diff options
Diffstat (limited to 'core/divelist.c')
| -rw-r--r-- | core/divelist.c | 168 |
1 files changed, 137 insertions, 31 deletions
diff --git a/core/divelist.c b/core/divelist.c index 162d87614..58376eef9 100644 --- a/core/divelist.c +++ b/core/divelist.c @@ -205,42 +205,19 @@ int const cns_table[][3] = { { 600, 720 * 60, 720 * 60 } }; -/* this only gets called if dive->maxcns == 0 which means we know that - * none of the divecomputers has tracked any CNS for us - * so we calculated it "by hand" */ -static int calculate_cns(struct dive *dive) +/* Calculate the CNS for a single dive */ +double calculate_cns_dive(struct dive *dive) { - int i, divenr; + int n; size_t j; - double cns = 0.0; struct divecomputer *dc = &dive->dc; - struct dive *prev_dive; - timestamp_t endtime; - - /* shortcut */ - if (dive->cns) - return dive->cns; - /* - * Do we start with a cns loading from a previous dive? - * Check if we did a dive 12 hours prior, and what cns we had from that. - * Then apply ha 90min halftime to see whats left. - */ - divenr = get_divenr(dive); - if (divenr) { - prev_dive = get_dive(divenr - 1); - if (prev_dive) { - endtime = dive_endtime(prev_dive); - if (dive->when < (endtime + 3600 * 12)) { - cns = calculate_cns(prev_dive); - cns = cns * 1 / pow(2, (dive->when - endtime) / (90.0 * 60.0)); - } - } - } - /* Caclulate the cns for each sample in this dive and sum them */ - for (i = 1; i < dc->samples; i++) { + double cns = 0.0; + + /* Caclulate the CNS for each sample in this dive and sum them */ + for (n = 1; n < dc->samples; n++) { int t; int po2; - struct sample *sample = dc->sample + i; + struct sample *sample = dc->sample + n; struct sample *psample = sample - 1; t = sample->time.seconds - psample->time.seconds; if (sample->setpoint.mbar) { @@ -259,6 +236,135 @@ static int calculate_cns(struct dive *dive) j--; cns += ((double)t) / ((double)cns_table[j][1]) * 100; } + + return cns; +} + +/* this only gets called if dive->maxcns == 0 which means we know that + * none of the divecomputers has tracked any CNS for us + * so we calculated it "by hand" */ +static int calculate_cns(struct dive *dive) +{ + int i, divenr; + double cns = 0.0; + timestamp_t last_starttime, last_endtime = 0; + + /* shortcut */ + if (dive->cns) + return dive->cns; + + divenr = get_divenr(dive); + i = divenr >= 0 ? divenr : dive_table.nr; +#if DECO_CALC_DEBUG & 2 + if (i >= 0 && i < dive_table.nr) + printf("\n\n*** CNS for dive #%d %d\n", i, get_dive(i)->number); + else + printf("\n\n*** CNS for dive #%d\n", i); +#endif + /* Look at next dive in dive list table and correct i when needed */ + while (i < dive_table.nr - 1) { + struct dive *pdive = get_dive(i); + if (!pdive || pdive->when > dive->when) + break; + i++; + } + /* Look at previous dive in dive list table and correct i when needed */ + while (i > 0) { + struct dive *pdive = get_dive(i - 1); + if (!pdive || pdive->when < dive->when) + break; + i--; + } +#if DECO_CALC_DEBUG & 2 + printf("Dive number corrected to #%d\n", i); +#endif + last_starttime = dive->when; + /* Walk backwards to check previous dives - how far do we need to go back? */ + while (i--) { + if (i == divenr && i > 0) + i--; +#if DECO_CALC_DEBUG & 2 + printf("Check if dive #%d %d has to be considered as prev dive: ", i, get_dive(i)->number); +#endif + struct dive *pdive = get_dive(i); + /* we don't want to mix dives from different trips as we keep looking + * for how far back we need to go */ + if (dive->divetrip && pdive->divetrip != dive->divetrip) { +#if DECO_CALC_DEBUG & 2 + printf("No - other dive trip\n"); +#endif + continue; + } + if (!pdive || pdive->when >= dive->when || dive_endtime(pdive) + 12 * 60 * 60 < last_starttime) { +#if DECO_CALC_DEBUG & 2 + printf("No\n"); +#endif + break; + } + last_starttime = pdive->when; +#if DECO_CALC_DEBUG & 2 + printf("Yes\n"); +#endif + } + /* Walk forward and add dives and surface intervals to CNS */ + while (++i < dive_table.nr) { +#if DECO_CALC_DEBUG & 2 + printf("Check if dive #%d %d will be really added to CNS calc: ", i, get_dive(i)->number); +#endif + struct dive *pdive = get_dive(i); + /* again skip dives from different trips */ + if (dive->divetrip && dive->divetrip != pdive->divetrip) { +#if DECO_CALC_DEBUG & 2 + printf("No - other dive trip\n"); +#endif + continue; + } + /* Don't add future dives */ + if (pdive->when >= dive->when) { +#if DECO_CALC_DEBUG & 2 + printf("No - future or same dive\n"); +#endif + break; + } + /* Don't add the copy of the dive itself */ + if (i == divenr) { +#if DECO_CALC_DEBUG & 2 + printf("No - copy of dive\n"); +#endif + continue; + } +#if DECO_CALC_DEBUG & 2 + printf("Yes\n"); +#endif + + /* CNS reduced with 90min halftime during surface interval */ + if (last_endtime) + cns /= pow(2, (pdive->when - last_endtime) / (90.0 * 60.0)); +#if DECO_CALC_DEBUG & 2 + printf("CNS after surface interval: %f\n", cns); +#endif + + cns += calculate_cns_dive(pdive); +#if DECO_CALC_DEBUG & 2 + printf("CNS after previous dive: %f\n", cns); +#endif + + last_starttime = pdive->when; + last_endtime = dive_endtime(pdive); + } + + /* CNS reduced with 90min halftime during surface interval */ + if (last_endtime) + cns /= pow(2, (dive->when - last_endtime) / (90.0 * 60.0)); +#if DECO_CALC_DEBUG & 2 + printf("CNS after last surface interval: %f\n", cns); +#endif + + cns += calculate_cns_dive(dive); +#if DECO_CALC_DEBUG & 2 + printf("CNS after dive: %f\n", cns); +#endif + /* save calculated cns in dive struct */ dive->cns = lrint(cns); return dive->cns; |