(cPoints, &area_size);
if (area_size == 0) {
G_warning(_("zero area size"));
check_poly = 0;
}
if (cPoints->x[0] != cPoints->x[cPoints->n_points - 1] ||
cPoints->y[0] != cPoints->y[cPoints->n_points - 1]) {
G_warning(_("Line was not closed"));
check_poly = 0;
}
if (check_poly && !Vect_point_in_poly(cPoints->x[0], cPoints->y[0], area_outer)) {
if (Vect_get_point_in_poly(cPoints, &px, &py) == 0) {
if (!point_in_buf(area_outer, px, py, da, db, dalpha)) {
add_line_to_array(cPoints, &arrPoints, &count, &allocated,
more);
cPoints = Vect_new_line_struct();
}
}
else {
G_warning(_("Vect_get_point_in_poly() failed"));
}
}
}
res = extract_inner_contour(pg2, &winding, cPoints);
}
pg_destroy_struct(pg2);
/* inner contours */
G_debug(3, " processing inner contours");
for (i = 0; i < isles_count; i++) {
if (auto_side)
side =
get_polygon_orientation(area_isles[i]->x, area_isles[i]->y,
area_isles[i]->n_points -
1) ? RIGHT_SIDE : LEFT_SIDE;
convolution_line(area_isles[i], da, db, dalpha, side, round, caps,
tol, sPoints);
pg2 = pg_create(sPoints);
extract_outer_contour(pg2, 0, cPoints);
res = extract_inner_contour(pg2, &winding, cPoints);
while (res != 0) {
if (winding == -1) {
int check_poly = 1;
double area_size;
dig_find_area_poly(cPoints, &area_size);
if (area_size == 0) {
G_warning(_("zero area size"));
check_poly = 0;
}
if (cPoints->x[0] != cPoints->x[cPoints->n_points - 1] ||
cPoints->y[0] != cPoints->y[cPoints->n_points - 1]) {
G_warning(_("Line was not closed"));
check_poly = 0;
}
/* we need to check if the area is in the buffer.
I've simplfied convolution_line(), so that it runs faster,
however that leads to ocasional problems */
if (check_poly && Vect_point_in_poly
(cPoints->x[0], cPoints->y[0], area_isles[i])) {
if (Vect_get_point_in_poly(cPoints, &px, &py) == 0) {
if (!point_in_buf(area_isles[i], px, py, da, db, dalpha)) {
add_line_to_array(cPoints, &arrPoints, &count,
&allocated, more);
cPoints = Vect_new_line_struct();
}
}
else {
G_warning(_("Vect_get_point_in_poly() failed"));
}
}
}
res = extract_inner_contour(pg2, &winding, cPoints);
}
pg_destroy_struct(pg2);
}
arrPoints = G_realloc(arrPoints, count * sizeof(struct line_pnts *));
*inner_count = count;
*iPoints = arrPoints;
Vect_destroy_line_struct(sPoints);
Vect_destroy_line_struct(cPoints);
G_debug(3, "buffer_lines() ... done");
return;
}