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Remove linear pressure interpolation detection code

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Dirk says that divinglog hasn't been doing the linear pressure
interpolation for a long while, so we're doing extra dive fixups that
really aren't needed any more.

Also, the code is actually buggy: it only ever worked on the first
cylinder anyway (because only the first cylinder pressure_delta[] would
be initialized).  That was probably perfectly fine in practice, since
it's unlikely that many tech divers used old versions of divinglog
anyway, so the bug per se isn't a reason to remove it - but it is a sign
that the code was a bit hard to read, so let's get rid of it if there is
no reason to maintain it or fix it.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
This commit is contained in:
Linus Torvalds 2016-04-02 07:28:03 -05:00 committed by Dirk Hohndel
parent 7be962bfc2
commit eb5907ab3b
1 changed files with 2 additions and 50 deletions
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52
core/dive.c
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@ -1306,17 +1306,12 @@ static void fixup_dc_cylinder_index(struct dive *dive, struct divecomputer *dc)
}
}
/*
* Simplify dc pressure information:
* (a) Remove redundant pressure information
* (b) Remove linearly interpolated pressure data
*/
/* Remove redundant pressure information */
static void simplify_dc_pressures(struct dive *dive, struct divecomputer *dc)
{
int i, j;
int i;
int lastindex = -1;
int lastpressure = 0, lasto2pressure = 0;
int pressure_delta[MAX_CYLINDERS] = { INT_MAX, };
for (i = 0; i < dc->samples; i++) {
struct sample *sample = dc->sample + i;
@ -1325,60 +1320,17 @@ static void simplify_dc_pressures(struct dive *dive, struct divecomputer *dc)
int index;
index = sample->sensor;
if (index == lastindex) {
/* Remove duplicate redundant pressure information */
if (pressure == lastpressure)
sample->cylinderpressure.mbar = 0;
if (o2_pressure == lasto2pressure)
sample->o2cylinderpressure.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;
lasto2pressure = o2_pressure;
}
/* 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 < dc->samples; i++)
if (dc->sample[i].sensor == j)
dc->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;
}
}
}
/* FIXME! sensor -> cylinder mapping? */