2 * viking -- GPS Data and Topo Analyzer, Explorer, and Manager
4 * Copyright (C) 2003-2008, Evan Battaglia <gtoevan@gmx.net>
5 * Copyright (C) 2007, Quy Tonthat <qtonthat@gmail.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
39 #include <sys/types.h>
45 #include <glib/gstdio.h>
46 #include <glib/gi18n.h>
52 #if ! GLIB_CHECK_VERSION(2,22,0)
53 #define g_mapped_file_unref g_mapped_file_free
56 #define DEM_BLOCK_SIZE 1024
57 #define GET_COLUMN(dem,n) ((VikDEMColumn *)g_ptr_array_index( (dem)->columns, (n) ))
59 static gboolean get_double_and_continue ( gchar **buffer, gdouble *tmp, gboolean warn )
62 *tmp = g_strtod(*buffer, &endptr);
63 if ( endptr == NULL|| endptr == *buffer ) {
65 g_warning(_("Invalid DEM"));
73 static gboolean get_int_and_continue ( gchar **buffer, gint *tmp, gboolean warn )
76 *tmp = strtol(*buffer, &endptr, 10);
77 if ( endptr == NULL|| endptr == *buffer ) {
79 g_warning(_("Invalid DEM"));
86 static gboolean dem_parse_header ( gchar *buffer, VikDEM *dem )
93 /* incomplete header */
94 if ( strlen(buffer) != 1024 )
97 /* fix Fortran-style exponentiation 1.0D5 -> 1.0E5 */
107 /* "DEM level code, pattern code, palaimetric reference system code" -- skip */
108 get_int_and_continue(&buffer, &int_val, TRUE);
109 get_int_and_continue(&buffer, &int_val, TRUE);
110 get_int_and_continue(&buffer, &int_val, TRUE);
113 get_int_and_continue(&buffer, &int_val, TRUE);
114 dem->utm_zone = int_val;
115 /* TODO -- southern or northern hemisphere?! */
116 dem->utm_letter = 'N';
118 /* skip numbers 5-19 */
119 for ( i = 0; i < 15; i++ ) {
120 if ( ! get_double_and_continue(&buffer, &val, FALSE) ) {
121 g_warning (_("Invalid DEM header"));
126 /* number 20 -- horizontal unit code (utm/ll) */
127 get_double_and_continue(&buffer, &val, TRUE);
128 dem->horiz_units = val;
129 get_double_and_continue(&buffer, &val, TRUE);
130 /* dem->orig_vert_units = val; now done below */
132 /* TODO: do this for real. these are only for 1:24k and 1:250k USGS */
133 if ( dem->horiz_units == VIK_DEM_HORIZ_UTM_METERS ) {
134 dem->east_scale = 10.0; /* meters */
135 dem->north_scale = 10.0;
136 dem->orig_vert_units = VIK_DEM_VERT_DECIMETERS;
138 dem->east_scale = 3.0; /* arcseconds */
139 dem->north_scale = 3.0;
140 dem->orig_vert_units = VIK_DEM_VERT_METERS;
144 get_double_and_continue(&buffer, &val, TRUE);
146 /* now we get the four corner points. record the min and max. */
147 get_double_and_continue(&buffer, &val, TRUE);
148 dem->min_east = dem->max_east = val;
149 get_double_and_continue(&buffer, &val, TRUE);
150 dem->min_north = dem->max_north = val;
152 for ( i = 0; i < 3; i++ ) {
153 get_double_and_continue(&buffer, &val, TRUE);
154 if ( val < dem->min_east ) dem->min_east = val;
155 if ( val > dem->max_east ) dem->max_east = val;
156 get_double_and_continue(&buffer, &val, TRUE);
157 if ( val < dem->min_north ) dem->min_north = val;
158 if ( val > dem->max_north ) dem->max_north = val;
164 static void dem_parse_block_as_cont ( gchar *buffer, VikDEM *dem, gint *cur_column, gint *cur_row )
167 while ( *cur_row < GET_COLUMN(dem, *cur_column)->n_points ) {
168 if ( get_int_and_continue(&buffer, &tmp,FALSE) ) {
169 if ( dem->orig_vert_units == VIK_DEM_VERT_DECIMETERS )
170 GET_COLUMN(dem, *cur_column)->points[*cur_row] = (gint16) (tmp / 10);
172 GET_COLUMN(dem, *cur_column)->points[*cur_row] = (gint16) tmp;
177 *cur_row = -1; /* expecting new column */
180 static void dem_parse_block_as_header ( gchar *buffer, VikDEM *dem, gint *cur_column, gint *cur_row )
184 gdouble east_west, south;
187 /* 1 x n_rows 1 east_west south x x x DATA */
189 if ( (!get_double_and_continue(&buffer, &tmp, TRUE)) || tmp != 1 ) {
190 g_warning(_("Incorrect DEM Class B record: expected 1"));
194 /* don't need this */
195 if ( !get_double_and_continue(&buffer, &tmp, TRUE ) ) return;
198 if ( !get_double_and_continue(&buffer, &tmp, TRUE ) )
200 n_rows = (guint) tmp;
202 if ( (!get_double_and_continue(&buffer, &tmp, TRUE)) || tmp != 1 ) {
203 g_warning(_("Incorrect DEM Class B record: expected 1"));
207 if ( !get_double_and_continue(&buffer, &east_west, TRUE) )
209 if ( !get_double_and_continue(&buffer, &south, TRUE) )
212 /* next three things we don't need */
213 if ( !get_double_and_continue(&buffer, &tmp, TRUE)) return;
214 if ( !get_double_and_continue(&buffer, &tmp, TRUE)) return;
215 if ( !get_double_and_continue(&buffer, &tmp, TRUE)) return;
221 /* empty spaces for things before that were skipped */
222 (*cur_row) = (south - dem->min_north) / dem->north_scale;
223 if ( south > dem->max_north || (*cur_row) < 0 )
228 g_ptr_array_add ( dem->columns, g_malloc(sizeof(VikDEMColumn)) );
229 GET_COLUMN(dem,*cur_column)->east_west = east_west;
230 GET_COLUMN(dem,*cur_column)->south = south;
231 GET_COLUMN(dem,*cur_column)->n_points = n_rows;
232 GET_COLUMN(dem,*cur_column)->points = g_malloc(sizeof(gint16)*n_rows);
234 /* no information for things before that */
235 for ( i = 0; i < (*cur_row); i++ )
236 GET_COLUMN(dem,*cur_column)->points[i] = VIK_DEM_INVALID_ELEVATION;
238 /* now just continue */
239 dem_parse_block_as_cont ( buffer, dem, cur_column, cur_row );
244 static void dem_parse_block ( gchar *buffer, VikDEM *dem, gint *cur_column, gint *cur_row )
246 /* if haven't read anything or have read all items in a columns and are expecting a new column */
247 if ( *cur_column == -1 || *cur_row == -1 ) {
248 dem_parse_block_as_header(buffer, dem, cur_column, cur_row);
250 dem_parse_block_as_cont(buffer, dem, cur_column, cur_row);
254 /* return size of unzip data or 0 if failed */
255 /* can be made generic to uncompress zip, gzip, bzip2 data */
256 static guint uncompress_data(void *uncompressed_buffer, guint uncompressed_size, void *compressed_data, guint compressed_size)
261 stream.next_in = compressed_data;
262 stream.avail_in = compressed_size;
263 stream.next_out = uncompressed_buffer;
264 stream.avail_out = uncompressed_size;
265 stream.zalloc = (alloc_func)0;
266 stream.zfree = (free_func)0;
267 stream.opaque = (voidpf)0;
269 /* negative windowBits to inflateInit2 means "no header" */
270 if ((err = inflateInit2(&stream, -MAX_WBITS)) != Z_OK) {
271 g_warning("%s(): inflateInit2 failed", __PRETTY_FUNCTION__);
275 err = inflate(&stream, Z_FINISH);
276 if ((err != Z_OK) && (err != Z_STREAM_END) && stream.msg) {
277 g_warning("%s() inflate failed err=%d \"%s\"", __PRETTY_FUNCTION__, err, stream.msg == NULL ? "unknown" : stream.msg);
283 return(stream.total_out);
286 static void *unzip_hgt_file(gchar *zip_file, gulong *unzip_size)
288 void *unzip_data = NULL;
292 guint16 extract_version;
298 guint32 compressed_size;
299 guint32 uncompressed_size;
300 guint16 filename_len;
301 guint16 extra_field_len;
302 } __attribute__ ((__packed__)) *local_file_header = NULL;
305 local_file_header = (struct _lfh *) zip_file;
306 if (GUINT32_FROM_LE(local_file_header->sig) != 0x04034b50) {
307 g_warning("%s(): wrong format", __PRETTY_FUNCTION__);
312 zip_data = zip_file + sizeof(struct _lfh)
313 + GUINT16_FROM_LE(local_file_header->filename_len)
314 + GUINT16_FROM_LE(local_file_header->extra_field_len);
315 gulong uncompressed_size = GUINT32_FROM_LE(local_file_header->uncompressed_size);
316 unzip_data = g_malloc(uncompressed_size);
318 if (!(*unzip_size = uncompress_data(unzip_data, uncompressed_size, zip_data, GUINT32_FROM_LE(local_file_header->compressed_size)))) {
328 static VikDEM *vik_dem_read_srtm_hgt(const gchar *file_name, const gchar *basename, gboolean zip)
333 gint16 *dem_mem = NULL;
334 gchar *dem_file = NULL;
335 const gint num_rows_3sec = 1201;
336 const gint num_rows_1sec = 3601;
340 GError *error = NULL;
342 dem = g_malloc(sizeof(VikDEM));
344 dem->horiz_units = VIK_DEM_HORIZ_LL_ARCSECONDS;
345 dem->orig_vert_units = VIK_DEM_VERT_DECIMETERS;
348 dem->min_north = atoi(basename+1) * 3600;
349 dem->min_east = atoi(basename+4) * 3600;
350 if ( basename[0] == 'S' )
351 dem->min_north = - dem->min_north;
352 if ( basename[3] == 'W' )
353 dem->min_east = - dem->min_east;
355 dem->max_north = 3600 + dem->min_north;
356 dem->max_east = 3600 + dem->min_east;
358 dem->columns = g_ptr_array_new();
361 if ((mf = g_mapped_file_new(file_name, FALSE, &error)) == NULL) {
362 g_critical(_("Couldn't map file %s: %s"), file_name, error->message);
367 file_size = g_mapped_file_get_length(mf);
368 dem_file = g_mapped_file_get_contents(mf);
371 void *unzip_mem = NULL;
374 if ((unzip_mem = unzip_hgt_file(dem_file, &ucsize)) == NULL) {
375 g_mapped_file_unref(mf);
376 g_ptr_array_foreach ( dem->columns, (GFunc)g_free, NULL );
377 g_ptr_array_free(dem->columns, TRUE);
386 dem_mem = (gint16 *)dem_file;
388 if (file_size == (num_rows_3sec * num_rows_3sec * sizeof(gint16)))
390 else if (file_size == (num_rows_1sec * num_rows_1sec * sizeof(gint16)))
393 g_warning("%s(): file %s does not have right size", __PRETTY_FUNCTION__, basename);
394 g_mapped_file_unref(mf);
399 num_rows = (arcsec == 3) ? num_rows_3sec : num_rows_1sec;
400 dem->east_scale = dem->north_scale = arcsec;
402 for ( i = 0; i < num_rows; i++ ) {
404 g_ptr_array_add ( dem->columns, g_malloc(sizeof(VikDEMColumn)) );
405 GET_COLUMN(dem,i)->east_west = dem->min_east + arcsec*i;
406 GET_COLUMN(dem,i)->south = dem->min_north;
407 GET_COLUMN(dem,i)->n_points = num_rows;
408 GET_COLUMN(dem,i)->points = g_malloc(sizeof(gint16)*num_rows);
412 for ( i = (num_rows - 1); i >= 0; i-- ) {
413 for ( j = 0; j < num_rows; j++ ) {
414 GET_COLUMN(dem,j)->points[i] = GINT16_FROM_BE(dem_mem[ent]);
422 g_mapped_file_unref(mf);
426 #define IS_SRTM_HGT(fn) (strlen((fn))==11 && (fn)[7]=='.' && (fn)[8]=='h' && (fn)[9]=='g' && (fn)[10]=='t' && ((fn)[0]=='N' || (fn)[0]=='S') && ((fn)[3]=='E' || (fn)[3]=='W'))
428 VikDEM *vik_dem_new_from_file(const gchar *file)
432 gchar buffer[DEM_BLOCK_SIZE+1];
434 /* use to record state for dem_parse_block */
435 gint cur_column = -1;
437 const gchar *basename = a_file_basename(file);
439 if ( g_access ( file, R_OK ) != 0 )
442 if ( (strlen(basename)==11 || ((strlen(basename) == 15) && (basename[11] == '.' && basename[12] == 'z' && basename[13] == 'i' && basename[14] == 'p'))) &&
443 basename[7]=='.' && basename[8]=='h' && basename[9]=='g' && basename[10]=='t' &&
444 (basename[0] == 'N' || basename[0] == 'S') && (basename[3] == 'E' || basename[3] =='W')) {
445 gboolean is_zip_file = (strlen(basename) == 15);
446 rv = vik_dem_read_srtm_hgt(file, basename, is_zip_file);
450 /* Create Structure */
451 rv = g_malloc(sizeof(VikDEM));
454 f = g_fopen(file, "r");
459 buffer[fread(buffer, 1, DEM_BLOCK_SIZE, f)] = '\0';
460 if ( ! dem_parse_header ( buffer, rv ) ) {
465 /* TODO: actually use header -- i.e. GET # OF COLUMNS EXPECTED */
467 rv->columns = g_ptr_array_new();
475 buffer[fread(buffer, 1, DEM_BLOCK_SIZE, f)] = '\0';
477 /* Fix Fortran-style exponentiation */
485 dem_parse_block(buffer, rv, &cur_column, &cur_row);
488 /* TODO - class C records (right now says 'Invalid' and dies) */
494 if ( rv->horiz_units == VIK_DEM_HORIZ_UTM_METERS && rv->n_columns >= 2 )
495 rv->north_scale = rv->east_scale = GET_COLUMN(rv, 1)->east_west - GET_COLUMN(rv,0)->east_west;
497 /* FIXME bug in 10m DEM's */
498 if ( rv->horiz_units == VIK_DEM_HORIZ_UTM_METERS && rv->north_scale == 10 ) {
500 rv->min_north += 200;
507 void vik_dem_free ( VikDEM *dem )
510 for ( i = 0; i < dem->n_columns; i++)
511 g_free ( GET_COLUMN(dem, i)->points );
512 g_ptr_array_foreach ( dem->columns, (GFunc)g_free, NULL );
513 g_ptr_array_free ( dem->columns, TRUE );
517 gint16 vik_dem_get_xy ( VikDEM *dem, guint col, guint row )
519 if ( col < dem->n_columns )
520 if ( row < GET_COLUMN(dem, col)->n_points )
521 return GET_COLUMN(dem, col)->points[row];
522 return VIK_DEM_INVALID_ELEVATION;
525 gint16 vik_dem_get_east_north ( VikDEM *dem, gdouble east, gdouble north )
529 if ( east > dem->max_east || east < dem->min_east ||
530 north > dem->max_north || north < dem->min_north )
531 return VIK_DEM_INVALID_ELEVATION;
533 col = (gint) floor((east - dem->min_east) / dem->east_scale);
534 row = (gint) floor((north - dem->min_north) / dem->north_scale);
536 return vik_dem_get_xy ( dem, col, row );
539 static gboolean dem_get_ref_points_elev_dist(VikDEM *dem,
540 gdouble east, gdouble north, /* in seconds */
541 gint16 *elevs, gint16 *dists)
544 int cols[4], rows[4];
548 if ( east > dem->max_east || east < dem->min_east ||
549 north > dem->max_north || north < dem->min_north )
550 return FALSE; /* got nothing */
553 pos.lat = north/3600;
555 /* order of the data: sw, nw, ne, se */
557 cols[0] = (gint) floor((east - dem->min_east) / dem->east_scale);
558 rows[0] = (gint) floor((north - dem->min_north) / dem->north_scale);
559 ll[0].lon = (dem->min_east + dem->east_scale*cols[0])/3600;
560 ll[0].lat = (dem->min_north + dem->north_scale*rows[0])/3600;
563 rows[1] = rows[0] + 1;
564 ll[1].lon = ll[0].lon;
565 ll[1].lat = ll[0].lat + (gdouble)dem->north_scale/3600;
567 cols[2] = cols[0] + 1;
568 rows[2] = rows[0] + 1;
569 ll[2].lon = ll[0].lon + (gdouble)dem->east_scale/3600;
570 ll[2].lat = ll[0].lat + (gdouble)dem->north_scale/3600;
572 cols[3] = cols[0] + 1;
574 ll[3].lon = ll[0].lon + (gdouble)dem->east_scale/3600;
575 ll[3].lat = ll[0].lat;
577 for (i = 0; i < 4; i++) {
578 if ((elevs[i] = vik_dem_get_xy(dem, cols[i], rows[i])) == VIK_DEM_INVALID_ELEVATION)
580 dists[i] = a_coords_latlon_diff(&pos, &ll[i]);
584 for (i = 0; i < 4; i++)
585 fprintf(stderr, "%f:%f:%d:%d ", ll[i].lat, ll[i].lon, dists[i], elevs[i]);
586 fprintf(stderr, " north_scale=%f\n", dem->north_scale);
589 return TRUE; /* all OK */
592 gint16 vik_dem_get_simple_interpol ( VikDEM *dem, gdouble east, gdouble north )
595 gint16 elevs[4], dists[4];
597 if (!dem_get_ref_points_elev_dist(dem, east, north, elevs, dists))
598 return VIK_DEM_INVALID_ELEVATION;
600 for (i = 0; i < 4; i++) {
606 gdouble t = (gdouble)elevs[0]/dists[0] + (gdouble)elevs[1]/dists[1] + (gdouble)elevs[2]/dists[2] + (gdouble)elevs[3]/dists[3];
607 gdouble b = 1.0/dists[0] + 1.0/dists[1] + 1.0/dists[2] + 1.0/dists[3];
612 gint16 vik_dem_get_shepard_interpol ( VikDEM *dem, gdouble east, gdouble north )
615 gint16 elevs[4], dists[4];
620 if (!dem_get_ref_points_elev_dist(dem, east, north, elevs, dists))
621 return VIK_DEM_INVALID_ELEVATION;
624 for (i = 0; i < 4; i++) {
628 if (dists[i] > max_dist)
633 #if 0 /* derived method by Franke & Nielson. Does not seem to work too well here */
634 for (i = 0; i < 4; i++) {
635 tmp = pow((1.0*(max_dist - dists[i])/max_dist*dists[i]), 2);
641 for (i = 0; i < 4; i++) {
642 tmp = pow((1.0/dists[i]), 2);
647 // fprintf(stderr, "DEBUG: tmp=%f t=%f b=%f %f\n", tmp, t, b, t/b);
653 void vik_dem_east_north_to_xy ( VikDEM *dem, gdouble east, gdouble north, guint *col, guint *row )
655 *col = (gint) floor((east - dem->min_east) / dem->east_scale);
656 *row = (gint) floor((north - dem->min_north) / dem->north_scale);
657 if ( *col < 0 ) *col = 0;
658 if ( *row < 0 ) *row = 0;