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1 | /* | |
2 | * viking -- GPS Data and Topo Analyzer, Explorer, and Manager | |
3 | * | |
4 | * Copyright (C) 2003-2005, Evan Battaglia <gtoevan@gmx.net> | |
5 | * | |
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. | |
10 | * | |
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. | |
15 | * | |
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 | |
19 | * | |
20 | */ | |
21 | ||
22 | #include <glib.h> | |
23 | #include <time.h> | |
24 | #include <stdio.h> | |
25 | #include <stdlib.h> | |
26 | #include <string.h> | |
27 | #include <math.h> | |
28 | #include "coords.h" | |
29 | #include "vikcoord.h" | |
30 | #include "viktrack.h" | |
31 | #include "globals.h" | |
32 | ||
33 | VikTrack *vik_track_new() | |
34 | { | |
35 | VikTrack *tr = g_malloc0 ( sizeof ( VikTrack ) ); | |
36 | tr->ref_count = 1; | |
37 | return tr; | |
38 | } | |
39 | ||
40 | void vik_track_set_comment_no_copy(VikTrack *tr, gchar *comment) | |
41 | { | |
42 | if ( tr->comment ) | |
43 | g_free ( tr->comment ); | |
44 | tr->comment = comment; | |
45 | } | |
46 | ||
47 | ||
48 | void vik_track_set_comment(VikTrack *tr, const gchar *comment) | |
49 | { | |
50 | if ( tr->comment ) | |
51 | g_free ( tr->comment ); | |
52 | ||
53 | if ( comment && comment[0] != '\0' ) | |
54 | tr->comment = g_strdup(comment); | |
55 | else | |
56 | tr->comment = NULL; | |
57 | } | |
58 | ||
59 | void vik_track_ref(VikTrack *tr) | |
60 | { | |
61 | tr->ref_count++; | |
62 | } | |
63 | ||
64 | void vik_track_free(VikTrack *tr) | |
65 | { | |
66 | if ( tr->ref_count-- > 1 ) | |
67 | return; | |
68 | ||
69 | if ( tr->comment ) | |
70 | g_free ( tr->comment ); | |
71 | g_list_foreach ( tr->trackpoints, (GFunc) g_free, NULL ); | |
72 | g_list_free( tr->trackpoints ); | |
73 | g_free ( tr ); | |
74 | } | |
75 | ||
76 | VikTrack *vik_track_copy ( const VikTrack *tr ) | |
77 | { | |
78 | VikTrack *new_tr = vik_track_new(); | |
79 | VikTrackpoint *new_tp; | |
80 | GList *tp_iter = tr->trackpoints; | |
81 | new_tr->visible = tr->visible; | |
82 | new_tr->trackpoints = NULL; | |
83 | while ( tp_iter ) | |
84 | { | |
85 | new_tp = g_malloc ( sizeof ( VikTrackpoint ) ); | |
86 | *new_tp = *((VikTrackpoint *)(tp_iter->data)); | |
87 | new_tr->trackpoints = g_list_append ( new_tr->trackpoints, new_tp ); | |
88 | tp_iter = tp_iter->next; | |
89 | } | |
90 | vik_track_set_comment(new_tr,tr->comment); | |
91 | return new_tr; | |
92 | } | |
93 | ||
94 | VikTrackpoint *vik_trackpoint_new() | |
95 | { | |
96 | return g_malloc0(sizeof(VikTrackpoint)); | |
97 | } | |
98 | ||
99 | void vik_trackpoint_free(VikTrackpoint *tp) | |
100 | { | |
101 | g_free(tp); | |
102 | } | |
103 | ||
104 | VikTrackpoint *vik_trackpoint_copy(VikTrackpoint *tp) | |
105 | { | |
106 | VikTrackpoint *rv = vik_trackpoint_new(); | |
107 | *rv = *tp; | |
108 | return rv; | |
109 | } | |
110 | ||
111 | gdouble vik_track_get_length(const VikTrack *tr) | |
112 | { | |
113 | gdouble len = 0.0; | |
114 | if ( tr->trackpoints ) | |
115 | { | |
116 | GList *iter = tr->trackpoints->next; | |
117 | while (iter) | |
118 | { | |
119 | if ( ! VIK_TRACKPOINT(iter->data)->newsegment ) | |
120 | len += vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord), | |
121 | &(VIK_TRACKPOINT(iter->prev->data)->coord) ); | |
122 | iter = iter->next; | |
123 | } | |
124 | } | |
125 | return len; | |
126 | } | |
127 | ||
128 | gdouble vik_track_get_length_including_gaps(const VikTrack *tr) | |
129 | { | |
130 | gdouble len = 0.0; | |
131 | if ( tr->trackpoints ) | |
132 | { | |
133 | GList *iter = tr->trackpoints->next; | |
134 | while (iter) | |
135 | { | |
136 | len += vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord), | |
137 | &(VIK_TRACKPOINT(iter->prev->data)->coord) ); | |
138 | iter = iter->next; | |
139 | } | |
140 | } | |
141 | return len; | |
142 | } | |
143 | ||
144 | gulong vik_track_get_tp_count(const VikTrack *tr) | |
145 | { | |
146 | gulong num = 0; | |
147 | GList *iter = tr->trackpoints; | |
148 | while ( iter ) | |
149 | { | |
150 | num++; | |
151 | iter = iter->next; | |
152 | } | |
153 | return num; | |
154 | } | |
155 | ||
156 | gulong vik_track_get_dup_point_count ( const VikTrack *tr ) | |
157 | { | |
158 | gulong num = 0; | |
159 | GList *iter = tr->trackpoints; | |
160 | while ( iter ) | |
161 | { | |
162 | if ( iter->next && vik_coord_equals ( &(VIK_TRACKPOINT(iter->data)->coord), | |
163 | &(VIK_TRACKPOINT(iter->next->data)->coord) ) ) | |
164 | num++; | |
165 | iter = iter->next; | |
166 | } | |
167 | return num; | |
168 | } | |
169 | ||
170 | void vik_track_remove_dup_points ( VikTrack *tr ) | |
171 | { | |
172 | GList *iter = tr->trackpoints; | |
173 | while ( iter ) | |
174 | { | |
175 | if ( iter->next && vik_coord_equals ( &(VIK_TRACKPOINT(iter->data)->coord), | |
176 | &(VIK_TRACKPOINT(iter->next->data)->coord) ) ) | |
177 | { | |
178 | g_free ( iter->next->data ); | |
179 | tr->trackpoints = g_list_delete_link ( tr->trackpoints, iter->next ); | |
180 | } | |
181 | else | |
182 | iter = iter->next; | |
183 | } | |
184 | } | |
185 | ||
186 | guint vik_track_get_segment_count(const VikTrack *tr) | |
187 | { | |
188 | guint num = 1; | |
189 | GList *iter = tr->trackpoints; | |
190 | if ( !iter ) | |
191 | return 0; | |
192 | while ( (iter = iter->next) ) | |
193 | { | |
194 | if ( VIK_TRACKPOINT(iter->data)->newsegment ) | |
195 | num++; | |
196 | } | |
197 | return num; | |
198 | } | |
199 | ||
200 | VikTrack **vik_track_split_into_segments(VikTrack *t, guint *ret_len) | |
201 | { | |
202 | VikTrack **rv; | |
203 | VikTrack *tr; | |
204 | guint i; | |
205 | guint segs = vik_track_get_segment_count(t); | |
206 | GList *iter; | |
207 | ||
208 | if ( segs < 2 ) | |
209 | { | |
210 | *ret_len = 0; | |
211 | return NULL; | |
212 | } | |
213 | ||
214 | rv = g_malloc ( segs * sizeof(VikTrack *) ); | |
215 | tr = vik_track_copy ( t ); | |
216 | rv[0] = tr; | |
217 | iter = tr->trackpoints; | |
218 | ||
219 | i = 1; | |
220 | while ( (iter = iter->next) ) | |
221 | { | |
222 | if ( VIK_TRACKPOINT(iter->data)->newsegment ) | |
223 | { | |
224 | iter->prev->next = NULL; | |
225 | iter->prev = NULL; | |
226 | rv[i] = vik_track_new(); | |
227 | if ( tr->comment ) | |
228 | vik_track_set_comment ( rv[i], tr->comment ); | |
229 | rv[i]->visible = tr->visible; | |
230 | rv[i]->trackpoints = iter; | |
231 | i++; | |
232 | } | |
233 | } | |
234 | *ret_len = segs; | |
235 | return rv; | |
236 | } | |
237 | ||
238 | void vik_track_reverse ( VikTrack *tr ) | |
239 | { | |
240 | GList *iter; | |
241 | tr->trackpoints = g_list_reverse(tr->trackpoints); | |
242 | ||
243 | /* fix 'newsegment' */ | |
244 | iter = g_list_last ( tr->trackpoints ); | |
245 | while ( iter ) | |
246 | { | |
247 | if ( ! iter->next ) /* last segment, was first, cancel newsegment. */ | |
248 | VIK_TRACKPOINT(iter->data)->newsegment = FALSE; | |
249 | if ( ! iter->prev ) /* first segment by convention has newsegment flag. */ | |
250 | VIK_TRACKPOINT(iter->data)->newsegment = TRUE; | |
251 | else if ( VIK_TRACKPOINT(iter->data)->newsegment && iter->next ) | |
252 | { | |
253 | VIK_TRACKPOINT(iter->next->data)->newsegment = TRUE; | |
254 | VIK_TRACKPOINT(iter->data)->newsegment = FALSE; | |
255 | } | |
256 | iter = iter->prev; | |
257 | } | |
258 | } | |
259 | ||
260 | gdouble vik_track_get_average_speed(const VikTrack *tr) | |
261 | { | |
262 | gdouble len = 0.0; | |
263 | guint32 time = 0; | |
264 | if ( tr->trackpoints ) | |
265 | { | |
266 | GList *iter = tr->trackpoints->next; | |
267 | while (iter) | |
268 | { | |
269 | if ( VIK_TRACKPOINT(iter->data)->has_timestamp && | |
270 | VIK_TRACKPOINT(iter->prev->data)->has_timestamp && | |
271 | (! VIK_TRACKPOINT(iter->data)->newsegment) ) | |
272 | { | |
273 | len += vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord), | |
274 | &(VIK_TRACKPOINT(iter->prev->data)->coord) ); | |
275 | time += ABS(VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(iter->prev->data)->timestamp); | |
276 | } | |
277 | iter = iter->next; | |
278 | } | |
279 | } | |
280 | return (time == 0) ? 0 : ABS(len/time); | |
281 | } | |
282 | ||
283 | gdouble vik_track_get_max_speed(const VikTrack *tr) | |
284 | { | |
285 | gdouble maxspeed = 0.0, speed = 0.0; | |
286 | if ( tr->trackpoints ) | |
287 | { | |
288 | GList *iter = tr->trackpoints->next; | |
289 | while (iter) | |
290 | { | |
291 | if ( VIK_TRACKPOINT(iter->data)->has_timestamp && | |
292 | VIK_TRACKPOINT(iter->prev->data)->has_timestamp && | |
293 | (! VIK_TRACKPOINT(iter->data)->newsegment) ) | |
294 | { | |
295 | speed = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord), &(VIK_TRACKPOINT(iter->prev->data)->coord) ) | |
296 | / ABS(VIK_TRACKPOINT(iter->data)->timestamp - VIK_TRACKPOINT(iter->prev->data)->timestamp); | |
297 | if ( speed > maxspeed ) | |
298 | maxspeed = speed; | |
299 | } | |
300 | iter = iter->next; | |
301 | } | |
302 | } | |
303 | return maxspeed; | |
304 | } | |
305 | ||
306 | void vik_track_convert ( VikTrack *tr, VikCoordMode dest_mode ) | |
307 | { | |
308 | GList *iter = tr->trackpoints; | |
309 | while (iter) | |
310 | { | |
311 | vik_coord_convert ( &(VIK_TRACKPOINT(iter->data)->coord), dest_mode ); | |
312 | iter = iter->next; | |
313 | } | |
314 | } | |
315 | ||
316 | /* I understood this when I wrote it ... maybe ... Basically it eats up the | |
317 | * proper amounts of length on the track and averages elevation over that. */ | |
318 | gdouble *vik_track_make_elevation_map ( const VikTrack *tr, guint16 num_chunks ) | |
319 | { | |
320 | gdouble *pts; | |
321 | gdouble total_length, chunk_length, current_dist, current_area_under_curve, current_seg_length, dist_along_seg = 0.0; | |
322 | gdouble altitude1, altitude2; | |
323 | guint16 current_chunk; | |
324 | gboolean ignore_it = FALSE; | |
325 | ||
326 | GList *iter = tr->trackpoints; | |
327 | ||
328 | if (!iter->next) /* one-point track */ | |
329 | return NULL; | |
330 | ||
331 | { /* test if there's anything worth calculating */ | |
332 | gboolean okay = FALSE; | |
333 | while ( iter ) | |
334 | { | |
335 | if ( VIK_TRACKPOINT(iter->data)->altitude != VIK_DEFAULT_ALTITUDE ) { | |
336 | okay = TRUE; break; | |
337 | } | |
338 | iter = iter->next; | |
339 | } | |
340 | if ( ! okay ) | |
341 | return NULL; | |
342 | } | |
343 | ||
344 | ||
345 | ||
346 | g_assert ( num_chunks < 16000 ); | |
347 | ||
348 | pts = g_malloc ( sizeof(gdouble) * num_chunks ); | |
349 | ||
350 | total_length = vik_track_get_length_including_gaps ( tr ); | |
351 | chunk_length = total_length / num_chunks; | |
352 | ||
353 | current_dist = 0.0; | |
354 | current_area_under_curve = 0; | |
355 | current_chunk = 0; | |
356 | current_seg_length = 0; | |
357 | ||
358 | current_seg_length = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord), | |
359 | &(VIK_TRACKPOINT(iter->next->data)->coord) ); | |
360 | altitude1 = VIK_TRACKPOINT(iter->data)->altitude; | |
361 | altitude2 = VIK_TRACKPOINT(iter->next->data)->altitude; | |
362 | dist_along_seg = 0; | |
363 | ||
364 | while ( current_chunk < num_chunks ) { | |
365 | ||
366 | /* go along current seg */ | |
367 | if ( current_seg_length && (current_seg_length - dist_along_seg) > chunk_length ) { | |
368 | dist_along_seg += chunk_length; | |
369 | ||
370 | /* / | |
371 | * pt2 * | |
372 | * /x altitude = alt_at_pt_1 + alt_at_pt_2 / 2 = altitude1 + slope * dist_value_of_pt_inbetween_pt1_and_pt2 | |
373 | * /xx avg altitude = area under curve / chunk len | |
374 | *pt1 *xxx avg altitude = altitude1 + (altitude2-altitude1)/(current_seg_length)*(dist_along_seg + (chunk_len/2)) | |
375 | * / xxx | |
376 | * / xxx | |
377 | **/ | |
378 | ||
379 | if ( ignore_it ) | |
380 | pts[current_chunk] = VIK_DEFAULT_ALTITUDE; | |
381 | else | |
382 | pts[current_chunk] = altitude1 + (altitude2-altitude1)*((dist_along_seg - (chunk_length/2))/current_seg_length); | |
383 | ||
384 | current_chunk++; | |
385 | } else { | |
386 | /* finish current seg */ | |
387 | if ( current_seg_length ) { | |
388 | gdouble altitude_at_dist_along_seg = altitude1 + (altitude2-altitude1)/(current_seg_length)*dist_along_seg; | |
389 | current_dist = current_seg_length - dist_along_seg; | |
390 | current_area_under_curve = current_dist*(altitude_at_dist_along_seg + altitude2)*0.5; | |
391 | } else { current_dist = current_area_under_curve = 0; } /* should only happen if first current_seg_length == 0 */ | |
392 | ||
393 | /* get intervening segs */ | |
394 | iter = iter->next; | |
395 | while ( iter && iter->next ) { | |
396 | current_seg_length = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord), | |
397 | &(VIK_TRACKPOINT(iter->next->data)->coord) ); | |
398 | altitude1 = VIK_TRACKPOINT(iter->data)->altitude; | |
399 | altitude2 = VIK_TRACKPOINT(iter->next->data)->altitude; | |
400 | ignore_it = VIK_TRACKPOINT(iter->next->data)->newsegment; | |
401 | ||
402 | if ( chunk_length - current_dist >= current_seg_length ) { | |
403 | current_dist += current_seg_length; | |
404 | current_area_under_curve += current_seg_length * (altitude1+altitude2) * 0.5; | |
405 | iter = iter->next; | |
406 | } else { | |
407 | break; | |
408 | } | |
409 | } | |
410 | ||
411 | /* final seg */ | |
412 | dist_along_seg = chunk_length - current_dist; | |
413 | if ( ignore_it || !iter->next ) { | |
414 | pts[current_chunk] = current_area_under_curve / current_dist; | |
415 | } | |
416 | else { | |
417 | current_area_under_curve += dist_along_seg * (altitude1 + (altitude2 - altitude1)*dist_along_seg/current_seg_length); | |
418 | pts[current_chunk] = current_area_under_curve / chunk_length; | |
419 | } | |
420 | ||
421 | current_dist = 0; | |
422 | current_chunk++; | |
423 | } | |
424 | } | |
425 | ||
426 | return pts; | |
427 | } | |
428 | ||
429 | ||
430 | void vik_track_get_total_elevation_gain(const VikTrack *tr, gdouble *up, gdouble *down) | |
431 | { | |
432 | gdouble diff; | |
433 | *up = *down = 0; | |
434 | if ( tr->trackpoints && VIK_TRACKPOINT(tr->trackpoints->data)->altitude != VIK_DEFAULT_ALTITUDE ) | |
435 | { | |
436 | GList *iter = tr->trackpoints->next; | |
437 | while (iter) | |
438 | { | |
439 | diff = VIK_TRACKPOINT(iter->data)->altitude - VIK_TRACKPOINT(iter->prev->data)->altitude; | |
440 | if ( diff > 0 ) | |
441 | *up += diff; | |
442 | else | |
443 | *down -= diff; | |
444 | iter = iter->next; | |
445 | } | |
446 | } else | |
447 | *up = *down = VIK_DEFAULT_ALTITUDE; | |
448 | } | |
449 | ||
450 | typedef struct { | |
451 | double a, b, c, d; | |
452 | } spline_coeff_t; | |
453 | ||
454 | void compute_spline(int n, double *x, double *f, spline_coeff_t *p) | |
455 | { | |
456 | double *h, *alpha, *B, *m; | |
457 | int i; | |
458 | int orig_n = n; | |
459 | double new_x[3], new_f[3]; | |
460 | ||
461 | if (n==0) return; | |
462 | if (n==1) { | |
463 | new_x[0] = x[0]; | |
464 | new_f[0] = f[0]; | |
465 | new_x[1] = x[0]+0.00001; | |
466 | new_f[1] = f[0]; | |
467 | x = new_x; | |
468 | f = new_f; | |
469 | n = 3; | |
470 | } | |
471 | if (n==2) { | |
472 | new_x[0] = x[0]; | |
473 | new_f[0] = f[0]; | |
474 | new_x[1] = x[1]; | |
475 | new_f[1] = f[1]; | |
476 | new_x[2] = x[1] + x[1]-x[0]; | |
477 | new_f[2] = f[1] + f[1]-f[0]; | |
478 | x = new_x; | |
479 | f = new_f; | |
480 | n = 3; | |
481 | } | |
482 | ||
483 | /* we're solving a linear system of equations of the form Ax = B. | |
484 | * The matrix a is tridiagonal and consists of coefficients in | |
485 | * the h[] and alpha[] arrays. | |
486 | */ | |
487 | ||
488 | h = (double *)malloc(sizeof(double) * (n-1)); | |
489 | for (i=0; i<n-1; i++) { | |
490 | h[i] = x[i+1]-x[i]; | |
491 | } | |
492 | ||
493 | alpha = (double *)malloc(sizeof(double) * (n-2)); | |
494 | for (i=0; i<n-2; i++) { | |
495 | alpha[i] = 2 * (h[i] + h[i+1]); | |
496 | } | |
497 | ||
498 | /* B[] is the vector on the right hand side of the equation */ | |
499 | B = (double *)malloc(sizeof(double) * (n-2)); | |
500 | for (i=0; i<n-2; i++) { | |
501 | B[i] = 6 * ((f[i+2] - f[i+1])/h[i+1] - (f[i+1] - f[i])/h[i]); | |
502 | } | |
503 | ||
504 | /* Now solve the n-2 by n-2 system */ | |
505 | m = (double *)malloc(sizeof(double) * (n-2)); | |
506 | for (i=1; i<=n-3; i++) { | |
507 | /* | |
508 | d0 = alpha 0 | |
509 | a0 = h1 | |
510 | c0 = h1 | |
511 | ||
512 | di = di - (ai-1 / di-1) * ci-1 | |
513 | bi = bi - (ai-1 / di-1) * bi-1 | |
514 | ; | |
515 | */ | |
516 | alpha[i] = alpha[i] - (h[i]/alpha[i-1]) * h[i]; | |
517 | B[i] = B[i] - (h[i]/alpha[i-1]) * B[i-1]; | |
518 | } | |
519 | /* xn-3 = bn-3 / dn-3; */ | |
520 | m[n-3] = B[n-3]/alpha[n-3]; | |
521 | for (i=n-4; i>=0; i--) { | |
522 | m[i] = (B[i]-h[i+1]*m[i+1])/alpha[i]; | |
523 | } | |
524 | ||
525 | for (i=0; i<orig_n-1; i++) { | |
526 | double mi, mi1; | |
527 | mi = (i==(n-2)) ? 0 : m[i]; | |
528 | mi1 = (i==0) ? 0 : m[i-1]; | |
529 | ||
530 | p[i].a = f[i+1]; | |
531 | p[i].b = (f[i+1] - f[i]) / h[i] + h[i] * (2*mi + mi1) / 6; | |
532 | p[i].c = mi/2; | |
533 | p[i].d = (mi-mi1)/(6*h[i]); | |
534 | } | |
535 | ||
536 | free(alpha); | |
537 | free(B); | |
538 | free(h); | |
539 | free(m); | |
540 | } | |
541 | ||
542 | /* by Alex Foobarian */ | |
543 | gdouble *vik_track_make_speed_map ( const VikTrack *tr, guint16 num_chunks ) | |
544 | { | |
545 | gdouble *v, *s, *t; | |
546 | gdouble duration, chunk_dur, T, s_prev, s_now; | |
547 | time_t t1, t2; | |
548 | int i, pt_count, numpts, spline; | |
549 | GList *iter; | |
550 | spline_coeff_t *p; | |
551 | GList *mytr; | |
552 | ||
553 | if ( ! tr->trackpoints ) | |
554 | return NULL; | |
555 | ||
556 | g_assert ( num_chunks < 16000 ); | |
557 | ||
558 | #ifdef XXXXXXXXXXXXXXXXXX | |
559 | iter = tr->trackpoints; | |
560 | while (iter) { | |
561 | ||
562 | } | |
563 | #endif /*XXXXXXXXXXXXXXXXXX*/ | |
564 | ||
565 | t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp; | |
566 | t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp; | |
567 | duration = t2 - t1; | |
568 | ||
569 | if ( !t1 || !t2 || !duration ) | |
570 | return NULL; | |
571 | ||
572 | if (duration < 0) { | |
573 | fprintf(stderr, "negative duration: unsorted trackpoint timestamps?\n"); | |
574 | return NULL; | |
575 | } | |
576 | pt_count = vik_track_get_tp_count(tr); | |
577 | ||
578 | v = g_malloc ( sizeof(gdouble) * num_chunks ); | |
579 | chunk_dur = duration / num_chunks; | |
580 | ||
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)); | |
584 | ||
585 | iter = tr->trackpoints->next; | |
586 | numpts = 0; | |
587 | s[0] = 0; | |
588 | t[0] = VIK_TRACKPOINT(iter->prev->data)->timestamp; | |
589 | numpts++; | |
590 | while (iter) { | |
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; | |
593 | numpts++; | |
594 | iter = iter->next; | |
595 | } | |
596 | ||
597 | compute_spline(numpts, t, s, p); | |
598 | ||
599 | /* | |
600 | printf("Got spline\n"); | |
601 | for (i=0; i<numpts-1; i++) { | |
602 | printf("a = %15f b = %15f c = %15f d = %15f\n", p[i].a, p[i].b, p[i].c, p[i].d); | |
603 | } | |
604 | */ | |
605 | ||
606 | /* the spline gives us distances at chunk_dur intervals. from these, | |
607 | * we obtain average speed in each interval. | |
608 | */ | |
609 | spline = 0; | |
610 | T = t[spline]; | |
611 | s_prev = | |
612 | p[spline].d * pow(T - t[spline+1], 3) + | |
613 | p[spline].c * pow(T - t[spline+1], 2) + | |
614 | p[spline].b * (T - t[spline+1]) + | |
615 | p[spline].a; | |
616 | for (i = 0; i < num_chunks; i++, T+=chunk_dur) { | |
617 | while (T > t[spline+1]) { | |
618 | spline++; | |
619 | } | |
620 | s_now = | |
621 | p[spline].d * pow(T - t[spline+1], 3) + | |
622 | p[spline].c * pow(T - t[spline+1], 2) + | |
623 | p[spline].b * (T - t[spline+1]) + | |
624 | p[spline].a; | |
625 | v[i] = (s_now - s_prev) / chunk_dur; | |
626 | s_prev = s_now; | |
627 | /* | |
628 | * old method of averages | |
629 | v[i] = (s[spline+1]-s[spline])/(t[spline+1]-t[spline]); | |
630 | */ | |
631 | } | |
632 | g_free(s); | |
633 | g_free(t); | |
634 | g_free(p); | |
635 | return v; | |
636 | } | |
637 | ||
638 | /* by Alex Foobarian */ | |
639 | VikTrackpoint *vik_track_get_closest_tp_by_percentage_dist ( VikTrack *tr, gdouble reldist ) | |
640 | { | |
641 | gdouble dist = vik_track_get_length_including_gaps(tr) * reldist; | |
642 | gdouble current_dist = 0.0; | |
643 | gdouble current_inc = 0.0; | |
644 | if ( tr->trackpoints ) | |
645 | { | |
646 | GList *iter = tr->trackpoints->next; | |
647 | GList *last_iter = NULL; | |
648 | while (iter) | |
649 | { | |
650 | current_inc = vik_coord_diff ( &(VIK_TRACKPOINT(iter->data)->coord), | |
651 | &(VIK_TRACKPOINT(iter->prev->data)->coord) ); | |
652 | current_dist += current_inc; | |
653 | if ( current_dist >= dist ) | |
654 | break; | |
655 | last_iter = iter; | |
656 | iter = iter->next; | |
657 | } | |
658 | if (!iter) /* passing the end the track */ | |
659 | return (last_iter ? last_iter->data : NULL); | |
660 | /* we've gone past the dist already, was prev trackpoint closer? */ | |
661 | /* should do a vik_coord_average_weighted() thingy. */ | |
662 | if ( iter->prev && abs(current_dist-current_inc-dist) < abs(current_dist-dist) ) | |
663 | iter = iter->prev; | |
664 | ||
665 | return VIK_TRACKPOINT(iter->data); | |
666 | ||
667 | } | |
668 | return NULL; | |
669 | } | |
670 | ||
671 | gboolean vik_track_get_minmax_alt ( const VikTrack *tr, gdouble *min_alt, gdouble *max_alt ) | |
672 | { | |
673 | *min_alt = 25000; | |
674 | *max_alt = -5000; | |
675 | if ( tr && tr->trackpoints && tr->trackpoints->data && (VIK_TRACKPOINT(tr->trackpoints->data)->altitude != VIK_DEFAULT_ALTITUDE) ) { | |
676 | GList *iter = tr->trackpoints->next; | |
677 | gdouble tmp_alt; | |
678 | while (iter) | |
679 | { | |
680 | tmp_alt = VIK_TRACKPOINT(iter->data)->altitude; | |
681 | if ( tmp_alt > *max_alt ) | |
682 | *max_alt = tmp_alt; | |
683 | if ( tmp_alt < *min_alt ) | |
684 | *min_alt = tmp_alt; | |
685 | iter = iter->next; | |
686 | } | |
687 | return TRUE; | |
688 | } | |
689 | return FALSE; | |
690 | } | |
691 | ||
692 | void vik_track_marshall ( VikTrack *tr, guint8 **data, guint *datalen) | |
693 | { | |
694 | GList *tps; | |
695 | GByteArray *b = g_byte_array_new(); | |
696 | guint len; | |
697 | guint intp, ntp; | |
698 | ||
699 | g_byte_array_append(b, (guint8 *)tr, sizeof(*tr)); | |
700 | ||
701 | /* we'll fill out number of trackpoints later */ | |
702 | intp = b->len; | |
703 | g_byte_array_append(b, (guint8 *)&len, sizeof(len)); | |
704 | ||
705 | tps = tr->trackpoints; | |
706 | ntp = 0; | |
707 | while (tps) { | |
708 | g_byte_array_append(b, (guint8 *)tps->data, sizeof(VikTrackpoint)); | |
709 | tps = tps->next; | |
710 | ntp++; | |
711 | } | |
712 | *(guint *)(b->data + intp) = ntp; | |
713 | ||
714 | len = (tr->comment) ? strlen(tr->comment)+1 : 0; | |
715 | g_byte_array_append(b, (guint8 *)&len, sizeof(len)); | |
716 | if (tr->comment) g_byte_array_append(b, (guint8 *)tr->comment, len); | |
717 | ||
718 | *data = b->data; | |
719 | *datalen = b->len; | |
720 | g_byte_array_free(b, FALSE); | |
721 | } | |
722 | ||
723 | VikTrack *vik_track_unmarshall (guint8 *data, guint datalen) | |
724 | { | |
725 | guint len; | |
726 | VikTrack *new_tr = vik_track_new(); | |
727 | VikTrackpoint *new_tp; | |
728 | guint ntp; | |
729 | gint i; | |
730 | ||
731 | /* only the visibility is needed */ | |
732 | new_tr->visible = ((VikTrack *)data)->visible; | |
733 | data += sizeof(*new_tr); | |
734 | ||
735 | ntp = *(guint *)data; | |
736 | data += sizeof(ntp); | |
737 | ||
738 | for (i=0; i<ntp; i++) { | |
739 | new_tp = vik_trackpoint_new(); | |
740 | memcpy(new_tp, data, sizeof(*new_tp)); | |
741 | data += sizeof(*new_tp); | |
742 | new_tr->trackpoints = g_list_append(new_tr->trackpoints, new_tp); | |
743 | } | |
744 | ||
745 | len = *(guint *)data; | |
746 | data += sizeof(len); | |
747 | if (len) { | |
748 | new_tr->comment = g_strdup((gchar *)data); | |
749 | } | |
750 | return new_tr; | |
751 | } | |
752 |