There was also a function not being used that could be safely removed.
Signed-off-by: Tomaz Canabrava <tomaz.canabrava@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Structs and classes in C++ are basically the same thing and we want to
create a few zero-initialized values for some of them; Sadly, C++ doesn't
have the nice static struct initialization that C has.
One way to deal with that is to create a constructor and pass default
values to it, another is lambda-initialization, but we don't use C++11,
yet.
Since we initializate stuff on the constructor, we don't need to
re-initializate things again on the initialization list (which is also why
I removed the QStrings from the initialization lists, they are
automatically initialized to empty)
Signed-off-by: Tomaz Canabrava <tomaz.canabrava@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
This is in the context of the iOS port and shouldn't impact any of the
other builds.
[Dirk Hohndel: refactored the iOS patches]
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
This is hard coded in version.cmake for now. The intent is to go to 1.0 in
the first release version and to increment from there whenever we create
an update.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
The "virial" form of the Z compression factor is of the form
Z = 1.0 + A*p + B*p^2 + C*p^3 + ..
and it's considered the "right" polynomial form to use. It happens to
also make for one constant less per gas (since the 1.0 can be added
later), and can be used to simplify the expression and avoid a few
floating point operations.
However, in order for that kind of expression simplification to make
sense, we need to make sure that we don't calculate the powers of the
pressure multiple times either, and that means we have to inline all the
actual calculations.
Our compiler options still mean that the generated code isn't optimal,
but that's a separate issue. And it is a lot better than it used to be.
Being clever about this does potentially make the code a tiny bit less
legible, but maybe that's not too bad for something that we'd expect to
not ever touch once we get it right.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Lubomir found better compressibility data for the pure gases that we
need for scuba, making the air table superfluous: we get good values
from just regular linear mixing of the Oxygen, Nitrogen and Helium
calculations.
Also, rather than using a quintic polynomial, a cubic one does
sufficiently well, making for smaller code and fewer coefficients.
And judging by the reactions from people on G+ (as well as just looking
at how good the fit is with the air data), this is all the right way to
do this, and this thus removes the Redlich-Kwong equation.
All-credit-goes-to: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
.. and use a linear mix of them for arbitrary gas mixes.
For the special case of air, we continue to use the air-specific
polynomial.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
This goes back to just doing air compressibility, but using the
least-squares quintic polynomial equation that Lubomir generated based
on the Wikipedia table for air at 300K in the 1-500 bar range.
We might be able to do similar things for mixed gases..
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
The gas compressibility is such a specialized thing that I really prefer
having it separate.
This keeps Robert's Redlich-Kwong equation as-is, but let's experiment
with other models soon...
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
The dive list might contain dives in the future, don't add the new dive to
then end but instead add it at the correct spot in the list
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
As it turns out, the van der Waals equation gives results that are
numerically not really useful, so we use the Redlich Kwong equation
which is, according to Wikipedia, much more accurate, which can be confirmed
given the empirical values for air.
As opposed to the previous approach with a look-up table, this takes
into account the actual gasmix. This always assumes the gas to be at
20 degrees Centigrade.
Signed-off-by: Robert C. Helling <helling@atdotde.de>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
"weights" and "cylinders" are QStringList Q_PROPERTIES, and Grantlee
should be able to render them, but it doesn't.
To be able to print the whole list of weights and cylinders we
introduce two new QString properties "weightList" and "cylinderList".
The variable replacement in the previous patch deals with the
conversation of the user side HTML, e.g.:
USER -> INTERNAL
"{{ dive.weights }} -> {{ dive.weightList }}"
"{{ dive.cylinders }} -> {{ dive.cylinderList }}"
Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
There was a reported case of an import of a dive that gave a salinity of
35g/l. This is an actual salinity (an amount of salt in the water) but
for subsurface the salinity is actually the density of the water. So for
too small values of the salinity add the density of fresh water.
Signed-off-by: Robert C. Helling <helling@atdotde.de>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
We could in theory make this dependent on the gasmix, but for now let's
just assume (incorrectly) that everything we breathe acts like air.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
We had two totally different usage cases for "get_volume_string()": one
that did the obvious "show this volume as a string", and one that tried
to show a cylinder size.
The function used a magic third argument (the working pressure of the
cylinder) to distinguish between the two cases, but it still got it
wrong.
A metric cylinder doesn't necessarily have a working pressure at all,
and the size is a wet size in liters. We'd pass in zero as the working
pressure, and if the volume units were set to cubic feet, the logic in
"get_volume_string()" would happily convert the metric wet size into the
wet size in cubic feet.
But that's completely wrong. An imperial cylinder size simply isn't a
wet size. If you don't have a working pressure, you cannot convert the
cylinder size to cubic feet. End of story.
So instead of having "get_volume_string()" have magical behavior
depending on working pressure, and getting it wrong anyway, just make
get_volume_string do a pure volume conversion, and create a whole new
function for showing the size of a cylinder.
Now, if the cylinder doesn't have a working pressure, we just show the
metric size, even if the user had asked for cubic feet.
[Dirk Hohndel: added call to translation functions for the units]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
This actually didn't make a difference for the common case, since our
simplified gas compressibility model had a compressibility factor of 1.0
up to 200 bar, and increased smoothly from there. As a result, the
common 2400 and 3000 psi workpressures didn't really see an effect from
this.
Not taking compressibility into account does kind of make sense for
cylinder naming, since the cylinder may be used for different gases with
very different compressibility characteristics.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
This marks "surface_volume_multiplier()" static in preparation for
changing it to use an actual honest-to-goodness compressibility
estimation. Without that, it wasn't obvious that the function wasn't
used in other random places.
Also, remove the "wet_volume()" function. It was unused, but more
importantly, it was wrong. Yes, it was the inverse of "gas_volume()",
but when you calculate wet volumes from the imperial sizes, you don't
actually use the "real" gas volume, you use the idealized one.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
The code was wrong (and in the case of metric display for weights >= 20kg,
spectacularly wrong) in more or less all cases.
Rounding. It's good for the sole.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
