2 * viking -- GPS Data and Topo Analyzer, Explorer, and Manager
4 * Copyright (C) 2003-2005, Evan Battaglia <gtoevan@gmx.net>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
34 VikTrack *vik_track_new()
36 VikTrack *tr = g_malloc0 ( sizeof ( VikTrack ) );
41 void vik_track_set_comment_no_copy(VikTrack *tr, gchar *comment)
44 g_free ( tr->comment );
45 tr->comment = comment;
49 void vik_track_set_comment(VikTrack *tr, const gchar *comment)
52 g_free ( tr->comment );
54 if ( comment && comment[0] != '\0' )
55 tr->comment = g_strdup(comment);
60 void vik_track_ref(VikTrack *tr)
65 void vik_track_free(VikTrack *tr)
67 if ( tr->ref_count-- > 1 )
71 g_free ( tr->comment );
72 g_list_foreach ( tr->trackpoints, (GFunc) g_free, NULL );
73 g_list_free( tr->trackpoints );
77 VikTrack *vik_track_copy ( const VikTrack *tr )
79 VikTrack *new_tr = vik_track_new();
80 VikTrackpoint *new_tp;
81 GList *tp_iter = tr->trackpoints;
82 new_tr->visible = tr->visible;
83 new_tr->trackpoints = NULL;
86 new_tp = g_malloc ( sizeof ( VikTrackpoint ) );
87 *new_tp = *((VikTrackpoint *)(tp_iter->data));
88 new_tr->trackpoints = g_list_append ( new_tr->trackpoints, new_tp );
89 tp_iter = tp_iter->next;
91 vik_track_set_comment(new_tr,tr->comment);
95 VikTrackpoint *vik_trackpoint_new()
97 VikTrackpoint *tp = g_malloc0(sizeof(VikTrackpoint));
104 void vik_trackpoint_free(VikTrackpoint *tp)
109 VikTrackpoint *vik_trackpoint_copy(VikTrackpoint *tp)
111 VikTrackpoint *rv = vik_trackpoint_new();
116 gdouble vik_track_get_length(const VikTrack *tr)
119 if ( tr->trackpoints )
121 GList *iter = tr->trackpoints->next;
124 if ( ! VIK_TRACKPOINT(iter->data)->newsegment )
125 len += vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
126 &(VIK_TRACKPOINT(iter->prev->data)->coord) );
133 gdouble vik_track_get_length_including_gaps(const VikTrack *tr)
136 if ( tr->trackpoints )
138 GList *iter = tr->trackpoints->next;
141 len += vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
142 &(VIK_TRACKPOINT(iter->prev->data)->coord) );
149 gulong vik_track_get_tp_count(const VikTrack *tr)
152 GList *iter = tr->trackpoints;
161 gulong vik_track_get_dup_point_count ( const VikTrack *tr )
164 GList *iter = tr->trackpoints;
167 if ( iter->next && vik_coord_equals ( &(VIK_TRACKPOINT(iter->data)->coord),
168 &(VIK_TRACKPOINT(iter->next->data)->coord) ) )
175 void vik_track_remove_dup_points ( VikTrack *tr )
177 GList *iter = tr->trackpoints;
180 if ( iter->next && vik_coord_equals ( &(VIK_TRACKPOINT(iter->data)->coord),
181 &(VIK_TRACKPOINT(iter->next->data)->coord) ) )
183 g_free ( iter->next->data );
184 tr->trackpoints = g_list_delete_link ( tr->trackpoints, iter->next );
191 guint vik_track_get_segment_count(const VikTrack *tr)
194 GList *iter = tr->trackpoints;
197 while ( (iter = iter->next) )
199 if ( VIK_TRACKPOINT(iter->data)->newsegment )
205 VikTrack **vik_track_split_into_segments(VikTrack *t, guint *ret_len)
210 guint segs = vik_track_get_segment_count(t);
219 rv = g_malloc ( segs * sizeof(VikTrack *) );
220 tr = vik_track_copy ( t );
222 iter = tr->trackpoints;
225 while ( (iter = iter->next) )
227 if ( VIK_TRACKPOINT(iter->data)->newsegment )
229 iter->prev->next = NULL;
231 rv[i] = vik_track_new();
233 vik_track_set_comment ( rv[i], tr->comment );
234 rv[i]->visible = tr->visible;
235 rv[i]->trackpoints = iter;
243 void vik_track_reverse ( VikTrack *tr )
246 tr->trackpoints = g_list_reverse(tr->trackpoints);
248 /* fix 'newsegment' */
249 iter = g_list_last ( tr->trackpoints );
252 if ( ! iter->next ) /* last segment, was first, cancel newsegment. */
253 VIK_TRACKPOINT(iter->data)->newsegment = FALSE;
254 if ( ! iter->prev ) /* first segment by convention has newsegment flag. */
255 VIK_TRACKPOINT(iter->data)->newsegment = TRUE;
256 else if ( VIK_TRACKPOINT(iter->data)->newsegment && iter->next )
258 VIK_TRACKPOINT(iter->next->data)->newsegment = TRUE;
259 VIK_TRACKPOINT(iter->data)->newsegment = FALSE;
265 gdouble vik_track_get_average_speed(const VikTrack *tr)
269 if ( tr->trackpoints )
271 GList *iter = tr->trackpoints->next;
274 if ( VIK_TRACKPOINT(iter->data)->has_timestamp &&
275 VIK_TRACKPOINT(iter->prev->data)->has_timestamp &&
276 (! VIK_TRACKPOINT(iter->data)->newsegment) )
278 len += vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
279 &(VIK_TRACKPOINT(iter->prev->data)->coord) );
280 time += ABS(VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(iter->prev->data)->timestamp);
285 return (time == 0) ? 0 : ABS(len/time);
288 gdouble vik_track_get_max_speed(const VikTrack *tr)
290 gdouble maxspeed = 0.0, speed = 0.0;
291 if ( tr->trackpoints )
293 GList *iter = tr->trackpoints->next;
296 if ( VIK_TRACKPOINT(iter->data)->has_timestamp &&
297 VIK_TRACKPOINT(iter->prev->data)->has_timestamp &&
298 (! VIK_TRACKPOINT(iter->data)->newsegment) )
300 speed = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord), &(VIK_TRACKPOINT(iter->prev->data)->coord) )
301 / ABS(VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(iter->prev->data)->timestamp);
302 if ( speed > maxspeed )
311 void vik_track_convert ( VikTrack *tr, VikCoordMode dest_mode )
313 GList *iter = tr->trackpoints;
316 vik_coord_convert ( &(VIK_TRACKPOINT(iter->data)->coord), dest_mode );
321 /* I understood this when I wrote it ... maybe ... Basically it eats up the
322 * proper amounts of length on the track and averages elevation over that. */
323 gdouble *vik_track_make_elevation_map ( const VikTrack *tr, guint16 num_chunks )
326 gdouble total_length, chunk_length, current_dist, current_area_under_curve, current_seg_length, dist_along_seg = 0.0;
327 gdouble altitude1, altitude2;
328 guint16 current_chunk;
329 gboolean ignore_it = FALSE;
331 GList *iter = tr->trackpoints;
333 if (!iter || !iter->next) /* zero- or one-point track */
336 { /* test if there's anything worth calculating */
337 gboolean okay = FALSE;
340 if ( VIK_TRACKPOINT(iter->data)->altitude != VIK_DEFAULT_ALTITUDE ) {
349 iter = tr->trackpoints;
351 g_assert ( num_chunks < 16000 );
353 pts = g_malloc ( sizeof(gdouble) * num_chunks );
355 total_length = vik_track_get_length_including_gaps ( tr );
356 chunk_length = total_length / num_chunks;
359 current_area_under_curve = 0;
361 current_seg_length = 0;
363 current_seg_length = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
364 &(VIK_TRACKPOINT(iter->next->data)->coord) );
365 altitude1 = VIK_TRACKPOINT(iter->data)->altitude;
366 altitude2 = VIK_TRACKPOINT(iter->next->data)->altitude;
369 while ( current_chunk < num_chunks ) {
371 /* go along current seg */
372 if ( current_seg_length && (current_seg_length - dist_along_seg) > chunk_length ) {
373 dist_along_seg += chunk_length;
377 * /x altitude = alt_at_pt_1 + alt_at_pt_2 / 2 = altitude1 + slope * dist_value_of_pt_inbetween_pt1_and_pt2
378 * /xx avg altitude = area under curve / chunk len
379 *pt1 *xxx avg altitude = altitude1 + (altitude2-altitude1)/(current_seg_length)*(dist_along_seg + (chunk_len/2))
385 pts[current_chunk] = VIK_DEFAULT_ALTITUDE;
387 pts[current_chunk] = altitude1 + (altitude2-altitude1)*((dist_along_seg - (chunk_length/2))/current_seg_length);
391 /* finish current seg */
392 if ( current_seg_length ) {
393 gdouble altitude_at_dist_along_seg = altitude1 + (altitude2-altitude1)/(current_seg_length)*dist_along_seg;
394 current_dist = current_seg_length - dist_along_seg;
395 current_area_under_curve = current_dist*(altitude_at_dist_along_seg + altitude2)*0.5;
396 } else { current_dist = current_area_under_curve = 0; } /* should only happen if first current_seg_length == 0 */
398 /* get intervening segs */
400 while ( iter && iter->next ) {
401 current_seg_length = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
402 &(VIK_TRACKPOINT(iter->next->data)->coord) );
403 altitude1 = VIK_TRACKPOINT(iter->data)->altitude;
404 altitude2 = VIK_TRACKPOINT(iter->next->data)->altitude;
405 ignore_it = VIK_TRACKPOINT(iter->next->data)->newsegment;
407 if ( chunk_length - current_dist >= current_seg_length ) {
408 current_dist += current_seg_length;
409 current_area_under_curve += current_seg_length * (altitude1+altitude2) * 0.5;
417 dist_along_seg = chunk_length - current_dist;
418 if ( ignore_it || !iter->next ) {
419 pts[current_chunk] = current_area_under_curve / current_dist;
422 current_area_under_curve += dist_along_seg * (altitude1 + (altitude2 - altitude1)*dist_along_seg/current_seg_length);
423 pts[current_chunk] = current_area_under_curve / chunk_length;
435 void vik_track_get_total_elevation_gain(const VikTrack *tr, gdouble *up, gdouble *down)
439 if ( tr->trackpoints && VIK_TRACKPOINT(tr->trackpoints->data)->altitude != VIK_DEFAULT_ALTITUDE )
441 GList *iter = tr->trackpoints->next;
444 diff = VIK_TRACKPOINT(iter->data)->altitude - VIK_TRACKPOINT(iter->prev->data)->altitude;
452 *up = *down = VIK_DEFAULT_ALTITUDE;
459 void compute_spline(int n, double *x, double *f, spline_coeff_t *p)
461 double *h, *alpha, *B, *m;
464 double new_x[3], new_f[3];
470 new_x[1] = x[0]+0.00001;
481 new_x[2] = x[1] + x[1]-x[0];
482 new_f[2] = f[1] + f[1]-f[0];
488 /* we're solving a linear system of equations of the form Ax = B.
489 * The matrix a is tridiagonal and consists of coefficients in
490 * the h[] and alpha[] arrays.
493 h = (double *)malloc(sizeof(double) * (n-1));
494 for (i=0; i<n-1; i++) {
498 alpha = (double *)malloc(sizeof(double) * (n-2));
499 for (i=0; i<n-2; i++) {
500 alpha[i] = 2 * (h[i] + h[i+1]);
503 /* B[] is the vector on the right hand side of the equation */
504 B = (double *)malloc(sizeof(double) * (n-2));
505 for (i=0; i<n-2; i++) {
506 B[i] = 6 * ((f[i+2] - f[i+1])/h[i+1] - (f[i+1] - f[i])/h[i]);
509 /* Now solve the n-2 by n-2 system */
510 m = (double *)malloc(sizeof(double) * (n-2));
511 for (i=1; i<=n-3; i++) {
517 di = di - (ai-1 / di-1) * ci-1
518 bi = bi - (ai-1 / di-1) * bi-1
521 alpha[i] = alpha[i] - (h[i]/alpha[i-1]) * h[i];
522 B[i] = B[i] - (h[i]/alpha[i-1]) * B[i-1];
524 /* xn-3 = bn-3 / dn-3; */
525 m[n-3] = B[n-3]/alpha[n-3];
526 for (i=n-4; i>=0; i--) {
527 m[i] = (B[i]-h[i+1]*m[i+1])/alpha[i];
530 for (i=0; i<orig_n-1; i++) {
532 mi = (i==(n-2)) ? 0 : m[i];
533 mi1 = (i==0) ? 0 : m[i-1];
536 p[i].b = (f[i+1] - f[i]) / h[i] + h[i] * (2*mi + mi1) / 6;
538 p[i].d = (mi-mi1)/(6*h[i]);
547 /* by Alex Foobarian */
548 gdouble *vik_track_make_speed_map ( const VikTrack *tr, guint16 num_chunks )
551 gdouble duration, chunk_dur, T, s_prev, s_now;
553 int i, pt_count, numpts, spline;
557 if ( ! tr->trackpoints )
560 g_assert ( num_chunks < 16000 );
562 #ifdef XXXXXXXXXXXXXXXXXX
563 iter = tr->trackpoints;
567 #endif /*XXXXXXXXXXXXXXXXXX*/
569 t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
570 t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
573 if ( !t1 || !t2 || !duration )
577 g_warning("negative duration: unsorted trackpoint timestamps?\n");
580 pt_count = vik_track_get_tp_count(tr);
582 v = g_malloc ( sizeof(gdouble) * num_chunks );
583 chunk_dur = duration / num_chunks;
585 s = g_malloc(sizeof(double) * pt_count);
586 t = g_malloc(sizeof(double) * pt_count);
587 p = g_malloc(sizeof(spline_coeff_t) * (pt_count-1));
589 iter = tr->trackpoints->next;
592 t[0] = VIK_TRACKPOINT(iter->prev->data)->timestamp;
595 s[numpts] = s[numpts-1] + vik_coord_diff ( &(VIK_TRACKPOINT(iter->prev->data)->coord), &(VIK_TRACKPOINT(iter->data)->coord) );
596 t[numpts] = VIK_TRACKPOINT(iter->data)->timestamp;
601 compute_spline(numpts, t, s, p);
603 /* the spline gives us distances at chunk_dur intervals. from these,
604 * we obtain average speed in each interval.
609 p[spline].d * pow(T - t[spline+1], 3) +
610 p[spline].c * pow(T - t[spline+1], 2) +
611 p[spline].b * (T - t[spline+1]) +
613 for (i = 0; i < num_chunks; i++, T+=chunk_dur) {
614 while (T > t[spline+1]) {
618 p[spline].d * pow(T - t[spline+1], 3) +
619 p[spline].c * pow(T - t[spline+1], 2) +
620 p[spline].b * (T - t[spline+1]) +
622 v[i] = (s_now - s_prev) / chunk_dur;
625 * old method of averages
626 v[i] = (s[spline+1]-s[spline])/(t[spline+1]-t[spline]);
635 /* by Alex Foobarian */
636 VikTrackpoint *vik_track_get_closest_tp_by_percentage_dist ( VikTrack *tr, gdouble reldist, gdouble *meters_from_start )
638 gdouble dist = vik_track_get_length_including_gaps(tr) * reldist;
639 gdouble current_dist = 0.0;
640 gdouble current_inc = 0.0;
641 if ( tr->trackpoints )
643 GList *iter = tr->trackpoints->next;
644 GList *last_iter = NULL;
645 gdouble last_dist = 0.0;
648 current_inc = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
649 &(VIK_TRACKPOINT(iter->prev->data)->coord) );
650 last_dist = current_dist;
651 current_dist += current_inc;
652 if ( current_dist >= dist )
657 if (!iter) { /* passing the end the track */
659 if (meters_from_start)
660 *meters_from_start = last_dist;
661 return(VIK_TRACKPOINT(last_iter->data));
666 /* we've gone past the dist already, was prev trackpoint closer? */
667 /* should do a vik_coord_average_weighted() thingy. */
668 if ( iter->prev && abs(current_dist-current_inc-dist) < abs(current_dist-dist) ) {
669 if (meters_from_start)
670 *meters_from_start = last_dist;
674 if (meters_from_start)
675 *meters_from_start = current_dist;
677 return VIK_TRACKPOINT(iter->data);
683 VikTrackpoint *vik_track_get_closest_tp_by_percentage_time ( VikTrack *tr, gdouble reltime, time_t *seconds_from_start )
685 time_t t_pos, t_start, t_end, t_total;
686 t_start = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
687 t_end = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
688 t_total = t_end - t_start;
690 t_pos = t_start + t_total * reltime;
692 if ( !tr->trackpoints )
695 GList *iter = tr->trackpoints;
698 if (VIK_TRACKPOINT(iter->data)->timestamp == t_pos)
700 if (VIK_TRACKPOINT(iter->data)->timestamp > t_pos) {
701 if (iter->prev == NULL) /* first trackpoint */
703 time_t t_before = t_pos - VIK_TRACKPOINT(iter->prev)->timestamp;
704 time_t t_after = VIK_TRACKPOINT(iter->data)->timestamp - t_pos;
705 if (t_before <= t_after)
709 else if ((iter->next == NULL) && (t_pos < (VIK_TRACKPOINT(iter->data)->timestamp + 3))) /* last trackpoint: accommodate for round-off */
716 if (seconds_from_start)
717 *seconds_from_start = VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
718 return VIK_TRACKPOINT(iter->data);
721 gboolean vik_track_get_minmax_alt ( const VikTrack *tr, gdouble *min_alt, gdouble *max_alt )
725 if ( tr && tr->trackpoints && tr->trackpoints->data && (VIK_TRACKPOINT(tr->trackpoints->data)->altitude != VIK_DEFAULT_ALTITUDE) ) {
726 GList *iter = tr->trackpoints->next;
730 tmp_alt = VIK_TRACKPOINT(iter->data)->altitude;
731 if ( tmp_alt > *max_alt )
733 if ( tmp_alt < *min_alt )
742 void vik_track_marshall ( VikTrack *tr, guint8 **data, guint *datalen)
745 GByteArray *b = g_byte_array_new();
749 g_byte_array_append(b, (guint8 *)tr, sizeof(*tr));
751 /* we'll fill out number of trackpoints later */
753 g_byte_array_append(b, (guint8 *)&len, sizeof(len));
755 tps = tr->trackpoints;
758 g_byte_array_append(b, (guint8 *)tps->data, sizeof(VikTrackpoint));
762 *(guint *)(b->data + intp) = ntp;
764 len = (tr->comment) ? strlen(tr->comment)+1 : 0;
765 g_byte_array_append(b, (guint8 *)&len, sizeof(len));
766 if (tr->comment) g_byte_array_append(b, (guint8 *)tr->comment, len);
770 g_byte_array_free(b, FALSE);
773 VikTrack *vik_track_unmarshall (guint8 *data, guint datalen)
776 VikTrack *new_tr = vik_track_new();
777 VikTrackpoint *new_tp;
781 /* only the visibility is needed */
782 new_tr->visible = ((VikTrack *)data)->visible;
783 data += sizeof(*new_tr);
785 ntp = *(guint *)data;
788 for (i=0; i<ntp; i++) {
789 new_tp = vik_trackpoint_new();
790 memcpy(new_tp, data, sizeof(*new_tp));
791 data += sizeof(*new_tp);
792 new_tr->trackpoints = g_list_append(new_tr->trackpoints, new_tp);
795 len = *(guint *)data;
798 new_tr->comment = g_strdup((gchar *)data);
803 void vik_track_apply_dem_data ( VikTrack *tr )
807 tp_iter = tr->trackpoints;
809 /* TODO: of the 4 possible choices we have for choosing an elevation
810 * (trackpoint in between samples), choose the one with the least elevation change
812 elev = a_dems_get_elev_by_coord ( &(VIK_TRACKPOINT(tp_iter->data)->coord) );
813 if ( elev != VIK_DEM_INVALID_ELEVATION )
814 VIK_TRACKPOINT(tp_iter->data)->altitude = elev;
815 tp_iter = tp_iter->next;
819 /* appends t2 to t1, leaving t2 with no trackpoints */
820 void vik_track_steal_and_append_trackpoints ( VikTrack *t1, VikTrack *t2 )
822 if ( t1->trackpoints ) {
823 GList *tpiter = t1->trackpoints;
824 while ( tpiter->next )
825 tpiter = tpiter->next;
826 tpiter->next = t2->trackpoints;
827 t2->trackpoints->prev = tpiter;
829 t1->trackpoints = t2->trackpoints;
830 t2->trackpoints = NULL;
833 /* starting at the end, looks backwards for the last "double point", a duplicate trackpoint.
834 * this is indicative of magic scissors continued use. If there is no double point,
835 * deletes all the trackpoints. Returns the new end of the track (or the start if
836 * there are no double points
838 VikCoord *vik_track_cut_back_to_double_point ( VikTrack *tr )
840 GList *iter = tr->trackpoints;
849 while ( iter->prev ) {
850 if ( vik_coord_equals((VikCoord *)iter->data, (VikCoord *)iter->prev->data) ) {
851 GList *prev = iter->prev;
853 rv = g_malloc(sizeof(VikCoord));
854 *rv = *((VikCoord *) iter->data);
856 /* truncate trackpoint list */
857 iter->prev = NULL; /* pretend it's the end */
858 g_list_foreach ( iter, (GFunc) g_free, NULL );
868 /* no double point found! */
869 rv = g_malloc(sizeof(VikCoord));
870 *rv = *((VikCoord *) tr->trackpoints->data);
871 g_list_foreach ( tr->trackpoints, (GFunc) g_free, NULL );
872 g_list_free( tr->trackpoints );
873 tr->trackpoints = NULL;