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 // Sometimes a GPS device (or indeed any random file) can have stupid numbers for elevations
503 // Since when is 9.9999e+24 a valid elevation!!
504 // This can happen when a track (with no elevations) is uploaded to a GPS device and then redownloaded (e.g. using a Garmin Legend EtrexHCx)
505 // Some protection against trying to work with crazily massive numbers (otherwise get SIGFPE, Arithmetic exception)
506 if ( VIK_TRACKPOINT(iter->data)->altitude != VIK_DEFAULT_ALTITUDE &&
507 VIK_TRACKPOINT(iter->data)->altitude < 1E9 ) {
516 iter = tr->trackpoints;
518 g_assert ( num_chunks < 16000 );
520 pts = g_malloc ( sizeof(gdouble) * num_chunks );
522 total_length = vik_track_get_length_including_gaps ( tr );
523 chunk_length = total_length / num_chunks;
525 /* Zero chunk_length (eg, track of 2 tp with the same loc) will cause crash */
526 if (chunk_length <= 0) {
532 current_area_under_curve = 0;
534 current_seg_length = 0;
536 current_seg_length = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
537 &(VIK_TRACKPOINT(iter->next->data)->coord) );
538 altitude1 = VIK_TRACKPOINT(iter->data)->altitude;
539 altitude2 = VIK_TRACKPOINT(iter->next->data)->altitude;
542 while ( current_chunk < num_chunks ) {
544 /* go along current seg */
545 if ( current_seg_length && (current_seg_length - dist_along_seg) > chunk_length ) {
546 dist_along_seg += chunk_length;
550 * /x altitude = alt_at_pt_1 + alt_at_pt_2 / 2 = altitude1 + slope * dist_value_of_pt_inbetween_pt1_and_pt2
551 * /xx avg altitude = area under curve / chunk len
552 *pt1 *xxx avg altitude = altitude1 + (altitude2-altitude1)/(current_seg_length)*(dist_along_seg + (chunk_len/2))
558 // Seemly can't determine average for this section - so use last known good value (much better than just sticking in zero)
559 pts[current_chunk] = altitude1;
561 pts[current_chunk] = altitude1 + (altitude2-altitude1)*((dist_along_seg - (chunk_length/2))/current_seg_length);
565 /* finish current seg */
566 if ( current_seg_length ) {
567 gdouble altitude_at_dist_along_seg = altitude1 + (altitude2-altitude1)/(current_seg_length)*dist_along_seg;
568 current_dist = current_seg_length - dist_along_seg;
569 current_area_under_curve = current_dist*(altitude_at_dist_along_seg + altitude2)*0.5;
570 } else { current_dist = current_area_under_curve = 0; } /* should only happen if first current_seg_length == 0 */
572 /* get intervening segs */
574 while ( iter && iter->next ) {
575 current_seg_length = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
576 &(VIK_TRACKPOINT(iter->next->data)->coord) );
577 altitude1 = VIK_TRACKPOINT(iter->data)->altitude;
578 altitude2 = VIK_TRACKPOINT(iter->next->data)->altitude;
579 ignore_it = VIK_TRACKPOINT(iter->next->data)->newsegment;
581 if ( chunk_length - current_dist >= current_seg_length ) {
582 current_dist += current_seg_length;
583 current_area_under_curve += current_seg_length * (altitude1+altitude2) * 0.5;
591 dist_along_seg = chunk_length - current_dist;
592 if ( ignore_it || ( iter && !iter->next ) ) {
593 pts[current_chunk] = current_area_under_curve / current_dist;
596 for (i = current_chunk + 1; i < num_chunks; i++)
597 pts[i] = pts[current_chunk];
602 current_area_under_curve += dist_along_seg * (altitude1 + (altitude2 - altitude1)*dist_along_seg/current_seg_length);
603 pts[current_chunk] = current_area_under_curve / chunk_length;
615 void vik_track_get_total_elevation_gain(const VikTrack *tr, gdouble *up, gdouble *down)
619 if ( tr->trackpoints && VIK_TRACKPOINT(tr->trackpoints->data)->altitude != VIK_DEFAULT_ALTITUDE )
621 GList *iter = tr->trackpoints->next;
624 diff = VIK_TRACKPOINT(iter->data)->altitude - VIK_TRACKPOINT(iter->prev->data)->altitude;
632 *up = *down = VIK_DEFAULT_ALTITUDE;
635 gdouble *vik_track_make_gradient_map ( const VikTrack *tr, guint16 num_chunks )
639 gdouble total_length, chunk_length, current_gradient;
640 gdouble altitude1, altitude2;
641 guint16 current_chunk;
643 g_assert ( num_chunks < 16000 );
645 total_length = vik_track_get_length_including_gaps ( tr );
646 chunk_length = total_length / num_chunks;
648 /* Zero chunk_length (eg, track of 2 tp with the same loc) will cause crash */
649 if (chunk_length <= 0) {
653 altitudes = vik_track_make_elevation_map (tr, num_chunks);
654 if (altitudes == NULL) {
658 current_gradient = 0.0;
659 pts = g_malloc ( sizeof(gdouble) * num_chunks );
660 for (current_chunk = 0; current_chunk < (num_chunks - 1); current_chunk++) {
661 altitude1 = altitudes[current_chunk];
662 altitude2 = altitudes[current_chunk + 1];
663 current_gradient = 100.0 * (altitude2 - altitude1) / chunk_length;
665 pts[current_chunk] = current_gradient;
668 pts[current_chunk] = current_gradient;
673 /* by Alex Foobarian */
674 gdouble *vik_track_make_speed_map ( const VikTrack *tr, guint16 num_chunks )
677 gdouble duration, chunk_dur;
679 int i, pt_count, numpts, index;
682 if ( ! tr->trackpoints )
685 g_assert ( num_chunks < 16000 );
687 t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
688 t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
691 if ( !t1 || !t2 || !duration )
695 g_warning("negative duration: unsorted trackpoint timestamps?");
698 pt_count = vik_track_get_tp_count(tr);
700 v = g_malloc ( sizeof(gdouble) * num_chunks );
701 chunk_dur = duration / num_chunks;
703 s = g_malloc(sizeof(double) * pt_count);
704 t = g_malloc(sizeof(double) * pt_count);
706 iter = tr->trackpoints->next;
709 t[0] = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
712 s[numpts] = s[numpts-1] + vik_coord_diff ( &(VIK_TRACKPOINT(iter->prev->data)->coord), &(VIK_TRACKPOINT(iter->data)->coord) );
713 t[numpts] = VIK_TRACKPOINT(iter->data)->timestamp;
718 /* In the following computation, we iterate through periods of time of duration chunk_dur.
719 * The first period begins at the beginning of the track. The last period ends at the end of the track.
721 index = 0; /* index of the current trackpoint. */
722 for (i = 0; i < num_chunks; i++) {
723 /* we are now covering the interval from t[0] + i*chunk_dur to t[0] + (i+1)*chunk_dur.
724 * find the first trackpoint outside the current interval, averaging the speeds between intermediate trackpoints.
726 if (t[0] + i*chunk_dur >= t[index]) {
727 gdouble acc_t = 0, acc_s = 0;
728 while (t[0] + i*chunk_dur >= t[index]) {
729 acc_s += (s[index+1]-s[index]);
730 acc_t += (t[index+1]-t[index]);
748 * Make a distance/time map, heavily based on the vik_track_make_speed_map method
750 gdouble *vik_track_make_distance_map ( const VikTrack *tr, guint16 num_chunks )
753 gdouble duration, chunk_dur;
755 int i, pt_count, numpts, index;
758 if ( ! tr->trackpoints )
761 t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
762 t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
765 if ( !t1 || !t2 || !duration )
769 g_warning("negative duration: unsorted trackpoint timestamps?");
772 pt_count = vik_track_get_tp_count(tr);
774 v = g_malloc ( sizeof(gdouble) * num_chunks );
775 chunk_dur = duration / num_chunks;
777 s = g_malloc(sizeof(double) * pt_count);
778 t = g_malloc(sizeof(double) * pt_count);
780 iter = tr->trackpoints->next;
783 t[0] = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
786 s[numpts] = s[numpts-1] + vik_coord_diff ( &(VIK_TRACKPOINT(iter->prev->data)->coord), &(VIK_TRACKPOINT(iter->data)->coord) );
787 t[numpts] = VIK_TRACKPOINT(iter->data)->timestamp;
792 /* In the following computation, we iterate through periods of time of duration chunk_dur.
793 * The first period begins at the beginning of the track. The last period ends at the end of the track.
795 index = 0; /* index of the current trackpoint. */
796 for (i = 0; i < num_chunks; i++) {
797 /* we are now covering the interval from t[0] + i*chunk_dur to t[0] + (i+1)*chunk_dur.
798 * find the first trackpoint outside the current interval, averaging the distance between intermediate trackpoints.
800 if (t[0] + i*chunk_dur >= t[index]) {
801 gdouble acc_s = 0; // No need for acc_t
802 while (t[0] + i*chunk_dur >= t[index]) {
803 acc_s += (s[index+1]-s[index]);
806 // The only bit that's really different from the speed map - just keep an accululative record distance
807 v[i] = i ? v[i-1]+acc_s : acc_s;
822 * This uses the 'time' based method to make the graph, (which is a simpler compared to the elevation/distance)
823 * This results in a slightly blocky graph when it does not have many trackpoints: <60
824 * NB Somehow the elevation/distance applies some kind of smoothing algorithm,
825 * but I don't think any one understands it any more (I certainly don't ATM)
827 gdouble *vik_track_make_elevation_time_map ( const VikTrack *tr, guint16 num_chunks )
830 gdouble duration, chunk_dur;
831 GList *iter = tr->trackpoints;
833 if (!iter || !iter->next) /* zero- or one-point track */
836 /* test if there's anything worth calculating */
837 gboolean okay = FALSE;
839 if ( VIK_TRACKPOINT(iter->data)->altitude != VIK_DEFAULT_ALTITUDE ) {
848 t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
849 t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
852 if ( !t1 || !t2 || !duration )
856 g_warning("negative duration: unsorted trackpoint timestamps?");
859 gint pt_count = vik_track_get_tp_count(tr);
861 // Reset iterator back to the beginning
862 iter = tr->trackpoints;
864 gdouble *pts = g_malloc ( sizeof(gdouble) * num_chunks ); // The return altitude values
865 gdouble *s = g_malloc(sizeof(double) * pt_count); // calculation altitudes
866 gdouble *t = g_malloc(sizeof(double) * pt_count); // calculation times
868 chunk_dur = duration / num_chunks;
870 s[0] = VIK_TRACKPOINT(iter->data)->altitude;
871 t[0] = VIK_TRACKPOINT(iter->data)->timestamp;
872 iter = tr->trackpoints->next;
875 s[numpts] = VIK_TRACKPOINT(iter->data)->altitude;
876 t[numpts] = VIK_TRACKPOINT(iter->data)->timestamp;
881 /* In the following computation, we iterate through periods of time of duration chunk_dur.
882 * The first period begins at the beginning of the track. The last period ends at the end of the track.
884 gint index = 0; /* index of the current trackpoint. */
886 for (i = 0; i < num_chunks; i++) {
887 /* we are now covering the interval from t[0] + i*chunk_dur to t[0] + (i+1)*chunk_dur.
888 * find the first trackpoint outside the current interval, averaging the heights between intermediate trackpoints.
890 if (t[0] + i*chunk_dur >= t[index]) {
891 gdouble acc_s = s[index]; // initialise to first point
892 while (t[0] + i*chunk_dur >= t[index]) {
893 acc_s += (s[index+1]-s[index]);
912 * Make a speed/distance map
914 gdouble *vik_track_make_speed_dist_map ( const VikTrack *tr, guint16 num_chunks )
918 gint i, pt_count, numpts, index;
920 gdouble duration, total_length, chunk_length;
922 if ( ! tr->trackpoints )
925 t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
926 t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
929 if ( !t1 || !t2 || !duration )
933 g_warning("negative duration: unsorted trackpoint timestamps?");
937 total_length = vik_track_get_length_including_gaps ( tr );
938 chunk_length = total_length / num_chunks;
939 pt_count = vik_track_get_tp_count(tr);
941 if (chunk_length <= 0) {
945 v = g_malloc ( sizeof(gdouble) * num_chunks );
946 s = g_malloc ( sizeof(double) * pt_count );
947 t = g_malloc ( sizeof(double) * pt_count );
949 // No special handling of segments ATM...
950 iter = tr->trackpoints->next;
953 t[0] = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
956 s[numpts] = s[numpts-1] + vik_coord_diff ( &(VIK_TRACKPOINT(iter->prev->data)->coord), &(VIK_TRACKPOINT(iter->data)->coord) );
957 t[numpts] = VIK_TRACKPOINT(iter->data)->timestamp;
962 // Iterate through a portion of the track to get an average speed for that part
963 // This will essentially interpolate between segments, which I think is right given the usage of 'get_length_including_gaps'
964 index = 0; /* index of the current trackpoint. */
965 for (i = 0; i < num_chunks; i++) {
966 // Similar to the make_speed_map, but instead of using a time chunk, use a distance chunk
967 if (s[0] + i*chunk_length >= s[index]) {
968 gdouble acc_t = 0, acc_s = 0;
969 while (s[0] + i*chunk_length >= s[index]) {
970 acc_s += (s[index+1]-s[index]);
971 acc_t += (t[index+1]-t[index]);
988 /* by Alex Foobarian */
989 VikTrackpoint *vik_track_get_closest_tp_by_percentage_dist ( VikTrack *tr, gdouble reldist, gdouble *meters_from_start )
991 gdouble dist = vik_track_get_length_including_gaps(tr) * reldist;
992 gdouble current_dist = 0.0;
993 gdouble current_inc = 0.0;
994 if ( tr->trackpoints )
996 GList *iter = tr->trackpoints->next;
997 GList *last_iter = NULL;
998 gdouble last_dist = 0.0;
1001 current_inc = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
1002 &(VIK_TRACKPOINT(iter->prev->data)->coord) );
1003 last_dist = current_dist;
1004 current_dist += current_inc;
1005 if ( current_dist >= dist )
1010 if (!iter) { /* passing the end the track */
1012 if (meters_from_start)
1013 *meters_from_start = last_dist;
1014 return(VIK_TRACKPOINT(last_iter->data));
1019 /* we've gone past the dist already, was prev trackpoint closer? */
1020 /* should do a vik_coord_average_weighted() thingy. */
1021 if ( iter->prev && abs(current_dist-current_inc-dist) < abs(current_dist-dist) ) {
1022 if (meters_from_start)
1023 *meters_from_start = last_dist;
1027 if (meters_from_start)
1028 *meters_from_start = current_dist;
1030 return VIK_TRACKPOINT(iter->data);
1036 VikTrackpoint *vik_track_get_closest_tp_by_percentage_time ( VikTrack *tr, gdouble reltime, time_t *seconds_from_start )
1038 time_t t_pos, t_start, t_end, t_total;
1039 t_start = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
1040 t_end = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
1041 t_total = t_end - t_start;
1043 t_pos = t_start + t_total * reltime;
1045 if ( !tr->trackpoints )
1048 GList *iter = tr->trackpoints;
1051 if (VIK_TRACKPOINT(iter->data)->timestamp == t_pos)
1053 if (VIK_TRACKPOINT(iter->data)->timestamp > t_pos) {
1054 if (iter->prev == NULL) /* first trackpoint */
1056 time_t t_before = t_pos - VIK_TRACKPOINT(iter->prev)->timestamp;
1057 time_t t_after = VIK_TRACKPOINT(iter->data)->timestamp - t_pos;
1058 if (t_before <= t_after)
1062 else if ((iter->next == NULL) && (t_pos < (VIK_TRACKPOINT(iter->data)->timestamp + 3))) /* last trackpoint: accommodate for round-off */
1069 if (seconds_from_start)
1070 *seconds_from_start = VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
1071 return VIK_TRACKPOINT(iter->data);
1074 VikTrackpoint* vik_track_get_tp_by_max_speed ( const VikTrack *tr )
1076 gdouble maxspeed = 0.0, speed = 0.0;
1078 if ( !tr->trackpoints )
1081 GList *iter = tr->trackpoints;
1082 VikTrackpoint *max_speed_tp = NULL;
1086 if ( VIK_TRACKPOINT(iter->data)->has_timestamp &&
1087 VIK_TRACKPOINT(iter->prev->data)->has_timestamp &&
1088 (! VIK_TRACKPOINT(iter->data)->newsegment) ) {
1089 speed = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord), &(VIK_TRACKPOINT(iter->prev->data)->coord) )
1090 / ABS(VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(iter->prev->data)->timestamp);
1091 if ( speed > maxspeed ) {
1093 max_speed_tp = VIK_TRACKPOINT(iter->data);
1103 return max_speed_tp;
1106 VikTrackpoint* vik_track_get_tp_by_max_alt ( const VikTrack *tr )
1108 gdouble maxalt = -5000.0;
1109 if ( !tr->trackpoints )
1112 GList *iter = tr->trackpoints;
1113 VikTrackpoint *max_alt_tp = NULL;
1116 if ( VIK_TRACKPOINT(iter->data)->altitude > maxalt ) {
1117 maxalt = VIK_TRACKPOINT(iter->data)->altitude;
1118 max_alt_tp = VIK_TRACKPOINT(iter->data);
1129 VikTrackpoint* vik_track_get_tp_by_min_alt ( const VikTrack *tr )
1131 gdouble minalt = 25000.0;
1132 if ( !tr->trackpoints )
1135 GList *iter = tr->trackpoints;
1136 VikTrackpoint *min_alt_tp = NULL;
1139 if ( VIK_TRACKPOINT(iter->data)->altitude < minalt ) {
1140 minalt = VIK_TRACKPOINT(iter->data)->altitude;
1141 min_alt_tp = VIK_TRACKPOINT(iter->data);
1152 gboolean vik_track_get_minmax_alt ( const VikTrack *tr, gdouble *min_alt, gdouble *max_alt )
1156 if ( tr && tr->trackpoints && tr->trackpoints->data && (VIK_TRACKPOINT(tr->trackpoints->data)->altitude != VIK_DEFAULT_ALTITUDE) ) {
1157 GList *iter = tr->trackpoints->next;
1161 tmp_alt = VIK_TRACKPOINT(iter->data)->altitude;
1162 if ( tmp_alt > *max_alt )
1164 if ( tmp_alt < *min_alt )
1173 void vik_track_marshall ( VikTrack *tr, guint8 **data, guint *datalen)
1176 GByteArray *b = g_byte_array_new();
1180 g_byte_array_append(b, (guint8 *)tr, sizeof(*tr));
1182 /* we'll fill out number of trackpoints later */
1184 g_byte_array_append(b, (guint8 *)&len, sizeof(len));
1186 tps = tr->trackpoints;
1189 g_byte_array_append(b, (guint8 *)tps->data, sizeof(VikTrackpoint));
1193 *(guint *)(b->data + intp) = ntp;
1195 len = (tr->name) ? strlen(tr->name)+1 : 0;
1196 g_byte_array_append(b, (guint8 *)&len, sizeof(len));
1197 if (tr->name) g_byte_array_append(b, (guint8 *)tr->name, len);
1199 len = (tr->comment) ? strlen(tr->comment)+1 : 0;
1200 g_byte_array_append(b, (guint8 *)&len, sizeof(len));
1201 if (tr->comment) g_byte_array_append(b, (guint8 *)tr->comment, len);
1205 g_byte_array_free(b, FALSE);
1208 VikTrack *vik_track_unmarshall (guint8 *data, guint datalen)
1211 VikTrack *new_tr = vik_track_new();
1212 VikTrackpoint *new_tp;
1216 /* only the visibility is needed */
1217 new_tr->visible = ((VikTrack *)data)->visible;
1218 data += sizeof(*new_tr);
1220 ntp = *(guint *)data;
1221 data += sizeof(ntp);
1223 for (i=0; i<ntp; i++) {
1224 new_tp = vik_trackpoint_new();
1225 memcpy(new_tp, data, sizeof(*new_tp));
1226 data += sizeof(*new_tp);
1227 new_tr->trackpoints = g_list_append(new_tr->trackpoints, new_tp);
1230 len = *(guint *)data;
1231 data += sizeof(len);
1233 new_tr->name = g_strdup((gchar *)data);
1237 len = *(guint *)data;
1238 data += sizeof(len);
1240 new_tr->comment = g_strdup((gchar *)data);
1245 void vik_track_apply_dem_data ( VikTrack *tr )
1249 tp_iter = tr->trackpoints;
1251 /* TODO: of the 4 possible choices we have for choosing an elevation
1252 * (trackpoint in between samples), choose the one with the least elevation change
1254 elev = a_dems_get_elev_by_coord ( &(VIK_TRACKPOINT(tp_iter->data)->coord), VIK_DEM_INTERPOL_BEST );
1255 if ( elev != VIK_DEM_INVALID_ELEVATION )
1256 VIK_TRACKPOINT(tp_iter->data)->altitude = elev;
1257 tp_iter = tp_iter->next;
1262 * Apply DEM data (if available) - to only the last trackpoint
1264 void vik_track_apply_dem_data_last_trackpoint ( VikTrack *tr )
1267 if ( tr->trackpoints ) {
1268 /* As in vik_track_apply_dem_data above - use 'best' interpolation method */
1269 elev = a_dems_get_elev_by_coord ( &(VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->coord), VIK_DEM_INTERPOL_BEST );
1270 if ( elev != VIK_DEM_INVALID_ELEVATION )
1271 VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->altitude = elev;
1275 /* appends t2 to t1, leaving t2 with no trackpoints */
1276 void vik_track_steal_and_append_trackpoints ( VikTrack *t1, VikTrack *t2 )
1278 if ( t1->trackpoints ) {
1279 GList *tpiter = t1->trackpoints;
1280 while ( tpiter->next )
1281 tpiter = tpiter->next;
1282 tpiter->next = t2->trackpoints;
1283 t2->trackpoints->prev = tpiter;
1285 t1->trackpoints = t2->trackpoints;
1286 t2->trackpoints = NULL;
1289 /* starting at the end, looks backwards for the last "double point", a duplicate trackpoint.
1290 * If there is no double point, deletes all the trackpoints.
1291 * Returns the new end of the track (or the start if there are no double points)
1293 VikCoord *vik_track_cut_back_to_double_point ( VikTrack *tr )
1295 GList *iter = tr->trackpoints;
1300 while ( iter->next )
1304 while ( iter->prev ) {
1305 if ( vik_coord_equals((VikCoord *)iter->data, (VikCoord *)iter->prev->data) ) {
1306 GList *prev = iter->prev;
1308 rv = g_malloc(sizeof(VikCoord));
1309 *rv = *((VikCoord *) iter->data);
1311 /* truncate trackpoint list */
1312 iter->prev = NULL; /* pretend it's the end */
1313 g_list_foreach ( iter, (GFunc) g_free, NULL );
1314 g_list_free( iter );
1323 /* no double point found! */
1324 rv = g_malloc(sizeof(VikCoord));
1325 *rv = *((VikCoord *) tr->trackpoints->data);
1326 g_list_foreach ( tr->trackpoints, (GFunc) g_free, NULL );
1327 g_list_free( tr->trackpoints );
1328 tr->trackpoints = NULL;