int do_cum(void)
{
int r, c, dr, dc;
int r_nbr, c_nbr, ct_dir, np_side, edge;
CELL is_swale, aspect, ele_nbr;
DCELL value, valued;
int killer, threshold;
int asp_r[9] = { 0, -1, -1, -1, 0, 1, 1, 1, 0 };
int asp_c[9] = { 0, 1, 0, -1, -1, -1, 0, 1, 1 };
int this_index, down_index, nbr_index;
double *dist_to_nbr, *contour;
double cell_size;
G_message(_("SECTION 3: Accumulating Surface Flow with SFD."));
/* distances to neighbours, contour lengths */
dist_to_nbr = (double *)G_malloc(sides * sizeof(double));
contour = (double *)G_malloc(sides * sizeof(double));
cell_size = get_dist(dist_to_nbr, contour);
if (bas_thres <= 0)
threshold = 60;
else
threshold = bas_thres;
for (killer = 1; killer <= do_points; killer++) {
G_percent(killer, do_points, 1);
this_index = astar_pts[killer];
aspect = asp[this_index];
seg_index_rc(alt_seg, this_index, &r, &c);
if (aspect) {
dr = r + asp_r[ABS(aspect)];
dc = c + asp_c[ABS(aspect)];
}
/* skip user-defined depressions */
else
dr = dc = -1;
if (dr >= 0 && dr < nrows && dc >= 0 && dc < ncols) { /* if ((dr = astar_pts[killer].downr) > -1) { */
down_index = SEG_INDEX(wat_seg, dr, dc);
value = wat[this_index];
if (fabs(value) >= threshold)
FLAG_SET(swale, r, c);
valued = wat[down_index];
edge = 0;
np_side = -1;
for (ct_dir = 0; ct_dir < sides; ct_dir++) {
/* get r, c (r_nbr, c_nbr) for neighbours */
r_nbr = r + nextdr[ct_dir];
c_nbr = c + nextdc[ct_dir];
if (dr == r_nbr && dc == c_nbr)
np_side = ct_dir;
/* check that neighbour is within region */
if (r_nbr >= 0 && r_nbr < nrows && c_nbr >= 0 &&
c_nbr < ncols) {
nbr_index = SEG_INDEX(wat_seg, r_nbr, c_nbr);
ele_nbr = alt[nbr_index];
if (Rast_is_c_null_value(&ele_nbr))
edge = 1;
}
else
edge = 1;
if (edge)
break;
}
/* do not distribute flow along edges, this causes artifacts */
if (edge) {
is_swale = FLAG_GET(swale, r, c);
if (is_swale && aspect > 0) {
aspect = -1 * drain[r - r_nbr + 1][c - c_nbr + 1];
asp[this_index] = aspect;
}
if (valued > 0)
wat[down_index] = -valued;
continue;
}
if (value > 0) {
if (valued > 0)
valued += value;
else
valued -= value;
}
else {
if (valued < 0)
valued += value;
else
valued = value - valued;
}
wat[down_index] = valued;
/* topographic wetness index ln(a / tan(beta)) and
* stream power index a * tan(beta) */
if (atanb_flag) {
sca[this_index] = fabs(wat[this_index]) *
(cell_size / contour[np_side]);
tanb[this_index] = get_slope_tci(alt[this_index],
alt[down_index],
dist_to_nbr[np_side]);
}
is_swale = FLAG_GET(swale, r, c);
if (is_swale || fabs(valued) >= threshold) {
FLAG_SET(swale, dr, dc);
}
else {
if (er_flag && !is_swale)
slope_length(r, c, dr, dc);
}
}
}
G_free(astar_pts);
return 0;
}
int do_cum_mfd(void)
{
int r, c, dr, dc;
CELL is_swale;
DCELL value, valued, tci_div, sum_contour, cell_size;
int killer, threshold;
/* MFD */
int mfd_cells, stream_cells, swale_cells, astar_not_set, is_null;
double *dist_to_nbr, *contour, *weight, sum_weight, max_weight;
int r_nbr, c_nbr, r_max, c_max, ct_dir, np_side;
CELL ele, ele_nbr, aspect, is_worked;
double prop, max_val;
int workedon, edge, flat;
int asp_r[9] = { 0, -1, -1, -1, 0, 1, 1, 1, 0 };
int asp_c[9] = { 0, 1, 0, -1, -1, -1, 0, 1, 1 };
int this_index, down_index, nbr_index;
G_message(_("SECTION 3a: Accumulating Surface Flow with MFD."));
G_debug(1, "MFD convergence factor set to %d.", c_fac);
/* distances to neighbours, weights, contour lengths */
dist_to_nbr = (double *)G_malloc(sides * sizeof(double));
weight = (double *)G_malloc(sides * sizeof(double));
contour = (double *)G_malloc(sides * sizeof(double));
cell_size = get_dist(dist_to_nbr, contour);
flag_clear_all(worked);
workedon = 0;
if (bas_thres <= 0)
threshold = 60;
else
threshold = bas_thres;
for (killer = 1; killer <= do_points; killer++) {
G_percent(killer, do_points, 1);
this_index = astar_pts[killer];
seg_index_rc(alt_seg, this_index, &r, &c);
FLAG_SET(worked, r, c);
aspect = asp[this_index];
if (aspect) {
dr = r + asp_r[ABS(aspect)];
dc = c + asp_c[ABS(aspect)];
}
else
dr = dc = -1;
if (dr >= 0 && dr < nrows && dc >= 0 && dc < ncols) { /* if ((dr = astar_pts[killer].downr) > -1) { */
value = wat[this_index];
down_index = SEG_INDEX(wat_seg, dr, dc);
/* get weights */
max_weight = 0;
sum_weight = 0;
np_side = -1;
mfd_cells = 0;
astar_not_set = 1;
ele = alt[this_index];
is_null = 0;
edge = 0;
/* this loop is needed to get the sum of weights */
for (ct_dir = 0; ct_dir < sides; ct_dir++) {
/* get r, c (r_nbr, c_nbr) for neighbours */
r_nbr = r + nextdr[ct_dir];
c_nbr = c + nextdc[ct_dir];
weight[ct_dir] = -1;
if (dr == r_nbr && dc == c_nbr)
np_side = ct_dir;
/* check that neighbour is within region */
if (r_nbr >= 0 && r_nbr < nrows && c_nbr >= 0 &&
c_nbr < ncols) {
nbr_index = SEG_INDEX(wat_seg, r_nbr, c_nbr);
valued = wat[nbr_index];
ele_nbr = alt[nbr_index];
is_worked = FLAG_GET(worked, r_nbr, c_nbr);
if (is_worked == 0) {
is_null = Rast_is_c_null_value(&ele_nbr);
edge = is_null;
if (!is_null && ele_nbr <= ele) {
if (ele_nbr < ele) {
weight[ct_dir] =
mfd_pow(((ele -
ele_nbr) / dist_to_nbr[ct_dir]),
c_fac);
}
if (ele_nbr == ele) {
weight[ct_dir] =
mfd_pow((0.5 / dist_to_nbr[ct_dir]),
c_fac);
}
sum_weight += weight[ct_dir];
mfd_cells++;
if (weight[ct_dir] > max_weight) {
max_weight = weight[ct_dir];
}
if (dr == r_nbr && dc == c_nbr) {
astar_not_set = 0;
}
if (value < 0 && valued > 0)
wat[nbr_index] = -valued;
}
}
}
else
edge = 1;
if (edge)
break;
}
/* do not distribute flow along edges, this causes artifacts */
if (edge) {
continue;
}
/* honour A * path
* mfd_cells == 0: fine, SFD along A * path
* mfd_cells == 1 && astar_not_set == 0: fine, SFD along A * path
* mfd_cells > 0 && astar_not_set == 1: A * path not included, add to mfd_cells
*/
/* MFD, A * path not included, add to mfd_cells */
if (mfd_cells > 0 && astar_not_set == 1) {
mfd_cells++;
sum_weight += max_weight;
weight[np_side] = max_weight;
}
/* set flow accumulation for neighbours */
max_val = -1;
tci_div = sum_contour = 0.;
if (mfd_cells > 1) {
prop = 0.0;
for (ct_dir = 0; ct_dir < sides; ct_dir++) {
r_nbr = r + nextdr[ct_dir];
c_nbr = c + nextdc[ct_dir];
/* check that neighbour is within region */
if (r_nbr >= 0 && r_nbr < nrows && c_nbr >= 0 &&
c_nbr < ncols && weight[ct_dir] > -0.5) {
is_worked = FLAG_GET(worked, r_nbr, c_nbr);
if (is_worked == 0) {
nbr_index = SEG_INDEX(wat_seg, r_nbr, c_nbr);
weight[ct_dir] = weight[ct_dir] / sum_weight;
/* check everything adds up to 1.0 */
prop += weight[ct_dir];
if (atanb_flag) {
sum_contour += contour[ct_dir];
tci_div += get_slope_tci(ele, alt[nbr_index],
dist_to_nbr[ct_dir]) *
weight[ct_dir];
}
valued = wat[nbr_index];
if (value > 0) {
if (valued > 0)
valued += value * weight[ct_dir];
else
valued -= value * weight[ct_dir];
}
else {
if (valued < 0)
valued += value * weight[ct_dir];
else
valued = value * weight[ct_dir] - valued;
}
wat[nbr_index] = valued;
}
else if (ct_dir == np_side) {
/* check for consistency with A * path */
workedon++;
}
}
}
if (ABS(prop - 1.0) > 5E-6f) {
G_warning(_("MFD: cumulative proportion of flow distribution not 1.0 but %f"),
prop);
}
}
/* SFD-like accumulation */
else {
valued = wat[down_index];
if (value > 0) {
if (valued > 0)
valued += value;
else
valued -= value;
}
else {
if (valued < 0)
valued += value;
else
valued = value - valued;
}
wat[down_index] = valued;
if (atanb_flag) {
sum_contour = contour[np_side];
tci_div = get_slope_tci(ele, alt[down_index],
dist_to_nbr[np_side]);
}
}
/* topographic wetness index ln(a / tan(beta)) and
* stream power index a * tan(beta) */
if (atanb_flag) {
sca[this_index] = fabs(wat[this_index]) *
(cell_size / sum_contour);
tanb[this_index] = tci_div;
}
}
}
if (workedon)
G_warning(n_("MFD: A * path already processed when distributing flow: %d of %d cell",
"MFD: A * path already processed when distributing flow: %d of %d cells",
do_points),
workedon, do_points);
G_message(_("SECTION 3b: Adjusting drainage directions."));
for (killer = 1; killer <= do_points; killer++) {
G_percent(killer, do_points, 1);
this_index = astar_pts[killer];
seg_index_rc(alt_seg, this_index, &r, &c);
FLAG_UNSET(worked, r, c);
aspect = asp[this_index];
if (aspect) {
dr = r + asp_r[ABS(aspect)];
dc = c + asp_c[ABS(aspect)];
}
else
dr = dc = -1;
if (dr >= 0 && dr < nrows && dc >= 0 && dc < ncols) { /* if ((dr = astar_pts[killer].downr) > -1) { */
value = wat[this_index];
down_index = SEG_INDEX(wat_seg, dr, dc);
r_max = dr;
c_max = dc;
/* get max flow accumulation */
max_val = -1;
stream_cells = 0;
swale_cells = 0;
ele = alt[this_index];
is_null = 0;
edge = 0;
flat = 1;
for (ct_dir = 0; ct_dir < sides; ct_dir++) {
/* get r, c (r_nbr, c_nbr) for neighbours */
r_nbr = r + nextdr[ct_dir];
c_nbr = c + nextdc[ct_dir];
/* check that neighbour is within region */
if (r_nbr >= 0 && r_nbr < nrows && c_nbr >= 0 &&
c_nbr < ncols) {
nbr_index = SEG_INDEX(wat_seg, r_nbr, c_nbr);
/* check for swale or stream cells */
is_swale = FLAG_GET(swale, r_nbr, c_nbr);
if (is_swale)
swale_cells++;
valued = wat[nbr_index];
ele_nbr = alt[nbr_index];
edge = Rast_is_c_null_value(&ele_nbr);
if ((ABS(valued) + 0.5) >= threshold &&
ele_nbr > ele)
stream_cells++;
is_worked = !(FLAG_GET(worked, r_nbr, c_nbr));
if (is_worked == 0) {
if (ele_nbr != ele)
flat = 0;
is_null = Rast_is_c_null_value(&ele_nbr);
edge = is_null;
if (!is_null && ABS(valued) > max_val) {
max_val = ABS(valued);
r_max = r_nbr;
c_max = c_nbr;
}
}
}
else
edge = 1;
if (edge)
break;
}
/* do not distribute flow along edges, this causes artifacts */
if (edge) {
is_swale = FLAG_GET(swale, r, c);
if (is_swale && aspect > 0) {
aspect = -1 * drain[r - r_nbr + 1][c - c_nbr + 1];
asp[this_index] = aspect;
}
continue;
}
/* update asp */
if (dr != r_max || dc != c_max) {
aspect = drain[r - r_max + 1][c - c_max + 1];
if (asp[this_index] < 0)
aspect = -aspect;
asp[this_index] = aspect;
}
is_swale = FLAG_GET(swale, r, c);
/* start new stream */
value = ABS(value) + 0.5;
if (!is_swale && (int)value >= threshold && stream_cells < 1 &&
swale_cells < 1 && !flat) {
FLAG_SET(swale, r, c);
is_swale = 1;
}
/* continue stream */
if (is_swale) {
FLAG_SET(swale, r_max, c_max);
}
else {
if (er_flag && !is_swale)
slope_length(r, c, r_max, c_max);
}
}
}
G_free(astar_pts);
flag_destroy(worked);
G_free(dist_to_nbr);
G_free(weight);
return 0;
}
/*
* return 0 if nothing was modidied
* return 1 if elevation was modified
*/
int do_flatarea(int index, CELL ele, CELL *alt_org, CELL *alt_new)
{
int upr, upc, r, c, ct_dir;
CELL is_in_list, is_worked, this_in_list;
int index_doer, index_up;
int n_flat_cells = 0, counter;
CELL ele_nbr, min_ele_diff;
int uphill_order, downhill_order, max_uphill_order, max_downhill_order;
int last_order;
struct pq *up_pq = pq_create();
struct pq *down_pq = pq_create();
struct orders inc_order, *order_found, *nbr_order_found;
struct RB_TREE *order_tree = rbtree_create(cmp_orders, sizeof(struct orders));
pq_add(index, down_pq);
pq_add(index, up_pq);
inc_order.downhill = -1;
inc_order.uphill = 0;
inc_order.index = index;
inc_order.flag = 0;
rbtree_insert(order_tree, &inc_order);
n_flat_cells = 1;
min_ele_diff = INT_MAX;
max_uphill_order = max_downhill_order = 0;
/* get uphill start points */
G_debug(2, "get uphill start points");
counter = 0;
while (down_pq->size) {
if ((index_doer = pq_drop(down_pq)) == -1)
G_fatal_error("get start points: no more points in down queue");
seg_index_rc(alt_seg, index_doer, &r, &c);
FLAG_SET(flat_done, r, c);
/* check all neighbours, breadth first search */
for (ct_dir = 0; ct_dir < sides; ct_dir++) {
/* get r, c (upr, upc) for this neighbour */
upr = r + nextdr[ct_dir];
upc = c + nextdc[ct_dir];
/* check if r, c are within region */
if (upr >= 0 && upr < nrows && upc >= 0 && upc < ncols) {
index_up = SEG_INDEX(alt_seg, upr, upc);
is_in_list = FLAG_GET(in_list, upr, upc);
is_worked = FLAG_GET(worked, upr, upc);
ele_nbr = alt_org[index_up];
if (ele_nbr == ele && !is_worked) {
inc_order.downhill = -1;
inc_order.uphill = -1;
inc_order.index = index_up;
inc_order.flag = 0;
/* not yet added to queue */
if ((order_found = rbtree_find(order_tree, &inc_order)) == NULL) {
n_flat_cells++;
/* add to down queue if not yet in there */
pq_add(index_up, down_pq);
/* add to up queue if not yet in there */
if (is_in_list) {
pq_add(index_up, up_pq);
/* set uphill order to 0 */
inc_order.uphill = 0;
counter++;
}
rbtree_insert(order_tree, &inc_order);
}
}
}
}
}
/* flat area too small, not worth the effort */
if (n_flat_cells < 5) {
/* clean up */
pq_destroy(up_pq);
pq_destroy(down_pq);
rbtree_destroy(order_tree);
return 0;
}
G_debug(2, "%d flat cells, %d cells in tree, %d start cells",
n_flat_cells, (int)order_tree->count, counter);
pq_destroy(down_pq);
down_pq = pq_create();
/* got uphill start points, do uphill correction */
G_debug(2, "got uphill start points, do uphill correction");
counter = 0;
uphill_order = 1;
while (up_pq->size) {
int is_in_down_queue = 0;
if ((index_doer = pq_drop(up_pq)) == -1)
G_fatal_error("uphill order: no more points in up queue");
seg_index_rc(alt_seg, index_doer, &r, &c);
this_in_list = FLAG_GET(in_list, r, c);
/* get uphill order for this point */
inc_order.index = index_doer;
if ((order_found = rbtree_find(order_tree, &inc_order)) == NULL)
G_fatal_error(_("flat cell escaped for uphill correction"));
last_order = uphill_order - 1;
uphill_order = order_found->uphill;
if (last_order > uphill_order)
G_warning(_("queue error: last uphill order %d > current uphill order %d"),
last_order, uphill_order);
/* debug */
if (uphill_order == -1)
G_fatal_error(_("uphill order not set"));
if (max_uphill_order < uphill_order)
max_uphill_order = uphill_order;
uphill_order++;
counter++;
/* check all neighbours, breadth first search */
for (ct_dir = 0; ct_dir < sides; ct_dir++) {
/* get r, c (upr, upc) for this neighbour */
upr = r + nextdr[ct_dir];
upc = c + nextdc[ct_dir];
/* check if r, c are within region */
if (upr >= 0 && upr < nrows && upc >= 0 && upc < ncols) {
index_up = SEG_INDEX(alt_seg, upr, upc);
is_in_list = FLAG_GET(in_list, upr, upc);
is_worked = FLAG_GET(worked, upr, upc);
ele_nbr = alt_org[index_up];
/* all cells that are in_list should have been added
* previously as uphill start points */
if (ele_nbr == ele && !is_worked) {
inc_order.index = index_up;
if ((nbr_order_found = rbtree_find(order_tree, &inc_order)) == NULL) {
G_fatal_error(_("flat cell escaped in uphill correction"));
}
/* not yet added to queue */
if (nbr_order_found->uphill == -1) {
if (is_in_list)
G_warning("cell should be in queue");
/* add to up queue */
pq_add(index_up, up_pq);
/* set nbr uphill order = current uphill order + 1 */
nbr_order_found->uphill = uphill_order;
}
}
/* add focus cell to down queue */
if (!this_in_list && !is_in_down_queue &&
ele_nbr != ele && !is_in_list && !is_worked) {
pq_add(index_doer, down_pq);
/* set downhill order to 0 */
order_found->downhill = 0;
is_in_down_queue = 1;
}
if (ele_nbr > ele && min_ele_diff > ele_nbr - ele)
min_ele_diff = ele_nbr - ele;
}
}
}
/* debug: all flags should be set to 0 */
pq_destroy(up_pq);
up_pq = pq_create();
/* got downhill start points, do downhill correction */
G_debug(2, "got downhill start points, do downhill correction");
downhill_order = 1;
while (down_pq->size) {
if ((index_doer = pq_drop(down_pq)) == -1)
G_fatal_error(_("downhill order: no more points in down queue"));
seg_index_rc(alt_seg, index_doer, &r, &c);
this_in_list = FLAG_GET(in_list, r, c);
/* get downhill order for this point */
inc_order.index = index_doer;
if ((order_found = rbtree_find(order_tree, &inc_order)) == NULL)
G_fatal_error(_("flat cell escaped for downhill correction"));
last_order = downhill_order - 1;
downhill_order = order_found->downhill;
if (last_order > downhill_order)
G_warning(_("queue error: last downhill order %d > current downhill order %d"),
last_order, downhill_order);
/* debug */
if (downhill_order == -1)
G_fatal_error(_("downhill order: downhill order not set"));
if (max_downhill_order < downhill_order)
max_downhill_order = downhill_order;
downhill_order++;
/* check all neighbours, breadth first search */
for (ct_dir = 0; ct_dir < sides; ct_dir++) {
/* get r, c (upr, upc) for this neighbour */
upr = r + nextdr[ct_dir];
upc = c + nextdc[ct_dir];
/* check if r, c are within region */
if (upr >= 0 && upr < nrows && upc >= 0 && upc < ncols) {
index_up = SEG_INDEX(alt_seg, upr, upc);
is_in_list = FLAG_GET(in_list, upr, upc);
is_worked = FLAG_GET(worked, upr, upc);
ele_nbr = alt_org[index_up];
if (ele_nbr == ele && !is_worked) {
inc_order.index = index_up;
if ((nbr_order_found = rbtree_find(order_tree, &inc_order)) == NULL)
G_fatal_error(_("flat cell escaped in downhill correction"));
/* not yet added to queue */
if (nbr_order_found->downhill == -1) {
/* add to down queue */
pq_add(index_up, down_pq);
/* set nbr downhill order = current downhill order + 1 */
nbr_order_found->downhill = downhill_order;
/* add to up queue */
if (is_in_list) {
pq_add(index_up, up_pq);
/* set flag */
nbr_order_found->flag = 1;
}
}
}
}
}
}
/* got uphill and downhill order, adjust ele */
/* increment: ele += uphill_order + max_downhill_order - downhill_order */
/* decrement: ele += uphill_order - max_uphill_order - downhill_order */
G_debug(2, "adjust ele");
while (up_pq->size) {
if ((index_doer = pq_drop(up_pq)) == -1)
G_fatal_error("no more points in up queue");
seg_index_rc(alt_seg, index_doer, &r, &c);
this_in_list = FLAG_GET(in_list, r, c);
/* get uphill and downhill order for this point */
inc_order.index = index_doer;
if ((order_found = rbtree_find(order_tree, &inc_order)) == NULL)
G_fatal_error(_("flat cell escaped for adjustment"));
uphill_order = order_found->uphill;
downhill_order = order_found->downhill;
/* debug */
if (uphill_order == -1)
G_fatal_error(_("adjustment: uphill order not set"));
if (!this_in_list && downhill_order == -1)
G_fatal_error(_("adjustment: downhill order not set"));
/* increment */
if (this_in_list) {
downhill_order = max_downhill_order;
uphill_order = 0;
}
alt_new[index_doer] +=
(uphill_order + (double)(max_downhill_order - downhill_order) / 2.0 + 0.5) / 2.0 + 0.5;
/* check all neighbours, breadth first search */
for (ct_dir = 0; ct_dir < sides; ct_dir++) {
/* get r, c (upr, upc) for this neighbour */
upr = r + nextdr[ct_dir];
upc = c + nextdc[ct_dir];
/* check if r, c are within region */
if (upr >= 0 && upr < nrows && upc >= 0 && upc < ncols) {
index_up = SEG_INDEX(alt_seg, upr, upc);
is_in_list = FLAG_GET(in_list, upr, upc);
is_worked = FLAG_GET(worked, upr, upc);
ele_nbr = alt_org[index_up];
if (ele_nbr == ele && !is_worked) {
inc_order.index = index_up;
if ((nbr_order_found = rbtree_find(order_tree, &inc_order)) == NULL)
G_fatal_error(_("flat cell escaped in adjustment"));
/* not yet added to queue */
if (nbr_order_found->flag == 0) {
if (is_in_list)
G_warning("adjustment: in_list cell should be in queue");
/* add to up queue */
pq_add(index_up, up_pq);
nbr_order_found->flag = 1;
}
}
}
}
}
/* clean up */
pq_destroy(up_pq);
pq_destroy(down_pq);
rbtree_destroy(order_tree);
return 1;
}
