/* dive.c */ /* maintains the internal dive list structure */ #include #include #include #include "dive.h" void add_event(struct dive *dive, int time, int type, int flags, int value, const char *name) { struct event *ev, **p; unsigned int size, len = strlen(name); size = sizeof(*ev) + len + 1; ev = malloc(size); if (!ev) return; memset(ev, 0, size); memcpy(ev->name, name, len); ev->time.seconds = time; ev->type = type; ev->flags = flags; ev->value = value; ev->next = NULL; p = &dive->events; while (*p) p = &(*p)->next; *p = ev; remember_event(name); } int get_pressure_units(unsigned int mb, const char **units) { int pressure; const char* unit; switch (output_units.pressure) { case PASCAL: pressure = mb * 100; unit = _("pascal"); break; case BAR: pressure = (mb + 500) / 1000; unit = _("bar"); break; case PSI: pressure = mbar_to_PSI(mb); unit = _("psi"); break; } if (units) *units = unit; return pressure; } double get_temp_units(unsigned int mk, const char **units) { double deg; const char *unit; if (output_units.temperature == FAHRENHEIT) { deg = mkelvin_to_F(mk); unit = UTF8_DEGREE "F"; } else { deg = mkelvin_to_C(mk); unit = UTF8_DEGREE "C"; } if (units) *units = unit; return deg; } double get_volume_units(unsigned int ml, int *frac, const char **units) { int decimals; double vol; const char *unit; switch (output_units.volume) { case LITER: vol = ml / 1000.0; unit = _("l"); decimals = 1; break; case CUFT: vol = ml_to_cuft(ml); unit = _("cuft"); decimals = 2; break; } if (frac) *frac = decimals; if (units) *units = unit; return vol; } double get_depth_units(unsigned int mm, int *frac, const char **units) { int decimals; double d; const char *unit; switch (output_units.length) { case METERS: d = mm / 1000.0; unit = _("m"); decimals = d < 20; break; case FEET: d = mm_to_feet(mm); unit = _("ft"); decimals = 0; break; } if (frac) *frac = decimals; if (units) *units = unit; return d; } double get_weight_units(unsigned int grams, int *frac, const char **units) { int decimals; double value; const char* unit; if (output_units.weight == LBS) { value = grams_to_lbs(grams); unit = _("lbs"); decimals = 0; } else { value = grams / 1000.0; unit = _("kg"); decimals = 1; } if (frac) *frac = decimals; if (units) *units = unit; return value; } struct dive *alloc_dive(void) { const int initial_samples = 5; unsigned int size; struct dive *dive; size = dive_size(initial_samples); dive = malloc(size); if (!dive) exit(1); memset(dive, 0, size); dive->alloc_samples = initial_samples; return dive; } struct sample *prepare_sample(struct dive **divep) { struct dive *dive = *divep; if (dive) { int nr = dive->samples; int alloc_samples = dive->alloc_samples; struct sample *sample; if (nr >= alloc_samples) { unsigned int size; alloc_samples = (alloc_samples * 3)/2 + 10; size = dive_size(alloc_samples); dive = realloc(dive, size); if (!dive) return NULL; dive->alloc_samples = alloc_samples; *divep = dive; } sample = dive->sample + nr; memset(sample, 0, sizeof(*sample)); return sample; } return NULL; } void finish_sample(struct dive *dive) { dive->samples++; } /* * So when we re-calculate maxdepth and meandepth, we will * not override the old numbers if they are close to the * new ones. * * Why? Because a dive computer may well actually track the * max depth and mean depth at finer granularity than the * samples it stores. So it's possible that the max and mean * have been reported more correctly originally. * * Only if the values calculated from the samples are clearly * different do we override the normal depth values. * * This considers 1m to be "clearly different". That's * a totally random number. */ static void update_depth(depth_t *depth, int new) { if (new) { int old = depth->mm; if (abs(old - new) > 1000) depth->mm = new; } } static void update_duration(duration_t *duration, int new) { if (new) duration->seconds = new; } static void update_temperature(temperature_t *temperature, int new) { if (new) { int old = temperature->mkelvin; if (abs(old - new) > 1000) temperature->mkelvin = new; } } static void fixup_pressure(struct dive *dive, struct sample *sample) { unsigned int pressure, index; cylinder_t *cyl; pressure = sample->cylinderpressure.mbar; if (!pressure) return; index = sample->cylinderindex; if (index >= MAX_CYLINDERS) return; cyl = dive->cylinder + index; if (!cyl->sample_start.mbar) cyl->sample_start.mbar = pressure; cyl->sample_end.mbar = pressure; } /* * If the cylinder tank pressures are within half a bar * (about 8 PSI) of the sample pressures, we consider it * to be a rounding error, and throw them away as redundant. */ static int same_rounded_pressure(pressure_t a, pressure_t b) { return abs(a.mbar - b.mbar) <= 500; } static void sanitize_gasmix(struct gasmix *mix) { unsigned int o2, he; o2 = mix->o2.permille; he = mix->he.permille; /* Regular air: leave empty */ if (!he) { if (!o2) return; /* 20.9% or 21% O2 is just air */ if (o2 >= 209 && o2 <= 210) { mix->o2.permille = 0; return; } } /* Sane mix? */ if (o2 <= 1000 && he <= 1000 && o2+he <= 1000) return; fprintf(stderr, "Odd gasmix: %u O2 %u He\n", o2, he); memset(mix, 0, sizeof(*mix)); } /* * See if the size/workingpressure looks like some standard cylinder * size, eg "AL80". */ static void match_standard_cylinder(cylinder_type_t *type) { double cuft; int psi, len; const char *fmt; char buffer[20], *p; /* Do we already have a cylinder description? */ if (type->description) return; cuft = ml_to_cuft(type->size.mliter); cuft *= to_ATM(type->workingpressure); psi = to_PSI(type->workingpressure); switch (psi) { case 2300 ... 2500: /* 2400 psi: LP tank */ fmt = "LP%d"; break; case 2600 ... 2700: /* 2640 psi: LP+10% */ fmt = "LP%d"; break; case 2900 ... 3100: /* 3000 psi: ALx tank */ fmt = "AL%d"; break; case 3400 ... 3500: /* 3442 psi: HP tank */ fmt = "HP%d"; break; case 3700 ... 3850: /* HP+10% */ fmt = "HP%d+"; break; default: return; } len = snprintf(buffer, sizeof(buffer), fmt, (int) (cuft+0.5)); p = malloc(len+1); if (!p) return; memcpy(p, buffer, len+1); type->description = p; } /* * There are two ways to give cylinder size information: * - total amount of gas in cuft (depends on working pressure and physical size) * - physical size * * where "physical size" is the one that actually matters and is sane. * * We internally use physical size only. But we save the workingpressure * so that we can do the conversion if required. */ static void sanitize_cylinder_type(cylinder_type_t *type) { double volume_of_air, atm, volume; /* If we have no working pressure, it had *better* be just a physical size! */ if (!type->workingpressure.mbar) return; /* No size either? Nothing to go on */ if (!type->size.mliter) return; if (input_units.volume == CUFT) { /* confusing - we don't really start from ml but millicuft !*/ volume_of_air = cuft_to_l(type->size.mliter); atm = to_ATM(type->workingpressure); /* working pressure in atm */ volume = volume_of_air / atm; /* milliliters at 1 atm: "true size" */ type->size.mliter = volume + 0.5; } /* Ok, we have both size and pressure: try to match a description */ match_standard_cylinder(type); } static void sanitize_cylinder_info(struct dive *dive) { int i; for (i = 0; i < MAX_CYLINDERS; i++) { sanitize_gasmix(&dive->cylinder[i].gasmix); sanitize_cylinder_type(&dive->cylinder[i].type); } } /* some events should never be thrown away */ static gboolean is_potentially_redundant(struct event *event) { if (!strcmp(event->name, "gaschange")) return FALSE; if (!strcmp(event->name, "bookmark")) return FALSE; if (!strcmp(event->name, "heading")) return FALSE; return TRUE; } /* match just by name - we compare the details in the code that uses this helper */ static struct event *find_previous_event(struct dive *dive, struct event *event) { struct event *ev = dive->events; struct event *previous = NULL; if (!event->name) return NULL; while (ev && ev != event) { if(ev->name && !strcmp(ev->name, event->name)) previous = ev; ev = ev->next; } return previous; } struct dive *fixup_dive(struct dive *dive) { int i,j; double depthtime = 0; int lasttime = 0; int lastindex = -1; int start = -1, end = -1; int maxdepth = 0, mintemp = 0; int lastdepth = 0; int lasttemp = 0, lastpressure = 0; int pressure_delta[MAX_CYLINDERS] = {INT_MAX, }; struct event *event; add_people(dive->buddy); add_people(dive->divemaster); add_location(dive->location); add_suit(dive->suit); sanitize_cylinder_info(dive); for (i = 0; i < dive->samples; i++) { struct sample *sample = dive->sample + i; int time = sample->time.seconds; int depth = sample->depth.mm; int temp = sample->temperature.mkelvin; int pressure = sample->cylinderpressure.mbar; int index = sample->cylinderindex; if (index == lastindex) { /* Remove duplicate redundant pressure information */ if (pressure == lastpressure) sample->cylinderpressure.mbar = 0; /* check for simply linear data in the samples +INT_MAX means uninitialized, -INT_MAX means not linear */ if (pressure_delta[index] != -INT_MAX && lastpressure) { if (pressure_delta[index] == INT_MAX) { pressure_delta[index] = abs(pressure - lastpressure); } else { int cur_delta = abs(pressure - lastpressure); if (cur_delta && abs(cur_delta - pressure_delta[index]) > 150) { /* ok the samples aren't just a linearisation * between start and end */ pressure_delta[index] = -INT_MAX; } } } } lastindex = index; lastpressure = pressure; if (lastdepth > SURFACE_THRESHOLD) end = time; if (depth > SURFACE_THRESHOLD) { if (start < 0) start = lasttime; if (depth > maxdepth) maxdepth = depth; } fixup_pressure(dive, sample); if (temp) { /* * If we have consecutive identical * temperature readings, throw away * the redundant ones. */ if (lasttemp == temp) sample->temperature.mkelvin = 0; else lasttemp = temp; if (!mintemp || temp < mintemp) mintemp = temp; } depthtime += (time - lasttime) * (lastdepth + depth) / 2; lastdepth = depth; lasttime = time; } dive->start = start; dive->end = end; /* if all the samples for a cylinder have pressure data that * is basically equidistant throw out the sample cylinder pressure * information but make sure we still have a valid start and end * pressure * this happens when DivingLog decides to linearalize the * pressure between beginning and end and for strange reasons * decides to put that in the sample data as if it came from * the dive computer; we don't want that (we'll visualize with * constant SAC rate instead) * WARNING WARNING - I have only seen this in single tank dives * --- maybe I should try to create a multi tank dive and see what * --- divinglog does there - but the code right now is only tested * --- for the single tank case */ for (j = 0; j < MAX_CYLINDERS; j++) { if (abs(pressure_delta[j]) != INT_MAX) { cylinder_t *cyl = dive->cylinder + j; for (i = 0; i < dive->samples; i++) if (dive->sample[i].cylinderindex == j) dive->sample[i].cylinderpressure.mbar = 0; if (! cyl->start.mbar) cyl->start.mbar = cyl->sample_start.mbar; if (! cyl->end.mbar) cyl->end.mbar = cyl->sample_end.mbar; cyl->sample_start.mbar = 0; cyl->sample_end.mbar = 0; } } if (end < 0) { /* Assume an ascent/descent rate of 9 m/min */ int depth = dive->maxdepth.mm; int asc_desc_time = depth*60/9000; int duration = dive->duration.seconds; /* Some sanity checks against insane dives */ if (duration < 2) duration = 2; if (asc_desc_time * 2 >= duration) asc_desc_time = duration/2; dive->meandepth.mm = depth*(duration-asc_desc_time)/duration; return dive; } update_duration(&dive->duration, end - start); if (start != end) depthtime /= (end - start); update_depth(&dive->meandepth, depthtime); update_temperature(&dive->watertemp, mintemp); update_depth(&dive->maxdepth, maxdepth); for (i = 0; i < MAX_CYLINDERS; i++) { cylinder_t *cyl = dive->cylinder + i; add_cylinder_description(&cyl->type); if (same_rounded_pressure(cyl->sample_start, cyl->start)) cyl->start.mbar = 0; if (same_rounded_pressure(cyl->sample_end, cyl->end)) cyl->end.mbar = 0; } for (i = 0; i < MAX_WEIGHTSYSTEMS; i++) { weightsystem_t *ws = dive->weightsystem + i; add_weightsystem_description(ws); } /* events are stored as a linked list, so the concept of * "consecutive, identical events" is somewhat hard to * implement correctly (especially given that on some dive * computers events are asynchronous, so they can come in * between what would be the non-constant sample rate). * * So what we do is that we throw away clearly redundant * events that are fewer than 61 seconds apart (assuming there * is no dive computer with a sample rate of more than 60 * seconds... that would be pretty pointless to plot the * profile with) * We first only mark the events for deletion so that we * still know when the previous event happened. */ event = dive->events; while (event) { struct event *prev; if (is_potentially_redundant(event)) { prev = find_previous_event(dive, event); if (prev && prev->value == event->value && prev->flags == event->flags && event->time.seconds - prev->time.seconds < 61) event->deleted = TRUE; } event = event->next; } event = dive->events; while (event) { if (event->next && event->next->deleted) { struct event *nextnext = event->next->next; free(event->next); event->next = nextnext; } else { event = event->next; } } return dive; } /* Don't pick a zero for MERGE_MIN() */ #define MERGE_MAX(res, a, b, n) res->n = MAX(a->n, b->n) #define MERGE_MIN(res, a, b, n) res->n = (a->n)?(b->n)?MIN(a->n, b->n):(a->n):(b->n) #define MERGE_TXT(res, a, b, n) res->n = merge_text(a->n, b->n) #define MERGE_NONZERO(res, a, b, n) res->n = a->n ? a->n : b->n #define MERGE_MAX_PREFDL(res, dl, a, b, n) res->n = (dl && dl->n) ? dl->n : MAX(a->n, b->n) #define MERGE_MIN_PREFDL(res, dl, a, b, n) res->n = (dl && dl->n) ? dl->n : (a->n)?(b->n)?MIN(a->n, b->n):(a->n):(b->n) static struct dive *add_sample(struct sample *sample, int time, struct dive *dive) { struct sample *p = prepare_sample(&dive); if (!p) return NULL; *p = *sample; p->time.seconds = time; finish_sample(dive); return dive; } /* * This is like add_sample(), but if the distance from the last sample * is excessive, we add two surface samples in between. * * This is so that if you merge two non-overlapping dives, we make sure * that the time in between the dives is at the surface, not some "last * sample that happened to be at a depth of 1.2m". */ static struct dive *merge_one_sample(struct sample *sample, int time, struct dive *dive) { int last = dive->samples-1; if (last >= 0) { static struct sample surface; int last_time = dive->sample[last].time.seconds; if (time > last_time + 60) { dive = add_sample(&surface, last_time+20, dive); dive = add_sample(&surface, time - 20, dive); } } return add_sample(sample, time, dive); } /* * Merge samples. Dive 'a' is "offset" seconds before Dive 'b' */ static struct dive *merge_samples(struct dive *res, struct dive *a, struct dive *b, int offset) { int asamples = a->samples; int bsamples = b->samples; struct sample *as = a->sample; struct sample *bs = b->sample; /* * We want a positive sample offset, so that sample * times are always positive. So if the samples for * 'b' are before the samples for 'a' (so the offset * is negative), we switch a and b around, and use * the reverse offset. */ if (offset < 0) { offset = -offset; asamples = bsamples; bsamples = a->samples; as = bs; bs = a->sample; } for (;;) { int at, bt; struct sample sample; if (!res) return NULL; at = asamples ? as->time.seconds : -1; bt = bsamples ? bs->time.seconds + offset : -1; /* No samples? All done! */ if (at < 0 && bt < 0) return fixup_dive(res); /* Only samples from a? */ if (bt < 0) { add_sample_a: res = merge_one_sample(as, at, res); as++; asamples--; continue; } /* Only samples from b? */ if (at < 0) { add_sample_b: res = merge_one_sample(bs, bt, res); bs++; bsamples--; continue; } if (at < bt) goto add_sample_a; if (at > bt) goto add_sample_b; /* same-time sample: add a merged sample. Take the non-zero ones */ sample = *bs; if (as->depth.mm) sample.depth = as->depth; if (as->temperature.mkelvin) sample.temperature = as->temperature; if (as->cylinderpressure.mbar) sample.cylinderpressure = as->cylinderpressure; if (as->cylinderindex) sample.cylinderindex = as->cylinderindex; res = merge_one_sample(&sample, at, res); as++; bs++; asamples--; bsamples--; } } static struct dive *copy_samples(struct dive *res, struct dive *src) { int samples = src->samples; struct sample *s = src->sample; while (samples) { if (!res) return NULL; res = add_sample(s, s->time.seconds, res); s++; samples--; } return fixup_dive(res); } static char *merge_text(const char *a, const char *b) { char *res; if (!a || !*a) return (char *)b; if (!b || !*b) return (char *)a; if (!strcmp(a,b)) return (char *)a; res = malloc(strlen(a) + strlen(b) + 9); if (!res) return (char *)a; sprintf(res, _("(%s) or (%s)"), a, b); return res; } #define SORT(a,b,field) \ if (a->field != b->field) return a->field < b->field ? -1 : 1 static int sort_event(struct event *a, struct event *b) { SORT(a,b,time.seconds); SORT(a,b,type); SORT(a,b,flags); SORT(a,b,value); return strcmp(a->name, b->name); } static void merge_events(struct dive *res, struct dive *src1, struct dive *src2, int offset) { struct event *a, *b; struct event **p = &res->events; /* Always use positive offsets */ if (offset < 0) { struct dive *tmp; offset = -offset; tmp = src1; src1 = src2; src2 = tmp; } a = src1->events; b = src2->events; while (b) { b->time.seconds += offset; b = b->next; } b = src2->events; while (a || b) { int s; if (!b) { *p = a; break; } if (!a) { *p = b; break; } s = sort_event(a, b); /* Pick b */ if (s > 0) { *p = b; p = &b->next; b = b->next; continue; } /* Pick 'a' or neither */ if (s < 0) { *p = a; p = &a->next; } a = a->next; continue; } } /* Pick whichever has any info (if either). Prefer 'a' */ static void merge_cylinder_type(cylinder_type_t *res, cylinder_type_t *a, cylinder_type_t *b) { if (a->size.mliter) b = a; *res = *b; } static void merge_cylinder_mix(struct gasmix *res, struct gasmix *a, struct gasmix *b) { if (a->o2.permille) b = a; *res = *b; } static void merge_cylinder_info(cylinder_t *res, cylinder_t *a, cylinder_t *b) { merge_cylinder_type(&res->type, &a->type, &b->type); merge_cylinder_mix(&res->gasmix, &a->gasmix, &b->gasmix); MERGE_MAX(res, a, b, start.mbar); MERGE_MIN(res, a, b, end.mbar); } static void merge_weightsystem_info(weightsystem_t *res, weightsystem_t *a, weightsystem_t *b) { if (!a->weight.grams) a = b; *res = *a; } static void merge_equipment(struct dive *res, struct dive *a, struct dive *b) { int i; for (i = 0; i < MAX_CYLINDERS; i++) merge_cylinder_info(res->cylinder+i, a->cylinder + i, b->cylinder + i); for (i = 0; i < MAX_WEIGHTSYSTEMS; i++) merge_weightsystem_info(res->weightsystem+i, a->weightsystem + i, b->weightsystem + i); } /* * When merging two dives, this picks the trip from one, and removes it * from the other. * * The 'next' dive is not involved in the dive merging, but is the dive * that will be the next dive after the merged dive. */ static void pick_trip(struct dive *res, struct dive *pick) { tripflag_t tripflag = pick->tripflag; dive_trip_t *trip = pick->divetrip; res->tripflag = tripflag; add_dive_to_trip(res, trip); } /* * Pick a trip for a dive */ static void merge_trip(struct dive *res, struct dive *a, struct dive *b) { /* * The larger tripflag is more relevant: we prefer * take manually assigned trips over auto-generated * ones. */ if (a->tripflag > b->tripflag) goto pick_a; if (a->tripflag < b->tripflag) goto pick_b; /* * Ok, so the divetrips are equally "important". * Pick the one with the better description. */ if (!a->location) goto pick_b; if (!b->location) goto pick_a; if (!a->notes) goto pick_b; if (!b->notes) goto pick_a; /* * Ok, so both have location and notes. * Pick the earlier one. */ if (a->when < b->when) goto pick_a; goto pick_b; pick_a: b = a; pick_b: pick_trip(res, b); } /* * Sample 's' is between samples 'a' and 'b'. It is 'offset' seconds before 'b'. * * If 's' and 'a' are at the same time, offset is 0, and b is NULL. */ static int compare_sample(struct sample *s, struct sample *a, struct sample *b, int offset) { unsigned int depth = a->depth.mm; int diff; if (offset) { unsigned int interval = b->time.seconds - a->time.seconds; unsigned int depth_a = a->depth.mm; unsigned int depth_b = b->depth.mm; if (offset > interval) return -1; /* pick the average depth, scaled by the offset from 'b' */ depth = (depth_a * offset) + (depth_b * (interval - offset)); depth /= interval; } diff = s->depth.mm - depth; if (diff < 0) diff = -diff; /* cut off at one meter difference */ if (diff > 1000) diff = 1000; return diff*diff; } /* * Calculate a "difference" in samples between the two dives, given * the offset in seconds between them. Use this to find the best * match of samples between two different dive computers. */ static unsigned long sample_difference(struct dive *a, struct dive *b, int offset) { int asamples = a->samples; int bsamples = b->samples; struct sample *as = a->sample; struct sample *bs = b->sample; unsigned long error = 0; int start = -1; if (!asamples || !bsamples) return 0; /* * skip the first sample - this way we know can always look at * as/bs[-1] to look at the samples around it in the loop. */ as++; bs++; asamples--; bsamples--; for (;;) { int at, bt, diff; /* If we run out of samples, punt */ if (!asamples) return INT_MAX; if (!bsamples) return INT_MAX; at = as->time.seconds; bt = bs->time.seconds + offset; /* b hasn't started yet? Ignore it */ if (bt < 0) { bs++; bsamples--; continue; } if (at < bt) { diff = compare_sample(as, bs-1, bs, bt - at); as++; asamples--; } else if (at > bt) { diff = compare_sample(bs, as-1, as, at - bt); bs++; bsamples--; } else { diff = compare_sample(as, bs, NULL, 0); as++; bs++; asamples--; bsamples--; } /* Invalid comparison point? */ if (diff < 0) continue; if (start < 0) start = at; error += diff; if (at - start > 120) break; } return error; } /* * Dive 'a' is 'offset' seconds before dive 'b' * * This is *not* because the dive computers clocks aren't in sync, * it is because the dive computers may "start" the dive at different * points in the dive, so the sample at time X in dive 'a' is the * same as the sample at time X+offset in dive 'b'. * * For example, some dive computers take longer to "wake up" when * they sense that you are under water (ie Uemis Zurich if it was off * when the dive started). And other dive computers have different * depths that they activate at, etc etc. * * If we cannot find a shared offset, don't try to merge. */ static int find_sample_offset(struct dive *a, struct dive *b) { int offset, best; unsigned long max; /* No samples? Merge at any time (0 offset) */ if (!a->samples) return 0; if (!b->samples) return 0; /* * Common special-case: merging a dive that came from * the same dive computer, so the samples are identical. * Check this first, without wasting time trying to find * some minimal offset case. */ best = 0; max = sample_difference(a, b, 0); if (!max) return 0; /* * Otherwise, look if we can find anything better within * a thirty second window.. */ for (offset = -30; offset <= 30; offset++) { unsigned long diff; diff = sample_difference(a, b, offset); if (diff > max) continue; best = offset; max = diff; } return best; } /* * This could do a lot more merging. Right now it really only * merges almost exact duplicates - something that happens easily * with overlapping dive downloads. */ struct dive *try_to_merge(struct dive *a, struct dive *b, gboolean prefer_downloaded) { int offset = 0; /* * This assumes that the clocks on the dive computers are * roughly synchronized. */ if ((a->when >= b->when + 60) || (a->when <= b->when - 60)) return NULL; if (prefer_downloaded && a->when != b->when) return NULL; if (!prefer_downloaded) { /* Dive 'a' is 'offset' seconds before dive 'b' */ offset = find_sample_offset(a, b); if (offset > 120 || offset < -120) return NULL; } return merge_dives(a, b, offset, prefer_downloaded); } struct dive *merge_dives(struct dive *a, struct dive *b, int offset, gboolean prefer_downloaded) { struct dive *res = alloc_dive(); struct dive *dl = NULL; if (a->downloaded) dl = a; else if (b->downloaded) dl = b; res->when = a->when; res->selected = a->selected || b->selected; merge_trip(res, a, b); MERGE_NONZERO(res, a, b, latitude); MERGE_NONZERO(res, a, b, longitude); MERGE_TXT(res, a, b, location); MERGE_TXT(res, a, b, notes); MERGE_TXT(res, a, b, buddy); MERGE_TXT(res, a, b, divemaster); MERGE_MAX(res, a, b, rating); MERGE_TXT(res, a, b, suit); MERGE_MAX(res, a, b, number); MERGE_MAX_PREFDL(res, dl, a, b, maxdepth.mm); res->meandepth.mm = 0; MERGE_NONZERO(res, a, b, salinity); MERGE_NONZERO(res, a, b, visibility); MERGE_NONZERO(res, a, b, surface_pressure.mbar); MERGE_MAX_PREFDL(res, dl, a, b, duration.seconds); MERGE_MAX_PREFDL(res, dl, a, b, surfacetime.seconds); MERGE_MAX_PREFDL(res, dl, a, b, airtemp.mkelvin); MERGE_MIN_PREFDL(res, dl, a, b, watertemp.mkelvin); merge_equipment(res, a, b); if (dl) { res->events = dl->events; return copy_samples(res, dl); } else { merge_events(res, a, b, offset); return merge_samples(res, a, b, offset); } }