/* store a raster map in a mem segment on disk */
void Segment_infile (char* map_name, char* mapset, char* search_mapset, int* map_fd,
char* seg_name, int* seg_fd, SEGMENT* seg, void *cell_buf, int fract,
RASTER_MAP_TYPE data_type)
{
int nrows, row;
strcpy (mapset, G_find_cell (map_name, search_mapset));
if (mapset == NULL)
G_fatal_error ("Can't find displayed data layer ");
if ((*map_fd = G_open_cell_old (map_name, mapset)) < 0)
G_fatal_error ("Can't open displayed data layer ");
nrows = G_window_rows ();
/* next line creates the actual segment, returns name of disk file */
strcpy (seg_name, Create_segment_file (nrows, fract, data_type));
*seg_fd = open (seg_name, O_RDWR);
if (*seg_fd < 0)
G_fatal_error ("Cannot open segment disk file ");
segment_init (seg, *seg_fd, 4);
/* store map data in segment file IGNORE MASK */
/* cell_buf must be pre-allocated by caller! */
for (row = 0; row < nrows; row++) {
if (G_get_raster_row_nomask (*map_fd, cell_buf, row, data_type) < 0) {
G_fatal_error ("Unable to read data layer into segment file ");
}
segment_put_row (seg, cell_buf, row); /* store raster map in segment file */
}
}
int main(int argc, char **argv)
{
int n, verbose = 1,
backrow, backcol,
col, row,
len, flag,
srows, scols,
backrow_fd, backcol_fd, path_fd, in_row_fd, in_col_fd, out_fd;
const char *current_mapset,
*search_mapset,
*path_mapset,
*backrow_mapset,
*backcol_mapset, *in_row_file, *in_col_file, *out_file;
CELL *cell;
POINT *PRES_PT, *PRESENT_PT, *OLD_PT;
struct Cell_head window;
double east, north;
struct Option *opt1, *opt2, *opt3, *opt4;
struct Flag *flag1;
struct GModule *module;
G_gisinit(argv[0]);
/* Set description */
module = G_define_module();
G_add_keyword(_("raster"));
G_add_keyword(_("fire"));
G_add_keyword(_("cumulative costs"));
module->description =
_("Recursively traces the least cost path backwards to "
"cells from which the cumulative cost was determined.");
opt1 = G_define_option();
opt1->key = "x_input";
opt1->type = TYPE_STRING;
opt1->required = YES;
opt1->gisprompt = "old,cell,raster";
opt1->description =
_("Name of raster map containing back-path easting information");
opt2 = G_define_option();
opt2->key = "y_input";
opt2->type = TYPE_STRING;
opt2->required = YES;
opt2->gisprompt = "old,cell,raster";
opt2->description =
_("Name of raster map containing back-path northing information");
opt3 = G_define_option();
opt3->key = "coordinate";
opt3->type = TYPE_STRING;
opt3->multiple = YES;
opt3->key_desc = "x,y";
opt3->description =
_("The map E and N grid coordinates of starting points");
opt4 = G_define_option();
opt4->key = "output";
opt4->type = TYPE_STRING;
opt4->required = YES;
opt4->gisprompt = "new,cell,raster";
opt4->description = _("Name of spread path raster map");
flag1 = G_define_flag();
flag1->key = 'v';
flag1->description = _("Run verbosely");
/* Do command line parsing */
if (G_parser(argc, argv))
exit(EXIT_FAILURE);
current_mapset = G_mapset();
in_row_file = G_tempfile();
in_col_file = G_tempfile();
out_file = G_tempfile();
/* Get database window parameters */
G_get_window(&window);
verbose = flag1->answer;
/* Check if backrow layer exists in data base */
search_mapset = "";
strcpy(backrow_layer, opt2->answer);
strcpy(backcol_layer, opt1->answer);
backrow_mapset = G_find_raster(backrow_layer, search_mapset);
backcol_mapset = G_find_raster(backcol_layer, search_mapset);
if (backrow_mapset == NULL)
G_fatal_error("%s - not found", backrow_layer);
if (backcol_mapset == NULL)
G_fatal_error("%s - not found", backcol_layer);
search_mapset = "";
strcpy(path_layer, opt4->answer);
path_mapset = G_find_raster(path_layer, search_mapset);
/* find number of rows and cols in window */
nrows = Rast_window_rows();
ncols = Rast_window_cols();
cell = Rast_allocate_c_buf();
/* Open back cell layers for reading */
backrow_fd = Rast_open_old(backrow_layer, backrow_mapset);
backcol_fd = Rast_open_old(backcol_layer, backcol_mapset);
/* Parameters for map submatrices */
len = sizeof(CELL);
srows = nrows / 4 + 1;
scols = ncols / 4 + 1;
if (verbose)
G_message
("\nReading the input map -%s- and -%s- and creating some temporary files...",
backrow_layer, backcol_layer);
/* Create segmented files for back cell and output layers */
in_row_fd = creat(in_row_file, 0666);
segment_format(in_row_fd, nrows, ncols, srows, scols, len);
close(in_row_fd);
in_col_fd = creat(in_col_file, 0666);
segment_format(in_col_fd, nrows, ncols, srows, scols, len);
close(in_col_fd);
out_fd = creat(out_file, 0666);
segment_format(out_fd, nrows, ncols, srows, scols, len);
close(out_fd);
/* Open initialize and segment all files */
in_row_fd = open(in_row_file, 2);
segment_init(&in_row_seg, in_row_fd, 4);
in_col_fd = open(in_col_file, 2);
segment_init(&in_col_seg, in_col_fd, 4);
out_fd = open(out_file, 2);
segment_init(&out_seg, out_fd, 4);
/* Write the back cell layers in the segmented files, and
* Change UTM coordinates to ROWs and COLUMNs */
for (row = 0; row < nrows; row++) {
Rast_get_c_row(backrow_fd, cell, row);
for (col = 0; col < ncols; col++)
if (cell[col] > 0)
cell[col] =
(window.north - cell[col]) / window.ns_res /* - 0.5 */ ;
else
cell[col] = -1;
segment_put_row(&in_row_seg, cell, row);
Rast_get_c_row(backcol_fd, cell, row);
for (col = 0; col < ncols; col++)
if (cell[col] > 0)
cell[col] =
(cell[col] - window.west) / window.ew_res /* - 0.5 */ ;
segment_put_row(&in_col_seg, cell, row);
}
/* Convert easting and northing from the command line to row and col */
if (opt3->answer) {
for (n = 0; opt3->answers[n] != NULL; n += 2) {
G_scan_easting(opt3->answers[n], &east, G_projection());
G_scan_northing(opt3->answers[n + 1], &north, G_projection());
row = (window.north - north) / window.ns_res;
col = (east - window.west) / window.ew_res;
/* ignore pt outside window */
if (east < window.west || east > window.east ||
north < window.south || north > window.north) {
G_warning("Ignoring point outside window: ");
G_warning(" %.4f,%.4f", east, north);
continue;
}
value = (char *)&backrow;
segment_get(&in_row_seg, value, row, col);
/* ignore pt in no-data area */
if (backrow < 0) {
G_warning("Ignoring point in NO-DATA area :");
G_warning(" %.4f,%.4f", east, north);
continue;
}
value = (char *)&backcol;
segment_get(&in_col_seg, value, row, col);
insert(&PRESENT_PT, row, col, backrow, backcol);
}
}
/* Set flag according to input */
if (path_mapset != NULL) {
if (head_start_pt == NULL)
/*output layer exists and start pts are not given on cmd line */
flag = 1;
/* output layer exists and starting pts are given on cmd line */
else
flag = 2;
}
else
flag = 3; /* output layer does not previously exist */
/* If the output layer containing the starting positions */
/* create a linked list of of them */
if (flag == 1) {
path_fd = Rast_open_old(path_layer, path_mapset);
/* Search for the marked starting pts and make list */
for (row = 0; row < nrows; row++) {
Rast_get_c_row(path_fd, cell, row);
for (col = 0; col < ncols; col++) {
if (cell[col] > 0) {
value = (char *)&backrow;
segment_get(&in_row_seg, value, row, col);
/* ignore pt in no-data area */
if (backrow < 0) {
G_warning("Ignoring point in NO-DATA area:");
G_warning(" %.4f,%.4f\n",
window.west + window.ew_res * (col + 0.5),
window.north - window.ns_res * (row + 0.5));
continue;
}
value = (char *)&backcol;
segment_get(&in_col_seg, value, row, col);
insert(&PRESENT_PT, row, col, backrow, backcol);
}
} /* loop over cols */
} /* loop over rows */
Rast_close(path_fd);
}
/* loop over the starting points to find the least cost paths */
if (verbose)
G_message("\nFinding the least cost paths ...");
PRES_PT = head_start_pt;
while (PRES_PT != NULL) {
path_finder(PRES_PT->row, PRES_PT->col, PRES_PT->backrow,
PRES_PT->backcol);
OLD_PT = PRES_PT;
PRES_PT = NEXT_PT;
G_free(OLD_PT);
}
/* Write pending updates by segment_put() to outputmap */
segment_flush(&out_seg);
if (verbose)
G_message("\nWriting the output map -%s-...", path_layer);
path_fd = Rast_open_c_new(path_layer);
for (row = 0; row < nrows; row++) {
segment_get_row(&out_seg, cell, row);
Rast_put_row(path_fd, cell, CELL_TYPE);
}
if (verbose)
G_message("finished.");
segment_release(&in_row_seg); /* release memory */
segment_release(&in_col_seg);
segment_release(&out_seg);
close(in_row_fd); /* close all files */
close(in_col_fd);
close(out_fd);
Rast_close(path_fd);
Rast_close(backrow_fd);
Rast_close(backcol_fd);
unlink(in_row_file); /* remove submatrix files */
unlink(in_col_file);
unlink(out_file);
exit(EXIT_SUCCESS);
}
