Commit graph

254 commits

Author SHA1 Message Date
Dirk Hohndel
6d69325185 For divecomputers without samples don't lose other data for profile
We create a fake divecomputer in order to draw a reasonable profile, but
when setting that up we used an empty divecomputer instead of starting
with the one that we have. This lost data (e.g., the model name of the
dc).

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-26 11:44:24 -08:00
Linus Torvalds
308d71ec39 Take incompressibility of gas into account at higher pressures
This creates a helper function called "gas_volume()" that takes the
cylinder and a particular pressure, and returns the estimated volume of
the gas at surface pressure, including proper approximation of the
incompressibility of gas.

It very much is an approximation, but it's closer to reality than
assuming a pure ideal gas.  See for example compressibility at

    http://en.wikipedia.org/wiki/Compressibility_factor

Suggested-by: Jukka Lind <jukka.lind@iki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-25 16:48:16 -08:00
Lubomir I. Ivanov
aa5f1f0ce2 Show a "No Events" label when there are no events in the filter dialog
Uses profile.c:evn_foreach() to retrieve the number of events, which
if zero, no table is added in the dialog and the label is added instead.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-25 13:56:22 -08:00
Linus Torvalds
bc5f82990d Fix divide-by-zero bug in statistics.c
GET_LOCAL_SAC did not check if the two entries had different time stamps
and could therefore cause a divide-by-zero. x86 doesn't fault on that -
it's still wrong. This now calls a function that does proper checking of
all the values involved in the calculation.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-20 21:24:08 -08:00
Dirk Hohndel
0755cc522b Show the actice divecomputer's data in the Info notebook
While the profile switched between different divecomputers, the Dive Info
notebook always showed either information from the first divecomputer or
(with some of the recent changes) information that had been collected from
all divecomputers and somehow consolidated for the dive.

With this commit we now show the data from the same divecomputer that is
also shown in the profile (which means if some data is available from one
of the divecomputers and not from another that will be correctly reflected
in the Dive Info notebook as the user cycles through the divecomputers.

This does beg the question if we should have some kind of "best data
available, considering all divecomputers" mode - but that's definitely not
something I'll tackle prior to 3.0.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-09 06:17:25 -08:00
Dirk Hohndel
1511271201 Add maxdepth back to the dive structure
Populate during dive fixup as the maximum depth shown by all the
divecomputers. Use this value (instead of the one in the first
divecomputer) in printing, statistics, etc.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-08 20:44:04 -08:00
Linus Torvalds
926fcef2a1 Do more dive fixup for each dive computer
In commit b6c9301e58 ("Move more dive computer filled data to the
divecomputer structure") we moved the fields that get filled in by the
dive computers to be per-divecomputer data structures.

This patch re-creates some of those fields back in the "struct dive",
but now the fields are initialized to be a reasonable average from the
dive computer data.  We already did some of this for the temperature
min/max fields for the statistics, so this just continues that trend.

The goal is to make it easy to look at "dive values" without having to
iterate over dive computers every time you do.  Just do it once in
"fixup_dive()" instead.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-08 18:22:30 -08:00
Dirk Hohndel
61861d2611 Clean up the handling of surface pressure
There are two ways to look at surface pressure. One is to say "what was
the surface pressure during that dive?" - in that case we now return an
average over the pressure reported by the different divecomputers (or the
standard 1013mbar if none reported any).

Or you want to do specific calculations for a specific divecomputer - in
which case we access only the pressure reported by THAT divecomputer, if
present (and fall back to the previous case, otherwise).

We still have lots of places in Subsurface that only act on the first
divecomputer. As a side effect of this change we now make this more
obvious as we in those cases pass a pointer to the first divecomputer
explicitly to the calculations.

Either way, this commit should prevent us from ever mistakenly basing our
calculations on a surface pressure of 0 (which is the initial bug in
deco.c that triggered all this).

Similar changes need to be made for other elements that we currently only
use from the first divecomputer, i.e., salinity.

Reported-by: Robert C. Helling <helling@atdotde.de>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-09 08:01:59 +11:00
Henrik Brautaset Aronsen
3fd6fd6e5b Align last temperature text end of temperature plot line
The temperature plot line was drawn to the end of the dive, but the last
temperature plot text was printed near the last temperature *sample*.

This was most visible on dives/test27.xml where two "20˚C" were
printed on top of each other at the start of the dive, while nothing
was printed at the end.

Signed-off-by: Henrik Brautaset Aronsen <subsurface@henrik.synth.no>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-06 06:30:21 +11:00
Dirk Hohndel
46a9a2b4d7 Mark missing strings for translation
Linus and Jan forgot to do so...

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-04 18:04:50 +11:00
Linus Torvalds
f507b05927 Get rid of dive->{start,end}
We had this special logic to not show the end of a dive when a dive
computer shows a series of very shallow samples (basically snorkeling
back to shore after the dive ended).  However, that logic ended up being
global per dive, which is very annoying when you have two or more dive
computers, and it decides to cut off the second one because the first
one surfaces.

So get rid of this per-dive state, and just use the plot-info 'maxtime'
field for this (we never used the 'start' case anyway).  That way we
will properly cut off boring surface entries only when they are past the
end of the interesting entries of *all* dive computers, and we won't be
cutting things short.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-04 06:48:34 +11:00
Dirk Hohndel
4ddea283a5 Imitialize gc y range for GF factor print
It seemed so smart to just base the coordinates on what's already in the
graphics context. Except that we apparently got a 0 to 0 range for y
coordinates if there are no pressure samples for a dive.

This fixes the problem and GF values are shown even for dives without
pressure samples.

Reported-by: Miika Turkia <miika.turkia@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-03 12:47:32 +11:00
Jan Schubert
99dbd667bf Fixing SP handling in planner, adding event
This moves some double/floating handling for po2 to plain integer. There
are still non int values around (also for phe and po2) in the plot area.

Signed-off-by: Jan Schubert <Jan.Schubert@GMX.li>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-03 07:07:12 +11:00
Jan Schubert
59cfa5c427 Fixing SP handling in planner, adding event
Fixing the SP change event and introducing a bailout scenario.

I decided not to use a event showing SP=0.0 nor using a gaschange event as
is in fact there is no gas change related to bailing out itself. If there
is also a gaschange for the event it will be displayed anyway.

Signed-off-by: Jan Schubert <Jan.Schubert@GMX.li>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-03 07:06:38 +11:00
Dirk Hohndel
0f2fac265f Clear the list of events when closing data file
When the data file is closed we should reset the events that we offer for
filtering.

Reported-by: Sergey Starosek <sergey.starosek@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-02-01 00:07:04 +11:00
Dirk Hohndel
c8f2622f2f Fix the tooltips
Commit a52b0aa5ea8d ("Show Gradient Factors in plot when showing
calculated ceilings") incorrectly modified the gc which caused the mouse
position no longer correctly being correlated to the time on the plot.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-31 14:55:37 +11:00
Linus Torvalds
1702eb3ab0 Add the begin/end markers to events with the proper flags
When we create the event names, the name itself does not include the
information about whether the event is the beginning or end of some
state, so we end up having things like events named "deco" and then in
the event flags it says whether this is the *beginning* of deco, or the
end.

And when we show the event, we only used to show the name.  This patch
makes us show whether it's the begin or end event for events that have
those flags.  So now you see "deco begin" and "deco end" instead of just
two events both called "deco".

It would perhaps be nice if we somehow showed the range between the
events too, and paired them up visually some way, but that's a separate
and much more difficult thing to do.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-31 11:11:30 +11:00
Dirk Hohndel
e3a8ed5183 Massive cleanup
Mostly coding style and whitespace changes plus making lots of functions
static that have no need to be extern. This also helped find a bit of code
that is actually no longer used.

This should have absolutely no functional impact - all changes should be
purely cosmetic. But it removes a bunch of lines of code and makes the
rest easier to read.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-30 08:31:53 +11:00
Dirk Hohndel
3ab3e4e892 Show Gradient Factors in plot when showing calculated ceilings
This adds the GFlow/high values used to calculate the ceiling (if any).
Right now it shows those numbers even if at no point of the dive there was
an actual ceiling (but only if showing the ceiling itself is enabled).

This should make it easier to for the user to make sense of the calculated
ceiling, especially if posting screen shots.

As an aside - for some dive computers like the OSTC and the Shearwaters we
should be able to also plot the GF used by its calculation which might be
interesting for comparison purposes, as both of them also give us the
ceiling (lowest deco stop) calculated during the dive..

See #13

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-30 06:22:35 +11:00
Dirk Hohndel
a61877d1d4 Add missing strings for translations
Mostly in new code, but some of them are strings in older code that have
been missed in the past.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-29 20:32:56 +11:00
Dirk Hohndel
da62919ae1 Stop filtering out events with beginning or end flags
This made sense briefly when libdivecomputer reported ceiling data through
events with those flags, but it actually made us hide valid events from
some divecomputers that give us only very limited information (e.g., deco
events from some Suunto divecomputers).

Reported-by: Henrik Brautaset Aronsen <subsurface@henrik.synth.no>
Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-28 22:00:19 -08:00
Dirk Hohndel
3f261f56f3 Remove some unnecessary variable initializations
Not really bugs, just wasted. They clutter up the output of static
analysis with cppcheck.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-25 16:28:37 -08:00
Linus Torvalds
cb0d6d6eaf Fix overly complicated and fragile "same_cylinder" logic
The plot-info per-event 'same_cylinder' logic was fragile, and caused
us to not print the beginning pressure of the first cylinder.

In particular, there was a nasty interaction with not all plot entries
having pressures, and the whole logic that avoid some of the early
plot entries because they are fake entries that are just there to make
sure that we don't step off the edge of the world. When we then only
do certain things on the particular entries that don't have the same
cylinder as the last plot entry, things don't always happen like they
should.

Fix this by:

 - get rid of the computed "same_cylinder" state entirely. All the
cases where we use it, we might as well just look at what the last
cylinder we used was, and thus "same_cylinder" is just about testing
the current cylinder index against that last index.

 - get rid of some of the edge conditions by just writing the loops
more clearly, so that they simply don't have special cases. For
example, instead of setting some "last_pressure" for a cylinder at
cylinder changes, just set the damn thing on every single sample. The
last pressure will automatically be the pressure we set last! The code
is simpler and more straightforward.

So this simplifies the code and just makes it less fragile - it
doesn't matter if the cylinder change happens to happen at a sample
that doesn't have a pressure reading, for example, because we no
longer care so deeply about exactly which sample the cylinder change
happens at. As a result, the bug Mika noticed just goes away.

Reported-by: Miika Turkia <miika.turkia@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-24 19:12:28 -08:00
Dirk Hohndel
51880785af Only display temperature graph if we have temperature data
Commit b625332ca5ff "Display even constant temperature graph" was a little
too aggressive. If we have no temperature data at all it caused us to plot
a temperature line for absolute zero...

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-24 14:12:17 -08:00
Miika Turkia
60d1c09a14 Display even constant temperature graph
Dive profile does not display the temperature graph, if we have a
constant temperature (e.g. only one reading at the start of the dive).
This patch draws the temperature graph even if max and min temperatures
are the same.

Signed-off-by: Miika Turkia <miika.turkia@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-24 13:14:53 -08:00
Linus Torvalds
413b9026dd Fix temperature rounding issues
Temperatures can actually be negative, which means that rounding by
adding 0.5 and casting to 'int' is not correct.

We could use '(int)(rint(val))' instead, but the only place we care
about might as well just print out the floating point representation
with a precision of two digits instead.  So if you have a dive computer
that gives you the precision, you might see '3.5˚C' as the temperature.

Remove the helper functions that nobody uses and that get the rounding
wrong anyway.

Reported-by: Henrik Brautaset Aronsen <subsurface@henrik.synth.no>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-23 12:55:39 -08:00
Linus Torvalds
b6c9301e58 Move more dive computer filled data to the divecomputer structure
This moves the fields 'duration', 'surfacetime', 'maxdepth',
'meandepth', 'airtemp', 'watertemp', 'salinity' and 'surface_pressure'
to the per-divecomputer data structure.  They are filled in by the dive
computer, and normally not edited.

NOTE! All actual *use* of this data was then changed from dive->field to
dive->dc.field programmatically with a shell-script and sed, and the
result then edited for details.  So while the XML save and restore code
has been updated, all the displaying etc will currently always just show
the first dive computer entry.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-23 12:55:33 -08:00
Jan Schubert
322410a845 Trivial pressure related fixes
This patch removes the need for the "string" pressurebuf in planner.c.

It also adds a unit to the partial pressures displayed in the mouse
overlay which are always displayed in bar.

BTW: Has anyone seen a pO2 shown in PSI?

Signed-off-by: Jan Schubert <Jan.Schubert@GMX.li>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-15 10:13:33 -08:00
Jan Schubert
90d3c5614a Centralising and redefining values as integers
This patch centralizes the definition for surface pressure, oxygen in
air, (re)defines all such values as plain integers and adapts calculations.

It eliminates 11 (!) occurrences of definitions for surface pressure and
also a few for oxygen in air.

It also rewrites the calculation for EAD, END and EADD using the new
definitons, harmonizing it for OC and CC and fixes a bug for EADD OC
calculation.

And finally it removes the unneeded variable entry_ead in gtk-gui.c.

Jan

Signed-off-by: Jan Schubert <Jan.Schubert@GMX.li>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-14 20:12:40 -08:00
Linus Torvalds
2e53a41525 Fix odd calculated deco "ripples"
Previously we calculate the ceiling at every single second, using the
interpolated depth but then only *save* the ceiling at the points where we
have a profile event (the whole deco_allowed_depth() function doesn't
change any state, so we can just drop it entirely at points that we aren't
going to save)

Why is it incorrect? I'll try to walk through my understanding of it, by
switching things around a bit.

- the whole "minimum tissue tolerance" thing could equally well be
  rewritten to be about "maximum ceiling". And that's easier to think
  about (since it's what we actually show), so let's do that.

- so turning "min_pressure" into "max_ceiling", doing the whole
  comparison inside the loop means is that we are calculating the
  maximum ceiling value for the duration of the last sample. And then
  instead of visualizing the ceiling AT THE TIME OF MAXIMUM CEILING, we
  visualize that maximal ceiling value AT THE TIME OF THE SAMPLE.

End result: we visualize the ceiling at the wrong time. We visualize
what was *a* ceiling somewhere in between that sample and the previous
one, but we then assign that value to the time of the sample itself.

So it ends up having random odd effects.

And that also explains why you only see the effect during the ascent.
During the descent, the max ceiling will be at the end of our
linearization of the sampling, which is - surprise surprise - the position
of the sample itself. So we end up seeing the right ceiling at the right
time while descending. So the visualization matches the math.

But during desaturation, the maximum ceiling is not at the end of the
sample period, it's at the beginning. So the whole "max ceiling" thing has
basically turned what should be a smooth graph into something that
approaches being a step-wise graph at each sample. Ergo: a ripple.

And doing the "max_ceiling during the sample interval" thing may sound
like the safe thing to do, but the thing is, that really *is* a false
sense of safety. The ceiling value is *not* what we compute. The ceiling
value is just a visualization of what we computed. Playing games with it
can only make the visualization of the real data worse, not better.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-14 11:13:33 -08:00
Dirk Hohndel
23ce727e62 Add support for MOD, EAD, AND and EADD in the mouse over display
- MOD: Maximum Operation Depth based on a configurable limit
- EAD: Equivalent Air Depth considering N2 and (!) O2 narcotic
- END: Equivalent Nitrogen (Narcotic) Depth considering just N2 narcotic
       (ignoring O2)
- EADD: Equivalent Air Density Depth

Please note that some people and even diving organisations have opposite
definitions for EAD and END. Considering A stands for Air, lets choose the
above. And considering N for Nitrogen it also fits in this scheme.

This patch moves N2_IN_AIR from deco.c to dive.h as this is already used
in several places and might be useful for future use also. It also
respecifies N2_IN_AIR to a more correct value of 78,084%, the former one
also included all other gases than oxygen appearing in air. If someone
needs to use the former value it would be more correct to use 1-O2_IN_AIR
instead.

Signed-off-by: Jan Schubert / Jan.Schubert@GMX.li
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-13 16:26:35 -08:00
Henrik Brautaset Aronsen
53dbccb87a Scale partial pressure graphs according to enabled gases
The max Y value of the partial pressure graph grid tends to be way too
high when only pO2 or pHe is enabled.

Signed-off-by: Henrik Brautaset Aronsen <subsurface@henrik.synth.no>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-13 10:30:42 -08:00
Linus Torvalds
868a2cc090 Split up preference data structure definition into 'pref.h'
.. and rename the badly named 'output_units/input_units' variables.

We used to have this confusing thing where we had two different units
(input vs output) that *look* like they are mirror images, but in fact
"output_units" was the user units, and "input_units" are the XML parsing
units.

So this renames them to be clearer.  "output_units" is now just "units"
(it's the units a user would ever see), and "input_units" is now
"xml_parsing_units" and set by the XML file parsers to reflect the units
of the parsed file.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-10 20:30:32 -08:00
Linus Torvalds
88313f1077 Clean up duplicated depth interpolation
We have several places where we interpolate the depth based on two
samples and the time between them. Some of them use floating point, some
of them don't, some of them meant to do it but didn't.

Just use a common helper function for it. I seriously doubt the floating
point here really matters, since doing it in integers is not going to
overflow unless we're interpolating between two samples that are hours
apart at hundreds of meters of depth, but hey, it gives that rounding to
the nearest millimeter. Which I'm sure matters.

Anyway, we can probably just get rid of the rounding and the floating
point math, but it won't really hurt either, so at least do it
consistently.

The interpolation could be for other things than just depth, but we
probably don't have anything else we'd want to interpolate. But make the
function naming generic just in case.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-09 16:17:57 -08:00
Dirk Hohndel
77f4802ed6 Minor cleanups
Coding style in deco.c.
Unneccessary if clause in profile.c (the loop starts with i = 1)

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-08 13:47:01 -08:00
Dirk Hohndel
8b24784a7a Fix deco display bug for dives with multiple samples at the same time
While one might argue that multiple samples with the same time are 'odd'
that still shouldn't be an excuse to incorrectly reset the ceiling value
for them back to 0.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-08 12:20:35 -08:00
Robert C. Helling
67d59ff018 Rewrite of the deco code
o) Instead of using gradient factors as means of comparison, I now use
   pressure (as in: maximal ambient pressure).

o) tissue_tolerance_calc() now computes the maximal ambient pressure now
   respecting gradient factors. For this, it needs to know about the
   surface pressure (as refernce for GF_high), thus gets *dive as an
   argument. It is called from add_segment() which this also needs *dive
   as an additional argument.

o) This implies deco_allowed_depth is now mainly a ambient-pressure to
   depth conversion with decorations to avoid negative depth (i.e. no deco
   obliation), implementation of quantization (!smooth => multiples of 3m)
   and explicit setting of last deco depth (e.g. 6m for O2 deco).

o) gf_low_pressure_this_dive (slight change of name), the max depth in
   pressure units is updated in add_segment. I set the minimal value in
   buehlmann_config to the equivalent of 20m as otherwise good values of
   GF_low add a lot of deco to shallow dives which do not need deep stops
   in the first place.

o) The bogus loop is gone as well as actual_gradient_limit() and
   gradient_factor_calculation() and large parts of deco_allowed_depth()
   although I did not delete the code but put it in comments.

o) The meat is in the formula in lines 147-154 of deco.c. Here is the
   rationale:

   Without gradient factors, the M-value (i.e the maximal tissue pressure)
   at a given depth is given by ambient_pressure / buehlmann_b + a.

   According to "Clearing Up The Confusion About "Deep Stops" by Erik C.
   Baker (as found via google) the effect of the gradient factors is no
   replace this by a reduced affine relation (i.e. another line) such that
   at the surface the difference between M-value and ambient pressure is
   reduced by a factor GF_high and at the maximal depth by a factor
   GF_low.

   That is, we are looking for parameters alpha and beta such that

   alpha surface + beta = surface + gf_high * (surface/b + a - surface)

   and

   alpha max_p + beta = max_p + gf_low * (max_p/b + a - max_p)

   This can be solved for alpha and beta and then inverted to obtain the
   max ambient pressure given tissue loadings. The result is the above
   mentioned formula.

Signed-off-by: Robert C. Helling <helling@atdotde.de>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-08 08:59:20 -08:00
Linus Torvalds
7e1f0d243b Don't walk back in time
A strange and buggy dive where time goes backwards (right now easy to
create with the dive plan editor) can cause us to run out of plot info
elements.

This prevents that from causing memory corruption by refusing to go back
in time.

Reported-by: Dirk Hohndel <dirk@hohndel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-07 15:44:23 -08:00
Linus Torvalds
d281ad84fd Do pressure-time integral using integer values
Now that the pressure_time calculations are done in our "native"
integer units (millibar and seconds), we might as well keep using
integer variables.

We still do floating point calculations at various stages for the
conversions (including turning a depth in mm into a pressure in mbar),
so it's not like this avoids floating point per se. And the final
approximation is still done as a fraction of the pressure-time values,
using floating point. So floating point is very much involved, but
it's used for conversions, not (for example) to sum up lots of small
values.

With floating point, I had to think about the dynamic range in order
to convince myself that summing up small values will not subtly lose
precision.

With integers, those kinds of issues do not exist. The "lost
precision" case is not subtle, it would be a very obvious overflow,
and it's easy to think about. It turns out that for the pressure-time
integral to overflow in "just" 31 bits, we'd have to have pressures
and times that aren't even close to the range of scuba cylinder air
use (eg "spend more than a day at a depth of 200+ m").

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-07 07:33:33 -08:00
Linus Torvalds
1ee0101b28 Don't bother with "correct" units for the pressure_time calculation
I fixed the pressure-time calculations to use "proper" units, but
thinking about it some more, it turns out that units don't really
matter. As long as we use the *same* unit for calculating the
integral, and then re-calculating the step-wise entries, the units
will cancel out.

So we can simplify the "pressure_time()" function a bit, and use
whatever units are most natural for our internal representation. So
instead of using atm, use "mbar".

Now, since the units don't matter, this patch doesn't really make much
of a difference conceptually. Sure, it's a slightly simpler function,
but maybe using more "natural" units for it would be worth it. But it
turns out that using milli-bar and seconds has an advantage: we could
do all the pressure_time integral using 32-bit integers, and we'd
still be able to represent values that would be equivalent to staying
at 24 bar for a whole day.

This patch doesn't actually change the code to use integers, but with
this unit choice, we at least have that possibility.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-07 07:33:22 -08:00
Linus Torvalds
d85d8421e0 Split up helper functions for interpolating gas pressure
This splits up the function to create the estimated pressures for
missing tank pressure information.

The code now has a separate pass to create the beginning and ending
pressures for segments that lack them, and fill them in to match the
overall SAC-rate for that cylinder.

In the process, it also fixes the calculation of the interpolated gas
pressure: you can see this in test-dive 13, where we switch back to the
first tank at the end of the dive.  It used to be that the latter
segment of that cylinder showed in a different color from the first
segment, showing that we had a different SAC-rate.  But that makes no
sense, since our interpolation is supposed to use a constant SAC-rate
for each cylinder.

The bug was that the "magic" calculation (which is just the pressure
change rate over pressure-time) was incorrect, and used the current
cylinder pressure for start-pressure calculation.  But that's wrong,
since we update the current cylinder pressure as we go along, but we
didn't update the total pressure_time.

With the separate phase to calculate the segment beginning/ending
pressures, the code got simplified and the bug stood out more.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-06 22:17:13 -08:00
Linus Torvalds
25209bfbb4 Fix pressure_time calculation for SAC-rate
The code was using bar, not atm to calculate the pressure_time
multiplier.  But SAC-rate is relative to atm.

We could do the correction at the end (and keep the pressure_time in
"bar-seconds"), but let's just use the expected units during the
integration.  Especially since this also makes a helper function to do
the calculations (with variables to keep the units obvious) instead of
having multi-line expressions that have the wrong units.

This fixes what I thought were rounding errors for the pressure graphs.
They were just unit confusion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-06 22:16:59 -08:00
Linus Torvalds
98ed131bda Split up and re-organize the plot entry calculations
This splits up the (very complex) function that calculates all the plot
info data, so that the gas pressure logic is in several helper
functions, and the deco and partial pressure calculations are in a
function of their own.

That makes the code almost readable.

This also changes the cylinder pressure calculations so that if you have
manually set the beginning and end pressures, those are the ones we will
show (by making them fake "sensor pressures").  We used to shopw some
random pressure that was related to the manually entered ones only
distantly (through various rounding phases and the SAC-rate calculations).

That does make the rounding errors more obvious in the graph, but we can
fix that separately.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-06 22:16:43 -08:00
Linus Torvalds
d7925dac44 Do a better job at creating plot info entries
This simplifies - and improves - the code to generate the plot info
entries from the samples.

We used to generate exactly one plot info entry per sample, and then -
because the result doesn't have high enough granularity - we'd
generate additional plot info entries at gas change events etc.

Which resulted in all kinds of ugly special case logic. Not only for
the gas switch, btw: you can see the effects of this in the deco graph
(done at plot entry boundaries) and in the gas pressure curves.

So this throws that "do special plot entries for gas switch events"
code away entirely, and replaces it with a much more straightforward
model: we generate plot entries at a minimum of ten-second intervals.
If you have samples more often than that, you'll get more frequent
plot entries, but you'll never get less than that "every ten seconds".

As a result, the code is smaller and simpler (99 insertions, 161
deletions), and actually does a better job too.

You can see the difference especially in the test dives that only have
a few entries (or if you create a new dive without a dive computer,
using the "Add Dive" menu entry). Look at the deco graph of test-dive
20 before and after, for example. You can also see it very subtly in
the cylinder pressure curves going from line segments to curves on
that same dive.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-06 14:42:19 -08:00
Linus Torvalds
635f190302 Fix profile display for dives with no samples
For dives with no samples, we crate a fake dive computer with a set of
made-up samples and use those to display the profile.

However, the actual calculations to do the maximum duration and depth
etc were always done with the "real" dive information, which is empty.
As a result, the scale of the plot ended up being bogus, and part of
the dive would be missing.

Trivially fix by just passing the same dive computer information to
calculate_max_limits() that we use for everything else.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-05 00:18:30 -08:00
Dirk Hohndel
cca847791a First stab at simplistic dive planning
This comes with absolutely no gui - so the plan literally needs to be
compiled into Subsurface. Not exactly a feature, but this allowed me to
focus on the planning part instead of spending time on tedious UI work.

A new menu "Planner" with entry "Test Planner" calls into the hard-coded
function in planner.c. There a simple dive plan can be constructed with
calls to plan_add_segment(&diveplan, duration, depth at the end, fO2, pO2)

Calling plan(&diveplan) does the deco calculations and creates deco stops
that keep us below the ceiling (with the GFlow/high values currently
configured). The stop levels used are defined at the top of planner.c in
the stoplevels array - there is no need to do the traditional multiples of
3m or anything like that.

The dive including the ascents and deco stops all the way to the surface
is completed and then added as simulated dive to the end of the divelist
(I guess we could automatically select it later) and can be viewed.

This is crude but shows the direction we can go with this. Envision a nice
UI that allows you to simply enter the segments and pick the desired
stops.

What is missing is the ability to give the algorithm additional gases that
it can use during the deco phase - right now it simply keeps using the
last gas used in the diveplan.

All that said, there are clear bugs here - and sadly they seem to be in
the deco calculations, as with the example given the ceiling that is
calculated makes no sense. When displayed in smooth mode it has very
strange jumps up and down that I wouldn't expect. For example with GF
35/75 (the default) the deco ceiling when looking at the simulated dive
jumps from 16m back up to 13m around 14:10 into the dive. That seems very
odd.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-04 23:56:55 -08:00
Dirk Hohndel
1b22ac16f2 Clean up DEBUG code
It's still a mess (and the symbols aren't used consistently), but it's a
tiny bit more logical...

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-04 11:56:43 -08:00
Dirk Hohndel
65c85b39ea Make sure that the calculated deco ends at 0
Without this the cairo_close_path call could do silly looking things
(intersecting polygons...).

Reported-by: "Robert C. Helling" <helling@atdotde.de>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-04 11:54:38 -08:00
Dirk Hohndel
6dc247ff78 Fix deco calculations to correctly use GF values and add CC support
The old implementation was broken in several ways.

For one thing the GF values are percentages, so they should normally be
0 < GF < 1 (well, some crazy people like to go above that).

With this most of the Bühlmann config constants were wrong.

Furthermore, after we adjust the pressure tolerance based on the gradient
factors, we need to convert this back into a depth (instead of passing
back the unmodified depth - oops).

Finally, this commit adds closed circuit support to the deco calculations.

Major progress and much more useful at this stage.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-04 11:13:14 -08:00
Dirk Hohndel
2c33603256 Consider previous dives when calculating deco
This also initializes the N2 tissue saturations to correct numbers
(setting them to zero was clearly silly).

With this commit we walk back in the dive_table until we find a surface
intervall that's longer than 48h. Or a dive that comes after the last one
we looked at; that would indicate that this is a divelist that contains
dives from multiple divers or dives that for other reasons are not
ordered. In a sane environment one would assume that the dives that need
to be taken into account when doing deco calculations are organized as one
trip in the XML file and so this logic should work.

One major downside of the current implementation is that we recalculate
everything whenever the plot_info is recreated - which happens quite
frequently, for example when resizing the window or even when we go into
loup mode. While this isn't all that compute intensive, this is an utter
waste and we should at least cache the saturation inherited from previous
dives (and clear that number when the selected dive changes). We don't
want to cache all of it as the recreation of the plot_info may be
triggered by the user changing equipment (and most importantly, gasmix)
information. In that case the deco data for this dive does indeed have to
be recreated. But without changing the current dive the saturation after
the last surface intervall should stay the same.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 20:45:20 -08:00