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 return g_malloc0(sizeof(VikTrackpoint));
100 void vik_trackpoint_free(VikTrackpoint *tp)
105 VikTrackpoint *vik_trackpoint_copy(VikTrackpoint *tp)
107 VikTrackpoint *rv = vik_trackpoint_new();
112 gdouble vik_track_get_length(const VikTrack *tr)
115 if ( tr->trackpoints )
117 GList *iter = tr->trackpoints->next;
120 if ( ! VIK_TRACKPOINT(iter->data)->newsegment )
121 len += vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
122 &(VIK_TRACKPOINT(iter->prev->data)->coord) );
129 gdouble vik_track_get_length_including_gaps(const VikTrack *tr)
132 if ( tr->trackpoints )
134 GList *iter = tr->trackpoints->next;
137 len += vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
138 &(VIK_TRACKPOINT(iter->prev->data)->coord) );
145 gulong vik_track_get_tp_count(const VikTrack *tr)
148 GList *iter = tr->trackpoints;
157 gulong vik_track_get_dup_point_count ( const VikTrack *tr )
160 GList *iter = tr->trackpoints;
163 if ( iter->next && vik_coord_equals ( &(VIK_TRACKPOINT(iter->data)->coord),
164 &(VIK_TRACKPOINT(iter->next->data)->coord) ) )
171 void vik_track_remove_dup_points ( VikTrack *tr )
173 GList *iter = tr->trackpoints;
176 if ( iter->next && vik_coord_equals ( &(VIK_TRACKPOINT(iter->data)->coord),
177 &(VIK_TRACKPOINT(iter->next->data)->coord) ) )
179 g_free ( iter->next->data );
180 tr->trackpoints = g_list_delete_link ( tr->trackpoints, iter->next );
187 guint vik_track_get_segment_count(const VikTrack *tr)
190 GList *iter = tr->trackpoints;
193 while ( (iter = iter->next) )
195 if ( VIK_TRACKPOINT(iter->data)->newsegment )
201 VikTrack **vik_track_split_into_segments(VikTrack *t, guint *ret_len)
206 guint segs = vik_track_get_segment_count(t);
215 rv = g_malloc ( segs * sizeof(VikTrack *) );
216 tr = vik_track_copy ( t );
218 iter = tr->trackpoints;
221 while ( (iter = iter->next) )
223 if ( VIK_TRACKPOINT(iter->data)->newsegment )
225 iter->prev->next = NULL;
227 rv[i] = vik_track_new();
229 vik_track_set_comment ( rv[i], tr->comment );
230 rv[i]->visible = tr->visible;
231 rv[i]->trackpoints = iter;
239 void vik_track_reverse ( VikTrack *tr )
242 tr->trackpoints = g_list_reverse(tr->trackpoints);
244 /* fix 'newsegment' */
245 iter = g_list_last ( tr->trackpoints );
248 if ( ! iter->next ) /* last segment, was first, cancel newsegment. */
249 VIK_TRACKPOINT(iter->data)->newsegment = FALSE;
250 if ( ! iter->prev ) /* first segment by convention has newsegment flag. */
251 VIK_TRACKPOINT(iter->data)->newsegment = TRUE;
252 else if ( VIK_TRACKPOINT(iter->data)->newsegment && iter->next )
254 VIK_TRACKPOINT(iter->next->data)->newsegment = TRUE;
255 VIK_TRACKPOINT(iter->data)->newsegment = FALSE;
261 gdouble vik_track_get_average_speed(const VikTrack *tr)
265 if ( tr->trackpoints )
267 GList *iter = tr->trackpoints->next;
270 if ( VIK_TRACKPOINT(iter->data)->has_timestamp &&
271 VIK_TRACKPOINT(iter->prev->data)->has_timestamp &&
272 (! VIK_TRACKPOINT(iter->data)->newsegment) )
274 len += vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
275 &(VIK_TRACKPOINT(iter->prev->data)->coord) );
276 time += ABS(VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(iter->prev->data)->timestamp);
281 return (time == 0) ? 0 : ABS(len/time);
284 gdouble vik_track_get_max_speed(const VikTrack *tr)
286 gdouble maxspeed = 0.0, speed = 0.0;
287 if ( tr->trackpoints )
289 GList *iter = tr->trackpoints->next;
292 if ( VIK_TRACKPOINT(iter->data)->has_timestamp &&
293 VIK_TRACKPOINT(iter->prev->data)->has_timestamp &&
294 (! VIK_TRACKPOINT(iter->data)->newsegment) )
296 speed = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord), &(VIK_TRACKPOINT(iter->prev->data)->coord) )
297 / ABS(VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(iter->prev->data)->timestamp);
298 if ( speed > maxspeed )
307 void vik_track_convert ( VikTrack *tr, VikCoordMode dest_mode )
309 GList *iter = tr->trackpoints;
312 vik_coord_convert ( &(VIK_TRACKPOINT(iter->data)->coord), dest_mode );
317 /* I understood this when I wrote it ... maybe ... Basically it eats up the
318 * proper amounts of length on the track and averages elevation over that. */
319 gdouble *vik_track_make_elevation_map ( const VikTrack *tr, guint16 num_chunks )
322 gdouble total_length, chunk_length, current_dist, current_area_under_curve, current_seg_length, dist_along_seg = 0.0;
323 gdouble altitude1, altitude2;
324 guint16 current_chunk;
325 gboolean ignore_it = FALSE;
327 GList *iter = tr->trackpoints;
329 if (!iter->next) /* one-point track */
332 { /* test if there's anything worth calculating */
333 gboolean okay = FALSE;
336 if ( VIK_TRACKPOINT(iter->data)->altitude != VIK_DEFAULT_ALTITUDE ) {
345 iter = tr->trackpoints;
347 g_assert ( num_chunks < 16000 );
349 pts = g_malloc ( sizeof(gdouble) * num_chunks );
351 total_length = vik_track_get_length_including_gaps ( tr );
352 chunk_length = total_length / num_chunks;
355 current_area_under_curve = 0;
357 current_seg_length = 0;
359 current_seg_length = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
360 &(VIK_TRACKPOINT(iter->next->data)->coord) );
361 altitude1 = VIK_TRACKPOINT(iter->data)->altitude;
362 altitude2 = VIK_TRACKPOINT(iter->next->data)->altitude;
365 while ( current_chunk < num_chunks ) {
367 /* go along current seg */
368 if ( current_seg_length && (current_seg_length - dist_along_seg) > chunk_length ) {
369 dist_along_seg += chunk_length;
373 * /x altitude = alt_at_pt_1 + alt_at_pt_2 / 2 = altitude1 + slope * dist_value_of_pt_inbetween_pt1_and_pt2
374 * /xx avg altitude = area under curve / chunk len
375 *pt1 *xxx avg altitude = altitude1 + (altitude2-altitude1)/(current_seg_length)*(dist_along_seg + (chunk_len/2))
381 pts[current_chunk] = VIK_DEFAULT_ALTITUDE;
383 pts[current_chunk] = altitude1 + (altitude2-altitude1)*((dist_along_seg - (chunk_length/2))/current_seg_length);
387 /* finish current seg */
388 if ( current_seg_length ) {
389 gdouble altitude_at_dist_along_seg = altitude1 + (altitude2-altitude1)/(current_seg_length)*dist_along_seg;
390 current_dist = current_seg_length - dist_along_seg;
391 current_area_under_curve = current_dist*(altitude_at_dist_along_seg + altitude2)*0.5;
392 } else { current_dist = current_area_under_curve = 0; } /* should only happen if first current_seg_length == 0 */
394 /* get intervening segs */
396 while ( iter && iter->next ) {
397 current_seg_length = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
398 &(VIK_TRACKPOINT(iter->next->data)->coord) );
399 altitude1 = VIK_TRACKPOINT(iter->data)->altitude;
400 altitude2 = VIK_TRACKPOINT(iter->next->data)->altitude;
401 ignore_it = VIK_TRACKPOINT(iter->next->data)->newsegment;
403 if ( chunk_length - current_dist >= current_seg_length ) {
404 current_dist += current_seg_length;
405 current_area_under_curve += current_seg_length * (altitude1+altitude2) * 0.5;
413 dist_along_seg = chunk_length - current_dist;
414 if ( ignore_it || !iter->next ) {
415 pts[current_chunk] = current_area_under_curve / current_dist;
418 current_area_under_curve += dist_along_seg * (altitude1 + (altitude2 - altitude1)*dist_along_seg/current_seg_length);
419 pts[current_chunk] = current_area_under_curve / chunk_length;
431 void vik_track_get_total_elevation_gain(const VikTrack *tr, gdouble *up, gdouble *down)
435 if ( tr->trackpoints && VIK_TRACKPOINT(tr->trackpoints->data)->altitude != VIK_DEFAULT_ALTITUDE )
437 GList *iter = tr->trackpoints->next;
440 diff = VIK_TRACKPOINT(iter->data)->altitude - VIK_TRACKPOINT(iter->prev->data)->altitude;
448 *up = *down = VIK_DEFAULT_ALTITUDE;
455 void compute_spline(int n, double *x, double *f, spline_coeff_t *p)
457 double *h, *alpha, *B, *m;
460 double new_x[3], new_f[3];
466 new_x[1] = x[0]+0.00001;
477 new_x[2] = x[1] + x[1]-x[0];
478 new_f[2] = f[1] + f[1]-f[0];
484 /* we're solving a linear system of equations of the form Ax = B.
485 * The matrix a is tridiagonal and consists of coefficients in
486 * the h[] and alpha[] arrays.
489 h = (double *)malloc(sizeof(double) * (n-1));
490 for (i=0; i<n-1; i++) {
494 alpha = (double *)malloc(sizeof(double) * (n-2));
495 for (i=0; i<n-2; i++) {
496 alpha[i] = 2 * (h[i] + h[i+1]);
499 /* B[] is the vector on the right hand side of the equation */
500 B = (double *)malloc(sizeof(double) * (n-2));
501 for (i=0; i<n-2; i++) {
502 B[i] = 6 * ((f[i+2] - f[i+1])/h[i+1] - (f[i+1] - f[i])/h[i]);
505 /* Now solve the n-2 by n-2 system */
506 m = (double *)malloc(sizeof(double) * (n-2));
507 for (i=1; i<=n-3; i++) {
513 di = di - (ai-1 / di-1) * ci-1
514 bi = bi - (ai-1 / di-1) * bi-1
517 alpha[i] = alpha[i] - (h[i]/alpha[i-1]) * h[i];
518 B[i] = B[i] - (h[i]/alpha[i-1]) * B[i-1];
520 /* xn-3 = bn-3 / dn-3; */
521 m[n-3] = B[n-3]/alpha[n-3];
522 for (i=n-4; i>=0; i--) {
523 m[i] = (B[i]-h[i+1]*m[i+1])/alpha[i];
526 for (i=0; i<orig_n-1; i++) {
528 mi = (i==(n-2)) ? 0 : m[i];
529 mi1 = (i==0) ? 0 : m[i-1];
532 p[i].b = (f[i+1] - f[i]) / h[i] + h[i] * (2*mi + mi1) / 6;
534 p[i].d = (mi-mi1)/(6*h[i]);
543 /* by Alex Foobarian */
544 gdouble *vik_track_make_speed_map ( const VikTrack *tr, guint16 num_chunks )
547 gdouble duration, chunk_dur, T, s_prev, s_now;
549 int i, pt_count, numpts, spline;
553 if ( ! tr->trackpoints )
556 g_assert ( num_chunks < 16000 );
558 #ifdef XXXXXXXXXXXXXXXXXX
559 iter = tr->trackpoints;
563 #endif /*XXXXXXXXXXXXXXXXXX*/
565 t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
566 t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
569 if ( !t1 || !t2 || !duration )
573 g_warning("negative duration: unsorted trackpoint timestamps?\n");
576 pt_count = vik_track_get_tp_count(tr);
578 v = g_malloc ( sizeof(gdouble) * num_chunks );
579 chunk_dur = duration / num_chunks;
581 s = g_malloc(sizeof(double) * pt_count);
582 t = g_malloc(sizeof(double) * pt_count);
583 p = g_malloc(sizeof(spline_coeff_t) * (pt_count-1));
585 iter = tr->trackpoints->next;
588 t[0] = VIK_TRACKPOINT(iter->prev->data)->timestamp;
591 s[numpts] = s[numpts-1] + vik_coord_diff ( &(VIK_TRACKPOINT(iter->prev->data)->coord), &(VIK_TRACKPOINT(iter->data)->coord) );
592 t[numpts] = VIK_TRACKPOINT(iter->data)->timestamp;
597 compute_spline(numpts, t, s, p);
599 /* the spline gives us distances at chunk_dur intervals. from these,
600 * we obtain average speed in each interval.
605 p[spline].d * pow(T - t[spline+1], 3) +
606 p[spline].c * pow(T - t[spline+1], 2) +
607 p[spline].b * (T - t[spline+1]) +
609 for (i = 0; i < num_chunks; i++, T+=chunk_dur) {
610 while (T > t[spline+1]) {
614 p[spline].d * pow(T - t[spline+1], 3) +
615 p[spline].c * pow(T - t[spline+1], 2) +
616 p[spline].b * (T - t[spline+1]) +
618 v[i] = (s_now - s_prev) / chunk_dur;
621 * old method of averages
622 v[i] = (s[spline+1]-s[spline])/(t[spline+1]-t[spline]);
631 /* by Alex Foobarian */
632 VikTrackpoint *vik_track_get_closest_tp_by_percentage_dist ( VikTrack *tr, gdouble reldist )
634 gdouble dist = vik_track_get_length_including_gaps(tr) * reldist;
635 gdouble current_dist = 0.0;
636 gdouble current_inc = 0.0;
637 if ( tr->trackpoints )
639 GList *iter = tr->trackpoints->next;
640 GList *last_iter = NULL;
643 current_inc = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord),
644 &(VIK_TRACKPOINT(iter->prev->data)->coord) );
645 current_dist += current_inc;
646 if ( current_dist >= dist )
651 if (!iter) /* passing the end the track */
652 return (last_iter ? last_iter->data : NULL);
653 /* we've gone past the dist already, was prev trackpoint closer? */
654 /* should do a vik_coord_average_weighted() thingy. */
655 if ( iter->prev && abs(current_dist-current_inc-dist) < abs(current_dist-dist) )
658 return VIK_TRACKPOINT(iter->data);
664 gboolean vik_track_get_minmax_alt ( const VikTrack *tr, gdouble *min_alt, gdouble *max_alt )
668 if ( tr && tr->trackpoints && tr->trackpoints->data && (VIK_TRACKPOINT(tr->trackpoints->data)->altitude != VIK_DEFAULT_ALTITUDE) ) {
669 GList *iter = tr->trackpoints->next;
673 tmp_alt = VIK_TRACKPOINT(iter->data)->altitude;
674 if ( tmp_alt > *max_alt )
676 if ( tmp_alt < *min_alt )
685 void vik_track_marshall ( VikTrack *tr, guint8 **data, guint *datalen)
688 GByteArray *b = g_byte_array_new();
692 g_byte_array_append(b, (guint8 *)tr, sizeof(*tr));
694 /* we'll fill out number of trackpoints later */
696 g_byte_array_append(b, (guint8 *)&len, sizeof(len));
698 tps = tr->trackpoints;
701 g_byte_array_append(b, (guint8 *)tps->data, sizeof(VikTrackpoint));
705 *(guint *)(b->data + intp) = ntp;
707 len = (tr->comment) ? strlen(tr->comment)+1 : 0;
708 g_byte_array_append(b, (guint8 *)&len, sizeof(len));
709 if (tr->comment) g_byte_array_append(b, (guint8 *)tr->comment, len);
713 g_byte_array_free(b, FALSE);
716 VikTrack *vik_track_unmarshall (guint8 *data, guint datalen)
719 VikTrack *new_tr = vik_track_new();
720 VikTrackpoint *new_tp;
724 /* only the visibility is needed */
725 new_tr->visible = ((VikTrack *)data)->visible;
726 data += sizeof(*new_tr);
728 ntp = *(guint *)data;
731 for (i=0; i<ntp; i++) {
732 new_tp = vik_trackpoint_new();
733 memcpy(new_tp, data, sizeof(*new_tp));
734 data += sizeof(*new_tp);
735 new_tr->trackpoints = g_list_append(new_tr->trackpoints, new_tp);
738 len = *(guint *)data;
741 new_tr->comment = g_strdup((gchar *)data);
746 void vik_track_apply_dem_data ( VikTrack *tr )
750 tp_iter = tr->trackpoints;
752 /* TODO: of the 4 possible choices we have for choosing an elevation
753 * (trackpoint in between samples), choose the one with the least elevation change
755 elev = a_dems_get_elev_by_coord ( &(VIK_TRACKPOINT(tp_iter->data)->coord) );
756 if ( elev != VIK_DEM_INVALID_ELEVATION )
757 VIK_TRACKPOINT(tp_iter->data)->altitude = elev;
758 tp_iter = tp_iter->next;
762 /* appends t2 to t1, leaving t2 with no trackpoints */
763 void vik_track_steal_and_append_trackpoints ( VikTrack *t1, VikTrack *t2 )
765 if ( t1->trackpoints ) {
766 GList *tpiter = t1->trackpoints;
767 while ( tpiter->next )
768 tpiter = tpiter->next;
769 tpiter->next = t2->trackpoints;
770 t2->trackpoints->prev = tpiter;
772 t1->trackpoints = t2->trackpoints;
773 t2->trackpoints = NULL;