int find_pourpts(void)
{
int row, col;
double easting, northing, stream_length;
CELL old_elev, basin_num, no_basin, curr_basin;
WAT_ALT wa;
ASP_FLAG af;
char is_swale;
ocs_alloced = 2 * bas_thres;
ocs = (OC_STACK *)G_malloc(ocs_alloced * sizeof(OC_STACK));
basin_num = 0;
Rast_set_c_null_value(&no_basin, 1);
stream_length = old_elev = 0;
for (row = 0; row < nrows; row++) {
G_percent(row, nrows, 1);
northing = window.north - (row + .5) * window.ns_res;
for (col = 0; col < ncols; col++) {
seg_get(&aspflag, (char *)&af, row, col);
cseg_get(&bas, &curr_basin, row, col);
if (curr_basin == 0)
cseg_put(&bas, &no_basin, row, col);
cseg_get(&haf, &curr_basin, row, col);
if (curr_basin == 0)
cseg_put(&haf, &no_basin, row, col);
is_swale = FLAG_GET(af.flag, SWALEFLAG);
if (af.asp <= 0 && is_swale > 0) {
basin_num += 2;
if (arm_flag) {
easting = window.west + (col + .5) * window.ew_res;
fprintf(fp, "%5d drains into %5d at %3d %3d %.3f %.3f",
(int)basin_num, 0, row, col, easting, northing);
if (col == 0 || col == ncols - 1) {
stream_length = .5 * window.ew_res;
}
else if (row == 0 || row == nrows - 1) {
stream_length = .5 * window.ns_res;
}
else {
stream_length = 0.0;
}
seg_get(&watalt, (char *) &wa, row, col);
old_elev = wa.ele;
}
basin_num =
def_basin(row, col, basin_num, stream_length, old_elev);
}
}
}
G_percent(nrows, nrows, 1); /* finish it */
n_basins = basin_num;
G_free(ocs);
return 0;
}
int slope_length(int r, int c, int dr, int dc)
{
CELL top_alt, bot_alt, ridge;
char asp_value;
double res, top_ls, bot_ls;
WAT_ALT wa;
if (sides == 8) {
if (r == dr)
res = window.ns_res;
else if (c == dc)
res = window.ew_res;
else
res = diag;
}
else { /* sides == 4 */
bseg_get(&asp, &asp_value, dr, dc);
if (r == dr) {
if (asp_value == 2 || asp_value == 6)
res = window.ns_res;
else /* asp_value == 4, 8, -2, -4, -6, or -8 */
res = diag; /* how can res be diag with sides == 4??? */
}
else { /* c == dc */
if (asp_value == 4 || asp_value == 8)
res = window.ew_res;
else /* asp_value == 2, 6, -2, -4, -6, or -8 */
res = diag;
}
}
dseg_get(&s_l, &top_ls, r, c);
if (top_ls == half_res)
top_ls = res;
else
top_ls += res;
dseg_put(&s_l, &top_ls, r, c);
seg_get(&watalt, (char *) &wa, r, c);
top_alt = wa.ele;
seg_get(&watalt, (char *) &wa, dr, dc);
bot_alt = wa.ele;
if (top_alt > bot_alt) {
dseg_get(&s_l, &bot_ls, dr, dc);
if (top_ls > bot_ls) {
bot_ls = top_ls + res;
dseg_put(&s_l, &bot_ls, dr, dc);
cseg_get(&r_h, &ridge, r, c);
cseg_put(&r_h, &ridge, dr, dc);
}
}
return 0;
}
int
overland_cells(int row, int col, CELL basin_num, CELL haf_num, CELL * hih_ele)
{
int r, rr, c, cc;
CELL new_ele, new_max_ele, value;
cseg_put(&bas, &basin_num, row, col);
cseg_put(&haf, &haf_num, row, col);
new_max_ele = BIGNEG;
for (r = row - 1, rr = 0; r <= row + 1; r++, rr++) {
for (c = col - 1, cc = 0; c <= col + 1; c++, cc++) {
if (r >= 0 && c >= 0 && r < nrows && c < ncols) {
cseg_get(&asp, &value, r, c);
if (value == drain[rr][cc]) {
if (r != row && c != col) {
overland_cells(r, c, basin_num, haf_num, &new_ele);
}
else if (r != row) {
overland_cells(r, c, basin_num, haf_num, &new_ele);
}
else {
overland_cells(r, c, basin_num, haf_num, &new_ele);
}
}
}
}
}
if (new_max_ele == BIGNEG) {
cseg_get(&alt, hih_ele, row, col);
}
else {
*hih_ele = new_max_ele;
}
return 0;
}
int thin_seg(int stream_id)
{
int thinned = 0;
int r, c, r_nbr, c_nbr, last_r, last_c;
CELL curr_stream, no_stream = 0;
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 };
ASP_FLAG af;
r = stream_node[stream_id].r;
c = stream_node[stream_id].c;
cseg_get(&stream, &curr_stream, r, c);
seg_get(&aspflag, (char *)&af, r, c);
if (af.asp > 0) {
/* get downstream point */
last_r = r + asp_r[(int)af.asp];
last_c = c + asp_c[(int)af.asp];
cseg_get(&stream, &curr_stream, last_r, last_c);
if (curr_stream != stream_id)
return thinned;
/* get next downstream point */
seg_get(&aspflag, (char *)&af, last_r, last_c);
while (af.asp > 0) {
r_nbr = last_r + asp_r[(int)af.asp];
c_nbr = last_c + asp_c[(int)af.asp];
if (r_nbr == last_r && c_nbr == last_c)
return thinned;
if (r_nbr < 0 || r_nbr >= nrows || c_nbr < 0 || c_nbr >= ncols)
return thinned;
cseg_get(&stream, &curr_stream, r_nbr, c_nbr);
if (curr_stream != stream_id)
return thinned;
if (abs(r_nbr - r) < 2 && abs(c_nbr - c) < 2) {
/* eliminate last point */
cseg_put(&stream, &no_stream, last_r, last_c);
FLAG_UNSET(af.flag, STREAMFLAG);
seg_put(&aspflag, (char *)&af, last_r, last_c);
/* update start point */
seg_get(&aspflag, (char *)&af, r, c);
af.asp = drain[r - r_nbr + 1][c - c_nbr + 1];
seg_put(&aspflag, (char *)&af, r, c);
thinned = 1;
}
else {
/* nothing to eliminate, continue from last point */
r = last_r;
c = last_c;
}
last_r = r_nbr;
last_c = c_nbr;
seg_get(&aspflag, (char *)&af, last_r, last_c);
}
}
return thinned;
}
