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#include <string.h>
#include <stdio.h>
#include "dive.h"
/*
* 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->start.mbar)
cyl->start.mbar = pressure;
if (!cyl->end.mbar || pressure < cyl->end.mbar)
cyl->end.mbar = pressure;
}
struct dive *fixup_dive(struct dive *dive)
{
int i;
double depthtime = 0;
int lasttime = 0;
int start = -1, end = -1;
int maxdepth = 0, mintemp = 0;
int lastdepth = 0;
int lasttemp = 0;
temperature_t *redundant_temp = NULL;
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;
if (lastdepth)
end = time;
if (depth) {
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. We care about
* the "edges" only.
*/
if (lasttemp == temp) {
if (redundant_temp)
redundant_temp->mkelvin = 0;
redundant_temp = &sample->temperature;
} else {
redundant_temp = NULL;
lasttemp = temp;
}
if (!mintemp || temp < mintemp)
mintemp = temp;
}
depthtime += (time - lasttime) * (lastdepth + depth) / 2;
lastdepth = depth;
lasttime = time;
}
if (end < 0)
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);
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)
static int alloc_samples;
static struct dive *add_sample(struct sample *sample, int time, struct dive *dive)
{
int nr = dive->samples;
struct sample *d;
if (nr >= alloc_samples) {
alloc_samples = (alloc_samples + 64) * 3 / 2;
dive = realloc(dive, dive_size(alloc_samples));
if (!dive)
return NULL;
}
dive->samples = nr+1;
d = dive->sample + nr;
*d = *sample;
d->time.seconds = time;
return 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;
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 = add_sample(as, at, res);
as++;
asamples--;
continue;
}
/* Only samples from b? */
if (at < 0) {
add_sample_b:
res = add_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 = add_sample(&sample, at, res);
as++;
bs++;
asamples--;
bsamples--;
}
}
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;
}
/* 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(gasmix_t *res, gasmix_t *a, gasmix_t *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);
}
/*
* 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)
{
int i;
struct dive *res;
if (a->when != b->when)
return NULL;
alloc_samples = 5;
res = malloc(dive_size(alloc_samples));
if (!res)
return NULL;
memset(res, 0, dive_size(alloc_samples));
res->when = a->when;
res->location = merge_text(a->location, b->location);
res->notes = merge_text(a->notes, b->notes);
MERGE_MAX(res, a, b, maxdepth.mm);
res->meandepth.mm = 0;
MERGE_MAX(res, a, b, duration.seconds);
MERGE_MAX(res, a, b, surfacetime.seconds);
MERGE_MAX(res, a, b, airtemp.mkelvin);
MERGE_MIN(res, a, b, watertemp.mkelvin);
for (i = 0; i < MAX_CYLINDERS; i++)
merge_cylinder_info(res->cylinder+i, a->cylinder + i, b->cylinder + i);
return merge_samples(res, a, b, 0);
}
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