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
41 VikTrack *vik_track_new()
43 VikTrack *tr = g_malloc0 ( sizeof ( VikTrack ) );
48 void vik_track_set_comment_no_copy(VikTrack *tr, gchar *comment)
51 g_free ( tr->comment );
52 tr->comment = comment;
56 void vik_track_set_name(VikTrack *tr, const gchar *name)
61 if ( name && name[0] != '\0' )
62 tr->name = g_strdup(name);
67 void vik_track_set_comment(VikTrack *tr, const gchar *comment)
70 g_free ( tr->comment );
72 if ( comment && comment[0] != '\0' )
73 tr->comment = g_strdup(comment);
78 void vik_track_ref(VikTrack *tr)
83 void vik_track_set_property_dialog(VikTrack *tr, GtkWidget *dialog)
85 /* Warning: does not check for existing dialog */
86 tr->property_dialog = dialog;
89 void vik_track_clear_property_dialog(VikTrack *tr)
91 tr->property_dialog = NULL;
94 void vik_track_free(VikTrack *tr)
96 if ( tr->ref_count-- > 1 )
102 g_free ( tr->comment );
103 g_list_foreach ( tr->trackpoints, (GFunc) g_free, NULL );
104 g_list_free( tr->trackpoints );
105 if (tr->property_dialog)
106 if ( GTK_IS_WIDGET(tr->property_dialog) )
107 gtk_widget_destroy ( GTK_WIDGET(tr->property_dialog) );
111 VikTrack *vik_track_copy ( const VikTrack *tr )
113 VikTrack *new_tr = vik_track_new();
114 VikTrackpoint *new_tp;
115 GList *tp_iter = tr->trackpoints;
116 new_tr->visible = tr->visible;
117 new_tr->trackpoints = NULL;
120 new_tp = g_malloc ( sizeof ( VikTrackpoint ) );
121 *new_tp = *((VikTrackpoint *)(tp_iter->data));
122 new_tr->trackpoints = g_list_append ( new_tr->trackpoints, new_tp );
123 tp_iter = tp_iter->next;
125 vik_track_set_name(new_tr,tr->name);
126 vik_track_set_comment(new_tr,tr->comment);
130 VikTrackpoint *vik_trackpoint_new()
132 VikTrackpoint *tp = g_malloc0(sizeof(VikTrackpoint));
135 tp->altitude = VIK_DEFAULT_ALTITUDE;
136 tp->hdop = VIK_DEFAULT_DOP;
137 tp->vdop = VIK_DEFAULT_DOP;
138 tp->pdop = VIK_DEFAULT_DOP;
142 void vik_trackpoint_free(VikTrackpoint *tp)
147 VikTrackpoint *vik_trackpoint_copy(VikTrackpoint *tp)
149 VikTrackpoint *rv = vik_trackpoint_new();
154 gdouble vik_track_get_length(const VikTrack *tr)
157 if ( tr->trackpoints )
159 GList *iter = tr->trackpoints->next;
162 if ( ! VIK_TRACKPOINT(iter->data)->newsegment )
163 len += vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
164 &(VIK_TRACKPOINT(iter->prev->data)->coord) );
171 gdouble vik_track_get_length_including_gaps(const VikTrack *tr)
174 if ( tr->trackpoints )
176 GList *iter = tr->trackpoints->next;
179 len += vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
180 &(VIK_TRACKPOINT(iter->prev->data)->coord) );
187 gulong vik_track_get_tp_count(const VikTrack *tr)
190 GList *iter = tr->trackpoints;
199 gulong vik_track_get_dup_point_count ( const VikTrack *tr )
202 GList *iter = tr->trackpoints;
205 if ( iter->next && vik_coord_equals ( &(VIK_TRACKPOINT(iter->data)->coord),
206 &(VIK_TRACKPOINT(iter->next->data)->coord) ) )
214 * Deletes adjacent points that have the same position
215 * Returns the number of points that were deleted
217 gulong vik_track_remove_dup_points ( VikTrack *tr )
220 GList *iter = tr->trackpoints;
223 if ( iter->next && vik_coord_equals ( &(VIK_TRACKPOINT(iter->data)->coord),
224 &(VIK_TRACKPOINT(iter->next->data)->coord) ) )
227 // Maintain track segments
228 if ( VIK_TRACKPOINT(iter->next->data)->newsegment && (iter->next)->next )
229 VIK_TRACKPOINT(((iter->next)->next)->data)->newsegment = TRUE;
231 vik_trackpoint_free ( iter->next->data );
232 tr->trackpoints = g_list_delete_link ( tr->trackpoints, iter->next );
241 * Get a count of trackpoints with the same defined timestamp
242 * Note is using timestamps with a resolution with 1 second
244 gulong vik_track_get_same_time_point_count ( const VikTrack *tr )
247 GList *iter = tr->trackpoints;
250 ( VIK_TRACKPOINT(iter->data)->has_timestamp &&
251 VIK_TRACKPOINT(iter->next->data)->has_timestamp ) &&
252 ( VIK_TRACKPOINT(iter->data)->timestamp ==
253 VIK_TRACKPOINT(iter->next->data)->timestamp) )
261 * Deletes adjacent points that have the same defined timestamp
262 * Returns the number of points that were deleted
264 gulong vik_track_remove_same_time_points ( VikTrack *tr )
267 GList *iter = tr->trackpoints;
270 ( VIK_TRACKPOINT(iter->data)->has_timestamp &&
271 VIK_TRACKPOINT(iter->next->data)->has_timestamp ) &&
272 ( VIK_TRACKPOINT(iter->data)->timestamp ==
273 VIK_TRACKPOINT(iter->next->data)->timestamp) ) {
277 // Maintain track segments
278 if ( VIK_TRACKPOINT(iter->next->data)->newsegment && (iter->next)->next )
279 VIK_TRACKPOINT(((iter->next)->next)->data)->newsegment = TRUE;
281 vik_trackpoint_free ( iter->next->data );
282 tr->trackpoints = g_list_delete_link ( tr->trackpoints, iter->next );
290 guint vik_track_get_segment_count(const VikTrack *tr)
293 GList *iter = tr->trackpoints;
296 while ( (iter = iter->next) )
298 if ( VIK_TRACKPOINT(iter->data)->newsegment )
304 VikTrack **vik_track_split_into_segments(VikTrack *t, guint *ret_len)
309 guint segs = vik_track_get_segment_count(t);
318 rv = g_malloc ( segs * sizeof(VikTrack *) );
319 tr = vik_track_copy ( t );
321 iter = tr->trackpoints;
324 while ( (iter = iter->next) )
326 if ( VIK_TRACKPOINT(iter->data)->newsegment )
328 iter->prev->next = NULL;
330 rv[i] = vik_track_new();
331 // TODO: consider new naming strategy here
333 vik_track_set_name ( rv[i], tr->name );
335 vik_track_set_comment ( rv[i], tr->comment );
336 rv[i]->visible = tr->visible;
337 rv[i]->trackpoints = iter;
346 * Simply remove any subsequent segment markers in a track to form one continuous track
347 * Return the number of segments merged
349 guint vik_track_merge_segments(VikTrack *tr)
352 GList *iter = tr->trackpoints;
356 // Always skip the first point as this should be the first segment
359 while ( (iter = iter->next) )
361 if ( VIK_TRACKPOINT(iter->data)->newsegment ) {
362 VIK_TRACKPOINT(iter->data)->newsegment = FALSE;
369 void vik_track_reverse ( VikTrack *tr )
372 tr->trackpoints = g_list_reverse(tr->trackpoints);
374 /* fix 'newsegment' */
375 iter = g_list_last ( tr->trackpoints );
378 if ( ! iter->next ) /* last segment, was first, cancel newsegment. */
379 VIK_TRACKPOINT(iter->data)->newsegment = FALSE;
380 if ( ! iter->prev ) /* first segment by convention has newsegment flag. */
381 VIK_TRACKPOINT(iter->data)->newsegment = TRUE;
382 else if ( VIK_TRACKPOINT(iter->data)->newsegment && iter->next )
384 VIK_TRACKPOINT(iter->next->data)->newsegment = TRUE;
385 VIK_TRACKPOINT(iter->data)->newsegment = FALSE;
391 gdouble vik_track_get_average_speed(const VikTrack *tr)
395 if ( tr->trackpoints )
397 GList *iter = tr->trackpoints->next;
400 if ( VIK_TRACKPOINT(iter->data)->has_timestamp &&
401 VIK_TRACKPOINT(iter->prev->data)->has_timestamp &&
402 (! VIK_TRACKPOINT(iter->data)->newsegment) )
404 len += vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
405 &(VIK_TRACKPOINT(iter->prev->data)->coord) );
406 time += ABS(VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(iter->prev->data)->timestamp);
411 return (time == 0) ? 0 : ABS(len/time);
415 * Based on a simple average speed, but with a twist - to give a moving average.
416 * . GPSs often report a moving average in their statistics output
417 * . bicycle speedos often don't factor in time when stopped - hence reporting a moving average for speed
419 * Often GPS track will record every second but not when stationary
420 * This method doesn't use samples that differ over the specified time limit - effectively skipping that time chunk from the total time
422 * Suggest to use 60 seconds as the stop length (as the default used in the TrackWaypoint draw stops factor)
424 gdouble vik_track_get_average_speed_moving (const VikTrack *tr, int stop_length_seconds)
428 if ( tr->trackpoints )
430 GList *iter = tr->trackpoints->next;
433 if ( VIK_TRACKPOINT(iter->data)->has_timestamp &&
434 VIK_TRACKPOINT(iter->prev->data)->has_timestamp &&
435 (! VIK_TRACKPOINT(iter->data)->newsegment) )
437 if ( ( VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(iter->prev->data)->timestamp ) < stop_length_seconds ) {
438 len += vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
439 &(VIK_TRACKPOINT(iter->prev->data)->coord) );
441 time += ABS(VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(iter->prev->data)->timestamp);
447 return (time == 0) ? 0 : ABS(len/time);
450 gdouble vik_track_get_max_speed(const VikTrack *tr)
452 gdouble maxspeed = 0.0, speed = 0.0;
453 if ( tr->trackpoints )
455 GList *iter = tr->trackpoints->next;
458 if ( VIK_TRACKPOINT(iter->data)->has_timestamp &&
459 VIK_TRACKPOINT(iter->prev->data)->has_timestamp &&
460 (! VIK_TRACKPOINT(iter->data)->newsegment) )
462 speed = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord), &(VIK_TRACKPOINT(iter->prev->data)->coord) )
463 / ABS(VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(iter->prev->data)->timestamp);
464 if ( speed > maxspeed )
473 void vik_track_convert ( VikTrack *tr, VikCoordMode dest_mode )
475 GList *iter = tr->trackpoints;
478 vik_coord_convert ( &(VIK_TRACKPOINT(iter->data)->coord), dest_mode );
483 /* I understood this when I wrote it ... maybe ... Basically it eats up the
484 * proper amounts of length on the track and averages elevation over that. */
485 gdouble *vik_track_make_elevation_map ( const VikTrack *tr, guint16 num_chunks )
488 gdouble total_length, chunk_length, current_dist, current_area_under_curve, current_seg_length, dist_along_seg = 0.0;
489 gdouble altitude1, altitude2;
490 guint16 current_chunk;
491 gboolean ignore_it = FALSE;
493 GList *iter = tr->trackpoints;
495 if (!iter || !iter->next) /* zero- or one-point track */
498 { /* test if there's anything worth calculating */
499 gboolean okay = FALSE;
502 if ( VIK_TRACKPOINT(iter->data)->altitude != VIK_DEFAULT_ALTITUDE ) {
511 iter = tr->trackpoints;
513 g_assert ( num_chunks < 16000 );
515 pts = g_malloc ( sizeof(gdouble) * num_chunks );
517 total_length = vik_track_get_length_including_gaps ( tr );
518 chunk_length = total_length / num_chunks;
520 /* Zero chunk_length (eg, track of 2 tp with the same loc) will cause crash */
521 if (chunk_length <= 0) {
527 current_area_under_curve = 0;
529 current_seg_length = 0;
531 current_seg_length = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
532 &(VIK_TRACKPOINT(iter->next->data)->coord) );
533 altitude1 = VIK_TRACKPOINT(iter->data)->altitude;
534 altitude2 = VIK_TRACKPOINT(iter->next->data)->altitude;
537 while ( current_chunk < num_chunks ) {
539 /* go along current seg */
540 if ( current_seg_length && (current_seg_length - dist_along_seg) > chunk_length ) {
541 dist_along_seg += chunk_length;
545 * /x altitude = alt_at_pt_1 + alt_at_pt_2 / 2 = altitude1 + slope * dist_value_of_pt_inbetween_pt1_and_pt2
546 * /xx avg altitude = area under curve / chunk len
547 *pt1 *xxx avg altitude = altitude1 + (altitude2-altitude1)/(current_seg_length)*(dist_along_seg + (chunk_len/2))
553 // Seemly can't determine average for this section - so use last known good value (much better than just sticking in zero)
554 pts[current_chunk] = altitude1;
556 pts[current_chunk] = altitude1 + (altitude2-altitude1)*((dist_along_seg - (chunk_length/2))/current_seg_length);
560 /* finish current seg */
561 if ( current_seg_length ) {
562 gdouble altitude_at_dist_along_seg = altitude1 + (altitude2-altitude1)/(current_seg_length)*dist_along_seg;
563 current_dist = current_seg_length - dist_along_seg;
564 current_area_under_curve = current_dist*(altitude_at_dist_along_seg + altitude2)*0.5;
565 } else { current_dist = current_area_under_curve = 0; } /* should only happen if first current_seg_length == 0 */
567 /* get intervening segs */
569 while ( iter && iter->next ) {
570 current_seg_length = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
571 &(VIK_TRACKPOINT(iter->next->data)->coord) );
572 altitude1 = VIK_TRACKPOINT(iter->data)->altitude;
573 altitude2 = VIK_TRACKPOINT(iter->next->data)->altitude;
574 ignore_it = VIK_TRACKPOINT(iter->next->data)->newsegment;
576 if ( chunk_length - current_dist >= current_seg_length ) {
577 current_dist += current_seg_length;
578 current_area_under_curve += current_seg_length * (altitude1+altitude2) * 0.5;
586 dist_along_seg = chunk_length - current_dist;
587 if ( ignore_it || ( iter && !iter->next ) ) {
588 pts[current_chunk] = current_area_under_curve / current_dist;
591 for (i = current_chunk + 1; i < num_chunks; i++)
592 pts[i] = pts[current_chunk];
597 current_area_under_curve += dist_along_seg * (altitude1 + (altitude2 - altitude1)*dist_along_seg/current_seg_length);
598 pts[current_chunk] = current_area_under_curve / chunk_length;
610 void vik_track_get_total_elevation_gain(const VikTrack *tr, gdouble *up, gdouble *down)
614 if ( tr->trackpoints && VIK_TRACKPOINT(tr->trackpoints->data)->altitude != VIK_DEFAULT_ALTITUDE )
616 GList *iter = tr->trackpoints->next;
619 diff = VIK_TRACKPOINT(iter->data)->altitude - VIK_TRACKPOINT(iter->prev->data)->altitude;
627 *up = *down = VIK_DEFAULT_ALTITUDE;
630 gdouble *vik_track_make_gradient_map ( const VikTrack *tr, guint16 num_chunks )
634 gdouble total_length, chunk_length, current_gradient;
635 gdouble altitude1, altitude2;
636 guint16 current_chunk;
638 g_assert ( num_chunks < 16000 );
640 total_length = vik_track_get_length_including_gaps ( tr );
641 chunk_length = total_length / num_chunks;
643 /* Zero chunk_length (eg, track of 2 tp with the same loc) will cause crash */
644 if (chunk_length <= 0) {
648 altitudes = vik_track_make_elevation_map (tr, num_chunks);
649 if (altitudes == NULL) {
653 current_gradient = 0.0;
654 pts = g_malloc ( sizeof(gdouble) * num_chunks );
655 for (current_chunk = 0; current_chunk < (num_chunks - 1); current_chunk++) {
656 altitude1 = altitudes[current_chunk];
657 altitude2 = altitudes[current_chunk + 1];
658 current_gradient = 100.0 * (altitude2 - altitude1) / chunk_length;
660 pts[current_chunk] = current_gradient;
663 pts[current_chunk] = current_gradient;
668 /* by Alex Foobarian */
669 gdouble *vik_track_make_speed_map ( const VikTrack *tr, guint16 num_chunks )
672 gdouble duration, chunk_dur;
674 int i, pt_count, numpts, index;
677 if ( ! tr->trackpoints )
680 g_assert ( num_chunks < 16000 );
682 t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
683 t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
686 if ( !t1 || !t2 || !duration )
690 g_warning("negative duration: unsorted trackpoint timestamps?");
693 pt_count = vik_track_get_tp_count(tr);
695 v = g_malloc ( sizeof(gdouble) * num_chunks );
696 chunk_dur = duration / num_chunks;
698 s = g_malloc(sizeof(double) * pt_count);
699 t = g_malloc(sizeof(double) * pt_count);
701 iter = tr->trackpoints->next;
704 t[0] = VIK_TRACKPOINT(iter->prev->data)->timestamp;
707 s[numpts] = s[numpts-1] + vik_coord_diff ( &(VIK_TRACKPOINT(iter->prev->data)->coord), &(VIK_TRACKPOINT(iter->data)->coord) );
708 t[numpts] = VIK_TRACKPOINT(iter->data)->timestamp;
713 /* In the following computation, we iterate through periods of time of duration chunk_dur.
714 * The first period begins at the beginning of the track. The last period ends at the end of the track.
716 index = 0; /* index of the current trackpoint. */
717 for (i = 0; i < num_chunks; i++) {
718 /* we are now covering the interval from t[0] + i*chunk_dur to t[0] + (i+1)*chunk_dur.
719 * find the first trackpoint outside the current interval, averaging the speeds between intermediate trackpoints.
721 if (t[0] + i*chunk_dur >= t[index]) {
722 gdouble acc_t = 0, acc_s = 0;
723 while (t[0] + i*chunk_dur >= t[index]) {
724 acc_s += (s[index+1]-s[index]);
725 acc_t += (t[index+1]-t[index]);
743 * Make a distance/time map, heavily based on the vik_track_make_speed_map method
745 gdouble *vik_track_make_distance_map ( const VikTrack *tr, guint16 num_chunks )
748 gdouble duration, chunk_dur;
750 int i, pt_count, numpts, index;
753 if ( ! tr->trackpoints )
756 t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
757 t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
760 if ( !t1 || !t2 || !duration )
764 g_warning("negative duration: unsorted trackpoint timestamps?");
767 pt_count = vik_track_get_tp_count(tr);
769 v = g_malloc ( sizeof(gdouble) * num_chunks );
770 chunk_dur = duration / num_chunks;
772 s = g_malloc(sizeof(double) * pt_count);
773 t = g_malloc(sizeof(double) * pt_count);
775 iter = tr->trackpoints->next;
778 t[0] = VIK_TRACKPOINT(iter->prev->data)->timestamp;
781 s[numpts] = s[numpts-1] + vik_coord_diff ( &(VIK_TRACKPOINT(iter->prev->data)->coord), &(VIK_TRACKPOINT(iter->data)->coord) );
782 t[numpts] = VIK_TRACKPOINT(iter->data)->timestamp;
787 /* In the following computation, we iterate through periods of time of duration chunk_dur.
788 * The first period begins at the beginning of the track. The last period ends at the end of the track.
790 index = 0; /* index of the current trackpoint. */
791 for (i = 0; i < num_chunks; i++) {
792 /* we are now covering the interval from t[0] + i*chunk_dur to t[0] + (i+1)*chunk_dur.
793 * find the first trackpoint outside the current interval, averaging the distance between intermediate trackpoints.
795 if (t[0] + i*chunk_dur >= t[index]) {
796 gdouble acc_s = 0; // No need for acc_t
797 while (t[0] + i*chunk_dur >= t[index]) {
798 acc_s += (s[index+1]-s[index]);
801 // The only bit that's really different from the speed map - just keep an accululative record distance
802 v[i] = i ? v[i-1]+acc_s : acc_s;
817 * This uses the 'time' based method to make the graph, (which is a simpler compared to the elevation/distance)
818 * This results in a slightly blocky graph when it does not have many trackpoints: <60
819 * NB Somehow the elevation/distance applies some kind of smoothing algorithm,
820 * but I don't think any one understands it any more (I certainly don't ATM)
822 gdouble *vik_track_make_elevation_time_map ( const VikTrack *tr, guint16 num_chunks )
825 gdouble duration, chunk_dur;
826 GList *iter = tr->trackpoints;
828 if (!iter || !iter->next) /* zero- or one-point track */
831 /* test if there's anything worth calculating */
832 gboolean okay = FALSE;
834 if ( VIK_TRACKPOINT(iter->data)->altitude != VIK_DEFAULT_ALTITUDE ) {
843 t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
844 t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
847 if ( !t1 || !t2 || !duration )
851 g_warning("negative duration: unsorted trackpoint timestamps?");
854 gint pt_count = vik_track_get_tp_count(tr);
856 // Reset iterator back to the beginning
857 iter = tr->trackpoints;
859 gdouble *pts = g_malloc ( sizeof(gdouble) * num_chunks ); // The return altitude values
860 gdouble *s = g_malloc(sizeof(double) * pt_count); // calculation altitudes
861 gdouble *t = g_malloc(sizeof(double) * pt_count); // calculation times
863 chunk_dur = duration / num_chunks;
865 s[0] = VIK_TRACKPOINT(iter->data)->altitude;
866 t[0] = VIK_TRACKPOINT(iter->data)->timestamp;
867 iter = tr->trackpoints->next;
870 s[numpts] = VIK_TRACKPOINT(iter->data)->altitude;
871 t[numpts] = VIK_TRACKPOINT(iter->data)->timestamp;
876 /* In the following computation, we iterate through periods of time of duration chunk_dur.
877 * The first period begins at the beginning of the track. The last period ends at the end of the track.
879 gint index = 0; /* index of the current trackpoint. */
881 for (i = 0; i < num_chunks; i++) {
882 /* we are now covering the interval from t[0] + i*chunk_dur to t[0] + (i+1)*chunk_dur.
883 * find the first trackpoint outside the current interval, averaging the heights between intermediate trackpoints.
885 if (t[0] + i*chunk_dur >= t[index]) {
886 gdouble acc_s = s[index]; // initialise to first point
887 while (t[0] + i*chunk_dur >= t[index]) {
888 acc_s += (s[index+1]-s[index]);
907 * Make a speed/distance map
909 gdouble *vik_track_make_speed_dist_map ( const VikTrack *tr, guint16 num_chunks )
913 gint i, pt_count, numpts, index;
915 gdouble duration, total_length, chunk_length;
917 if ( ! tr->trackpoints )
920 t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
921 t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
924 if ( !t1 || !t2 || !duration )
928 g_warning("negative duration: unsorted trackpoint timestamps?");
932 total_length = vik_track_get_length_including_gaps ( tr );
933 chunk_length = total_length / num_chunks;
934 pt_count = vik_track_get_tp_count(tr);
936 if (chunk_length <= 0) {
940 v = g_malloc ( sizeof(gdouble) * num_chunks );
941 s = g_malloc ( sizeof(double) * pt_count );
942 t = g_malloc ( sizeof(double) * pt_count );
944 // No special handling of segments ATM...
945 iter = tr->trackpoints->next;
948 t[0] = VIK_TRACKPOINT(iter->prev->data)->timestamp;
951 s[numpts] = s[numpts-1] + vik_coord_diff ( &(VIK_TRACKPOINT(iter->prev->data)->coord), &(VIK_TRACKPOINT(iter->data)->coord) );
952 t[numpts] = VIK_TRACKPOINT(iter->data)->timestamp;
957 // Iterate through a portion of the track to get an average speed for that part
958 // This will essentially interpolate between segments, which I think is right given the usage of 'get_length_including_gaps'
959 index = 0; /* index of the current trackpoint. */
960 for (i = 0; i < num_chunks; i++) {
961 // Similar to the make_speed_map, but instead of using a time chunk, use a distance chunk
962 if (s[0] + i*chunk_length >= s[index]) {
963 gdouble acc_t = 0, acc_s = 0;
964 while (s[0] + i*chunk_length >= s[index]) {
965 acc_s += (s[index+1]-s[index]);
966 acc_t += (t[index+1]-t[index]);
983 /* by Alex Foobarian */
984 VikTrackpoint *vik_track_get_closest_tp_by_percentage_dist ( VikTrack *tr, gdouble reldist, gdouble *meters_from_start )
986 gdouble dist = vik_track_get_length_including_gaps(tr) * reldist;
987 gdouble current_dist = 0.0;
988 gdouble current_inc = 0.0;
989 if ( tr->trackpoints )
991 GList *iter = tr->trackpoints->next;
992 GList *last_iter = NULL;
993 gdouble last_dist = 0.0;
996 current_inc = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
997 &(VIK_TRACKPOINT(iter->prev->data)->coord) );
998 last_dist = current_dist;
999 current_dist += current_inc;
1000 if ( current_dist >= dist )
1005 if (!iter) { /* passing the end the track */
1007 if (meters_from_start)
1008 *meters_from_start = last_dist;
1009 return(VIK_TRACKPOINT(last_iter->data));
1014 /* we've gone past the dist already, was prev trackpoint closer? */
1015 /* should do a vik_coord_average_weighted() thingy. */
1016 if ( iter->prev && abs(current_dist-current_inc-dist) < abs(current_dist-dist) ) {
1017 if (meters_from_start)
1018 *meters_from_start = last_dist;
1022 if (meters_from_start)
1023 *meters_from_start = current_dist;
1025 return VIK_TRACKPOINT(iter->data);
1031 VikTrackpoint *vik_track_get_closest_tp_by_percentage_time ( VikTrack *tr, gdouble reltime, time_t *seconds_from_start )
1033 time_t t_pos, t_start, t_end, t_total;
1034 t_start = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
1035 t_end = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
1036 t_total = t_end - t_start;
1038 t_pos = t_start + t_total * reltime;
1040 if ( !tr->trackpoints )
1043 GList *iter = tr->trackpoints;
1046 if (VIK_TRACKPOINT(iter->data)->timestamp == t_pos)
1048 if (VIK_TRACKPOINT(iter->data)->timestamp > t_pos) {
1049 if (iter->prev == NULL) /* first trackpoint */
1051 time_t t_before = t_pos - VIK_TRACKPOINT(iter->prev)->timestamp;
1052 time_t t_after = VIK_TRACKPOINT(iter->data)->timestamp - t_pos;
1053 if (t_before <= t_after)
1057 else if ((iter->next == NULL) && (t_pos < (VIK_TRACKPOINT(iter->data)->timestamp + 3))) /* last trackpoint: accommodate for round-off */
1064 if (seconds_from_start)
1065 *seconds_from_start = VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
1066 return VIK_TRACKPOINT(iter->data);
1069 VikTrackpoint* vik_track_get_tp_by_max_speed ( const VikTrack *tr )
1071 gdouble maxspeed = 0.0, speed = 0.0;
1073 if ( !tr->trackpoints )
1076 GList *iter = tr->trackpoints;
1077 VikTrackpoint *max_speed_tp = NULL;
1081 if ( VIK_TRACKPOINT(iter->data)->has_timestamp &&
1082 VIK_TRACKPOINT(iter->prev->data)->has_timestamp &&
1083 (! VIK_TRACKPOINT(iter->data)->newsegment) ) {
1084 speed = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord), &(VIK_TRACKPOINT(iter->prev->data)->coord) )
1085 / ABS(VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(iter->prev->data)->timestamp);
1086 if ( speed > maxspeed ) {
1088 max_speed_tp = VIK_TRACKPOINT(iter->data);
1098 return max_speed_tp;
1101 VikTrackpoint* vik_track_get_tp_by_max_alt ( const VikTrack *tr )
1103 gdouble maxalt = -5000.0;
1104 if ( !tr->trackpoints )
1107 GList *iter = tr->trackpoints;
1108 VikTrackpoint *max_alt_tp = NULL;
1111 if ( VIK_TRACKPOINT(iter->data)->altitude > maxalt ) {
1112 maxalt = VIK_TRACKPOINT(iter->data)->altitude;
1113 max_alt_tp = VIK_TRACKPOINT(iter->data);
1124 VikTrackpoint* vik_track_get_tp_by_min_alt ( const VikTrack *tr )
1126 gdouble minalt = 25000.0;
1127 if ( !tr->trackpoints )
1130 GList *iter = tr->trackpoints;
1131 VikTrackpoint *min_alt_tp = NULL;
1134 if ( VIK_TRACKPOINT(iter->data)->altitude < minalt ) {
1135 minalt = VIK_TRACKPOINT(iter->data)->altitude;
1136 min_alt_tp = VIK_TRACKPOINT(iter->data);
1147 gboolean vik_track_get_minmax_alt ( const VikTrack *tr, gdouble *min_alt, gdouble *max_alt )
1151 if ( tr && tr->trackpoints && tr->trackpoints->data && (VIK_TRACKPOINT(tr->trackpoints->data)->altitude != VIK_DEFAULT_ALTITUDE) ) {
1152 GList *iter = tr->trackpoints->next;
1156 tmp_alt = VIK_TRACKPOINT(iter->data)->altitude;
1157 if ( tmp_alt > *max_alt )
1159 if ( tmp_alt < *min_alt )
1168 void vik_track_marshall ( VikTrack *tr, guint8 **data, guint *datalen)
1171 GByteArray *b = g_byte_array_new();
1175 g_byte_array_append(b, (guint8 *)tr, sizeof(*tr));
1177 /* we'll fill out number of trackpoints later */
1179 g_byte_array_append(b, (guint8 *)&len, sizeof(len));
1181 tps = tr->trackpoints;
1184 g_byte_array_append(b, (guint8 *)tps->data, sizeof(VikTrackpoint));
1188 *(guint *)(b->data + intp) = ntp;
1190 len = (tr->name) ? strlen(tr->name)+1 : 0;
1191 g_byte_array_append(b, (guint8 *)&len, sizeof(len));
1192 if (tr->name) g_byte_array_append(b, (guint8 *)tr->name, len);
1194 len = (tr->comment) ? strlen(tr->comment)+1 : 0;
1195 g_byte_array_append(b, (guint8 *)&len, sizeof(len));
1196 if (tr->comment) g_byte_array_append(b, (guint8 *)tr->comment, len);
1200 g_byte_array_free(b, FALSE);
1203 VikTrack *vik_track_unmarshall (guint8 *data, guint datalen)
1206 VikTrack *new_tr = vik_track_new();
1207 VikTrackpoint *new_tp;
1211 /* only the visibility is needed */
1212 new_tr->visible = ((VikTrack *)data)->visible;
1213 data += sizeof(*new_tr);
1215 ntp = *(guint *)data;
1216 data += sizeof(ntp);
1218 for (i=0; i<ntp; i++) {
1219 new_tp = vik_trackpoint_new();
1220 memcpy(new_tp, data, sizeof(*new_tp));
1221 data += sizeof(*new_tp);
1222 new_tr->trackpoints = g_list_append(new_tr->trackpoints, new_tp);
1225 len = *(guint *)data;
1226 data += sizeof(len);
1228 new_tr->name = g_strdup((gchar *)data);
1232 len = *(guint *)data;
1233 data += sizeof(len);
1235 new_tr->comment = g_strdup((gchar *)data);
1240 void vik_track_apply_dem_data ( VikTrack *tr )
1244 tp_iter = tr->trackpoints;
1246 /* TODO: of the 4 possible choices we have for choosing an elevation
1247 * (trackpoint in between samples), choose the one with the least elevation change
1249 elev = a_dems_get_elev_by_coord ( &(VIK_TRACKPOINT(tp_iter->data)->coord), VIK_DEM_INTERPOL_BEST );
1250 if ( elev != VIK_DEM_INVALID_ELEVATION )
1251 VIK_TRACKPOINT(tp_iter->data)->altitude = elev;
1252 tp_iter = tp_iter->next;
1257 * Apply DEM data (if available) - to only the last trackpoint
1259 void vik_track_apply_dem_data_last_trackpoint ( VikTrack *tr )
1262 if ( tr->trackpoints ) {
1263 /* As in vik_track_apply_dem_data above - use 'best' interpolation method */
1264 elev = a_dems_get_elev_by_coord ( &(VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->coord), VIK_DEM_INTERPOL_BEST );
1265 if ( elev != VIK_DEM_INVALID_ELEVATION )
1266 VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->altitude = elev;
1270 /* appends t2 to t1, leaving t2 with no trackpoints */
1271 void vik_track_steal_and_append_trackpoints ( VikTrack *t1, VikTrack *t2 )
1273 if ( t1->trackpoints ) {
1274 GList *tpiter = t1->trackpoints;
1275 while ( tpiter->next )
1276 tpiter = tpiter->next;
1277 tpiter->next = t2->trackpoints;
1278 t2->trackpoints->prev = tpiter;
1280 t1->trackpoints = t2->trackpoints;
1281 t2->trackpoints = NULL;
1284 /* starting at the end, looks backwards for the last "double point", a duplicate trackpoint.
1285 * If there is no double point, deletes all the trackpoints.
1286 * Returns the new end of the track (or the start if there are no double points)
1288 VikCoord *vik_track_cut_back_to_double_point ( VikTrack *tr )
1290 GList *iter = tr->trackpoints;
1295 while ( iter->next )
1299 while ( iter->prev ) {
1300 if ( vik_coord_equals((VikCoord *)iter->data, (VikCoord *)iter->prev->data) ) {
1301 GList *prev = iter->prev;
1303 rv = g_malloc(sizeof(VikCoord));
1304 *rv = *((VikCoord *) iter->data);
1306 /* truncate trackpoint list */
1307 iter->prev = NULL; /* pretend it's the end */
1308 g_list_foreach ( iter, (GFunc) g_free, NULL );
1309 g_list_free( iter );
1318 /* no double point found! */
1319 rv = g_malloc(sizeof(VikCoord));
1320 *rv = *((VikCoord *) tr->trackpoints->data);
1321 g_list_foreach ( tr->trackpoints, (GFunc) g_free, NULL );
1322 g_list_free( tr->trackpoints );
1323 tr->trackpoints = NULL;